1 /*
2 *
3 * Copyright 2015 gRPC authors.
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 *
17 */
18
19 #include <grpc/support/port_platform.h>
20
21 #include <limits.h>
22 #include <string.h>
23
24 #include <grpc/compression.h>
25 #include <grpc/grpc.h>
26 #include <grpc/support/alloc.h>
27 #include <grpc/support/log.h>
28 #include <grpc/support/string_util.h>
29
30 #include "src/core/lib/channel/channel_args.h"
31 #include "src/core/lib/compression/compression_args.h"
32 #include "src/core/lib/gpr/string.h"
33 #include "src/core/lib/gpr/useful.h"
34
35 grpc_compression_algorithm
grpc_channel_args_get_channel_default_compression_algorithm(const grpc_channel_args * a)36 grpc_channel_args_get_channel_default_compression_algorithm(
37 const grpc_channel_args* a) {
38 size_t i;
39 if (a == nullptr) return GRPC_COMPRESS_NONE;
40 for (i = 0; i < a->num_args; ++i) {
41 if (a->args[i].type == GRPC_ARG_INTEGER &&
42 !strcmp(GRPC_COMPRESSION_CHANNEL_DEFAULT_ALGORITHM, a->args[i].key)) {
43 grpc_compression_algorithm default_algorithm =
44 static_cast<grpc_compression_algorithm>(a->args[i].value.integer);
45 return default_algorithm < GRPC_COMPRESS_ALGORITHMS_COUNT
46 ? default_algorithm
47 : GRPC_COMPRESS_NONE;
48 }
49 }
50 return GRPC_COMPRESS_NONE;
51 }
52
grpc_channel_args_set_channel_default_compression_algorithm(grpc_channel_args * a,grpc_compression_algorithm algorithm)53 grpc_channel_args* grpc_channel_args_set_channel_default_compression_algorithm(
54 grpc_channel_args* a, grpc_compression_algorithm algorithm) {
55 GPR_ASSERT(algorithm < GRPC_COMPRESS_ALGORITHMS_COUNT);
56 grpc_arg tmp;
57 tmp.type = GRPC_ARG_INTEGER;
58 tmp.key = const_cast<char*>(GRPC_COMPRESSION_CHANNEL_DEFAULT_ALGORITHM);
59 tmp.value.integer = algorithm;
60 return grpc_channel_args_copy_and_add(a, &tmp, 1);
61 }
62
63 /** Returns 1 if the argument for compression algorithm's enabled states bitset
64 * was found in \a a, returning the arg's value in \a states. Otherwise, returns
65 * 0. */
find_compression_algorithm_states_bitset(const grpc_channel_args * a,int ** states_arg)66 static int find_compression_algorithm_states_bitset(const grpc_channel_args* a,
67 int** states_arg) {
68 if (a != nullptr) {
69 size_t i;
70 for (i = 0; i < a->num_args; ++i) {
71 if (a->args[i].type == GRPC_ARG_INTEGER &&
72 !strcmp(GRPC_COMPRESSION_CHANNEL_ENABLED_ALGORITHMS_BITSET,
73 a->args[i].key)) {
74 *states_arg = &a->args[i].value.integer;
75 **states_arg =
76 (**states_arg & ((1 << GRPC_COMPRESS_ALGORITHMS_COUNT) - 1)) |
77 0x1; /* forcefully enable support for no compression */
78 return 1;
79 }
80 }
81 }
82 return 0; /* GPR_FALSE */
83 }
84
grpc_channel_args_compression_algorithm_set_state(grpc_channel_args ** a,grpc_compression_algorithm algorithm,int state)85 grpc_channel_args* grpc_channel_args_compression_algorithm_set_state(
86 grpc_channel_args** a, grpc_compression_algorithm algorithm, int state) {
87 int* states_arg = nullptr;
88 grpc_channel_args* result = *a;
89 const int states_arg_found =
90 find_compression_algorithm_states_bitset(*a, &states_arg);
91
92 if (grpc_channel_args_get_channel_default_compression_algorithm(*a) ==
93 algorithm &&
94 state == 0) {
95 const char* algo_name = nullptr;
96 GPR_ASSERT(grpc_compression_algorithm_name(algorithm, &algo_name) != 0);
97 gpr_log(GPR_ERROR,
98 "Tried to disable default compression algorithm '%s'. The "
99 "operation has been ignored.",
100 algo_name);
101 } else if (states_arg_found) {
102 if (state != 0) {
103 GPR_BITSET((unsigned*)states_arg, algorithm);
104 } else if (algorithm != GRPC_COMPRESS_NONE) {
105 GPR_BITCLEAR((unsigned*)states_arg, algorithm);
106 }
107 } else {
108 /* create a new arg */
109 grpc_arg tmp;
110 tmp.type = GRPC_ARG_INTEGER;
111 tmp.key =
112 const_cast<char*>(GRPC_COMPRESSION_CHANNEL_ENABLED_ALGORITHMS_BITSET);
113 /* all enabled by default */
114 tmp.value.integer = (1u << GRPC_COMPRESS_ALGORITHMS_COUNT) - 1;
115 if (state != 0) {
116 GPR_BITSET((unsigned*)&tmp.value.integer, algorithm);
117 } else if (algorithm != GRPC_COMPRESS_NONE) {
118 GPR_BITCLEAR((unsigned*)&tmp.value.integer, algorithm);
119 }
120 result = grpc_channel_args_copy_and_add(*a, &tmp, 1);
121 grpc_channel_args_destroy(*a);
122 *a = result;
123 }
124 return result;
125 }
126
grpc_channel_args_compression_algorithm_get_states(const grpc_channel_args * a)127 uint32_t grpc_channel_args_compression_algorithm_get_states(
128 const grpc_channel_args* a) {
129 int* states_arg;
130 if (find_compression_algorithm_states_bitset(a, &states_arg)) {
131 return static_cast<uint32_t>(*states_arg);
132 } else {
133 return (1u << GRPC_COMPRESS_ALGORITHMS_COUNT) - 1; /* All algs. enabled */
134 }
135 }
136