1 /*
2 *
3 * Copyright 2017 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 <grpc/support/alloc.h>
22 #include <grpc/support/log.h>
23
24 #include "src/core/lib/compression/stream_compression_identity.h"
25 #include "src/core/lib/slice/slice_internal.h"
26
27 #define OUTPUT_BLOCK_SIZE (1024)
28
29 /* Singleton context used for all identity streams. */
30 static grpc_stream_compression_context identity_ctx = {
31 &grpc_stream_compression_identity_vtable};
32
grpc_stream_compression_pass_through(grpc_slice_buffer * in,grpc_slice_buffer * out,size_t * output_size,size_t max_output_size)33 static void grpc_stream_compression_pass_through(grpc_slice_buffer* in,
34 grpc_slice_buffer* out,
35 size_t* output_size,
36 size_t max_output_size) {
37 if (max_output_size >= in->length) {
38 if (output_size) {
39 *output_size = in->length;
40 }
41 grpc_slice_buffer_move_into(in, out);
42 } else {
43 if (output_size) {
44 *output_size = max_output_size;
45 }
46 grpc_slice_buffer_move_first(in, max_output_size, out);
47 }
48 }
49
grpc_stream_compress_identity(grpc_stream_compression_context * ctx,grpc_slice_buffer * in,grpc_slice_buffer * out,size_t * output_size,size_t max_output_size,grpc_stream_compression_flush flush)50 static bool grpc_stream_compress_identity(grpc_stream_compression_context* ctx,
51 grpc_slice_buffer* in,
52 grpc_slice_buffer* out,
53 size_t* output_size,
54 size_t max_output_size,
55 grpc_stream_compression_flush flush) {
56 if (ctx == nullptr) {
57 return false;
58 }
59 grpc_stream_compression_pass_through(in, out, output_size, max_output_size);
60 return true;
61 }
62
grpc_stream_decompress_identity(grpc_stream_compression_context * ctx,grpc_slice_buffer * in,grpc_slice_buffer * out,size_t * output_size,size_t max_output_size,bool * end_of_context)63 static bool grpc_stream_decompress_identity(
64 grpc_stream_compression_context* ctx, grpc_slice_buffer* in,
65 grpc_slice_buffer* out, size_t* output_size, size_t max_output_size,
66 bool* end_of_context) {
67 if (ctx == nullptr) {
68 return false;
69 }
70 grpc_stream_compression_pass_through(in, out, output_size, max_output_size);
71 if (end_of_context) {
72 *end_of_context = false;
73 }
74 return true;
75 }
76
77 static grpc_stream_compression_context*
grpc_stream_compression_context_create_identity(grpc_stream_compression_method method)78 grpc_stream_compression_context_create_identity(
79 grpc_stream_compression_method method) {
80 GPR_ASSERT(method == GRPC_STREAM_COMPRESSION_IDENTITY_COMPRESS ||
81 method == GRPC_STREAM_COMPRESSION_IDENTITY_DECOMPRESS);
82 /* No context needed in this case. Use fake context instead. */
83 return &identity_ctx;
84 }
85
grpc_stream_compression_context_destroy_identity(grpc_stream_compression_context * ctx)86 static void grpc_stream_compression_context_destroy_identity(
87 grpc_stream_compression_context* ctx) {
88 return;
89 }
90
91 const grpc_stream_compression_vtable grpc_stream_compression_identity_vtable = {
92 grpc_stream_compress_identity, grpc_stream_decompress_identity,
93 grpc_stream_compression_context_create_identity,
94 grpc_stream_compression_context_destroy_identity};
95