| /* |
| * |
| * 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_INTERNAL_CORE_TRANSPORT_CHTTP2_VARINT_H |
| #define GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_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 */ |
| int grpc_chttp2_hpack_varint_length(gpr_uint32 tail_value); |
| |
| void grpc_chttp2_hpack_write_varint_tail(gpr_uint32 tail_value, |
| gpr_uint8* target, int 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) ((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) \ |
| ? 1 \ |
| : 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 { \ |
| gpr_uint8* tgt = target; \ |
| if ((length) == 1) { \ |
| (tgt)[0] = (prefix_or) | (n); \ |
| } else { \ |
| (tgt)[0] = (prefix_or) | 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_INTERNAL_CORE_TRANSPORT_CHTTP2_VARINT_H */ |