Nicolas Noble | b7ebd3b | 2014-11-26 16:33:03 -0800 | [diff] [blame] | 1 | /* |
| 2 | * |
Craig Tiller | 0605995 | 2015-02-18 08:34:56 -0800 | [diff] [blame] | 3 | * Copyright 2015, Google Inc. |
Nicolas Noble | b7ebd3b | 2014-11-26 16:33:03 -0800 | [diff] [blame] | 4 | * All rights reserved. |
| 5 | * |
| 6 | * Redistribution and use in source and binary forms, with or without |
| 7 | * modification, are permitted provided that the following conditions are |
| 8 | * met: |
| 9 | * |
| 10 | * * Redistributions of source code must retain the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer. |
| 12 | * * Redistributions in binary form must reproduce the above |
| 13 | * copyright notice, this list of conditions and the following disclaimer |
| 14 | * in the documentation and/or other materials provided with the |
| 15 | * distribution. |
| 16 | * * Neither the name of Google Inc. nor the names of its |
| 17 | * contributors may be used to endorse or promote products derived from |
| 18 | * this software without specific prior written permission. |
| 19 | * |
| 20 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 21 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 22 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 23 | * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| 24 | * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 25 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| 26 | * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 27 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 28 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 29 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| 30 | * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 31 | * |
| 32 | */ |
| 33 | |
Nicolas "Pixel" Noble | 1ff52d5 | 2015-03-01 05:24:36 +0100 | [diff] [blame] | 34 | #ifndef GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_VARINT_H |
| 35 | #define GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_VARINT_H |
Nicolas Noble | b7ebd3b | 2014-11-26 16:33:03 -0800 | [diff] [blame] | 36 | |
| 37 | #include <grpc/support/port_platform.h> |
| 38 | |
| 39 | /* Helpers for hpack varint encoding */ |
| 40 | |
| 41 | /* length of a value that needs varint tail encoding (it's bigger than can be |
| 42 | bitpacked into the opcode byte) - returned value includes the length of the |
| 43 | opcode byte */ |
Craig Tiller | 32ca48c | 2015-09-10 11:47:15 -0700 | [diff] [blame] | 44 | gpr_uint32 grpc_chttp2_hpack_varint_length(gpr_uint32 tail_value); |
Nicolas Noble | b7ebd3b | 2014-11-26 16:33:03 -0800 | [diff] [blame] | 45 | |
| 46 | void grpc_chttp2_hpack_write_varint_tail(gpr_uint32 tail_value, |
Craig Tiller | 32ca48c | 2015-09-10 11:47:15 -0700 | [diff] [blame] | 47 | gpr_uint8* target, |
| 48 | gpr_uint32 tail_length); |
Nicolas Noble | b7ebd3b | 2014-11-26 16:33:03 -0800 | [diff] [blame] | 49 | |
| 50 | /* maximum value that can be bitpacked with the opcode if the opcode has a |
| 51 | prefix |
| 52 | of length prefix_bits */ |
Craig Tiller | 5a640a4 | 2015-12-08 22:23:11 -0800 | [diff] [blame] | 53 | #define GRPC_CHTTP2_MAX_IN_PREFIX(prefix_bits) \ |
| 54 | ((gpr_uint32)((1 << (8 - (prefix_bits))) - 1)) |
Nicolas Noble | b7ebd3b | 2014-11-26 16:33:03 -0800 | [diff] [blame] | 55 | |
| 56 | /* length required to bitpack a value */ |
| 57 | #define GRPC_CHTTP2_VARINT_LENGTH(n, prefix_bits) \ |
| 58 | ((n) < GRPC_CHTTP2_MAX_IN_PREFIX(prefix_bits) \ |
Craig Tiller | 32ca48c | 2015-09-10 11:47:15 -0700 | [diff] [blame] | 59 | ? 1u \ |
Nicolas Noble | b7ebd3b | 2014-11-26 16:33:03 -0800 | [diff] [blame] | 60 | : grpc_chttp2_hpack_varint_length( \ |
Craig Tiller | 4aa71a1 | 2015-06-15 13:00:55 -0700 | [diff] [blame] | 61 | (n)-GRPC_CHTTP2_MAX_IN_PREFIX(prefix_bits))) |
Nicolas Noble | b7ebd3b | 2014-11-26 16:33:03 -0800 | [diff] [blame] | 62 | |
Craig Tiller | 4aa71a1 | 2015-06-15 13:00:55 -0700 | [diff] [blame] | 63 | #define GRPC_CHTTP2_WRITE_VARINT(n, prefix_bits, prefix_or, target, length) \ |
| 64 | do { \ |
| 65 | gpr_uint8* tgt = target; \ |
Craig Tiller | 32ca48c | 2015-09-10 11:47:15 -0700 | [diff] [blame] | 66 | if ((length) == 1u) { \ |
Craig Tiller | 6a6b36c | 2015-09-10 16:00:22 -0700 | [diff] [blame] | 67 | (tgt)[0] = (gpr_uint8)((prefix_or) | (n)); \ |
Craig Tiller | 4aa71a1 | 2015-06-15 13:00:55 -0700 | [diff] [blame] | 68 | } else { \ |
Craig Tiller | 8ab91b2 | 2015-12-07 11:28:51 -0800 | [diff] [blame] | 69 | (tgt)[0] = (prefix_or) | (gpr_uint8)GRPC_CHTTP2_MAX_IN_PREFIX(prefix_bits); \ |
Craig Tiller | 4aa71a1 | 2015-06-15 13:00:55 -0700 | [diff] [blame] | 70 | grpc_chttp2_hpack_write_varint_tail( \ |
| 71 | (n)-GRPC_CHTTP2_MAX_IN_PREFIX(prefix_bits), (tgt) + 1, (length)-1); \ |
| 72 | } \ |
Nicolas Noble | b7ebd3b | 2014-11-26 16:33:03 -0800 | [diff] [blame] | 73 | } while (0) |
| 74 | |
Craig Tiller | 4aa71a1 | 2015-06-15 13:00:55 -0700 | [diff] [blame] | 75 | #endif /* GRPC_INTERNAL_CORE_TRANSPORT_CHTTP2_VARINT_H */ |