Merge pull request #9428 from grpc/revert-8842-metadata_filter

Revert "Metadata handling rewrite"

25 files changed, 680 insertions, 567 deletions

diff --git a/src/core/ext/transport/chttp2/server/chttp2_server.c b/src/core/ext/transport/chttp2/server/chttp2_server.c
index 56a1a0de9b..574d1a7710 100644
--- a/src/core/ext/transport/chttp2/server/chttp2_server.c
+++ b/src/core/ext/transport/chttp2/server/chttp2_server.c
@@ -121,7 +121,7 @@ static void on_handshake_done(grpc_exec_ctx *exec_ctx, void *arg,
   if (error != GRPC_ERROR_NONE || connection_state->server_state->shutdown) {
     const char *error_str = grpc_error_string(error);
     gpr_log(GPR_ERROR, "Handshaking failed: %s", error_str);
-
+    grpc_error_free_string(error_str);
     if (error == GRPC_ERROR_NONE && args->endpoint != NULL) {
       // We were shut down after handshaking completed successfully, so
       // destroy the endpoint here.
@@ -307,7 +307,7 @@ grpc_error *grpc_chttp2_server_add_port(grpc_exec_ctx *exec_ctx,
 
     const char *warning_message = grpc_error_string(err);
     gpr_log(GPR_INFO, "WARNING: %s", warning_message);
-
+    grpc_error_free_string(warning_message);
     /* we managed to bind some addresses: continue */
   }
   grpc_resolved_addresses_destroy(resolved);
diff --git a/src/core/ext/transport/chttp2/server/insecure/server_chttp2.c b/src/core/ext/transport/chttp2/server/insecure/server_chttp2.c
index c219a7d85f..bf5026bea6 100644
--- a/src/core/ext/transport/chttp2/server/insecure/server_chttp2.c
+++ b/src/core/ext/transport/chttp2/server/insecure/server_chttp2.c
@@ -51,7 +51,7 @@ int grpc_server_add_insecure_http2_port(grpc_server *server, const char *addr) {
   if (err != GRPC_ERROR_NONE) {
     const char *msg = grpc_error_string(err);
     gpr_log(GPR_ERROR, "%s", msg);
-
+    grpc_error_free_string(msg);
     GRPC_ERROR_UNREF(err);
   }
   grpc_exec_ctx_finish(&exec_ctx);
diff --git a/src/core/ext/transport/chttp2/server/secure/server_secure_chttp2.c b/src/core/ext/transport/chttp2/server/secure/server_secure_chttp2.c
index cb2b3f5502..395c79a71d 100644
--- a/src/core/ext/transport/chttp2/server/secure/server_secure_chttp2.c
+++ b/src/core/ext/transport/chttp2/server/secure/server_secure_chttp2.c
@@ -94,7 +94,7 @@ done:
   if (err != GRPC_ERROR_NONE) {
     const char *msg = grpc_error_string(err);
     gpr_log(GPR_ERROR, "%s", msg);
-
+    grpc_error_free_string(msg);
     GRPC_ERROR_UNREF(err);
   }
   return port_num;
diff --git a/src/core/ext/transport/chttp2/transport/bin_decoder.c b/src/core/ext/transport/chttp2/transport/bin_decoder.c
index 8c87de112e..8db36e4a7f 100644
--- a/src/core/ext/transport/chttp2/transport/bin_decoder.c
+++ b/src/core/ext/transport/chttp2/transport/bin_decoder.c
@@ -157,7 +157,7 @@ grpc_slice grpc_chttp2_base64_decode(grpc_exec_ctx *exec_ctx,
             "grpc_chttp2_base64_decode has a length of %d, which is not a "
             "multiple of 4.\n",
             (int)input_length);
-    return grpc_empty_slice();
+    return gpr_empty_slice();
   }
 
   if (input_length > 0) {
@@ -178,11 +178,11 @@ grpc_slice grpc_chttp2_base64_decode(grpc_exec_ctx *exec_ctx,
   ctx.contains_tail = false;
 
   if (!grpc_base64_decode_partial(&ctx)) {
-    char *s = grpc_slice_to_c_string(input);
+    char *s = grpc_dump_slice(input, GPR_DUMP_ASCII);
     gpr_log(GPR_ERROR, "Base64 decoding failed, input string:\n%s\n", s);
     gpr_free(s);
     grpc_slice_unref_internal(exec_ctx, output);
-    return grpc_empty_slice();
+    return gpr_empty_slice();
   }
   GPR_ASSERT(ctx.output_cur == GRPC_SLICE_END_PTR(output));
   GPR_ASSERT(ctx.input_cur == GRPC_SLICE_END_PTR(input));
@@ -204,7 +204,7 @@ grpc_slice grpc_chttp2_base64_decode_with_length(grpc_exec_ctx *exec_ctx,
             "has a tail of 1 byte.\n",
             (int)input_length);
     grpc_slice_unref_internal(exec_ctx, output);
-    return grpc_empty_slice();
+    return gpr_empty_slice();
   }
 
   if (output_length > input_length / 4 * 3 + tail_xtra[input_length % 4]) {
@@ -214,7 +214,7 @@ grpc_slice grpc_chttp2_base64_decode_with_length(grpc_exec_ctx *exec_ctx,
             (int)output_length,
             (int)(input_length / 4 * 3 + tail_xtra[input_length % 4]));
     grpc_slice_unref_internal(exec_ctx, output);
-    return grpc_empty_slice();
+    return gpr_empty_slice();
   }
 
   ctx.input_cur = GRPC_SLICE_START_PTR(input);
@@ -224,11 +224,11 @@ grpc_slice grpc_chttp2_base64_decode_with_length(grpc_exec_ctx *exec_ctx,
   ctx.contains_tail = true;
 
   if (!grpc_base64_decode_partial(&ctx)) {
-    char *s = grpc_slice_to_c_string(input);
+    char *s = grpc_dump_slice(input, GPR_DUMP_ASCII);
     gpr_log(GPR_ERROR, "Base64 decoding failed, input string:\n%s\n", s);
     gpr_free(s);
     grpc_slice_unref_internal(exec_ctx, output);
-    return grpc_empty_slice();
+    return gpr_empty_slice();
   }
   GPR_ASSERT(ctx.output_cur == GRPC_SLICE_END_PTR(output));
   GPR_ASSERT(ctx.input_cur <= GRPC_SLICE_END_PTR(input));
diff --git a/src/core/ext/transport/chttp2/transport/bin_encoder.c b/src/core/ext/transport/chttp2/transport/bin_encoder.c
index e301c073f3..af25a4352a 100644
--- a/src/core/ext/transport/chttp2/transport/bin_encoder.c
+++ b/src/core/ext/transport/chttp2/transport/bin_encoder.c
@@ -177,7 +177,8 @@ static void enc_add1(huff_out *out, uint8_t a) {
   enc_flush_some(out);
 }
 
-grpc_slice grpc_chttp2_base64_encode_and_huffman_compress(grpc_slice input) {
+grpc_slice grpc_chttp2_base64_encode_and_huffman_compress_impl(
+    grpc_slice input) {
   size_t input_length = GRPC_SLICE_LENGTH(input);
   size_t input_triplets = input_length / 3;
   size_t tail_case = input_length % 3;
diff --git a/src/core/ext/transport/chttp2/transport/bin_encoder.h b/src/core/ext/transport/chttp2/transport/bin_encoder.h
index 0f899c8e34..477559d0e2 100644
--- a/src/core/ext/transport/chttp2/transport/bin_encoder.h
+++ b/src/core/ext/transport/chttp2/transport/bin_encoder.h
@@ -49,6 +49,7 @@ grpc_slice grpc_chttp2_huffman_compress(grpc_slice input);
    grpc_slice y = grpc_chttp2_huffman_compress(x);
    grpc_slice_unref_internal(exec_ctx, x);
    return y; */
-grpc_slice grpc_chttp2_base64_encode_and_huffman_compress(grpc_slice input);
+grpc_slice grpc_chttp2_base64_encode_and_huffman_compress_impl(
+    grpc_slice input);
 
 #endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_BIN_ENCODER_H */
diff --git a/src/core/ext/transport/chttp2/transport/chttp2_plugin.c b/src/core/ext/transport/chttp2/transport/chttp2_plugin.c
index 59b21e3330..bd87253ed3 100644
--- a/src/core/ext/transport/chttp2/transport/chttp2_plugin.c
+++ b/src/core/ext/transport/chttp2/transport/chttp2_plugin.c
@@ -31,11 +31,14 @@
  *
  */
 
+#include "src/core/ext/transport/chttp2/transport/bin_encoder.h"
 #include "src/core/ext/transport/chttp2/transport/chttp2_transport.h"
 #include "src/core/lib/debug/trace.h"
 #include "src/core/lib/transport/metadata.h"
 
 void grpc_chttp2_plugin_init(void) {
+  grpc_chttp2_base64_encode_and_huffman_compress =
+      grpc_chttp2_base64_encode_and_huffman_compress_impl;
   grpc_register_tracer("http", &grpc_http_trace);
   grpc_register_tracer("flowctl", &grpc_flowctl_trace);
 }
diff --git a/src/core/ext/transport/chttp2/transport/chttp2_transport.c b/src/core/ext/transport/chttp2/transport/chttp2_transport.c
index 2004bc6437..68a6a2155d 100644
--- a/src/core/ext/transport/chttp2/transport/chttp2_transport.c
+++ b/src/core/ext/transport/chttp2/transport/chttp2_transport.c
@@ -44,7 +44,9 @@
 #include <grpc/support/string_util.h>
 #include <grpc/support/useful.h>
 
+#include "src/core/ext/transport/chttp2/transport/http2_errors.h"
 #include "src/core/ext/transport/chttp2/transport/internal.h"
+#include "src/core/ext/transport/chttp2/transport/status_conversion.h"
 #include "src/core/ext/transport/chttp2/transport/varint.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/http/parser.h"
@@ -53,10 +55,7 @@
 #include "src/core/lib/slice/slice_internal.h"
 #include "src/core/lib/slice/slice_string_helpers.h"
 #include "src/core/lib/support/string.h"
-#include "src/core/lib/transport/error_utils.h"
-#include "src/core/lib/transport/http2_errors.h"
 #include "src/core/lib/transport/static_metadata.h"
-#include "src/core/lib/transport/status_conversion.h"
 #include "src/core/lib/transport/timeout_encoding.h"
 #include "src/core/lib/transport/transport_impl.h"
 
@@ -410,7 +409,7 @@ static void close_transport_locked(grpc_exec_ctx *exec_ctx,
           grpc_error_add_child(t->close_transport_on_writes_finished, error);
       return;
     }
-    if (!grpc_error_has_clear_grpc_status(error)) {
+    if (!grpc_error_get_int(error, GRPC_ERROR_INT_GRPC_STATUS, NULL)) {
       error = grpc_error_set_int(error, GRPC_ERROR_INT_GRPC_STATUS,
                                  GRPC_STATUS_UNAVAILABLE);
     }
@@ -867,6 +866,7 @@ void grpc_chttp2_complete_closure_step(grpc_exec_ctx *exec_ctx,
             (int)(closure->next_data.scratch / CLOSURE_BARRIER_FIRST_REF_BIT),
             (int)(closure->next_data.scratch % CLOSURE_BARRIER_FIRST_REF_BIT),
             desc, errstr);
+    grpc_error_free_string(errstr);
   }
   if (error != GRPC_ERROR_NONE) {
     if (closure->error_data.error == GRPC_ERROR_NONE) {
@@ -895,9 +895,12 @@ void grpc_chttp2_complete_closure_step(grpc_exec_ctx *exec_ctx,
 }
 
 static bool contains_non_ok_status(grpc_metadata_batch *batch) {
-  if (batch->idx.named.grpc_status != NULL) {
-    return !grpc_mdelem_eq(batch->idx.named.grpc_status->md,
-                           GRPC_MDELEM_GRPC_STATUS_0);
+  grpc_linked_mdelem *l;
+  for (l = batch->list.head; l; l = l->next) {
+    if (l->md->key == GRPC_MDSTR_GRPC_STATUS &&
+        l->md != GRPC_MDELEM_GRPC_STATUS_0) {
+      return true;
+    }
   }
   return false;
 }
@@ -977,12 +980,9 @@ static void log_metadata(const grpc_metadata_batch *md_batch, uint32_t id,
                          bool is_client, bool is_initial) {
   for (grpc_linked_mdelem *md = md_batch->list.head; md != md_batch->list.tail;
        md = md->next) {
-    char *key = grpc_slice_to_c_string(GRPC_MDKEY(md->md));
-    char *value = grpc_slice_to_c_string(GRPC_MDVALUE(md->md));
     gpr_log(GPR_INFO, "HTTP:%d:%s:%s: %s: %s", id, is_initial ? "HDR" : "TRL",
-            is_client ? "CLI" : "SVR", key, value);
-    gpr_free(key);
-    gpr_free(value);
+            is_client ? "CLI" : "SVR", grpc_mdstr_as_c_string(md->md->key),
+            grpc_mdstr_as_c_string(md->md->value));
   }
 }
 
@@ -1025,7 +1025,11 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx, void *stream_op,
   }
 
   if (op->cancel_error != GRPC_ERROR_NONE) {
-    grpc_chttp2_cancel_stream(exec_ctx, t, s, op->cancel_error);
+    grpc_chttp2_cancel_stream(exec_ctx, t, s, GRPC_ERROR_REF(op->cancel_error));
+  }
+
+  if (op->close_error != GRPC_ERROR_NONE) {
+    close_from_api(exec_ctx, t, s, GRPC_ERROR_REF(op->close_error));
   }
 
   if (op->send_initial_metadata != NULL) {
@@ -1076,9 +1080,8 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx, void *stream_op,
         s->send_initial_metadata = NULL;
         grpc_chttp2_complete_closure_step(
             exec_ctx, t, s, &s->send_initial_metadata_finished,
-            GRPC_ERROR_CREATE_REFERENCING(
-                "Attempt to send initial metadata after stream was closed",
-                &s->write_closed_error, 1),
+            GRPC_ERROR_CREATE(
+                "Attempt to send initial metadata after stream was closed"),
             "send_initial_metadata_finished");
       }
     }
@@ -1090,9 +1093,7 @@ static void perform_stream_op_locked(grpc_exec_ctx *exec_ctx, void *stream_op,
     if (s->write_closed) {
       grpc_chttp2_complete_closure_step(
           exec_ctx, t, s, &s->fetching_send_message_finished,
-          GRPC_ERROR_CREATE_REFERENCING(
-              "Attempt to send message after stream was closed",
-              &s->write_closed_error, 1),
+          GRPC_ERROR_CREATE("Attempt to send message after stream was closed"),
           "fetching_send_message_finished");
     } else {
       GPR_ASSERT(s->fetching_send_message == NULL);
@@ -1264,16 +1265,11 @@ void grpc_chttp2_ack_ping(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
 }
 
 static void send_goaway(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
-                        grpc_error *error) {
+                        grpc_chttp2_error_code error, grpc_slice data) {
   t->sent_goaway_state = GRPC_CHTTP2_GOAWAY_SEND_SCHEDULED;
-  grpc_http2_error_code http_error;
-  const char *msg;
-  grpc_error_get_status(error, gpr_inf_future(GPR_CLOCK_MONOTONIC), NULL, &msg,
-                        &http_error);
-  grpc_chttp2_goaway_append(t->last_new_stream_id, (uint32_t)http_error,
-                            grpc_slice_from_copied_string(msg), &t->qbuf);
+  grpc_chttp2_goaway_append(t->last_new_stream_id, (uint32_t)error, data,
+                            &t->qbuf);
   grpc_chttp2_initiate_write(exec_ctx, t, false, "goaway_sent");
-  GRPC_ERROR_UNREF(error);
 }
 
 static void perform_transport_op_locked(grpc_exec_ctx *exec_ctx,
@@ -1289,8 +1285,10 @@ static void perform_transport_op_locked(grpc_exec_ctx *exec_ctx,
         op->on_connectivity_state_change);
   }
 
-  if (op->goaway_error) {
-    send_goaway(exec_ctx, t, op->goaway_error);
+  if (op->send_goaway) {
+    send_goaway(exec_ctx, t,
+                grpc_chttp2_grpc_status_to_http2_error(op->goaway_status),
+                grpc_slice_ref_internal(*op->goaway_message));
   }
 
   if (op->set_accept_stream) {
@@ -1350,8 +1348,8 @@ void grpc_chttp2_maybe_complete_recv_initial_metadata(grpc_exec_ctx *exec_ctx,
         incoming_byte_stream_destroy_locked(exec_ctx, bs, GRPC_ERROR_NONE);
       }
     }
-    grpc_chttp2_incoming_metadata_buffer_publish(
-        exec_ctx, &s->metadata_buffer[0], s->recv_initial_metadata);
+    grpc_chttp2_incoming_metadata_buffer_publish(&s->metadata_buffer[0],
+                                                 s->recv_initial_metadata);
     null_then_run_closure(exec_ctx, &s->recv_initial_metadata_ready,
                           GRPC_ERROR_NONE);
   }
@@ -1394,8 +1392,8 @@ void grpc_chttp2_maybe_complete_recv_trailing_metadata(grpc_exec_ctx *exec_ctx,
     }
     if (s->all_incoming_byte_streams_finished &&
         s->recv_trailing_metadata_finished != NULL) {
-      grpc_chttp2_incoming_metadata_buffer_publish(
-          exec_ctx, &s->metadata_buffer[1], s->recv_trailing_metadata);
+      grpc_chttp2_incoming_metadata_buffer_publish(&s->metadata_buffer[1],
+                                                   s->recv_trailing_metadata);
       grpc_chttp2_complete_closure_step(
           exec_ctx, t, s, &s->recv_trailing_metadata_finished, GRPC_ERROR_NONE,
           "recv_trailing_metadata_finished");
@@ -1443,37 +1441,70 @@ static void remove_stream(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
   maybe_start_some_streams(exec_ctx, t);
 }
 
+static void status_codes_from_error(grpc_error *error, gpr_timespec deadline,
+                                    grpc_chttp2_error_code *http2_error,
+                                    grpc_status_code *grpc_status) {
+  intptr_t ip_http;
+  intptr_t ip_grpc;
+  bool have_http =
+      grpc_error_get_int(error, GRPC_ERROR_INT_HTTP2_ERROR, &ip_http);
+  bool have_grpc =
+      grpc_error_get_int(error, GRPC_ERROR_INT_GRPC_STATUS, &ip_grpc);
+  if (have_http) {
+    *http2_error = (grpc_chttp2_error_code)ip_http;
+  } else if (have_grpc) {
+    *http2_error =
+        grpc_chttp2_grpc_status_to_http2_error((grpc_status_code)ip_grpc);
+  } else {
+    *http2_error = GRPC_CHTTP2_INTERNAL_ERROR;
+  }
+  if (have_grpc) {
+    *grpc_status = (grpc_status_code)ip_grpc;
+  } else if (have_http) {
+    *grpc_status = grpc_chttp2_http2_error_to_grpc_status(
+        (grpc_chttp2_error_code)ip_http, deadline);
+  } else {
+    *grpc_status = GRPC_STATUS_INTERNAL;
+  }
+}
+
 void grpc_chttp2_cancel_stream(grpc_exec_ctx *exec_ctx,
                                grpc_chttp2_transport *t, grpc_chttp2_stream *s,
                                grpc_error *due_to_error) {
-  if (!t->is_client && !s->sent_trailing_metadata &&
-      grpc_error_has_clear_grpc_status(due_to_error)) {
-    close_from_api(exec_ctx, t, s, due_to_error);
-    return;
-  }
-
   if (!s->read_closed || !s->write_closed) {
+    grpc_status_code grpc_status;
+    grpc_chttp2_error_code http_error;
+    status_codes_from_error(due_to_error, s->deadline, &http_error,
+                            &grpc_status);
+
     if (s->id != 0) {
-      grpc_http2_error_code http_error;
-      grpc_error_get_status(due_to_error, s->deadline, NULL, NULL, &http_error);
       grpc_slice_buffer_add(
           &t->qbuf, grpc_chttp2_rst_stream_create(s->id, (uint32_t)http_error,
                                                   &s->stats.outgoing));
       grpc_chttp2_initiate_write(exec_ctx, t, false, "rst_stream");
     }
+
+    const char *msg =
+        grpc_error_get_str(due_to_error, GRPC_ERROR_STR_GRPC_MESSAGE);
+    bool free_msg = false;
+    if (msg == NULL) {
+      free_msg = true;
+      msg = grpc_error_string(due_to_error);
+    }
+    grpc_slice msg_slice = grpc_slice_from_copied_string(msg);
+    grpc_chttp2_fake_status(exec_ctx, t, s, grpc_status, &msg_slice);
+    if (free_msg) grpc_error_free_string(msg);
   }
   if (due_to_error != GRPC_ERROR_NONE && !s->seen_error) {
     s->seen_error = true;
+    grpc_chttp2_maybe_complete_recv_trailing_metadata(exec_ctx, t, s);
   }
   grpc_chttp2_mark_stream_closed(exec_ctx, t, s, 1, 1, due_to_error);
 }
 
 void grpc_chttp2_fake_status(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
-                             grpc_chttp2_stream *s, grpc_error *error) {
-  grpc_status_code status;
-  const char *msg;
-  grpc_error_get_status(error, s->deadline, &status, &msg, NULL);
-
+                             grpc_chttp2_stream *s, grpc_status_code status,
+                             grpc_slice *slice) {
   if (status != GRPC_STATUS_OK) {
     s->seen_error = true;
   }
@@ -1487,21 +1518,24 @@ void grpc_chttp2_fake_status(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
       s->recv_trailing_metadata_finished != NULL) {
     char status_string[GPR_LTOA_MIN_BUFSIZE];
     gpr_ltoa(status, status_string);
-    grpc_chttp2_incoming_metadata_buffer_replace_or_add(
-        exec_ctx, &s->metadata_buffer[1],
-        grpc_mdelem_from_slices(exec_ctx, GRPC_MDSTR_GRPC_STATUS,
-                                grpc_slice_from_copied_string(status_string)));
-    if (msg != NULL) {
-      grpc_chttp2_incoming_metadata_buffer_replace_or_add(
-          exec_ctx, &s->metadata_buffer[1],
-          grpc_mdelem_from_slices(exec_ctx, GRPC_MDSTR_GRPC_MESSAGE,
-                                  grpc_slice_from_copied_string(msg)));
+    grpc_chttp2_incoming_metadata_buffer_add(
+        &s->metadata_buffer[1], grpc_mdelem_from_metadata_strings(
+                                    exec_ctx, GRPC_MDSTR_GRPC_STATUS,
+                                    grpc_mdstr_from_string(status_string)));
+    if (slice) {
+      grpc_chttp2_incoming_metadata_buffer_add(
+          &s->metadata_buffer[1],
+          grpc_mdelem_from_metadata_strings(
+              exec_ctx, GRPC_MDSTR_GRPC_MESSAGE,
+              grpc_mdstr_from_slice(exec_ctx,
+                                    grpc_slice_ref_internal(*slice))));
     }
     s->published_metadata[1] = GRPC_METADATA_SYNTHESIZED_FROM_FAKE;
     grpc_chttp2_maybe_complete_recv_trailing_metadata(exec_ctx, t, s);
   }
-
-  GRPC_ERROR_UNREF(error);
+  if (slice) {
+    grpc_slice_unref_internal(exec_ctx, *slice);
+  }
 }
 
 static void add_error(grpc_error *error, grpc_error **refs, size_t *nrefs) {
@@ -1567,48 +1601,36 @@ void grpc_chttp2_mark_stream_closed(grpc_exec_ctx *exec_ctx,
                                     int close_writes, grpc_error *error) {
   if (s->read_closed && s->write_closed) {
     /* already closed */
-    grpc_chttp2_maybe_complete_recv_trailing_metadata(exec_ctx, t, s);
     GRPC_ERROR_UNREF(error);
     return;
   }
-  bool closed_read = false;
-  bool became_closed = false;
   if (close_reads && !s->read_closed) {
     s->read_closed_error = GRPC_ERROR_REF(error);
     s->read_closed = true;
-    closed_read = true;
+    for (int i = 0; i < 2; i++) {
+      if (s->published_metadata[i] == GRPC_METADATA_NOT_PUBLISHED) {
+        s->published_metadata[i] = GPRC_METADATA_PUBLISHED_AT_CLOSE;
+      }
+    }
+    decrement_active_streams_locked(exec_ctx, t, s);
+    grpc_chttp2_maybe_complete_recv_initial_metadata(exec_ctx, t, s);
+    grpc_chttp2_maybe_complete_recv_message(exec_ctx, t, s);
+    grpc_chttp2_maybe_complete_recv_trailing_metadata(exec_ctx, t, s);
   }
   if (close_writes && !s->write_closed) {
     s->write_closed_error = GRPC_ERROR_REF(error);
     s->write_closed = true;
     grpc_chttp2_fail_pending_writes(exec_ctx, t, s, GRPC_ERROR_REF(error));
+    grpc_chttp2_maybe_complete_recv_trailing_metadata(exec_ctx, t, s);
   }
   if (s->read_closed && s->write_closed) {
-    became_closed = true;
-    grpc_error *overall_error =
-        removal_error(GRPC_ERROR_REF(error), s, "Stream removed");
     if (s->id != 0) {
-      remove_stream(exec_ctx, t, s->id, GRPC_ERROR_REF(overall_error));
+      remove_stream(exec_ctx, t, s->id,
+                    removal_error(GRPC_ERROR_REF(error), s, "Stream removed"));
     } else {
       /* Purge streams waiting on concurrency still waiting for id assignment */
       grpc_chttp2_list_remove_waiting_for_concurrency(t, s);
     }
-    if (overall_error != GRPC_ERROR_NONE) {
-      grpc_chttp2_fake_status(exec_ctx, t, s, overall_error);
-    }
-  }
-  if (closed_read) {
-    for (int i = 0; i < 2; i++) {
-      if (s->published_metadata[i] == GRPC_METADATA_NOT_PUBLISHED) {
-        s->published_metadata[i] = GPRC_METADATA_PUBLISHED_AT_CLOSE;
-      }
-    }
-    decrement_active_streams_locked(exec_ctx, t, s);
-    grpc_chttp2_maybe_complete_recv_initial_metadata(exec_ctx, t, s);
-    grpc_chttp2_maybe_complete_recv_message(exec_ctx, t, s);
-  }
-  if (became_closed) {
-    grpc_chttp2_maybe_complete_recv_trailing_metadata(exec_ctx, t, s);
     GRPC_CHTTP2_STREAM_UNREF(exec_ctx, s, "chttp2");
   }
   GRPC_ERROR_UNREF(error);
@@ -1622,92 +1644,112 @@ static void close_from_api(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
   uint8_t *p;
   uint32_t len = 0;
   grpc_status_code grpc_status;
-  const char *msg;
-  grpc_error_get_status(error, s->deadline, &grpc_status, &msg, NULL);
+  grpc_chttp2_error_code http_error;
+  status_codes_from_error(error, s->deadline, &http_error, &grpc_status);
 
   GPR_ASSERT(grpc_status >= 0 && (int)grpc_status < 100);
 
-  /* Hand roll a header block.
-     This is unnecessarily ugly - at some point we should find a more
-     elegant solution.
-     It's complicated by the fact that our send machinery would be dead by
-     the time we got around to sending this, so instead we ignore HPACK
-     compression and just write the uncompressed bytes onto the wire. */
-  status_hdr = grpc_slice_malloc(15 + (grpc_status >= 10));
-  p = GRPC_SLICE_START_PTR(status_hdr);
-  *p++ = 0x00; /* literal header, not indexed */
-  *p++ = 11;   /* len(grpc-status) */
-  *p++ = 'g';
-  *p++ = 'r';
-  *p++ = 'p';
-  *p++ = 'c';
-  *p++ = '-';
-  *p++ = 's';
-  *p++ = 't';
-  *p++ = 'a';
-  *p++ = 't';
-  *p++ = 'u';
-  *p++ = 's';
-  if (grpc_status < 10) {
-    *p++ = 1;
-    *p++ = (uint8_t)('0' + grpc_status);
-  } else {
-    *p++ = 2;
-    *p++ = (uint8_t)('0' + (grpc_status / 10));
-    *p++ = (uint8_t)('0' + (grpc_status % 10));
-  }
-  GPR_ASSERT(p == GRPC_SLICE_END_PTR(status_hdr));
-  len += (uint32_t)GRPC_SLICE_LENGTH(status_hdr);
-
-  if (msg != NULL) {
-    size_t msg_len = strlen(msg);
-    GPR_ASSERT(msg_len <= UINT32_MAX);
-    uint32_t msg_len_len = GRPC_CHTTP2_VARINT_LENGTH((uint32_t)msg_len, 0);
-    message_pfx = grpc_slice_malloc(14 + msg_len_len);
-    p = GRPC_SLICE_START_PTR(message_pfx);
-    *p++ = 0x00; /* literal header, not indexed */
-    *p++ = 12;   /* len(grpc-message) */
+  if (s->id != 0 && !t->is_client) {
+    /* Hand roll a header block.
+       This is unnecessarily ugly - at some point we should find a more
+       elegant
+       solution.
+       It's complicated by the fact that our send machinery would be dead by
+       the
+       time we got around to sending this, so instead we ignore HPACK
+       compression
+       and just write the uncompressed bytes onto the wire. */
+    status_hdr = grpc_slice_malloc(15 + (grpc_status >= 10));
+    p = GRPC_SLICE_START_PTR(status_hdr);
+    *p++ = 0x40; /* literal header */
+    *p++ = 11;   /* len(grpc-status) */
     *p++ = 'g';
     *p++ = 'r';
     *p++ = 'p';
     *p++ = 'c';
     *p++ = '-';
-    *p++ = 'm';
-    *p++ = 'e';
-    *p++ = 's';
     *p++ = 's';
+    *p++ = 't';
     *p++ = 'a';
-    *p++ = 'g';
-    *p++ = 'e';
-    GRPC_CHTTP2_WRITE_VARINT((uint32_t)msg_len, 0, 0, p, (uint32_t)msg_len_len);
-    p += msg_len_len;
-    GPR_ASSERT(p == GRPC_SLICE_END_PTR(message_pfx));
-    len += (uint32_t)GRPC_SLICE_LENGTH(message_pfx);
-    len += (uint32_t)msg_len;
-  }
-
-  hdr = grpc_slice_malloc(9);
-  p = GRPC_SLICE_START_PTR(hdr);
-  *p++ = (uint8_t)(len >> 16);
-  *p++ = (uint8_t)(len >> 8);
-  *p++ = (uint8_t)(len);
-  *p++ = GRPC_CHTTP2_FRAME_HEADER;
-  *p++ = GRPC_CHTTP2_DATA_FLAG_END_STREAM | GRPC_CHTTP2_DATA_FLAG_END_HEADERS;
-  *p++ = (uint8_t)(s->id >> 24);
-  *p++ = (uint8_t)(s->id >> 16);
-  *p++ = (uint8_t)(s->id >> 8);
-  *p++ = (uint8_t)(s->id);
-  GPR_ASSERT(p == GRPC_SLICE_END_PTR(hdr));
-
-  grpc_slice_buffer_add(&t->qbuf, hdr);
-  grpc_slice_buffer_add(&t->qbuf, status_hdr);
-  if (msg != NULL) {
-    grpc_slice_buffer_add(&t->qbuf, message_pfx);
-    grpc_slice_buffer_add(&t->qbuf, grpc_slice_from_copied_string(msg));
-  }
-  grpc_slice_buffer_add(
-      &t->qbuf, grpc_chttp2_rst_stream_create(s->id, GRPC_HTTP2_NO_ERROR,
-                                              &s->stats.outgoing));
+    *p++ = 't';
+    *p++ = 'u';
+    *p++ = 's';
+    if (grpc_status < 10) {
+      *p++ = 1;
+      *p++ = (uint8_t)('0' + grpc_status);
+    } else {
+      *p++ = 2;
+      *p++ = (uint8_t)('0' + (grpc_status / 10));
+      *p++ = (uint8_t)('0' + (grpc_status % 10));
+    }
+    GPR_ASSERT(p == GRPC_SLICE_END_PTR(status_hdr));
+    len += (uint32_t)GRPC_SLICE_LENGTH(status_hdr);
+
+    const char *optional_message =
+        grpc_error_get_str(error, GRPC_ERROR_STR_GRPC_MESSAGE);
+
+    if (optional_message != NULL) {
+      size_t msg_len = strlen(optional_message);
+      GPR_ASSERT(msg_len <= UINT32_MAX);
+      uint32_t msg_len_len = GRPC_CHTTP2_VARINT_LENGTH((uint32_t)msg_len, 0);
+      message_pfx = grpc_slice_malloc(14 + msg_len_len);
+      p = GRPC_SLICE_START_PTR(message_pfx);
+      *p++ = 0x40;
+      *p++ = 12; /* len(grpc-message) */
+      *p++ = 'g';
+      *p++ = 'r';
+      *p++ = 'p';
+      *p++ = 'c';
+      *p++ = '-';
+      *p++ = 'm';
+      *p++ = 'e';
+      *p++ = 's';
+      *p++ = 's';
+      *p++ = 'a';
+      *p++ = 'g';
+      *p++ = 'e';
+      GRPC_CHTTP2_WRITE_VARINT((uint32_t)msg_len, 0, 0, p,
+                               (uint32_t)msg_len_len);
+      p += msg_len_len;
+      GPR_ASSERT(p == GRPC_SLICE_END_PTR(message_pfx));
+      len += (uint32_t)GRPC_SLICE_LENGTH(message_pfx);
+      len += (uint32_t)msg_len;
+    }
+
+    hdr = grpc_slice_malloc(9);
+    p = GRPC_SLICE_START_PTR(hdr);
+    *p++ = (uint8_t)(len >> 16);
+    *p++ = (uint8_t)(len >> 8);
+    *p++ = (uint8_t)(len);
+    *p++ = GRPC_CHTTP2_FRAME_HEADER;
+    *p++ = GRPC_CHTTP2_DATA_FLAG_END_STREAM | GRPC_CHTTP2_DATA_FLAG_END_HEADERS;
+    *p++ = (uint8_t)(s->id >> 24);
+    *p++ = (uint8_t)(s->id >> 16);
+    *p++ = (uint8_t)(s->id >> 8);
+    *p++ = (uint8_t)(s->id);
+    GPR_ASSERT(p == GRPC_SLICE_END_PTR(hdr));
+
+    grpc_slice_buffer_add(&t->qbuf, hdr);
+    grpc_slice_buffer_add(&t->qbuf, status_hdr);
+    if (optional_message) {
+      grpc_slice_buffer_add(&t->qbuf, message_pfx);
+      grpc_slice_buffer_add(&t->qbuf,
+                            grpc_slice_from_copied_string(optional_message));
+    }
+    grpc_slice_buffer_add(
+        &t->qbuf, grpc_chttp2_rst_stream_create(s->id, GRPC_CHTTP2_NO_ERROR,
+                                                &s->stats.outgoing));
+  }
+
+  const char *msg = grpc_error_get_str(error, GRPC_ERROR_STR_GRPC_MESSAGE);
+  bool free_msg = false;
+  if (msg == NULL) {
+    free_msg = true;
+    msg = grpc_error_string(error);
+  }
+  grpc_slice msg_slice = grpc_slice_from_copied_string(msg);
+  grpc_chttp2_fake_status(exec_ctx, t, s, grpc_status, &msg_slice);
+  if (free_msg) grpc_error_free_string(msg);
 
   grpc_chttp2_mark_stream_closed(exec_ctx, t, s, 1, 1, error);
   grpc_chttp2_initiate_write(exec_ctx, t, false, "close_from_api");
@@ -1785,10 +1827,8 @@ static grpc_error *try_http_parsing(grpc_exec_ctx *exec_ctx,
   if (parse_error == GRPC_ERROR_NONE &&
       (parse_error = grpc_http_parser_eof(&parser)) == GRPC_ERROR_NONE) {
     error = grpc_error_set_int(
-        grpc_error_set_int(
-            GRPC_ERROR_CREATE("Trying to connect an http1.x server"),
-            GRPC_ERROR_INT_HTTP_STATUS, response.status),
-        GRPC_ERROR_INT_GRPC_STATUS, GRPC_STATUS_UNAVAILABLE);
+        GRPC_ERROR_CREATE("Trying to connect an http1.x server"),
+        GRPC_ERROR_INT_HTTP_STATUS, response.status);
   }
   GRPC_ERROR_UNREF(parse_error);
 
@@ -2049,8 +2089,6 @@ static void incoming_byte_stream_publish_error(
   grpc_closure_sched(exec_ctx, bs->on_next, GRPC_ERROR_REF(error));
   bs->on_next = NULL;
   GRPC_ERROR_UNREF(bs->error);
-  grpc_chttp2_cancel_stream(exec_ctx, bs->transport, bs->stream,
-                            GRPC_ERROR_REF(error));
   bs->error = error;
 }
 
@@ -2159,10 +2197,8 @@ static void benign_reclaimer_locked(grpc_exec_ctx *exec_ctx, void *arg,
       gpr_log(GPR_DEBUG, "HTTP2: %s - send goaway to free memory",
               t->peer_string);
     }
-    send_goaway(exec_ctx, t,
-                grpc_error_set_int(GRPC_ERROR_CREATE("Buffers full"),
-                                   GRPC_ERROR_INT_HTTP2_ERROR,
-                                   GRPC_HTTP2_ENHANCE_YOUR_CALM));
+    send_goaway(exec_ctx, t, GRPC_CHTTP2_ENHANCE_YOUR_CALM,
+                grpc_slice_from_static_string("Buffers full"));
   } else if (error == GRPC_ERROR_NONE && grpc_resource_quota_trace) {
     gpr_log(GPR_DEBUG,
             "HTTP2: %s - skip benign reclamation, there are still %" PRIdPTR
@@ -2191,7 +2227,7 @@ static void destructive_reclaimer_locked(grpc_exec_ctx *exec_ctx, void *arg,
     grpc_chttp2_cancel_stream(
         exec_ctx, t, s, grpc_error_set_int(GRPC_ERROR_CREATE("Buffers full"),
                                            GRPC_ERROR_INT_HTTP2_ERROR,
-                                           GRPC_HTTP2_ENHANCE_YOUR_CALM));
+                                           GRPC_CHTTP2_ENHANCE_YOUR_CALM));
     if (n > 1) {
       /* Since we cancel one stream per destructive reclamation, if
          there are more streams left, we can immediately post a new
diff --git a/src/core/ext/transport/chttp2/transport/frame_rst_stream.c b/src/core/ext/transport/chttp2/transport/frame_rst_stream.c
index 7d5beed09d..20043f5fbf 100644
--- a/src/core/ext/transport/chttp2/transport/frame_rst_stream.c
+++ b/src/core/ext/transport/chttp2/transport/frame_rst_stream.c
@@ -39,7 +39,8 @@
 #include <grpc/support/string_util.h>
 
 #include "src/core/ext/transport/chttp2/transport/frame.h"
-#include "src/core/lib/transport/http2_errors.h"
+#include "src/core/ext/transport/chttp2/transport/http2_errors.h"
+#include "src/core/ext/transport/chttp2/transport/status_conversion.h"
 
 grpc_slice grpc_chttp2_rst_stream_create(uint32_t id, uint32_t code,
                                          grpc_transport_one_way_stats *stats) {
@@ -108,9 +109,17 @@ grpc_error *grpc_chttp2_rst_stream_parser_parse(grpc_exec_ctx *exec_ctx,
                       (((uint32_t)p->reason_bytes[2]) << 8) |
                       (((uint32_t)p->reason_bytes[3]));
     grpc_error *error = GRPC_ERROR_NONE;
-    if (reason != GRPC_HTTP2_NO_ERROR || s->header_frames_received < 2) {
+    if (reason != GRPC_CHTTP2_NO_ERROR || s->header_frames_received < 2) {
       error = grpc_error_set_int(GRPC_ERROR_CREATE("RST_STREAM"),
                                  GRPC_ERROR_INT_HTTP2_ERROR, (intptr_t)reason);
+      grpc_status_code status_code = grpc_chttp2_http2_error_to_grpc_status(
+          (grpc_chttp2_error_code)reason, s->deadline);
+      char *status_details;
+      gpr_asprintf(&status_details, "Received RST_STREAM with error code %d",
+                   reason);
+      grpc_slice slice_details = grpc_slice_from_copied_string(status_details);
+      gpr_free(status_details);
+      grpc_chttp2_fake_status(exec_ctx, t, s, status_code, &slice_details);
     }
     grpc_chttp2_mark_stream_closed(exec_ctx, t, s, true, true, error);
   }
diff --git a/src/core/ext/transport/chttp2/transport/frame_settings.c b/src/core/ext/transport/chttp2/transport/frame_settings.c
index be9b663ac1..98facae87f 100644
--- a/src/core/ext/transport/chttp2/transport/frame_settings.c
+++ b/src/core/ext/transport/chttp2/transport/frame_settings.c
@@ -43,8 +43,8 @@
 
 #include "src/core/ext/transport/chttp2/transport/chttp2_transport.h"
 #include "src/core/ext/transport/chttp2/transport/frame.h"
+#include "src/core/ext/transport/chttp2/transport/http2_errors.h"
 #include "src/core/lib/debug/trace.h"
-#include "src/core/lib/transport/http2_errors.h"
 
 #define MAX_MAX_HEADER_LIST_SIZE (1024 * 1024 * 1024)
 
@@ -52,21 +52,21 @@
 const grpc_chttp2_setting_parameters
     grpc_chttp2_settings_parameters[GRPC_CHTTP2_NUM_SETTINGS] = {
         {NULL, 0, 0, 0, GRPC_CHTTP2_DISCONNECT_ON_INVALID_VALUE,
-         GRPC_HTTP2_PROTOCOL_ERROR},
+         GRPC_CHTTP2_PROTOCOL_ERROR},
         {"HEADER_TABLE_SIZE", 4096, 0, 0xffffffff,
-         GRPC_CHTTP2_CLAMP_INVALID_VALUE, GRPC_HTTP2_PROTOCOL_ERROR},
+         GRPC_CHTTP2_CLAMP_INVALID_VALUE, GRPC_CHTTP2_PROTOCOL_ERROR},
         {"ENABLE_PUSH", 1, 0, 1, GRPC_CHTTP2_DISCONNECT_ON_INVALID_VALUE,
-         GRPC_HTTP2_PROTOCOL_ERROR},
+         GRPC_CHTTP2_PROTOCOL_ERROR},
         {"MAX_CONCURRENT_STREAMS", 0xffffffffu, 0, 0xffffffffu,
-         GRPC_CHTTP2_DISCONNECT_ON_INVALID_VALUE, GRPC_HTTP2_PROTOCOL_ERROR},
+         GRPC_CHTTP2_DISCONNECT_ON_INVALID_VALUE, GRPC_CHTTP2_PROTOCOL_ERROR},
         {"INITIAL_WINDOW_SIZE", 65535, 0, 0x7fffffffu,
          GRPC_CHTTP2_DISCONNECT_ON_INVALID_VALUE,
-         GRPC_HTTP2_FLOW_CONTROL_ERROR},
+         GRPC_CHTTP2_FLOW_CONTROL_ERROR},
         {"MAX_FRAME_SIZE", 16384, 16384, 16777215,
-         GRPC_CHTTP2_DISCONNECT_ON_INVALID_VALUE, GRPC_HTTP2_PROTOCOL_ERROR},
+         GRPC_CHTTP2_DISCONNECT_ON_INVALID_VALUE, GRPC_CHTTP2_PROTOCOL_ERROR},
         {"MAX_HEADER_LIST_SIZE", MAX_MAX_HEADER_LIST_SIZE, 0,
          MAX_MAX_HEADER_LIST_SIZE, GRPC_CHTTP2_CLAMP_INVALID_VALUE,
-         GRPC_HTTP2_PROTOCOL_ERROR},
+         GRPC_CHTTP2_PROTOCOL_ERROR},
 };
 
 static uint8_t *fill_header(uint8_t *out, uint32_t length, uint8_t flags) {
diff --git a/src/core/ext/transport/chttp2/transport/hpack_encoder.c b/src/core/ext/transport/chttp2/transport/hpack_encoder.c
index 63df8e135f..49a8326f62 100644
--- a/src/core/ext/transport/chttp2/transport/hpack_encoder.c
+++ b/src/core/ext/transport/chttp2/transport/hpack_encoder.c
@@ -49,7 +49,6 @@
 #include "src/core/ext/transport/chttp2/transport/hpack_table.h"
 #include "src/core/ext/transport/chttp2/transport/varint.h"
 #include "src/core/lib/slice/slice_internal.h"
-#include "src/core/lib/slice/slice_string_helpers.h"
 #include "src/core/lib/transport/metadata.h"
 #include "src/core/lib/transport/static_metadata.h"
 #include "src/core/lib/transport/timeout_encoding.h"
@@ -65,10 +64,6 @@
 /* don't consider adding anything bigger than this to the hpack table */
 #define MAX_DECODER_SPACE_USAGE 512
 
-static grpc_slice_refcount terminal_slice_refcount = {NULL, NULL};
-static const grpc_slice terminal_slice = {&terminal_slice_refcount,
-                                          .data.refcounted = {0, 0}};
-
 extern int grpc_http_trace;
 
 typedef struct {
@@ -190,12 +185,9 @@ static void evict_entry(grpc_chttp2_hpack_compressor *c) {
 
 /* add an element to the decoder table */
 static void add_elem(grpc_exec_ctx *exec_ctx, grpc_chttp2_hpack_compressor *c,
-                     grpc_mdelem elem) {
-  GPR_ASSERT(GRPC_MDELEM_IS_INTERNED(elem));
-
-  uint32_t key_hash = grpc_slice_hash(GRPC_MDKEY(elem));
-  uint32_t value_hash = grpc_slice_hash(GRPC_MDVALUE(elem));
-  uint32_t elem_hash = GRPC_MDSTR_KV_HASH(key_hash, value_hash);
+                     grpc_mdelem *elem) {
+  uint32_t key_hash = elem->key->hash;
+  uint32_t elem_hash = GRPC_MDSTR_KV_HASH(key_hash, elem->value->hash);
   uint32_t new_index = c->tail_remote_index + c->table_elems + 1;
   size_t elem_size = grpc_mdelem_get_size_in_hpack_table(elem);
 
@@ -220,18 +212,17 @@ static void add_elem(grpc_exec_ctx *exec_ctx, grpc_chttp2_hpack_compressor *c,
   c->table_elems++;
 
   /* Store this element into {entries,indices}_elem */
-  if (grpc_mdelem_eq(c->entries_elems[HASH_FRAGMENT_2(elem_hash)], elem)) {
+  if (c->entries_elems[HASH_FRAGMENT_2(elem_hash)] == elem) {
     /* already there: update with new index */
     c->indices_elems[HASH_FRAGMENT_2(elem_hash)] = new_index;
-  } else if (grpc_mdelem_eq(c->entries_elems[HASH_FRAGMENT_3(elem_hash)],
-                            elem)) {
+  } else if (c->entries_elems[HASH_FRAGMENT_3(elem_hash)] == elem) {
     /* already there (cuckoo): update with new index */
     c->indices_elems[HASH_FRAGMENT_3(elem_hash)] = new_index;
-  } else if (GRPC_MDISNULL(c->entries_elems[HASH_FRAGMENT_2(elem_hash)])) {
+  } else if (c->entries_elems[HASH_FRAGMENT_2(elem_hash)] == NULL) {
     /* not there, but a free element: add */
     c->entries_elems[HASH_FRAGMENT_2(elem_hash)] = GRPC_MDELEM_REF(elem);
     c->indices_elems[HASH_FRAGMENT_2(elem_hash)] = new_index;
-  } else if (GRPC_MDISNULL(c->entries_elems[HASH_FRAGMENT_3(elem_hash)])) {
+  } else if (c->entries_elems[HASH_FRAGMENT_3(elem_hash)] == NULL) {
     /* not there (cuckoo), but a free element: add */
     c->entries_elems[HASH_FRAGMENT_3(elem_hash)] = GRPC_MDELEM_REF(elem);
     c->indices_elems[HASH_FRAGMENT_3(elem_hash)] = new_index;
@@ -250,34 +241,24 @@ static void add_elem(grpc_exec_ctx *exec_ctx, grpc_chttp2_hpack_compressor *c,
 
   /* do exactly the same for the key (so we can find by that again too) */
 
-  if (grpc_slice_eq(c->entries_keys[HASH_FRAGMENT_2(key_hash)],
-                    GRPC_MDKEY(elem))) {
+  if (c->entries_keys[HASH_FRAGMENT_2(key_hash)] == elem->key) {
     c->indices_keys[HASH_FRAGMENT_2(key_hash)] = new_index;
-  } else if (grpc_slice_eq(c->entries_keys[HASH_FRAGMENT_3(key_hash)],
-                           GRPC_MDKEY(elem))) {
+  } else if (c->entries_keys[HASH_FRAGMENT_3(key_hash)] == elem->key) {
     c->indices_keys[HASH_FRAGMENT_3(key_hash)] = new_index;
-  } else if (c->entries_keys[HASH_FRAGMENT_2(key_hash)].refcount ==
-             &terminal_slice_refcount) {
-    c->entries_keys[HASH_FRAGMENT_2(key_hash)] =
-        grpc_slice_ref_internal(GRPC_MDKEY(elem));
+  } else if (c->entries_keys[HASH_FRAGMENT_2(key_hash)] == NULL) {
+    c->entries_keys[HASH_FRAGMENT_2(key_hash)] = GRPC_MDSTR_REF(elem->key);
     c->indices_keys[HASH_FRAGMENT_2(key_hash)] = new_index;
-  } else if (c->entries_keys[HASH_FRAGMENT_3(key_hash)].refcount ==
-             &terminal_slice_refcount) {
-    c->entries_keys[HASH_FRAGMENT_3(key_hash)] =
-        grpc_slice_ref_internal(GRPC_MDKEY(elem));
+  } else if (c->entries_keys[HASH_FRAGMENT_3(key_hash)] == NULL) {
+    c->entries_keys[HASH_FRAGMENT_3(key_hash)] = GRPC_MDSTR_REF(elem->key);
     c->indices_keys[HASH_FRAGMENT_3(key_hash)] = new_index;
   } else if (c->indices_keys[HASH_FRAGMENT_2(key_hash)] <
              c->indices_keys[HASH_FRAGMENT_3(key_hash)]) {
-    grpc_slice_unref_internal(exec_ctx,
-                              c->entries_keys[HASH_FRAGMENT_2(key_hash)]);
-    c->entries_keys[HASH_FRAGMENT_2(key_hash)] =
-        grpc_slice_ref_internal(GRPC_MDKEY(elem));
+    GRPC_MDSTR_UNREF(exec_ctx, c->entries_keys[HASH_FRAGMENT_2(key_hash)]);
+    c->entries_keys[HASH_FRAGMENT_2(key_hash)] = GRPC_MDSTR_REF(elem->key);
     c->indices_keys[HASH_FRAGMENT_2(key_hash)] = new_index;
   } else {
-    grpc_slice_unref_internal(exec_ctx,
-                              c->entries_keys[HASH_FRAGMENT_3(key_hash)]);
-    c->entries_keys[HASH_FRAGMENT_3(key_hash)] =
-        grpc_slice_ref_internal(GRPC_MDKEY(elem));
+    GRPC_MDSTR_UNREF(exec_ctx, c->entries_keys[HASH_FRAGMENT_3(key_hash)]);
+    c->entries_keys[HASH_FRAGMENT_3(key_hash)] = GRPC_MDSTR_REF(elem->key);
     c->indices_keys[HASH_FRAGMENT_3(key_hash)] = new_index;
   }
 }
@@ -289,18 +270,20 @@ static void emit_indexed(grpc_chttp2_hpack_compressor *c, uint32_t elem_index,
                            len);
 }
 
-static grpc_slice get_wire_value(grpc_mdelem elem, uint8_t *huffman_prefix) {
-  if (grpc_is_binary_header(GRPC_MDKEY(elem))) {
+static grpc_slice get_wire_value(grpc_mdelem *elem, uint8_t *huffman_prefix) {
+  if (grpc_is_binary_header(
+          (const char *)GRPC_SLICE_START_PTR(elem->key->slice),
+          GRPC_SLICE_LENGTH(elem->key->slice))) {
     *huffman_prefix = 0x80;
-    return grpc_chttp2_base64_encode_and_huffman_compress(GRPC_MDVALUE(elem));
+    return grpc_mdstr_as_base64_encoded_and_huffman_compressed(elem->value);
   }
   /* TODO(ctiller): opportunistically compress non-binary headers */
   *huffman_prefix = 0x00;
-  return grpc_slice_ref_internal(GRPC_MDVALUE(elem));
+  return elem->value->slice;
 }
 
 static void emit_lithdr_incidx(grpc_chttp2_hpack_compressor *c,
-                               uint32_t key_index, grpc_mdelem elem,
+                               uint32_t key_index, grpc_mdelem *elem,
                                framer_state *st) {
   uint32_t len_pfx = GRPC_CHTTP2_VARINT_LENGTH(key_index, 2);
   uint8_t huffman_prefix;
@@ -313,11 +296,11 @@ static void emit_lithdr_incidx(grpc_chttp2_hpack_compressor *c,
                            add_tiny_header_data(st, len_pfx), len_pfx);
   GRPC_CHTTP2_WRITE_VARINT((uint32_t)len_val, 1, huffman_prefix,
                            add_tiny_header_data(st, len_val_len), len_val_len);
-  add_header_data(st, value_slice);
+  add_header_data(st, grpc_slice_ref_internal(value_slice));
 }
 
 static void emit_lithdr_noidx(grpc_chttp2_hpack_compressor *c,
-                              uint32_t key_index, grpc_mdelem elem,
+                              uint32_t key_index, grpc_mdelem *elem,
                               framer_state *st) {
   uint32_t len_pfx = GRPC_CHTTP2_VARINT_LENGTH(key_index, 4);
   uint8_t huffman_prefix;
@@ -330,12 +313,12 @@ static void emit_lithdr_noidx(grpc_chttp2_hpack_compressor *c,
                            add_tiny_header_data(st, len_pfx), len_pfx);
   GRPC_CHTTP2_WRITE_VARINT((uint32_t)len_val, 1, huffman_prefix,
                            add_tiny_header_data(st, len_val_len), len_val_len);
-  add_header_data(st, value_slice);
+  add_header_data(st, grpc_slice_ref_internal(value_slice));
 }
 
 static void emit_lithdr_incidx_v(grpc_chttp2_hpack_compressor *c,
-                                 grpc_mdelem elem, framer_state *st) {
-  uint32_t len_key = (uint32_t)GRPC_SLICE_LENGTH(GRPC_MDKEY(elem));
+                                 grpc_mdelem *elem, framer_state *st) {
+  uint32_t len_key = (uint32_t)GRPC_SLICE_LENGTH(elem->key->slice);
   uint8_t huffman_prefix;
   grpc_slice value_slice = get_wire_value(elem, &huffman_prefix);
   uint32_t len_val = (uint32_t)GRPC_SLICE_LENGTH(value_slice);
@@ -346,15 +329,15 @@ static void emit_lithdr_incidx_v(grpc_chttp2_hpack_compressor *c,
   *add_tiny_header_data(st, 1) = 0x40;
   GRPC_CHTTP2_WRITE_VARINT(len_key, 1, 0x00,
                            add_tiny_header_data(st, len_key_len), len_key_len);
-  add_header_data(st, grpc_slice_ref_internal(GRPC_MDKEY(elem)));
+  add_header_data(st, grpc_slice_ref_internal(elem->key->slice));
   GRPC_CHTTP2_WRITE_VARINT(len_val, 1, huffman_prefix,
                            add_tiny_header_data(st, len_val_len), len_val_len);
-  add_header_data(st, value_slice);
+  add_header_data(st, grpc_slice_ref_internal(value_slice));
 }
 
 static void emit_lithdr_noidx_v(grpc_chttp2_hpack_compressor *c,
-                                grpc_mdelem elem, framer_state *st) {
-  uint32_t len_key = (uint32_t)GRPC_SLICE_LENGTH(GRPC_MDKEY(elem));
+                                grpc_mdelem *elem, framer_state *st) {
+  uint32_t len_key = (uint32_t)GRPC_SLICE_LENGTH(elem->key->slice);
   uint8_t huffman_prefix;
   grpc_slice value_slice = get_wire_value(elem, &huffman_prefix);
   uint32_t len_val = (uint32_t)GRPC_SLICE_LENGTH(value_slice);
@@ -365,10 +348,10 @@ static void emit_lithdr_noidx_v(grpc_chttp2_hpack_compressor *c,
   *add_tiny_header_data(st, 1) = 0x00;
   GRPC_CHTTP2_WRITE_VARINT(len_key, 1, 0x00,
                            add_tiny_header_data(st, len_key_len), len_key_len);
-  add_header_data(st, grpc_slice_ref_internal(GRPC_MDKEY(elem)));
+  add_header_data(st, grpc_slice_ref_internal(elem->key->slice));
   GRPC_CHTTP2_WRITE_VARINT(len_val, 1, huffman_prefix,
                            add_tiny_header_data(st, len_val_len), len_val_len);
-  add_header_data(st, value_slice);
+  add_header_data(st, grpc_slice_ref_internal(value_slice));
 }
 
 static void emit_advertise_table_size_change(grpc_chttp2_hpack_compressor *c,
@@ -386,9 +369,15 @@ static uint32_t dynidx(grpc_chttp2_hpack_compressor *c, uint32_t elem_index) {
 
 /* encode an mdelem */
 static void hpack_enc(grpc_exec_ctx *exec_ctx, grpc_chttp2_hpack_compressor *c,
-                      grpc_mdelem elem, framer_state *st) {
-  GPR_ASSERT(GRPC_SLICE_LENGTH(GRPC_MDKEY(elem)) > 0);
-  if (GRPC_SLICE_START_PTR(GRPC_MDKEY(elem))[0] != ':') { /* regular header */
+                      grpc_mdelem *elem, framer_state *st) {
+  uint32_t key_hash = elem->key->hash;
+  uint32_t elem_hash = GRPC_MDSTR_KV_HASH(key_hash, elem->value->hash);
+  size_t decoder_space_usage;
+  uint32_t indices_key;
+  int should_add_elem;
+
+  GPR_ASSERT(GRPC_SLICE_LENGTH(elem->key->slice) > 0);
+  if (GRPC_SLICE_START_PTR(elem->key->slice)[0] != ':') { /* regular header */
     st->seen_regular_header = 1;
   } else {
     GPR_ASSERT(
@@ -396,39 +385,11 @@ static void hpack_enc(grpc_exec_ctx *exec_ctx, grpc_chttp2_hpack_compressor *c,
         "Reserved header (colon-prefixed) happening after regular ones.");
   }
 
-  if (grpc_http_trace && !GRPC_MDELEM_IS_INTERNED(elem)) {
-    char *k = grpc_slice_to_c_string(GRPC_MDKEY(elem));
-    char *v = grpc_slice_to_c_string(GRPC_MDVALUE(elem));
-    gpr_log(
-        GPR_DEBUG,
-        "Encode: '%s: %s', elem_interned=%d [%d], k_interned=%d, v_interned=%d",
-        k, v, GRPC_MDELEM_IS_INTERNED(elem), GRPC_MDELEM_STORAGE(elem),
-        grpc_slice_is_interned(GRPC_MDKEY(elem)),
-        grpc_slice_is_interned(GRPC_MDVALUE(elem)));
-    gpr_free(k);
-    gpr_free(v);
-  }
-  if (!GRPC_MDELEM_IS_INTERNED(elem)) {
-    emit_lithdr_noidx_v(c, elem, st);
-    return;
-  }
-
-  uint32_t key_hash;
-  uint32_t value_hash;
-  uint32_t elem_hash;
-  size_t decoder_space_usage;
-  uint32_t indices_key;
-  int should_add_elem;
-
-  key_hash = grpc_slice_hash(GRPC_MDKEY(elem));
-  value_hash = grpc_slice_hash(GRPC_MDVALUE(elem));
-  elem_hash = GRPC_MDSTR_KV_HASH(key_hash, value_hash);
-
   inc_filter(HASH_FRAGMENT_1(elem_hash), &c->filter_elems_sum, c->filter_elems);
 
   /* is this elem currently in the decoders table? */
 
-  if (grpc_mdelem_eq(c->entries_elems[HASH_FRAGMENT_2(elem_hash)], elem) &&
+  if (c->entries_elems[HASH_FRAGMENT_2(elem_hash)] == elem &&
       c->indices_elems[HASH_FRAGMENT_2(elem_hash)] > c->tail_remote_index) {
     /* HIT: complete element (first cuckoo hash) */
     emit_indexed(c, dynidx(c, c->indices_elems[HASH_FRAGMENT_2(elem_hash)]),
@@ -436,7 +397,7 @@ static void hpack_enc(grpc_exec_ctx *exec_ctx, grpc_chttp2_hpack_compressor *c,
     return;
   }
 
-  if (grpc_mdelem_eq(c->entries_elems[HASH_FRAGMENT_3(elem_hash)], elem) &&
+  if (c->entries_elems[HASH_FRAGMENT_3(elem_hash)] == elem &&
       c->indices_elems[HASH_FRAGMENT_3(elem_hash)] > c->tail_remote_index) {
     /* HIT: complete element (second cuckoo hash) */
     emit_indexed(c, dynidx(c, c->indices_elems[HASH_FRAGMENT_3(elem_hash)]),
@@ -453,8 +414,7 @@ static void hpack_enc(grpc_exec_ctx *exec_ctx, grpc_chttp2_hpack_compressor *c,
   /* no hits for the elem... maybe there's a key? */
 
   indices_key = c->indices_keys[HASH_FRAGMENT_2(key_hash)];
-  if (grpc_slice_eq(c->entries_keys[HASH_FRAGMENT_2(key_hash)],
-                    GRPC_MDKEY(elem)) &&
+  if (c->entries_keys[HASH_FRAGMENT_2(key_hash)] == elem->key &&
       indices_key > c->tail_remote_index) {
     /* HIT: key (first cuckoo hash) */
     if (should_add_elem) {
@@ -469,8 +429,7 @@ static void hpack_enc(grpc_exec_ctx *exec_ctx, grpc_chttp2_hpack_compressor *c,
   }
 
   indices_key = c->indices_keys[HASH_FRAGMENT_3(key_hash)];
-  if (grpc_slice_eq(c->entries_keys[HASH_FRAGMENT_3(key_hash)],
-                    GRPC_MDKEY(elem)) &&
+  if (c->entries_keys[HASH_FRAGMENT_3(key_hash)] == elem->key &&
       indices_key > c->tail_remote_index) {
     /* HIT: key (first cuckoo hash) */
     if (should_add_elem) {
@@ -504,11 +463,11 @@ static void deadline_enc(grpc_exec_ctx *exec_ctx,
                          grpc_chttp2_hpack_compressor *c, gpr_timespec deadline,
                          framer_state *st) {
   char timeout_str[GRPC_HTTP2_TIMEOUT_ENCODE_MIN_BUFSIZE];
-  grpc_mdelem mdelem;
+  grpc_mdelem *mdelem;
   grpc_http2_encode_timeout(
       gpr_time_sub(deadline, gpr_now(deadline.clock_type)), timeout_str);
-  mdelem = grpc_mdelem_from_slices(exec_ctx, GRPC_MDSTR_GRPC_TIMEOUT,
-                                   grpc_slice_from_copied_string(timeout_str));
+  mdelem = grpc_mdelem_from_metadata_strings(
+      exec_ctx, GRPC_MDSTR_GRPC_TIMEOUT, grpc_mdstr_from_string(timeout_str));
   hpack_enc(exec_ctx, c, mdelem, st);
   GRPC_MDELEM_UNREF(exec_ctx, mdelem);
 }
@@ -525,19 +484,14 @@ void grpc_chttp2_hpack_compressor_init(grpc_chttp2_hpack_compressor *c) {
       gpr_malloc(sizeof(*c->table_elem_size) * c->cap_table_elems);
   memset(c->table_elem_size, 0,
          sizeof(*c->table_elem_size) * c->cap_table_elems);
-  for (size_t i = 0; i < GPR_ARRAY_SIZE(c->entries_keys); i++) {
-    c->entries_keys[i] = terminal_slice;
-  }
 }
 
 void grpc_chttp2_hpack_compressor_destroy(grpc_exec_ctx *exec_ctx,
                                           grpc_chttp2_hpack_compressor *c) {
   int i;
   for (i = 0; i < GRPC_CHTTP2_HPACKC_NUM_VALUES; i++) {
-    if (c->entries_keys[i].refcount != &terminal_slice_refcount) {
-      grpc_slice_unref_internal(exec_ctx, c->entries_keys[i]);
-    }
-    GRPC_MDELEM_UNREF(exec_ctx, c->entries_elems[i]);
+    if (c->entries_keys[i]) GRPC_MDSTR_UNREF(exec_ctx, c->entries_keys[i]);
+    if (c->entries_elems[i]) GRPC_MDELEM_UNREF(exec_ctx, c->entries_elems[i]);
   }
   gpr_free(c->table_elem_size);
 }
diff --git a/src/core/ext/transport/chttp2/transport/hpack_encoder.h b/src/core/ext/transport/chttp2/transport/hpack_encoder.h
index 83ba5b1b3e..3a35496ec8 100644
--- a/src/core/ext/transport/chttp2/transport/hpack_encoder.h
+++ b/src/core/ext/transport/chttp2/transport/hpack_encoder.h
@@ -74,8 +74,8 @@ typedef struct {
 
   /* entry tables for keys & elems: these tables track values that have been
      seen and *may* be in the decompressor table */
-  grpc_slice entries_keys[GRPC_CHTTP2_HPACKC_NUM_VALUES];
-  grpc_mdelem entries_elems[GRPC_CHTTP2_HPACKC_NUM_VALUES];
+  grpc_mdstr *entries_keys[GRPC_CHTTP2_HPACKC_NUM_VALUES];
+  grpc_mdelem *entries_elems[GRPC_CHTTP2_HPACKC_NUM_VALUES];
   uint32_t indices_keys[GRPC_CHTTP2_HPACKC_NUM_VALUES];
   uint32_t indices_elems[GRPC_CHTTP2_HPACKC_NUM_VALUES];
 
diff --git a/src/core/ext/transport/chttp2/transport/hpack_parser.c b/src/core/ext/transport/chttp2/transport/hpack_parser.c
index 40f5120308..8b91cc760b 100644
--- a/src/core/ext/transport/chttp2/transport/hpack_parser.c
+++ b/src/core/ext/transport/chttp2/transport/hpack_parser.c
@@ -50,13 +50,9 @@
 #include <grpc/support/useful.h>
 
 #include "src/core/ext/transport/chttp2/transport/bin_encoder.h"
+#include "src/core/ext/transport/chttp2/transport/http2_errors.h"
 #include "src/core/lib/profiling/timers.h"
-#include "src/core/lib/slice/slice_internal.h"
 #include "src/core/lib/support/string.h"
-#include "src/core/lib/transport/http2_errors.h"
-
-/* TODO(ctiller): remove before submission */
-#include "src/core/lib/slice/slice_string_helpers.h"
 
 extern int grpc_http_trace;
 
@@ -672,22 +668,8 @@ static const uint8_t inverse_base64[256] = {
 
 /* emission helpers */
 static grpc_error *on_hdr(grpc_exec_ctx *exec_ctx, grpc_chttp2_hpack_parser *p,
-                          grpc_mdelem md, int add_to_table) {
-  if (grpc_http_trace && !GRPC_MDELEM_IS_INTERNED(md)) {
-    char *k = grpc_slice_to_c_string(GRPC_MDKEY(md));
-    char *v = grpc_slice_to_c_string(GRPC_MDVALUE(md));
-    gpr_log(
-        GPR_DEBUG,
-        "Decode: '%s: %s', elem_interned=%d [%d], k_interned=%d, v_interned=%d",
-        k, v, GRPC_MDELEM_IS_INTERNED(md), GRPC_MDELEM_STORAGE(md),
-        grpc_slice_is_interned(GRPC_MDKEY(md)),
-        grpc_slice_is_interned(GRPC_MDVALUE(md)));
-    gpr_free(k);
-    gpr_free(v);
-  }
+                          grpc_mdelem *md, int add_to_table) {
   if (add_to_table) {
-    GPR_ASSERT(GRPC_MDELEM_STORAGE(md) == GRPC_MDELEM_STORAGE_INTERNED ||
-               GRPC_MDELEM_STORAGE(md) == GRPC_MDELEM_STORAGE_STATIC);
     grpc_error *err = grpc_chttp2_hptbl_add(exec_ctx, &p->table, md);
     if (err != GRPC_ERROR_NONE) return err;
   }
@@ -699,28 +681,10 @@ static grpc_error *on_hdr(grpc_exec_ctx *exec_ctx, grpc_chttp2_hpack_parser *p,
   return GRPC_ERROR_NONE;
 }
 
-static grpc_slice take_string(grpc_exec_ctx *exec_ctx,
-                              grpc_chttp2_hpack_parser *p,
-                              grpc_chttp2_hpack_parser_string *str,
-                              bool intern) {
-  grpc_slice s;
-  if (!str->copied) {
-    if (intern) {
-      s = grpc_slice_intern(str->data.referenced);
-      grpc_slice_unref_internal(exec_ctx, str->data.referenced);
-    } else {
-      s = str->data.referenced;
-    }
-    str->copied = true;
-    str->data.referenced = grpc_empty_slice();
-  } else if (intern) {
-    s = grpc_slice_intern(grpc_slice_from_static_buffer(
-        str->data.copied.str, str->data.copied.length));
-  } else {
-    s = grpc_slice_from_copied_buffer(str->data.copied.str,
-                                      str->data.copied.length);
-  }
-  str->data.copied.length = 0;
+static grpc_mdstr *take_string(grpc_chttp2_hpack_parser *p,
+                               grpc_chttp2_hpack_parser_string *str) {
+  grpc_mdstr *s = grpc_mdstr_from_buffer((uint8_t *)str->str, str->length);
+  str->length = 0;
   return s;
 }
 
@@ -807,8 +771,8 @@ static grpc_error *finish_indexed_field(grpc_exec_ctx *exec_ctx,
                                         grpc_chttp2_hpack_parser *p,
                                         const uint8_t *cur,
                                         const uint8_t *end) {
-  grpc_mdelem md = grpc_chttp2_hptbl_lookup(&p->table, p->index);
-  if (GRPC_MDISNULL(md)) {
+  grpc_mdelem *md = grpc_chttp2_hptbl_lookup(&p->table, p->index);
+  if (md == NULL) {
     return grpc_error_set_int(
         grpc_error_set_int(GRPC_ERROR_CREATE("Invalid HPACK index received"),
                            GRPC_ERROR_INT_INDEX, (intptr_t)p->index),
@@ -849,13 +813,12 @@ static grpc_error *finish_lithdr_incidx(grpc_exec_ctx *exec_ctx,
                                         grpc_chttp2_hpack_parser *p,
                                         const uint8_t *cur,
                                         const uint8_t *end) {
-  grpc_mdelem md = grpc_chttp2_hptbl_lookup(&p->table, p->index);
-  GPR_ASSERT(!GRPC_MDISNULL(md)); /* handled in string parsing */
-  grpc_error *err = on_hdr(
-      exec_ctx, p,
-      grpc_mdelem_from_slices(exec_ctx, grpc_slice_ref_internal(GRPC_MDKEY(md)),
-                              take_string(exec_ctx, p, &p->value, true)),
-      1);
+  grpc_mdelem *md = grpc_chttp2_hptbl_lookup(&p->table, p->index);
+  GPR_ASSERT(md != NULL); /* handled in string parsing */
+  grpc_error *err = on_hdr(exec_ctx, p, grpc_mdelem_from_metadata_strings(
+                                            exec_ctx, GRPC_MDSTR_REF(md->key),
+                                            take_string(p, &p->value)),
+                           1);
   if (err != GRPC_ERROR_NONE) return parse_error(exec_ctx, p, cur, end, err);
   return parse_begin(exec_ctx, p, cur, end);
 }
@@ -865,11 +828,10 @@ static grpc_error *finish_lithdr_incidx_v(grpc_exec_ctx *exec_ctx,
                                           grpc_chttp2_hpack_parser *p,
                                           const uint8_t *cur,
                                           const uint8_t *end) {
-  grpc_error *err = on_hdr(
-      exec_ctx, p,
-      grpc_mdelem_from_slices(exec_ctx, take_string(exec_ctx, p, &p->key, true),
-                              take_string(exec_ctx, p, &p->value, true)),
-      1);
+  grpc_error *err = on_hdr(exec_ctx, p, grpc_mdelem_from_metadata_strings(
+                                            exec_ctx, take_string(p, &p->key),
+                                            take_string(p, &p->value)),
+                           1);
   if (err != GRPC_ERROR_NONE) return parse_error(exec_ctx, p, cur, end, err);
   return parse_begin(exec_ctx, p, cur, end);
 }
@@ -919,13 +881,12 @@ static grpc_error *finish_lithdr_notidx(grpc_exec_ctx *exec_ctx,
                                         grpc_chttp2_hpack_parser *p,
                                         const uint8_t *cur,
                                         const uint8_t *end) {
-  grpc_mdelem md = grpc_chttp2_hptbl_lookup(&p->table, p->index);
-  GPR_ASSERT(!GRPC_MDISNULL(md)); /* handled in string parsing */
-  grpc_error *err = on_hdr(
-      exec_ctx, p,
-      grpc_mdelem_from_slices(exec_ctx, grpc_slice_ref_internal(GRPC_MDKEY(md)),
-                              take_string(exec_ctx, p, &p->value, false)),
-      0);
+  grpc_mdelem *md = grpc_chttp2_hptbl_lookup(&p->table, p->index);
+  GPR_ASSERT(md != NULL); /* handled in string parsing */
+  grpc_error *err = on_hdr(exec_ctx, p, grpc_mdelem_from_metadata_strings(
+                                            exec_ctx, GRPC_MDSTR_REF(md->key),
+                                            take_string(p, &p->value)),
+                           0);
   if (err != GRPC_ERROR_NONE) return parse_error(exec_ctx, p, cur, end, err);
   return parse_begin(exec_ctx, p, cur, end);
 }
@@ -935,11 +896,10 @@ static grpc_error *finish_lithdr_notidx_v(grpc_exec_ctx *exec_ctx,
                                           grpc_chttp2_hpack_parser *p,
                                           const uint8_t *cur,
                                           const uint8_t *end) {
-  grpc_error *err = on_hdr(
-      exec_ctx, p,
-      grpc_mdelem_from_slices(exec_ctx, take_string(exec_ctx, p, &p->key, true),
-                              take_string(exec_ctx, p, &p->value, false)),
-      0);
+  grpc_error *err = on_hdr(exec_ctx, p, grpc_mdelem_from_metadata_strings(
+                                            exec_ctx, take_string(p, &p->key),
+                                            take_string(p, &p->value)),
+                           0);
   if (err != GRPC_ERROR_NONE) return parse_error(exec_ctx, p, cur, end, err);
   return parse_begin(exec_ctx, p, cur, end);
 }
@@ -989,13 +949,12 @@ static grpc_error *finish_lithdr_nvridx(grpc_exec_ctx *exec_ctx,
                                         grpc_chttp2_hpack_parser *p,
                                         const uint8_t *cur,
                                         const uint8_t *end) {
-  grpc_mdelem md = grpc_chttp2_hptbl_lookup(&p->table, p->index);
-  GPR_ASSERT(!GRPC_MDISNULL(md)); /* handled in string parsing */
-  grpc_error *err = on_hdr(
-      exec_ctx, p,
-      grpc_mdelem_from_slices(exec_ctx, grpc_slice_ref_internal(GRPC_MDKEY(md)),
-                              take_string(exec_ctx, p, &p->value, false)),
-      0);
+  grpc_mdelem *md = grpc_chttp2_hptbl_lookup(&p->table, p->index);
+  GPR_ASSERT(md != NULL); /* handled in string parsing */
+  grpc_error *err = on_hdr(exec_ctx, p, grpc_mdelem_from_metadata_strings(
+                                            exec_ctx, GRPC_MDSTR_REF(md->key),
+                                            take_string(p, &p->value)),
+                           0);
   if (err != GRPC_ERROR_NONE) return parse_error(exec_ctx, p, cur, end, err);
   return parse_begin(exec_ctx, p, cur, end);
 }
@@ -1005,11 +964,10 @@ static grpc_error *finish_lithdr_nvridx_v(grpc_exec_ctx *exec_ctx,
                                           grpc_chttp2_hpack_parser *p,
                                           const uint8_t *cur,
                                           const uint8_t *end) {
-  grpc_error *err = on_hdr(
-      exec_ctx, p,
-      grpc_mdelem_from_slices(exec_ctx, take_string(exec_ctx, p, &p->key, true),
-                              take_string(exec_ctx, p, &p->value, false)),
-      0);
+  grpc_error *err = on_hdr(exec_ctx, p, grpc_mdelem_from_metadata_strings(
+                                            exec_ctx, take_string(p, &p->key),
+                                            take_string(p, &p->value)),
+                           0);
   if (err != GRPC_ERROR_NONE) return parse_error(exec_ctx, p, cur, end, err);
   return parse_begin(exec_ctx, p, cur, end);
 }
@@ -1303,15 +1261,14 @@ static grpc_error *parse_string_prefix(grpc_exec_ctx *exec_ctx,
 static void append_bytes(grpc_chttp2_hpack_parser_string *str,
                          const uint8_t *data, size_t length) {
   if (length == 0) return;
-  if (length + str->data.copied.length > str->data.copied.capacity) {
-    GPR_ASSERT(str->data.copied.length + length <= UINT32_MAX);
-    str->data.copied.capacity = (uint32_t)(str->data.copied.length + length);
-    str->data.copied.str =
-        gpr_realloc(str->data.copied.str, str->data.copied.capacity);
+  if (length + str->length > str->capacity) {
+    GPR_ASSERT(str->length + length <= UINT32_MAX);
+    str->capacity = (uint32_t)(str->length + length);
+    str->str = gpr_realloc(str->str, str->capacity);
   }
-  memcpy(str->data.copied.str + str->data.copied.length, data, length);
-  GPR_ASSERT(length <= UINT32_MAX - str->data.copied.length);
-  str->data.copied.length += (uint32_t)length;
+  memcpy(str->str + str->length, data, length);
+  GPR_ASSERT(length <= UINT32_MAX - str->length);
+  str->length += (uint32_t)length;
 }
 
 static grpc_error *append_string(grpc_exec_ctx *exec_ctx,
@@ -1394,9 +1351,11 @@ static grpc_error *append_string(grpc_exec_ctx *exec_ctx,
       exec_ctx, p, cur, end, GRPC_ERROR_CREATE("Should never reach here")));
 }
 
+/* append a null terminator to a string */
 static grpc_error *finish_str(grpc_exec_ctx *exec_ctx,
                               grpc_chttp2_hpack_parser *p, const uint8_t *cur,
                               const uint8_t *end) {
+  uint8_t terminator = 0;
   uint8_t decoded[2];
   uint32_t bits;
   grpc_chttp2_hpack_parser_string *str = p->parsing.str;
@@ -1437,6 +1396,8 @@ static grpc_error *finish_str(grpc_exec_ctx *exec_ctx,
       append_bytes(str, decoded, 2);
       break;
   }
+  append_bytes(str, &terminator, 1);
+  p->parsing.str->length--; /* don't actually count the null terminator */
   return GRPC_ERROR_NONE;
 }
 
@@ -1511,18 +1472,8 @@ static grpc_error *begin_parse_string(grpc_exec_ctx *exec_ctx,
                                       const uint8_t *cur, const uint8_t *end,
                                       uint8_t binary,
                                       grpc_chttp2_hpack_parser_string *str) {
-  if (!p->huff && binary == NOT_BINARY && (end - cur) >= (intptr_t)p->strlen &&
-      p->current_slice_refcount != NULL) {
-    str->copied = false;
-    str->data.referenced.refcount = p->current_slice_refcount;
-    str->data.referenced.data.refcounted.bytes = (uint8_t *)cur;
-    str->data.referenced.data.refcounted.length = p->strlen;
-    grpc_slice_ref_internal(str->data.referenced);
-    return parse_next(exec_ctx, p, cur + p->strlen, end);
-  }
   p->strgot = 0;
-  str->copied = true;
-  str->data.copied.length = 0;
+  str->length = 0;
   p->parsing.str = str;
   p->huff_state = 0;
   p->binary = binary;
@@ -1539,22 +1490,21 @@ static grpc_error *parse_key_string(grpc_exec_ctx *exec_ctx,
 /* check if a key represents a binary header or not */
 
 static bool is_binary_literal_header(grpc_chttp2_hpack_parser *p) {
-  return grpc_is_binary_header(
-      p->key.copied ? grpc_slice_from_static_buffer(p->key.data.copied.str,
-                                                    p->key.data.copied.length)
-                    : p->key.data.referenced);
+  return grpc_is_binary_header(p->key.str, p->key.length);
 }
 
 static grpc_error *is_binary_indexed_header(grpc_chttp2_hpack_parser *p,
                                             bool *is) {
-  grpc_mdelem elem = grpc_chttp2_hptbl_lookup(&p->table, p->index);
-  if (GRPC_MDISNULL(elem)) {
+  grpc_mdelem *elem = grpc_chttp2_hptbl_lookup(&p->table, p->index);
+  if (!elem) {
     return grpc_error_set_int(
         grpc_error_set_int(GRPC_ERROR_CREATE("Invalid HPACK index received"),
                            GRPC_ERROR_INT_INDEX, (intptr_t)p->index),
         GRPC_ERROR_INT_SIZE, (intptr_t)p->table.num_ents);
   }
-  *is = grpc_is_binary_header(GRPC_MDKEY(elem));
+  *is = grpc_is_binary_header(
+      (const char *)GRPC_SLICE_START_PTR(elem->key->slice),
+      GRPC_SLICE_LENGTH(elem->key->slice));
   return GRPC_ERROR_NONE;
 }
 
@@ -1589,14 +1539,12 @@ void grpc_chttp2_hpack_parser_init(grpc_exec_ctx *exec_ctx,
   p->on_header = NULL;
   p->on_header_user_data = NULL;
   p->state = parse_begin;
-  p->key.data.referenced = grpc_empty_slice();
-  p->key.data.copied.str = NULL;
-  p->key.data.copied.capacity = 0;
-  p->key.data.copied.length = 0;
-  p->value.data.referenced = grpc_empty_slice();
-  p->value.data.copied.str = NULL;
-  p->value.data.copied.capacity = 0;
-  p->value.data.copied.length = 0;
+  p->key.str = NULL;
+  p->key.capacity = 0;
+  p->key.length = 0;
+  p->value.str = NULL;
+  p->value.capacity = 0;
+  p->value.length = 0;
   p->dynamic_table_update_allowed = 2;
   p->last_error = GRPC_ERROR_NONE;
   grpc_chttp2_hptbl_init(exec_ctx, &p->table);
@@ -1611,24 +1559,19 @@ void grpc_chttp2_hpack_parser_destroy(grpc_exec_ctx *exec_ctx,
                                       grpc_chttp2_hpack_parser *p) {
   grpc_chttp2_hptbl_destroy(exec_ctx, &p->table);
   GRPC_ERROR_UNREF(p->last_error);
-  grpc_slice_unref_internal(exec_ctx, p->key.data.referenced);
-  grpc_slice_unref_internal(exec_ctx, p->value.data.referenced);
-  gpr_free(p->key.data.copied.str);
-  gpr_free(p->value.data.copied.str);
+  gpr_free(p->key.str);
+  gpr_free(p->value.str);
 }
 
 grpc_error *grpc_chttp2_hpack_parser_parse(grpc_exec_ctx *exec_ctx,
                                            grpc_chttp2_hpack_parser *p,
-                                           grpc_slice slice) {
+                                           const uint8_t *beg,
+                                           const uint8_t *end) {
   /* TODO(ctiller): limit the distance of end from beg, and perform multiple
      steps in the event of a large chunk of data to limit
      stack space usage when no tail call optimization is
      available */
-  p->current_slice_refcount = slice.refcount;
-  grpc_error *error = p->state(exec_ctx, p, GRPC_SLICE_START_PTR(slice),
-                               GRPC_SLICE_END_PTR(slice));
-  p->current_slice_refcount = NULL;
-  return error;
+  return p->state(exec_ctx, p, beg, end);
 }
 
 typedef void (*maybe_complete_func_type)(grpc_exec_ctx *exec_ctx,
@@ -1644,7 +1587,7 @@ static void force_client_rst_stream(grpc_exec_ctx *exec_ctx, void *sp,
   grpc_chttp2_transport *t = s->t;
   if (!s->write_closed) {
     grpc_slice_buffer_add(
-        &t->qbuf, grpc_chttp2_rst_stream_create(s->id, GRPC_HTTP2_NO_ERROR,
+        &t->qbuf, grpc_chttp2_rst_stream_create(s->id, GRPC_CHTTP2_NO_ERROR,
                                                 &s->stats.outgoing));
     grpc_chttp2_initiate_write(exec_ctx, t, false, "force_rst_stream");
     grpc_chttp2_mark_stream_closed(exec_ctx, t, s, true, true, GRPC_ERROR_NONE);
@@ -1662,7 +1605,8 @@ grpc_error *grpc_chttp2_header_parser_parse(grpc_exec_ctx *exec_ctx,
   if (s != NULL) {
     s->stats.incoming.header_bytes += GRPC_SLICE_LENGTH(slice);
   }
-  grpc_error *error = grpc_chttp2_hpack_parser_parse(exec_ctx, parser, slice);
+  grpc_error *error = grpc_chttp2_hpack_parser_parse(
+      exec_ctx, parser, GRPC_SLICE_START_PTR(slice), GRPC_SLICE_END_PTR(slice));
   if (error != GRPC_ERROR_NONE) {
     GPR_TIMER_END("grpc_chttp2_hpack_parser_parse", 0);
     return error;
diff --git a/src/core/ext/transport/chttp2/transport/hpack_parser.h b/src/core/ext/transport/chttp2/transport/hpack_parser.h
index a817183eb5..52ccf1e7a7 100644
--- a/src/core/ext/transport/chttp2/transport/hpack_parser.h
+++ b/src/core/ext/transport/chttp2/transport/hpack_parser.h
@@ -49,20 +49,14 @@ typedef grpc_error *(*grpc_chttp2_hpack_parser_state)(
     const uint8_t *end);
 
 typedef struct {
-  bool copied;
-  struct {
-    grpc_slice referenced;
-    struct {
-      char *str;
-      uint32_t length;
-      uint32_t capacity;
-    } copied;
-  } data;
+  char *str;
+  uint32_t length;
+  uint32_t capacity;
 } grpc_chttp2_hpack_parser_string;
 
 struct grpc_chttp2_hpack_parser {
   /* user specified callback for each header output */
-  void (*on_header)(grpc_exec_ctx *exec_ctx, void *user_data, grpc_mdelem md);
+  void (*on_header)(grpc_exec_ctx *exec_ctx, void *user_data, grpc_mdelem *md);
   void *on_header_user_data;
 
   grpc_error *last_error;
@@ -73,8 +67,6 @@ struct grpc_chttp2_hpack_parser {
   const grpc_chttp2_hpack_parser_state *next_state;
   /* what to do after skipping prioritization data */
   grpc_chttp2_hpack_parser_state after_prioritization;
-  /* the refcount of the slice that we're currently parsing */
-  grpc_slice_refcount *current_slice_refcount;
   /* the value we're currently parsing */
   union {
     uint32_t *value;
@@ -114,9 +106,11 @@ void grpc_chttp2_hpack_parser_destroy(grpc_exec_ctx *exec_ctx,
 
 void grpc_chttp2_hpack_parser_set_has_priority(grpc_chttp2_hpack_parser *p);
 
+/* returns 1 on success, 0 on error */
 grpc_error *grpc_chttp2_hpack_parser_parse(grpc_exec_ctx *exec_ctx,
                                            grpc_chttp2_hpack_parser *p,
-                                           grpc_slice slice);
+                                           const uint8_t *beg,
+                                           const uint8_t *end);
 
 /* wraps grpc_chttp2_hpack_parser_parse to provide a frame level parser for
    the transport */
diff --git a/src/core/ext/transport/chttp2/transport/hpack_table.c b/src/core/ext/transport/chttp2/transport/hpack_table.c
index 62dd1b8cab..26d4036d49 100644
--- a/src/core/ext/transport/chttp2/transport/hpack_table.c
+++ b/src/core/ext/transport/chttp2/transport/hpack_table.c
@@ -190,11 +190,8 @@ void grpc_chttp2_hptbl_init(grpc_exec_ctx *exec_ctx, grpc_chttp2_hptbl *tbl) {
   tbl->ents = gpr_malloc(sizeof(*tbl->ents) * tbl->cap_entries);
   memset(tbl->ents, 0, sizeof(*tbl->ents) * tbl->cap_entries);
   for (i = 1; i <= GRPC_CHTTP2_LAST_STATIC_ENTRY; i++) {
-    tbl->static_ents[i - 1] = grpc_mdelem_from_slices(
-        exec_ctx,
-        grpc_slice_intern(grpc_slice_from_static_string(static_table[i].key)),
-        grpc_slice_intern(
-            grpc_slice_from_static_string(static_table[i].value)));
+    tbl->static_ents[i - 1] = grpc_mdelem_from_strings(
+        exec_ctx, static_table[i].key, static_table[i].value);
   }
 }
 
@@ -211,8 +208,8 @@ void grpc_chttp2_hptbl_destroy(grpc_exec_ctx *exec_ctx,
   gpr_free(tbl->ents);
 }
 
-grpc_mdelem grpc_chttp2_hptbl_lookup(const grpc_chttp2_hptbl *tbl,
-                                     uint32_t tbl_index) {
+grpc_mdelem *grpc_chttp2_hptbl_lookup(const grpc_chttp2_hptbl *tbl,
+                                      uint32_t tbl_index) {
   /* Static table comes first, just return an entry from it */
   if (tbl_index <= GRPC_CHTTP2_LAST_STATIC_ENTRY) {
     return tbl->static_ents[tbl_index - 1];
@@ -225,14 +222,14 @@ grpc_mdelem grpc_chttp2_hptbl_lookup(const grpc_chttp2_hptbl *tbl,
     return tbl->ents[offset];
   }
   /* Invalid entry: return error */
-  return GRPC_MDNULL;
+  return NULL;
 }
 
 /* Evict one element from the table */
 static void evict1(grpc_exec_ctx *exec_ctx, grpc_chttp2_hptbl *tbl) {
-  grpc_mdelem first_ent = tbl->ents[tbl->first_ent];
-  size_t elem_bytes = GRPC_SLICE_LENGTH(GRPC_MDKEY(first_ent)) +
-                      GRPC_SLICE_LENGTH(GRPC_MDVALUE(first_ent)) +
+  grpc_mdelem *first_ent = tbl->ents[tbl->first_ent];
+  size_t elem_bytes = GRPC_SLICE_LENGTH(first_ent->key->slice) +
+                      GRPC_SLICE_LENGTH(first_ent->value->slice) +
                       GRPC_CHTTP2_HPACK_ENTRY_OVERHEAD;
   GPR_ASSERT(elem_bytes <= tbl->mem_used);
   tbl->mem_used -= (uint32_t)elem_bytes;
@@ -242,7 +239,7 @@ static void evict1(grpc_exec_ctx *exec_ctx, grpc_chttp2_hptbl *tbl) {
 }
 
 static void rebuild_ents(grpc_chttp2_hptbl *tbl, uint32_t new_cap) {
-  grpc_mdelem *ents = gpr_malloc(sizeof(*ents) * new_cap);
+  grpc_mdelem **ents = gpr_malloc(sizeof(*ents) * new_cap);
   uint32_t i;
 
   for (i = 0; i < tbl->num_ents; i++) {
@@ -304,10 +301,10 @@ grpc_error *grpc_chttp2_hptbl_set_current_table_size(grpc_exec_ctx *exec_ctx,
 }
 
 grpc_error *grpc_chttp2_hptbl_add(grpc_exec_ctx *exec_ctx,
-                                  grpc_chttp2_hptbl *tbl, grpc_mdelem md) {
+                                  grpc_chttp2_hptbl *tbl, grpc_mdelem *md) {
   /* determine how many bytes of buffer this entry represents */
-  size_t elem_bytes = GRPC_SLICE_LENGTH(GRPC_MDKEY(md)) +
-                      GRPC_SLICE_LENGTH(GRPC_MDVALUE(md)) +
+  size_t elem_bytes = GRPC_SLICE_LENGTH(md->key->slice) +
+                      GRPC_SLICE_LENGTH(md->value->slice) +
                       GRPC_CHTTP2_HPACK_ENTRY_OVERHEAD;
 
   if (tbl->current_table_bytes > tbl->max_bytes) {
@@ -355,16 +352,16 @@ grpc_error *grpc_chttp2_hptbl_add(grpc_exec_ctx *exec_ctx,
 }
 
 grpc_chttp2_hptbl_find_result grpc_chttp2_hptbl_find(
-    const grpc_chttp2_hptbl *tbl, grpc_mdelem md) {
+    const grpc_chttp2_hptbl *tbl, grpc_mdelem *md) {
   grpc_chttp2_hptbl_find_result r = {0, 0};
   uint32_t i;
 
   /* See if the string is in the static table */
   for (i = 0; i < GRPC_CHTTP2_LAST_STATIC_ENTRY; i++) {
-    grpc_mdelem ent = tbl->static_ents[i];
-    if (!grpc_slice_eq(GRPC_MDKEY(md), GRPC_MDKEY(ent))) continue;
+    grpc_mdelem *ent = tbl->static_ents[i];
+    if (md->key != ent->key) continue;
     r.index = i + 1u;
-    r.has_value = grpc_slice_eq(GRPC_MDVALUE(md), GRPC_MDVALUE(ent));
+    r.has_value = md->value == ent->value;
     if (r.has_value) return r;
   }
 
@@ -372,10 +369,10 @@ grpc_chttp2_hptbl_find_result grpc_chttp2_hptbl_find(
   for (i = 0; i < tbl->num_ents; i++) {
     uint32_t idx =
         (uint32_t)(tbl->num_ents - i + GRPC_CHTTP2_LAST_STATIC_ENTRY);
-    grpc_mdelem ent = tbl->ents[(tbl->first_ent + i) % tbl->cap_entries];
-    if (!grpc_slice_eq(GRPC_MDKEY(md), GRPC_MDKEY(ent))) continue;
+    grpc_mdelem *ent = tbl->ents[(tbl->first_ent + i) % tbl->cap_entries];
+    if (md->key != ent->key) continue;
     r.index = idx;
-    r.has_value = grpc_slice_eq(GRPC_MDVALUE(md), GRPC_MDVALUE(ent));
+    r.has_value = md->value == ent->value;
     if (r.has_value) return r;
   }
 
diff --git a/src/core/ext/transport/chttp2/transport/hpack_table.h b/src/core/ext/transport/chttp2/transport/hpack_table.h
index 32a0380e00..144574ef06 100644
--- a/src/core/ext/transport/chttp2/transport/hpack_table.h
+++ b/src/core/ext/transport/chttp2/transport/hpack_table.h
@@ -79,8 +79,8 @@ typedef struct {
   /* a circular buffer of headers - this is stored in the opposite order to
      what hpack specifies, in order to simplify table management a little...
      meaning lookups need to SUBTRACT from the end position */
-  grpc_mdelem *ents;
-  grpc_mdelem static_ents[GRPC_CHTTP2_LAST_STATIC_ENTRY];
+  grpc_mdelem **ents;
+  grpc_mdelem *static_ents[GRPC_CHTTP2_LAST_STATIC_ENTRY];
 } grpc_chttp2_hptbl;
 
 /* initialize a hpack table */
@@ -94,12 +94,12 @@ grpc_error *grpc_chttp2_hptbl_set_current_table_size(grpc_exec_ctx *exec_ctx,
                                                      uint32_t bytes);
 
 /* lookup a table entry based on its hpack index */
-grpc_mdelem grpc_chttp2_hptbl_lookup(const grpc_chttp2_hptbl *tbl,
-                                     uint32_t index);
+grpc_mdelem *grpc_chttp2_hptbl_lookup(const grpc_chttp2_hptbl *tbl,
+                                      uint32_t index);
 /* add a table entry to the index */
 grpc_error *grpc_chttp2_hptbl_add(grpc_exec_ctx *exec_ctx,
                                   grpc_chttp2_hptbl *tbl,
-                                  grpc_mdelem md) GRPC_MUST_USE_RESULT;
+                                  grpc_mdelem *md) GRPC_MUST_USE_RESULT;
 /* Find a key/value pair in the table... returns the index in the table of the
    most similar entry, or 0 if the value was not found */
 typedef struct {
@@ -107,6 +107,6 @@ typedef struct {
   int has_value;
 } grpc_chttp2_hptbl_find_result;
 grpc_chttp2_hptbl_find_result grpc_chttp2_hptbl_find(
-    const grpc_chttp2_hptbl *tbl, grpc_mdelem md);
+    const grpc_chttp2_hptbl *tbl, grpc_mdelem *md);
 
 #endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_HPACK_TABLE_H */
diff --git a/src/core/ext/transport/chttp2/transport/http2_errors.h b/src/core/ext/transport/chttp2/transport/http2_errors.h
new file mode 100644
index 0000000000..deab2b7e3e
--- /dev/null
+++ b/src/core/ext/transport/chttp2/transport/http2_errors.h
@@ -0,0 +1,56 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_HTTP2_ERRORS_H
+#define GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_HTTP2_ERRORS_H
+
+/* error codes for RST_STREAM from http2 draft 14 section 7 */
+typedef enum {
+  GRPC_CHTTP2_NO_ERROR = 0x0,
+  GRPC_CHTTP2_PROTOCOL_ERROR = 0x1,
+  GRPC_CHTTP2_INTERNAL_ERROR = 0x2,
+  GRPC_CHTTP2_FLOW_CONTROL_ERROR = 0x3,
+  GRPC_CHTTP2_SETTINGS_TIMEOUT = 0x4,
+  GRPC_CHTTP2_STREAM_CLOSED = 0x5,
+  GRPC_CHTTP2_FRAME_SIZE_ERROR = 0x6,
+  GRPC_CHTTP2_REFUSED_STREAM = 0x7,
+  GRPC_CHTTP2_CANCEL = 0x8,
+  GRPC_CHTTP2_COMPRESSION_ERROR = 0x9,
+  GRPC_CHTTP2_CONNECT_ERROR = 0xa,
+  GRPC_CHTTP2_ENHANCE_YOUR_CALM = 0xb,
+  GRPC_CHTTP2_INADEQUATE_SECURITY = 0xc,
+  /* force use of a default clause */
+  GRPC_CHTTP2__ERROR_DO_NOT_USE = -1
+} grpc_chttp2_error_code;
+
+#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_HTTP2_ERRORS_H */
diff --git a/src/core/ext/transport/chttp2/transport/incoming_metadata.c b/src/core/ext/transport/chttp2/transport/incoming_metadata.c
index c91b019aa0..5d1094999c 100644
--- a/src/core/ext/transport/chttp2/transport/incoming_metadata.c
+++ b/src/core/ext/transport/chttp2/transport/incoming_metadata.c
@@ -57,7 +57,7 @@ void grpc_chttp2_incoming_metadata_buffer_destroy(
 }
 
 void grpc_chttp2_incoming_metadata_buffer_add(
-    grpc_chttp2_incoming_metadata_buffer *buffer, grpc_mdelem elem) {
+    grpc_chttp2_incoming_metadata_buffer *buffer, grpc_mdelem *elem) {
   GPR_ASSERT(!buffer->published);
   if (buffer->capacity == buffer->count) {
     buffer->capacity = GPR_MAX(8, 2 * buffer->capacity);
@@ -68,19 +68,6 @@ void grpc_chttp2_incoming_metadata_buffer_add(
   buffer->size += GRPC_MDELEM_LENGTH(elem);
 }
 
-void grpc_chttp2_incoming_metadata_buffer_replace_or_add(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_incoming_metadata_buffer *buffer,
-    grpc_mdelem elem) {
-  for (size_t i = 0; i < buffer->count; i++) {
-    if (grpc_slice_eq(GRPC_MDKEY(buffer->elems[i].md), GRPC_MDKEY(elem))) {
-      GRPC_MDELEM_UNREF(exec_ctx, buffer->elems[i].md);
-      buffer->elems[i].md = elem;
-      return;
-    }
-  }
-  grpc_chttp2_incoming_metadata_buffer_add(buffer, elem);
-}
-
 void grpc_chttp2_incoming_metadata_buffer_set_deadline(
     grpc_chttp2_incoming_metadata_buffer *buffer, gpr_timespec deadline) {
   GPR_ASSERT(!buffer->published);
@@ -88,20 +75,21 @@ void grpc_chttp2_incoming_metadata_buffer_set_deadline(
 }
 
 void grpc_chttp2_incoming_metadata_buffer_publish(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_incoming_metadata_buffer *buffer,
-    grpc_metadata_batch *batch) {
+    grpc_chttp2_incoming_metadata_buffer *buffer, grpc_metadata_batch *batch) {
   GPR_ASSERT(!buffer->published);
   buffer->published = 1;
   if (buffer->count > 0) {
     size_t i;
-    for (i = 0; i < buffer->count; i++) {
-      /* TODO(ctiller): do something better here */
-      if (!GRPC_LOG_IF_ERROR("grpc_chttp2_incoming_metadata_buffer_publish",
-                             grpc_metadata_batch_link_tail(
-                                 exec_ctx, batch, &buffer->elems[i]))) {
-        GRPC_MDELEM_UNREF(exec_ctx, buffer->elems[i].md);
-      }
+    for (i = 1; i < buffer->count; i++) {
+      buffer->elems[i].prev = &buffer->elems[i - 1];
+    }
+    for (i = 0; i < buffer->count - 1; i++) {
+      buffer->elems[i].next = &buffer->elems[i + 1];
     }
+    buffer->elems[0].prev = NULL;
+    buffer->elems[buffer->count - 1].next = NULL;
+    batch->list.head = &buffer->elems[0];
+    batch->list.tail = &buffer->elems[buffer->count - 1];
   } else {
     batch->list.head = batch->list.tail = NULL;
   }
diff --git a/src/core/ext/transport/chttp2/transport/incoming_metadata.h b/src/core/ext/transport/chttp2/transport/incoming_metadata.h
index 1eac6fc150..7a0c4da15f 100644
--- a/src/core/ext/transport/chttp2/transport/incoming_metadata.h
+++ b/src/core/ext/transport/chttp2/transport/incoming_metadata.h
@@ -51,14 +51,10 @@ void grpc_chttp2_incoming_metadata_buffer_init(
 void grpc_chttp2_incoming_metadata_buffer_destroy(
     grpc_exec_ctx *exec_ctx, grpc_chttp2_incoming_metadata_buffer *buffer);
 void grpc_chttp2_incoming_metadata_buffer_publish(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_incoming_metadata_buffer *buffer,
-    grpc_metadata_batch *batch);
+    grpc_chttp2_incoming_metadata_buffer *buffer, grpc_metadata_batch *batch);
 
 void grpc_chttp2_incoming_metadata_buffer_add(
-    grpc_chttp2_incoming_metadata_buffer *buffer, grpc_mdelem elem);
-void grpc_chttp2_incoming_metadata_buffer_replace_or_add(
-    grpc_exec_ctx *exec_ctx, grpc_chttp2_incoming_metadata_buffer *buffer,
-    grpc_mdelem elem);
+    grpc_chttp2_incoming_metadata_buffer *buffer, grpc_mdelem *elem);
 void grpc_chttp2_incoming_metadata_buffer_set_deadline(
     grpc_chttp2_incoming_metadata_buffer *buffer, gpr_timespec deadline);
 
diff --git a/src/core/ext/transport/chttp2/transport/internal.h b/src/core/ext/transport/chttp2/transport/internal.h
index ee5edc92df..ea7beb4c2b 100644
--- a/src/core/ext/transport/chttp2/transport/internal.h
+++ b/src/core/ext/transport/chttp2/transport/internal.h
@@ -618,7 +618,8 @@ void grpc_chttp2_flowctl_trace(const char *file, int line, const char *phase,
                                uint32_t stream_id, int64_t val1, int64_t val2);
 
 void grpc_chttp2_fake_status(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
-                             grpc_chttp2_stream *stream, grpc_error *error);
+                             grpc_chttp2_stream *stream,
+                             grpc_status_code status, grpc_slice *details);
 void grpc_chttp2_mark_stream_closed(grpc_exec_ctx *exec_ctx,
                                     grpc_chttp2_transport *t,
                                     grpc_chttp2_stream *s, int close_reads,
diff --git a/src/core/ext/transport/chttp2/transport/parsing.c b/src/core/ext/transport/chttp2/transport/parsing.c
index f58cd696f9..4fb5dc7bd2 100644
--- a/src/core/ext/transport/chttp2/transport/parsing.c
+++ b/src/core/ext/transport/chttp2/transport/parsing.c
@@ -39,11 +39,10 @@
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 
+#include "src/core/ext/transport/chttp2/transport/http2_errors.h"
+#include "src/core/ext/transport/chttp2/transport/status_conversion.h"
 #include "src/core/lib/profiling/timers.h"
-#include "src/core/lib/slice/slice_string_helpers.h"
-#include "src/core/lib/transport/http2_errors.h"
 #include "src/core/lib/transport/static_metadata.h"
-#include "src/core/lib/transport/status_conversion.h"
 #include "src/core/lib/transport/timeout_encoding.h"
 
 static grpc_error *init_frame_parser(grpc_exec_ctx *exec_ctx,
@@ -201,7 +200,7 @@ grpc_error *grpc_chttp2_perform_read(grpc_exec_ctx *exec_ctx,
         return err;
       }
       if (t->incoming_frame_size == 0) {
-        err = parse_frame_slice(exec_ctx, t, grpc_empty_slice(), 1);
+        err = parse_frame_slice(exec_ctx, t, gpr_empty_slice(), 1);
         if (err != GRPC_ERROR_NONE) {
           return err;
         }
@@ -336,7 +335,7 @@ static grpc_error *skip_parser(grpc_exec_ctx *exec_ctx, void *parser,
   return GRPC_ERROR_NONE;
 }
 
-static void skip_header(grpc_exec_ctx *exec_ctx, void *tp, grpc_mdelem md) {
+static void skip_header(grpc_exec_ctx *exec_ctx, void *tp, grpc_mdelem *md) {
   GRPC_MDELEM_UNREF(exec_ctx, md);
 }
 
@@ -433,7 +432,7 @@ error_handler:
     }
     grpc_slice_buffer_add(
         &t->qbuf, grpc_chttp2_rst_stream_create(t->incoming_stream_id,
-                                                GRPC_HTTP2_PROTOCOL_ERROR,
+                                                GRPC_CHTTP2_PROTOCOL_ERROR,
                                                 &s->stats.outgoing));
     return init_skip_frame_parser(exec_ctx, t, 0);
   } else {
@@ -444,7 +443,7 @@ error_handler:
 static void free_timeout(void *p) { gpr_free(p); }
 
 static void on_initial_header(grpc_exec_ctx *exec_ctx, void *tp,
-                              grpc_mdelem md) {
+                              grpc_mdelem *md) {
   grpc_chttp2_transport *t = tp;
   grpc_chttp2_stream *s = t->incoming_stream;
 
@@ -452,42 +451,32 @@ static void on_initial_header(grpc_exec_ctx *exec_ctx, void *tp,
 
   GPR_ASSERT(s != NULL);
 
-  if (grpc_http_trace) {
-    char *key = grpc_slice_to_c_string(GRPC_MDKEY(md));
-    char *value =
-        grpc_dump_slice(GRPC_MDVALUE(md), GPR_DUMP_HEX | GPR_DUMP_ASCII);
-    gpr_log(GPR_INFO, "HTTP:%d:HDR:%s: %s: %s", s->id,
-            t->is_client ? "CLI" : "SVR", key, value);
-    gpr_free(key);
-    gpr_free(value);
-  }
+  GRPC_CHTTP2_IF_TRACING(gpr_log(
+      GPR_INFO, "HTTP:%d:HDR:%s: %s: %s", s->id, t->is_client ? "CLI" : "SVR",
+      grpc_mdstr_as_c_string(md->key), grpc_mdstr_as_c_string(md->value)));
 
-  if (grpc_slice_eq(GRPC_MDKEY(md), GRPC_MDSTR_GRPC_STATUS) &&
-      !grpc_mdelem_eq(md, GRPC_MDELEM_GRPC_STATUS_0)) {
+  if (md->key == GRPC_MDSTR_GRPC_STATUS && md != GRPC_MDELEM_GRPC_STATUS_0) {
     /* TODO(ctiller): check for a status like " 0" */
     s->seen_error = true;
   }
 
-  if (grpc_slice_eq(GRPC_MDKEY(md), GRPC_MDSTR_GRPC_TIMEOUT)) {
+  if (md->key == GRPC_MDSTR_GRPC_TIMEOUT) {
     gpr_timespec *cached_timeout = grpc_mdelem_get_user_data(md, free_timeout);
-    gpr_timespec timeout;
-    if (cached_timeout == NULL) {
+    if (!cached_timeout) {
       /* not already parsed: parse it now, and store the result away */
       cached_timeout = gpr_malloc(sizeof(gpr_timespec));
-      if (!grpc_http2_decode_timeout(GRPC_MDVALUE(md), cached_timeout)) {
-        char *val = grpc_slice_to_c_string(GRPC_MDVALUE(md));
-        gpr_log(GPR_ERROR, "Ignoring bad timeout value '%s'", val);
-        gpr_free(val);
+      if (!grpc_http2_decode_timeout(grpc_mdstr_as_c_string(md->value),
+                                     cached_timeout)) {
+        gpr_log(GPR_ERROR, "Ignoring bad timeout value '%s'",
+                grpc_mdstr_as_c_string(md->value));
         *cached_timeout = gpr_inf_future(GPR_TIMESPAN);
       }
-      timeout = *cached_timeout;
-      grpc_mdelem_set_user_data(md, free_timeout, cached_timeout);
-    } else {
-      timeout = *cached_timeout;
+      cached_timeout =
+          grpc_mdelem_set_user_data(md, free_timeout, cached_timeout);
     }
     grpc_chttp2_incoming_metadata_buffer_set_deadline(
         &s->metadata_buffer[0],
-        gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC), timeout));
+        gpr_time_add(gpr_now(GPR_CLOCK_MONOTONIC), *cached_timeout));
     GRPC_MDELEM_UNREF(exec_ctx, md);
   } else {
     const size_t new_size = s->metadata_buffer[0].size + GRPC_MDELEM_LENGTH(md);
@@ -516,7 +505,7 @@ static void on_initial_header(grpc_exec_ctx *exec_ctx, void *tp,
 }
 
 static void on_trailing_header(grpc_exec_ctx *exec_ctx, void *tp,
-                               grpc_mdelem md) {
+                               grpc_mdelem *md) {
   grpc_chttp2_transport *t = tp;
   grpc_chttp2_stream *s = t->incoming_stream;
 
@@ -524,18 +513,11 @@ static void on_trailing_header(grpc_exec_ctx *exec_ctx, void *tp,
 
   GPR_ASSERT(s != NULL);
 
-  if (grpc_http_trace) {
-    char *key = grpc_slice_to_c_string(GRPC_MDKEY(md));
-    char *value =
-        grpc_dump_slice(GRPC_MDVALUE(md), GPR_DUMP_HEX | GPR_DUMP_ASCII);
-    gpr_log(GPR_INFO, "HTTP:%d:TRL:%s: %s: %s", s->id,
-            t->is_client ? "CLI" : "SVR", key, value);
-    gpr_free(key);
-    gpr_free(value);
-  }
+  GRPC_CHTTP2_IF_TRACING(gpr_log(
+      GPR_INFO, "HTTP:%d:TRL:%s: %s: %s", s->id, t->is_client ? "CLI" : "SVR",
+      grpc_mdstr_as_c_string(md->key), grpc_mdstr_as_c_string(md->value)));
 
-  if (grpc_slice_eq(GRPC_MDKEY(md), GRPC_MDSTR_GRPC_STATUS) &&
-      !grpc_mdelem_eq(md, GRPC_MDELEM_GRPC_STATUS_0)) {
+  if (md->key == GRPC_MDSTR_GRPC_STATUS && md != GRPC_MDELEM_GRPC_STATUS_0) {
     /* TODO(ctiller): check for a status like " 0" */
     s->seen_error = true;
   }
@@ -751,13 +733,14 @@ static grpc_error *parse_frame_slice(grpc_exec_ctx *exec_ctx,
     if (grpc_http_trace) {
       const char *msg = grpc_error_string(err);
       gpr_log(GPR_ERROR, "%s", msg);
+      grpc_error_free_string(msg);
     }
     grpc_chttp2_parsing_become_skip_parser(exec_ctx, t);
     if (s) {
       s->forced_close_error = err;
       grpc_slice_buffer_add(
           &t->qbuf, grpc_chttp2_rst_stream_create(t->incoming_stream_id,
-                                                  GRPC_HTTP2_PROTOCOL_ERROR,
+                                                  GRPC_CHTTP2_PROTOCOL_ERROR,
                                                   &s->stats.outgoing));
     } else {
       GRPC_ERROR_UNREF(err);
diff --git a/src/core/ext/transport/chttp2/transport/status_conversion.c b/src/core/ext/transport/chttp2/transport/status_conversion.c
new file mode 100644
index 0000000000..5dce2f2d0c
--- /dev/null
+++ b/src/core/ext/transport/chttp2/transport/status_conversion.c
@@ -0,0 +1,115 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/ext/transport/chttp2/transport/status_conversion.h"
+
+int grpc_chttp2_grpc_status_to_http2_error(grpc_status_code status) {
+  switch (status) {
+    case GRPC_STATUS_OK:
+      return GRPC_CHTTP2_NO_ERROR;
+    case GRPC_STATUS_CANCELLED:
+      return GRPC_CHTTP2_CANCEL;
+    case GRPC_STATUS_DEADLINE_EXCEEDED:
+      return GRPC_CHTTP2_CANCEL;
+    case GRPC_STATUS_RESOURCE_EXHAUSTED:
+      return GRPC_CHTTP2_ENHANCE_YOUR_CALM;
+    case GRPC_STATUS_PERMISSION_DENIED:
+      return GRPC_CHTTP2_INADEQUATE_SECURITY;
+    case GRPC_STATUS_UNAVAILABLE:
+      return GRPC_CHTTP2_REFUSED_STREAM;
+    default:
+      return GRPC_CHTTP2_INTERNAL_ERROR;
+  }
+}
+
+grpc_status_code grpc_chttp2_http2_error_to_grpc_status(
+    grpc_chttp2_error_code error, gpr_timespec deadline) {
+  switch (error) {
+    case GRPC_CHTTP2_NO_ERROR:
+      /* should never be received */
+      return GRPC_STATUS_INTERNAL;
+    case GRPC_CHTTP2_CANCEL:
+      /* http2 cancel translates to STATUS_CANCELLED iff deadline hasn't been
+       * exceeded */
+      return gpr_time_cmp(gpr_now(deadline.clock_type), deadline) >= 0
+                 ? GRPC_STATUS_DEADLINE_EXCEEDED
+                 : GRPC_STATUS_CANCELLED;
+    case GRPC_CHTTP2_ENHANCE_YOUR_CALM:
+      return GRPC_STATUS_RESOURCE_EXHAUSTED;
+    case GRPC_CHTTP2_INADEQUATE_SECURITY:
+      return GRPC_STATUS_PERMISSION_DENIED;
+    case GRPC_CHTTP2_REFUSED_STREAM:
+      return GRPC_STATUS_UNAVAILABLE;
+    default:
+      return GRPC_STATUS_INTERNAL;
+  }
+}
+
+grpc_status_code grpc_chttp2_http2_status_to_grpc_status(int status) {
+  switch (status) {
+    /* these HTTP2 status codes are called out explicitly in status.proto */
+    case 200:
+      return GRPC_STATUS_OK;
+    case 400:
+      return GRPC_STATUS_INVALID_ARGUMENT;
+    case 401:
+      return GRPC_STATUS_UNAUTHENTICATED;
+    case 403:
+      return GRPC_STATUS_PERMISSION_DENIED;
+    case 404:
+      return GRPC_STATUS_NOT_FOUND;
+    case 409:
+      return GRPC_STATUS_ABORTED;
+    case 412:
+      return GRPC_STATUS_FAILED_PRECONDITION;
+    case 429:
+      return GRPC_STATUS_RESOURCE_EXHAUSTED;
+    case 499:
+      return GRPC_STATUS_CANCELLED;
+    case 500:
+      return GRPC_STATUS_UNKNOWN;
+    case 501:
+      return GRPC_STATUS_UNIMPLEMENTED;
+    case 503:
+      return GRPC_STATUS_UNAVAILABLE;
+    case 504:
+      return GRPC_STATUS_DEADLINE_EXCEEDED;
+    /* everything else is unknown */
+    default:
+      return GRPC_STATUS_UNKNOWN;
+  }
+}
+
+int grpc_chttp2_grpc_status_to_http2_status(grpc_status_code status) {
+  return 200;
+}
diff --git a/src/core/ext/transport/chttp2/transport/status_conversion.h b/src/core/ext/transport/chttp2/transport/status_conversion.h
new file mode 100644
index 0000000000..953bc9f1e1
--- /dev/null
+++ b/src/core/ext/transport/chttp2/transport/status_conversion.h
@@ -0,0 +1,50 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_STATUS_CONVERSION_H
+#define GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_STATUS_CONVERSION_H
+
+#include <grpc/grpc.h>
+#include "src/core/ext/transport/chttp2/transport/http2_errors.h"
+
+/* Conversion of grpc status codes to http2 error codes (for RST_STREAM) */
+grpc_chttp2_error_code grpc_chttp2_grpc_status_to_http2_error(
+    grpc_status_code status);
+grpc_status_code grpc_chttp2_http2_error_to_grpc_status(
+    grpc_chttp2_error_code error, gpr_timespec deadline);
+
+/* Conversion of HTTP status codes (:status) to grpc status codes */
+grpc_status_code grpc_chttp2_http2_status_to_grpc_status(int status);
+int grpc_chttp2_grpc_status_to_http2_status(grpc_status_code status);
+
+#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_STATUS_CONVERSION_H */
diff --git a/src/core/ext/transport/chttp2/transport/writing.c b/src/core/ext/transport/chttp2/transport/writing.c
index 182aff1e3f..ef2010af7b 100644
--- a/src/core/ext/transport/chttp2/transport/writing.c
+++ b/src/core/ext/transport/chttp2/transport/writing.c
@@ -37,9 +37,9 @@
 
 #include <grpc/support/log.h>
 
+#include "src/core/ext/transport/chttp2/transport/http2_errors.h"
 #include "src/core/lib/profiling/timers.h"
 #include "src/core/lib/slice/slice_internal.h"
-#include "src/core/lib/transport/http2_errors.h"
 
 static void add_to_write_list(grpc_chttp2_write_cb **list,
                               grpc_chttp2_write_cb *cb) {
@@ -164,7 +164,7 @@ bool grpc_chttp2_begin_write(grpc_exec_ctx *exec_ctx,
             s->sent_trailing_metadata = true;
             if (!t->is_client && !s->read_closed) {
               grpc_slice_buffer_add(&t->outbuf, grpc_chttp2_rst_stream_create(
-                                                    s->id, GRPC_HTTP2_NO_ERROR,
+                                                    s->id, GRPC_CHTTP2_NO_ERROR,
                                                     &s->stats.outgoing));
             }
           }
@@ -197,7 +197,7 @@ bool grpc_chttp2_begin_write(grpc_exec_ctx *exec_ctx,
         if (!t->is_client && !s->read_closed) {
           grpc_slice_buffer_add(
               &t->outbuf, grpc_chttp2_rst_stream_create(
-                              s->id, GRPC_HTTP2_NO_ERROR, &s->stats.outgoing));
+                              s->id, GRPC_CHTTP2_NO_ERROR, &s->stats.outgoing));
         }
         now_writing = true;
       }
diff --git a/src/core/ext/transport/cronet/transport/cronet_transport.c b/src/core/ext/transport/cronet/transport/cronet_transport.c
index 025ae30df2..6f5816390a 100644
--- a/src/core/ext/transport/cronet/transport/cronet_transport.c
+++ b/src/core/ext/transport/cronet/transport/cronet_transport.c
@@ -44,8 +44,6 @@
 #include "src/core/ext/transport/chttp2/transport/incoming_metadata.h"
 #include "src/core/lib/iomgr/endpoint.h"
 #include "src/core/lib/iomgr/exec_ctx.h"
-#include "src/core/lib/slice/slice_internal.h"
-#include "src/core/lib/slice/slice_string_helpers.h"
 #include "src/core/lib/support/string.h"
 #include "src/core/lib/surface/channel.h"
 #include "src/core/lib/transport/metadata_batch.h"
@@ -439,11 +437,9 @@ static void on_response_headers_received(
   for (size_t i = 0; i < headers->count; i++) {
     grpc_chttp2_incoming_metadata_buffer_add(
         &s->state.rs.initial_metadata,
-        grpc_mdelem_from_slices(
-            &exec_ctx, grpc_slice_intern(grpc_slice_from_static_string(
-                           headers->headers[i].key)),
-            grpc_slice_intern(
-                grpc_slice_from_static_string(headers->headers[i].value))));
+        grpc_mdelem_from_metadata_strings(
+            &exec_ctx, grpc_mdstr_from_string(headers->headers[i].key),
+            grpc_mdstr_from_string(headers->headers[i].value)));
   }
   s->state.state_callback_received[OP_RECV_INITIAL_METADATA] = true;
   if (!(s->state.state_op_done[OP_CANCEL_ERROR] ||
@@ -538,11 +534,9 @@ static void on_response_trailers_received(
                trailers->headers[i].value);
     grpc_chttp2_incoming_metadata_buffer_add(
         &s->state.rs.trailing_metadata,
-        grpc_mdelem_from_slices(
-            &exec_ctx, grpc_slice_intern(grpc_slice_from_static_string(
-                           trailers->headers[i].key)),
-            grpc_slice_intern(
-                grpc_slice_from_static_string(trailers->headers[i].value))));
+        grpc_mdelem_from_metadata_strings(
+            &exec_ctx, grpc_mdstr_from_string(trailers->headers[i].key),
+            grpc_mdstr_from_string(trailers->headers[i].value)));
     s->state.rs.trailing_metadata_valid = true;
     if (0 == strcmp(trailers->headers[i].key, "grpc-status") &&
         0 != strcmp(trailers->headers[i].value, "0")) {
@@ -622,41 +616,33 @@ static void convert_metadata_to_cronet_headers(
   curr = head;
   size_t num_headers = 0;
   while (num_headers < num_headers_available) {
-    grpc_mdelem mdelem = curr->md;
+    grpc_mdelem *mdelem = curr->md;
     curr = curr->next;
-    char *key = grpc_slice_to_c_string(GRPC_MDKEY(mdelem));
-    char *value = grpc_slice_to_c_string(GRPC_MDVALUE(mdelem));
-    if (grpc_slice_eq(GRPC_MDKEY(mdelem), GRPC_MDSTR_SCHEME) ||
-        grpc_slice_eq(GRPC_MDKEY(mdelem), GRPC_MDSTR_AUTHORITY)) {
+    const char *key = grpc_mdstr_as_c_string(mdelem->key);
+    const char *value = grpc_mdstr_as_c_string(mdelem->value);
+    if (mdelem->key == GRPC_MDSTR_SCHEME ||
+        mdelem->key == GRPC_MDSTR_AUTHORITY) {
       /* Cronet populates these fields on its own */
-      gpr_free(key);
-      gpr_free(value);
       continue;
     }
-    if (grpc_slice_eq(GRPC_MDKEY(mdelem), GRPC_MDSTR_METHOD)) {
-      if (grpc_slice_eq(GRPC_MDVALUE(mdelem), GRPC_MDSTR_PUT)) {
+    if (mdelem->key == GRPC_MDSTR_METHOD) {
+      if (mdelem->value == GRPC_MDSTR_PUT) {
         *method = "PUT";
       } else {
         /* POST method in default*/
         *method = "POST";
       }
-      gpr_free(key);
-      gpr_free(value);
       continue;
     }
-    if (grpc_slice_eq(GRPC_MDKEY(mdelem), GRPC_MDSTR_PATH)) {
+    if (mdelem->key == GRPC_MDSTR_PATH) {
       /* Create URL by appending :path value to the hostname */
       gpr_asprintf(pp_url, "https://%s%s", host, value);
-      gpr_free(key);
-      gpr_free(value);
       continue;
     }
     CRONET_LOG(GPR_DEBUG, "header %s = %s", key, value);
     headers[num_headers].key = key;
     headers[num_headers].value = value;
     num_headers++;
-    gpr_free(key);
-    gpr_free(value);
     if (curr == NULL) {
       break;
     }
@@ -676,7 +662,7 @@ static int parse_grpc_header(const uint8_t *data) {
 
 static bool header_has_authority(grpc_linked_mdelem *head) {
   while (head != NULL) {
-    if (grpc_slice_eq(GRPC_MDKEY(head->md), GRPC_MDSTR_AUTHORITY)) {
+    if (head->md->key == GRPC_MDSTR_AUTHORITY) {
       return true;
     }
     head = head->next;
@@ -871,8 +857,7 @@ static enum e_op_result execute_stream_op(grpc_exec_ctx *exec_ctx,
                          GRPC_ERROR_NONE);
     } else {
       grpc_chttp2_incoming_metadata_buffer_publish(
-          exec_ctx, &oas->s->state.rs.initial_metadata,
-          stream_op->recv_initial_metadata);
+          &oas->s->state.rs.initial_metadata, stream_op->recv_initial_metadata);
       grpc_closure_sched(exec_ctx, stream_op->recv_initial_metadata_ready,
                          GRPC_ERROR_NONE);
     }
@@ -1028,7 +1013,7 @@ static enum e_op_result execute_stream_op(grpc_exec_ctx *exec_ctx,
     CRONET_LOG(GPR_DEBUG, "running: %p  OP_RECV_TRAILING_METADATA", oas);
     if (oas->s->state.rs.trailing_metadata_valid) {
       grpc_chttp2_incoming_metadata_buffer_publish(
-          exec_ctx, &oas->s->state.rs.trailing_metadata,
+          &oas->s->state.rs.trailing_metadata,
           stream_op->recv_trailing_metadata);
       stream_state->rs.trailing_metadata_valid = false;
     }