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/*
*
* Copyright 2015 gRPC authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
#ifndef GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_HPACK_ENCODER_H
#define GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_HPACK_ENCODER_H
#include <grpc/slice.h>
#include <grpc/slice_buffer.h>
#include <grpc/support/port_platform.h>
#include "src/core/ext/transport/chttp2/transport/frame.h"
#include "src/core/lib/transport/metadata.h"
#include "src/core/lib/transport/metadata_batch.h"
#include "src/core/lib/transport/transport.h"
#define GRPC_CHTTP2_HPACKC_NUM_FILTERS 256
#define GRPC_CHTTP2_HPACKC_NUM_VALUES 256
/* initial table size, per spec */
#define GRPC_CHTTP2_HPACKC_INITIAL_TABLE_SIZE 4096
/* maximum table size we'll actually use */
#define GRPC_CHTTP2_HPACKC_MAX_TABLE_SIZE (1024 * 1024)
#ifdef __cplusplus
extern "C" {
#endif
typedef struct {
uint32_t filter_elems_sum;
uint32_t max_table_size;
uint32_t max_table_elems;
uint32_t cap_table_elems;
/** if non-zero, advertise to the decoder that we'll start using a table
of this size */
uint8_t advertise_table_size_change;
/** maximum number of bytes we'll use for the decode table (to guard against
peers ooming us by setting decode table size high) */
uint32_t max_usable_size;
/* one before the lowest usable table index */
uint32_t tail_remote_index;
uint32_t table_size;
uint32_t table_elems;
/* filter tables for elems: this tables provides an approximate
popularity count for particular hashes, and are used to determine whether
a new literal should be added to the compression table or not.
They track a single integer that counts how often a particular value has
been seen. When that count reaches max (255), all values are halved. */
uint8_t filter_elems[GRPC_CHTTP2_HPACKC_NUM_FILTERS];
/* 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];
uint32_t indices_keys[GRPC_CHTTP2_HPACKC_NUM_VALUES];
uint32_t indices_elems[GRPC_CHTTP2_HPACKC_NUM_VALUES];
uint16_t* table_elem_size;
} grpc_chttp2_hpack_compressor;
void grpc_chttp2_hpack_compressor_init(grpc_chttp2_hpack_compressor* c);
void grpc_chttp2_hpack_compressor_destroy(grpc_exec_ctx* exec_ctx,
grpc_chttp2_hpack_compressor* c);
void grpc_chttp2_hpack_compressor_set_max_table_size(
grpc_chttp2_hpack_compressor* c, uint32_t max_table_size);
void grpc_chttp2_hpack_compressor_set_max_usable_size(
grpc_chttp2_hpack_compressor* c, uint32_t max_table_size);
typedef struct {
uint32_t stream_id;
bool is_eof;
bool use_true_binary_metadata;
size_t max_frame_size;
grpc_transport_one_way_stats* stats;
} grpc_encode_header_options;
void grpc_chttp2_encode_header(grpc_exec_ctx* exec_ctx,
grpc_chttp2_hpack_compressor* c,
grpc_mdelem** extra_headers,
size_t extra_headers_size,
grpc_metadata_batch* metadata,
const grpc_encode_header_options* options,
grpc_slice_buffer* outbuf);
#ifdef __cplusplus
}
#endif
#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_HPACK_ENCODER_H */
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