1 files changed, 194 insertions, 0 deletions
diff --git a/src/core/lib/transport/metadata_batch.c b/src/core/lib/transport/metadata_batch.c
new file mode 100644
index 0000000000..4567221a48
--- /dev/null
+++ b/src/core/lib/transport/metadata_batch.c
@@ -0,0 +1,194 @@
+/*
+ *
+ * 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/lib/transport/metadata_batch.h"
+
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+
+#include "src/core/lib/profiling/timers.h"
+
+static void assert_valid_list(grpc_mdelem_list *list) {
+#ifndef NDEBUG
+  grpc_linked_mdelem *l;
+
+  GPR_ASSERT((list->head == NULL) == (list->tail == NULL));
+  if (!list->head) return;
+  GPR_ASSERT(list->head->prev == NULL);
+  GPR_ASSERT(list->tail->next == NULL);
+  GPR_ASSERT((list->head == list->tail) == (list->head->next == NULL));
+
+  for (l = list->head; l; l = l->next) {
+    GPR_ASSERT(l->md);
+    GPR_ASSERT((l->prev == NULL) == (l == list->head));
+    GPR_ASSERT((l->next == NULL) == (l == list->tail));
+    if (l->next) GPR_ASSERT(l->next->prev == l);
+    if (l->prev) GPR_ASSERT(l->prev->next == l);
+  }
+#endif /* NDEBUG */
+}
+
+#ifndef NDEBUG
+void grpc_metadata_batch_assert_ok(grpc_metadata_batch *batch) {
+  assert_valid_list(&batch->list);
+}
+#endif /* NDEBUG */
+
+void grpc_metadata_batch_init(grpc_metadata_batch *batch) {
+  batch->list.head = batch->list.tail = NULL;
+  batch->deadline = gpr_inf_future(GPR_CLOCK_REALTIME);
+}
+
+void grpc_metadata_batch_destroy(grpc_metadata_batch *batch) {
+  grpc_linked_mdelem *l;
+  for (l = batch->list.head; l; l = l->next) {
+    GRPC_MDELEM_UNREF(l->md);
+  }
+}
+
+void grpc_metadata_batch_add_head(grpc_metadata_batch *batch,
+                                  grpc_linked_mdelem *storage,
+                                  grpc_mdelem *elem_to_add) {
+  GPR_ASSERT(elem_to_add);
+  storage->md = elem_to_add;
+  grpc_metadata_batch_link_head(batch, storage);
+}
+
+static void link_head(grpc_mdelem_list *list, grpc_linked_mdelem *storage) {
+  assert_valid_list(list);
+  GPR_ASSERT(storage->md);
+  storage->prev = NULL;
+  storage->next = list->head;
+  if (list->head != NULL) {
+    list->head->prev = storage;
+  } else {
+    list->tail = storage;
+  }
+  list->head = storage;
+  assert_valid_list(list);
+}
+
+void grpc_metadata_batch_link_head(grpc_metadata_batch *batch,
+                                   grpc_linked_mdelem *storage) {
+  link_head(&batch->list, storage);
+}
+
+void grpc_metadata_batch_add_tail(grpc_metadata_batch *batch,
+                                  grpc_linked_mdelem *storage,
+                                  grpc_mdelem *elem_to_add) {
+  GPR_ASSERT(elem_to_add);
+  storage->md = elem_to_add;
+  grpc_metadata_batch_link_tail(batch, storage);
+}
+
+static void link_tail(grpc_mdelem_list *list, grpc_linked_mdelem *storage) {
+  assert_valid_list(list);
+  GPR_ASSERT(storage->md);
+  storage->prev = list->tail;
+  storage->next = NULL;
+  storage->reserved = NULL;
+  if (list->tail != NULL) {
+    list->tail->next = storage;
+  } else {
+    list->head = storage;
+  }
+  list->tail = storage;
+  assert_valid_list(list);
+}
+
+void grpc_metadata_batch_link_tail(grpc_metadata_batch *batch,
+                                   grpc_linked_mdelem *storage) {
+  link_tail(&batch->list, storage);
+}
+
+void grpc_metadata_batch_move(grpc_metadata_batch *dst,
+                              grpc_metadata_batch *src) {
+  *dst = *src;
+  memset(src, 0, sizeof(grpc_metadata_batch));
+}
+
+void grpc_metadata_batch_filter(grpc_metadata_batch *batch,
+                                grpc_mdelem *(*filter)(void *user_data,
+                                                       grpc_mdelem *elem),
+                                void *user_data) {
+  grpc_linked_mdelem *l;
+  grpc_linked_mdelem *next;
+
+  GPR_TIMER_BEGIN("grpc_metadata_batch_filter", 0);
+
+  assert_valid_list(&batch->list);
+  for (l = batch->list.head; l; l = next) {
+    grpc_mdelem *orig = l->md;
+    grpc_mdelem *filt = filter(user_data, orig);
+    next = l->next;
+    if (filt == NULL) {
+      if (l->prev) {
+        l->prev->next = l->next;
+      }
+      if (l->next) {
+        l->next->prev = l->prev;
+      }
+      if (batch->list.head == l) {
+        batch->list.head = l->next;
+      }
+      if (batch->list.tail == l) {
+        batch->list.tail = l->prev;
+      }
+      assert_valid_list(&batch->list);
+      GRPC_MDELEM_UNREF(l->md);
+    } else if (filt != orig) {
+      GRPC_MDELEM_UNREF(orig);
+      l->md = filt;
+    }
+  }
+  assert_valid_list(&batch->list);
+
+  GPR_TIMER_END("grpc_metadata_batch_filter", 0);
+}
+
+static grpc_mdelem *no_metadata_for_you(void *user_data, grpc_mdelem *elem) {
+  return NULL;
+}
+
+void grpc_metadata_batch_clear(grpc_metadata_batch *batch) {
+  batch->deadline = gpr_inf_future(GPR_CLOCK_REALTIME);
+  grpc_metadata_batch_filter(batch, no_metadata_for_you, NULL);
+}
+
+int grpc_metadata_batch_is_empty(grpc_metadata_batch *batch) {
+  return batch->list.head == NULL &&
+         gpr_time_cmp(gpr_inf_future(batch->deadline.clock_type),
+                      batch->deadline) == 0;
+}