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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_VARINT_H
#define GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_VARINT_H
#include <grpc/support/port_platform.h>
/* Helpers for hpack varint encoding */
/* length of a value that needs varint tail encoding (it's bigger than can be
bitpacked into the opcode byte) - returned value includes the length of the
opcode byte */
uint32_t grpc_chttp2_hpack_varint_length(uint32_t tail_value);
void grpc_chttp2_hpack_write_varint_tail(uint32_t tail_value, uint8_t* target,
uint32_t tail_length);
/* maximum value that can be bitpacked with the opcode if the opcode has a
prefix
of length prefix_bits */
#define GRPC_CHTTP2_MAX_IN_PREFIX(prefix_bits) \
((uint32_t)((1 << (8 - (prefix_bits))) - 1))
/* length required to bitpack a value */
#define GRPC_CHTTP2_VARINT_LENGTH(n, prefix_bits) \
((n) < GRPC_CHTTP2_MAX_IN_PREFIX(prefix_bits) \
? 1u \
: grpc_chttp2_hpack_varint_length( \
(n)-GRPC_CHTTP2_MAX_IN_PREFIX(prefix_bits)))
#define GRPC_CHTTP2_WRITE_VARINT(n, prefix_bits, prefix_or, target, length) \
do { \
uint8_t* tgt = target; \
if ((length) == 1u) { \
(tgt)[0] = (uint8_t)((prefix_or) | (n)); \
} else { \
(tgt)[0] = \
(prefix_or) | (uint8_t)GRPC_CHTTP2_MAX_IN_PREFIX(prefix_bits); \
grpc_chttp2_hpack_write_varint_tail( \
(n)-GRPC_CHTTP2_MAX_IN_PREFIX(prefix_bits), (tgt) + 1, (length)-1); \
} \
} while (0)
#endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_VARINT_H */
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