1 files changed, 37 insertions, 47 deletions

diff --git a/src/core/ext/load_reporting/load_reporting_filter.c b/src/core/ext/load_reporting/load_reporting_filter.c
index 07ef10e6a8..8af6191c3b 100644
--- a/src/core/ext/load_reporting/load_reporting_filter.c
+++ b/src/core/ext/load_reporting/load_reporting_filter.c
@@ -41,13 +41,17 @@
 #include "src/core/ext/load_reporting/load_reporting_filter.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/profiling/timers.h"
+#include "src/core/lib/slice/slice_internal.h"
 #include "src/core/lib/transport/static_metadata.h"
 
 typedef struct call_data {
   intptr_t id; /**< an id unique to the call */
-  char *trailing_md_string;
-  char *initial_md_string;
-  const char *service_method;
+  bool have_trailing_md_string;
+  grpc_slice trailing_md_string;
+  bool have_initial_md_string;
+  grpc_slice initial_md_string;
+  bool have_service_method;
+  grpc_slice service_method;
 
   /* stores the recv_initial_metadata op's ready closure, which we wrap with our
    * own (on_initial_md_ready) in order to capture the incoming initial metadata
@@ -63,42 +67,28 @@ typedef struct channel_data {
   intptr_t id; /**< an id unique to the channel */
 } channel_data;
 
-typedef struct {
-  grpc_call_element *elem;
-  grpc_exec_ctx *exec_ctx;
-} recv_md_filter_args;
-
-static grpc_mdelem *recv_md_filter(grpc_exec_ctx *exec_ctx, void *user_data,
-                                   grpc_mdelem *md) {
-  recv_md_filter_args *a = user_data;
-  grpc_call_element *elem = a->elem;
-  call_data *calld = elem->call_data;
-
-  if (md->key == GRPC_MDSTR_PATH) {
-    calld->service_method = grpc_mdstr_as_c_string(md->value);
-  } else if (md->key == GRPC_MDSTR_LB_TOKEN) {
-    calld->initial_md_string = gpr_strdup(grpc_mdstr_as_c_string(md->value));
-    return NULL;
-  }
-
-  return md;
-}
-
 static void on_initial_md_ready(grpc_exec_ctx *exec_ctx, void *user_data,
                                 grpc_error *err) {
   grpc_call_element *elem = user_data;
   call_data *calld = elem->call_data;
 
   if (err == GRPC_ERROR_NONE) {
-    recv_md_filter_args a;
-    a.elem = elem;
-    a.exec_ctx = exec_ctx;
-    grpc_metadata_batch_filter(exec_ctx, calld->recv_initial_metadata,
-                               recv_md_filter, &a);
-    if (calld->service_method == NULL) {
+    if (calld->recv_initial_metadata->idx.named.path != NULL) {
+      calld->service_method = grpc_slice_ref_internal(
+          GRPC_MDVALUE(calld->recv_initial_metadata->idx.named.path->md));
+      calld->have_service_method = true;
+    } else {
       err =
           grpc_error_add_child(err, GRPC_ERROR_CREATE("Missing :path header"));
     }
+    if (calld->recv_initial_metadata->idx.named.lb_token != NULL) {
+      calld->initial_md_string = grpc_slice_ref_internal(
+          GRPC_MDVALUE(calld->recv_initial_metadata->idx.named.lb_token->md));
+      calld->have_initial_md_string = true;
+      grpc_metadata_batch_remove(
+          exec_ctx, calld->recv_initial_metadata,
+          calld->recv_initial_metadata->idx.named.lb_token);
+    }
   } else {
     GRPC_ERROR_REF(err);
   }
@@ -149,8 +139,15 @@ static void destroy_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
                                                 calld->service_method};
   */
 
-  gpr_free(calld->initial_md_string);
-  gpr_free(calld->trailing_md_string);
+  if (calld->have_initial_md_string) {
+    grpc_slice_unref_internal(exec_ctx, calld->initial_md_string);
+  }
+  if (calld->have_trailing_md_string) {
+    grpc_slice_unref_internal(exec_ctx, calld->trailing_md_string);
+  }
+  if (calld->have_service_method) {
+    grpc_slice_unref_internal(exec_ctx, calld->service_method);
+  }
 }
 
 /* Constructor for channel_data */
@@ -193,19 +190,6 @@ static void destroy_channel_elem(grpc_exec_ctx *exec_ctx,
   */
 }
 
-static grpc_mdelem *lr_trailing_md_filter(grpc_exec_ctx *exec_ctx,
-                                          void *user_data, grpc_mdelem *md) {
-  grpc_call_element *elem = user_data;
-  call_data *calld = elem->call_data;
-
-  if (md->key == GRPC_MDSTR_LB_COST_BIN) {
-    calld->trailing_md_string = gpr_strdup(grpc_mdstr_as_c_string(md->value));
-    return NULL;
-  }
-
-  return md;
-}
-
 static void lr_start_transport_stream_op(grpc_exec_ctx *exec_ctx,
                                          grpc_call_element *elem,
                                          grpc_transport_stream_op *op) {
@@ -218,8 +202,14 @@ static void lr_start_transport_stream_op(grpc_exec_ctx *exec_ctx,
     calld->ops_recv_initial_metadata_ready = op->recv_initial_metadata_ready;
     op->recv_initial_metadata_ready = &calld->on_initial_md_ready;
   } else if (op->send_trailing_metadata) {
-    grpc_metadata_batch_filter(exec_ctx, op->send_trailing_metadata,
-                               lr_trailing_md_filter, elem);
+    if (op->send_trailing_metadata->idx.named.lb_cost_bin != NULL) {
+      calld->trailing_md_string = grpc_slice_ref_internal(
+          GRPC_MDVALUE(op->send_trailing_metadata->idx.named.lb_cost_bin->md));
+      calld->have_trailing_md_string = true;
+      grpc_metadata_batch_remove(
+          exec_ctx, op->send_trailing_metadata,
+          op->send_trailing_metadata->idx.named.lb_cost_bin);
+    }
   }
   grpc_call_next_op(exec_ctx, elem, op);