| /* |
| * |
| * 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 */ |