1 /*
2 * Copyright (C) 2022 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #ifndef INCLUDE_PERFETTO_PUBLIC_PB_MSG_H_
18 #define INCLUDE_PERFETTO_PUBLIC_PB_MSG_H_
19
20 #include <assert.h>
21 #include <stdint.h>
22 #include <string.h>
23
24 #include "perfetto/public/abi/stream_writer_abi.h"
25 #include "perfetto/public/compiler.h"
26 #include "perfetto/public/pb_utils.h"
27 #include "perfetto/public/stream_writer.h"
28
29 // The number of bytes reserved by this implementation to encode a protobuf type
30 // 2 field size as var-int. Keep this in sync with kMessageLengthFieldSize in
31 // proto_utils.h.
32 #define PROTOZERO_MESSAGE_LENGTH_FIELD_SIZE 4
33
34 // Points to the memory used by a `PerfettoPbMsg` for writing.
35 struct PerfettoPbMsgWriter {
36 struct PerfettoStreamWriter writer;
37 };
38
39 struct PerfettoPbMsg {
40 // Pointer to a non-aligned pre-reserved var-int slot of
41 // PROTOZERO_MESSAGE_LENGTH_FIELD_SIZE bytes. If not NULL,
42 // protozero_length_buf_finalize() will write the size of proto-encoded
43 // message in the pointed memory region.
44 uint8_t* size_field;
45
46 // Current size of the buffer.
47 uint32_t size;
48
49 struct PerfettoPbMsgWriter* writer;
50
51 struct PerfettoPbMsg* nested;
52 struct PerfettoPbMsg* parent;
53 };
54
PerfettoPbMsgInit(struct PerfettoPbMsg * msg,struct PerfettoPbMsgWriter * writer)55 static inline void PerfettoPbMsgInit(struct PerfettoPbMsg* msg,
56 struct PerfettoPbMsgWriter* writer) {
57 msg->size_field = PERFETTO_NULL;
58 msg->size = 0;
59 msg->writer = writer;
60 msg->nested = PERFETTO_NULL;
61 msg->parent = PERFETTO_NULL;
62 }
63
PerfettoPbMsgPatch(struct PerfettoPbMsg * msg)64 static inline void PerfettoPbMsgPatch(struct PerfettoPbMsg* msg) {
65 static_assert(
66 PROTOZERO_MESSAGE_LENGTH_FIELD_SIZE == PERFETTO_STREAM_WRITER_PATCH_SIZE,
67 "PROTOZERO_MESSAGE_LENGTH_FIELD_SIZE doesn't match patch size");
68 msg->size_field =
69 PerfettoStreamWriterAnnotatePatch(&msg->writer->writer, msg->size_field);
70 }
71
PerfettoPbMsgPatchStack(struct PerfettoPbMsg * msg)72 static inline void PerfettoPbMsgPatchStack(struct PerfettoPbMsg* msg) {
73 uint8_t* const cur_range_end = msg->writer->writer.end;
74 uint8_t* const cur_range_begin = msg->writer->writer.begin;
75 while (msg && cur_range_begin <= msg->size_field &&
76 msg->size_field < cur_range_end) {
77 PerfettoPbMsgPatch(msg);
78 msg = msg->parent;
79 }
80 }
81
PerfettoPbMsgAppendBytes(struct PerfettoPbMsg * msg,const uint8_t * begin,size_t size)82 static inline void PerfettoPbMsgAppendBytes(struct PerfettoPbMsg* msg,
83 const uint8_t* begin,
84 size_t size) {
85 if (PERFETTO_UNLIKELY(
86 size > PerfettoStreamWriterAvailableBytes(&msg->writer->writer))) {
87 PerfettoPbMsgPatchStack(msg);
88 }
89 PerfettoStreamWriterAppendBytes(&msg->writer->writer, begin, size);
90 msg->size += size;
91 }
92
PerfettoPbMsgAppendByte(struct PerfettoPbMsg * msg,uint8_t value)93 static inline void PerfettoPbMsgAppendByte(struct PerfettoPbMsg* msg,
94 uint8_t value) {
95 PerfettoPbMsgAppendBytes(msg, &value, 1);
96 }
97
PerfettoPbMsgAppendVarInt(struct PerfettoPbMsg * msg,uint64_t value)98 static inline void PerfettoPbMsgAppendVarInt(struct PerfettoPbMsg* msg,
99 uint64_t value) {
100 uint8_t* buf_end;
101 uint8_t buf[PERFETTO_PB_VARINT_MAX_SIZE_64];
102 buf_end = PerfettoPbWriteVarInt(value, buf);
103
104 PerfettoPbMsgAppendBytes(msg, buf,
105 PERFETTO_STATIC_CAST(size_t, buf_end - buf));
106 }
107
PerfettoPbMsgAppendFixed64(struct PerfettoPbMsg * msg,uint64_t value)108 static inline void PerfettoPbMsgAppendFixed64(struct PerfettoPbMsg* msg,
109 uint64_t value) {
110 uint8_t buf[8];
111 PerfettoPbWriteFixed64(value, buf);
112
113 PerfettoPbMsgAppendBytes(msg, buf, 8);
114 }
115
PerfettoPbMsgAppendFixed32(struct PerfettoPbMsg * msg,uint32_t value)116 static inline void PerfettoPbMsgAppendFixed32(struct PerfettoPbMsg* msg,
117 uint32_t value) {
118 uint8_t buf[4];
119 PerfettoPbWriteFixed32(value, buf);
120
121 PerfettoPbMsgAppendBytes(msg, buf, 4);
122 }
123
PerfettoPbMsgAppendType0Field(struct PerfettoPbMsg * msg,int32_t field_id,uint64_t value)124 static inline void PerfettoPbMsgAppendType0Field(struct PerfettoPbMsg* msg,
125 int32_t field_id,
126 uint64_t value) {
127 uint8_t* buf_end;
128 uint8_t buf[PERFETTO_PB_VARINT_MAX_SIZE_64 + PERFETTO_PB_VARINT_MAX_SIZE_32];
129 buf_end = PerfettoPbWriteVarInt(
130 PerfettoPbMakeTag(field_id, PERFETTO_PB_WIRE_TYPE_VARINT), buf);
131 buf_end = PerfettoPbWriteVarInt(value, buf_end);
132
133 PerfettoPbMsgAppendBytes(msg, buf,
134 PERFETTO_STATIC_CAST(size_t, buf_end - buf));
135 }
136
PerfettoPbMsgAppendType2Field(struct PerfettoPbMsg * msg,int32_t field_id,const uint8_t * data,size_t size)137 static inline void PerfettoPbMsgAppendType2Field(struct PerfettoPbMsg* msg,
138 int32_t field_id,
139 const uint8_t* data,
140 size_t size) {
141 uint8_t* buf_end;
142 uint8_t buf[PERFETTO_PB_VARINT_MAX_SIZE_64 + PERFETTO_PB_VARINT_MAX_SIZE_32];
143 buf_end = PerfettoPbWriteVarInt(
144 PerfettoPbMakeTag(field_id, PERFETTO_PB_WIRE_TYPE_DELIMITED), buf);
145 buf_end =
146 PerfettoPbWriteVarInt(PERFETTO_STATIC_CAST(uint64_t, size), buf_end);
147 PerfettoPbMsgAppendBytes(msg, buf,
148 PERFETTO_STATIC_CAST(size_t, buf_end - buf));
149
150 PerfettoPbMsgAppendBytes(msg, data, size);
151 }
152
PerfettoPbMsgAppendFixed32Field(struct PerfettoPbMsg * msg,int32_t field_id,uint32_t value)153 static inline void PerfettoPbMsgAppendFixed32Field(struct PerfettoPbMsg* msg,
154 int32_t field_id,
155 uint32_t value) {
156 uint8_t* buf_end;
157 uint8_t buf[PERFETTO_PB_VARINT_MAX_SIZE_32 + 4];
158 buf_end = PerfettoPbWriteVarInt(
159 PerfettoPbMakeTag(field_id, PERFETTO_PB_WIRE_TYPE_FIXED32), buf);
160 buf_end = PerfettoPbWriteFixed32(value, buf_end);
161
162 PerfettoPbMsgAppendBytes(msg, buf,
163 PERFETTO_STATIC_CAST(size_t, buf_end - buf));
164 }
165
PerfettoPbMsgAppendFloatField(struct PerfettoPbMsg * msg,int32_t field_id,float value)166 static inline void PerfettoPbMsgAppendFloatField(struct PerfettoPbMsg* msg,
167 int32_t field_id,
168 float value) {
169 uint32_t val;
170 memcpy(&val, &value, sizeof val);
171 PerfettoPbMsgAppendFixed32Field(msg, field_id, val);
172 }
173
PerfettoPbMsgAppendFixed64Field(struct PerfettoPbMsg * msg,int32_t field_id,uint64_t value)174 static inline void PerfettoPbMsgAppendFixed64Field(struct PerfettoPbMsg* msg,
175 int32_t field_id,
176 uint64_t value) {
177 uint8_t* buf_end;
178 uint8_t buf[PERFETTO_PB_VARINT_MAX_SIZE_32 + 8];
179 buf_end = PerfettoPbWriteVarInt(
180 PerfettoPbMakeTag(field_id, PERFETTO_PB_WIRE_TYPE_FIXED64), buf);
181 buf_end = PerfettoPbWriteFixed64(value, buf_end);
182
183 PerfettoPbMsgAppendBytes(msg, buf,
184 PERFETTO_STATIC_CAST(size_t, buf_end - buf));
185 }
186
PerfettoPbMsgAppendDoubleField(struct PerfettoPbMsg * msg,int32_t field_id,double value)187 static inline void PerfettoPbMsgAppendDoubleField(struct PerfettoPbMsg* msg,
188 int32_t field_id,
189 double value) {
190 uint64_t val;
191 memcpy(&val, &value, sizeof val);
192 PerfettoPbMsgAppendFixed64Field(msg, field_id, val);
193 }
194
PerfettoPbMsgAppendCStrField(struct PerfettoPbMsg * msg,int32_t field_id,const char * c_str)195 static inline void PerfettoPbMsgAppendCStrField(struct PerfettoPbMsg* msg,
196 int32_t field_id,
197 const char* c_str) {
198 PerfettoPbMsgAppendType2Field(
199 msg, field_id, PERFETTO_REINTERPRET_CAST(const uint8_t*, c_str),
200 strlen(c_str));
201 }
202
PerfettoPbMsgBeginNested(struct PerfettoPbMsg * parent,struct PerfettoPbMsg * nested,int32_t field_id)203 static inline void PerfettoPbMsgBeginNested(struct PerfettoPbMsg* parent,
204 struct PerfettoPbMsg* nested,
205 int32_t field_id) {
206 PerfettoPbMsgAppendVarInt(
207 parent, PerfettoPbMakeTag(field_id, PERFETTO_PB_WIRE_TYPE_DELIMITED));
208
209 PerfettoPbMsgInit(nested, parent->writer);
210 if (PERFETTO_UNLIKELY(
211 PROTOZERO_MESSAGE_LENGTH_FIELD_SIZE >
212 PerfettoStreamWriterAvailableBytes(&parent->writer->writer))) {
213 PerfettoPbMsgPatchStack(parent);
214 }
215 nested->size_field = PERFETTO_REINTERPRET_CAST(
216 uint8_t*,
217 PerfettoStreamWriterReserveBytes(&nested->writer->writer,
218 PROTOZERO_MESSAGE_LENGTH_FIELD_SIZE));
219 nested->parent = parent;
220 parent->size += PROTOZERO_MESSAGE_LENGTH_FIELD_SIZE;
221 parent->nested = nested;
222 }
223
224 static inline size_t PerfettoPbMsgFinalize(struct PerfettoPbMsg* msg);
225
PerfettoPbMsgEndNested(struct PerfettoPbMsg * parent)226 static inline void PerfettoPbMsgEndNested(struct PerfettoPbMsg* parent) {
227 parent->size += PerfettoPbMsgFinalize(parent->nested);
228 parent->nested = PERFETTO_NULL;
229 }
230
PerfettoPbMsgFinalize(struct PerfettoPbMsg * msg)231 static inline size_t PerfettoPbMsgFinalize(struct PerfettoPbMsg* msg) {
232 if (msg->nested)
233 PerfettoPbMsgEndNested(msg);
234
235 // Write the length of the nested message a posteriori, using a leading-zero
236 // redundant varint encoding.
237 if (msg->size_field) {
238 uint32_t size_to_write;
239 size_to_write = msg->size;
240 for (size_t i = 0; i < PROTOZERO_MESSAGE_LENGTH_FIELD_SIZE; i++) {
241 const uint8_t msb = (i < 3) ? 0x80 : 0;
242 msg->size_field[i] = (size_to_write & 0xFF) | msb;
243 size_to_write >>= 7;
244 }
245 msg->size_field = PERFETTO_NULL;
246 }
247
248 return msg->size;
249 }
250
251 #endif // INCLUDE_PERFETTO_PUBLIC_PB_MSG_H_
252