include/grpc/byte_buffer.h

/*
 *
 * 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_BYTE_BUFFER_H
#define GRPC_BYTE_BUFFER_H

#include <grpc/support/slice_buffer.h>

typedef enum {
  GRPC_BB_SLICE_BUFFER,

  /* Keep the GRPC_BB_COMPRESSED_* entries in the same order as the
   * grpc_compression_algorithm enum entries. */
  GRPC_BB_COMPRESSED_NONE, /* for overriding otherwise compressed channels */
  GRPC_BB_COMPRESSED_DEFLATE,
  GRPC_BB_COMPRESSED_GZIP
} grpc_byte_buffer_type;

/* byte buffers are containers for messages passed in from the public api's */
struct grpc_byte_buffer {
  grpc_byte_buffer_type type;
  union {
    gpr_slice_buffer slice_buffer;
  } data;
};
typedef struct grpc_byte_buffer grpc_byte_buffer;

/** Returns the grpc_compression_algorithm enum value for a
 * grpc_byte_buffer_type GRPC_BB_COMPRESSED_* value. */
#define GRPC_COMPRESS_ALGORITHM_FROM_BB_TYPE(bb_type) \
  (bb_type - GRPC_BB_COMPRESSED_NONE)

/** Returns a byte buffer instance over the given slices (up to \a nslices) of
 * \a type type.
 *
 * Increases the reference count for all \a slices processed.
 *
 * The user is responsible for invoking grpc_byte_buffer_destroy on
 * the returned instance. */
grpc_byte_buffer *grpc_byte_buffer_typed_create(gpr_slice *slices,
                                                size_t nslices,
                                                grpc_byte_buffer_type type);
/** Convenience method for creating GRPC_BB_SLICE_BUFFER byte buffers. \sa
 * grpc_byte_buffer_typed_create */
grpc_byte_buffer *grpc_byte_buffer_create(gpr_slice *slices, size_t nslices);

/** Copies input byte buffer \a bb.
 *
 * Increases the reference count of all the source slices. The user is
 * responsible for calling grpc_byte_buffer_destroy over the returned copy. */
grpc_byte_buffer *grpc_byte_buffer_copy(grpc_byte_buffer *bb);

/** Returns the size of the given byte buffer, in bytes. */
size_t grpc_byte_buffer_length(grpc_byte_buffer *bb);

/** Destroys \a byte_buffer deallocating all its memory. */
void grpc_byte_buffer_destroy(grpc_byte_buffer *byte_buffer);


/** Reader for byte buffers. Iterates over slices in the byte buffer */
struct grpc_byte_buffer_reader;
typedef struct grpc_byte_buffer_reader grpc_byte_buffer_reader;

/** Initialize \a reader to read over \a buffer */
void grpc_byte_buffer_reader_init(grpc_byte_buffer_reader *reader,
                                  grpc_byte_buffer *buffer);

/** Cleanup and destroy \a reader */
void grpc_byte_buffer_reader_destroy(grpc_byte_buffer_reader *reader);

/** Updates \a slice with the next piece of data from from \a reader and returns
 * 1. Returns 0 at the end of the stream. Caller is responsible for calling
 * gpr_slice_unref on the result. */
int grpc_byte_buffer_reader_next(grpc_byte_buffer_reader *reader,
                                 gpr_slice *slice);

#endif  /* GRPC_BYTE_BUFFER_H */