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diff --git a/src/core/channel/metadata_buffer.h b/src/core/channel/metadata_buffer.h
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+/*
+ *
+ * Copyright 2014, 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_INTERNAL_CHANNEL_METADATA_BUFFER_H__
+#define __GRPC_INTERNAL_CHANNEL_METADATA_BUFFER_H__
+
+#include "src/core/channel/channel_stack.h"
+
+/* Utility code to buffer GRPC_SEND_METADATA calls and pass them down the stack
+   all at once at some otherwise-determined time. Useful for implementing
+   filters that want to queue metadata until a START event chooses some
+   underlying filter stack to send an rpc on. */
+
+/* Clients should declare a member of grpc_metadata_buffer. This may at some
+   point become a typedef for a struct, but for now a pointer suffices */
+typedef struct grpc_metadata_buffer_impl grpc_metadata_buffer_impl;
+typedef grpc_metadata_buffer_impl *grpc_metadata_buffer;
+
+/* Initializes the metadata buffer. Allocates no memory. */
+void grpc_metadata_buffer_init(grpc_metadata_buffer *buffer);
+/* Destroy the metadata buffer. */
+void grpc_metadata_buffer_destroy(grpc_metadata_buffer *buffer,
+                                  grpc_op_error error);
+/* Append a call to the end of a metadata buffer: may allocate memory */
+void grpc_metadata_buffer_queue(grpc_metadata_buffer *buffer, grpc_call_op *op);
+/* Flush all queued operations from the metadata buffer to the element below
+   self */
+void grpc_metadata_buffer_flush(grpc_metadata_buffer *buffer,
+                                grpc_call_element *self);
+/* Count the number of queued elements in the buffer. */
+size_t grpc_metadata_buffer_count(const grpc_metadata_buffer *buffer);
+/* Extract elements as a grpc_metadata*, for presentation to applications.
+   The returned buffer must be freed with
+   grpc_metadata_buffer_cleanup_elements.
+   Clears the metadata buffer (this is a one-shot operation) */
+grpc_metadata *grpc_metadata_buffer_extract_elements(
+    grpc_metadata_buffer *buffer);
+void grpc_metadata_buffer_cleanup_elements(void *elements, grpc_op_error error);
+
+#endif  /* __GRPC_INTERNAL_CHANNEL_METADATA_BUFFER_H__ */