Line data Source code
1 : // Copyright 2016 the V8 project authors. All rights reserved.
2 : // Use of this source code is governed by a BSD-style license that can be
3 : // found in the LICENSE file.
4 :
5 : #include "src/libplatform/tracing/trace-writer.h"
6 :
7 : #include <cmath>
8 :
9 : #include "base/trace_event/common/trace_event_common.h"
10 : #include "include/v8-platform.h"
11 : #include "src/base/platform/platform.h"
12 :
13 : namespace v8 {
14 : namespace platform {
15 : namespace tracing {
16 :
17 : // Writes the given string to a stream, taking care to escape characters
18 : // when necessary.
19 : V8_INLINE static void WriteJSONStringToStream(const char* str,
20 : std::ostream& stream) {
21 49 : size_t len = strlen(str);
22 49 : stream << "\"";
23 224 : for (size_t i = 0; i < len; ++i) {
24 : // All of the permitted escape sequences in JSON strings, as per
25 : // https://mathiasbynens.be/notes/javascript-escapes
26 224 : switch (str[i]) {
27 : case '\b':
28 0 : stream << "\\b";
29 : break;
30 : case '\f':
31 0 : stream << "\\f";
32 : break;
33 : case '\n':
34 0 : stream << "\\n";
35 : break;
36 : case '\r':
37 0 : stream << "\\r";
38 : break;
39 : case '\t':
40 0 : stream << "\\t";
41 : break;
42 : case '\"':
43 42 : stream << "\\\"";
44 : break;
45 : case '\\':
46 0 : stream << "\\\\";
47 : break;
48 : // Note that because we use double quotes for JSON strings,
49 : // we don't need to escape single quotes.
50 : default:
51 182 : stream << str[i];
52 : break;
53 : }
54 : }
55 49 : stream << "\"";
56 : }
57 :
58 168 : void JSONTraceWriter::AppendArgValue(uint8_t type,
59 : TraceObject::ArgValue value) {
60 168 : switch (type) {
61 : case TRACE_VALUE_TYPE_BOOL:
62 14 : stream_ << (value.as_bool ? "true" : "false");
63 14 : break;
64 : case TRACE_VALUE_TYPE_UINT:
65 35 : stream_ << value.as_uint;
66 : break;
67 : case TRACE_VALUE_TYPE_INT:
68 28 : stream_ << value.as_int;
69 : break;
70 : case TRACE_VALUE_TYPE_DOUBLE: {
71 : std::string real;
72 35 : double val = value.as_double;
73 35 : if (std::isfinite(val)) {
74 14 : std::ostringstream convert_stream;
75 : convert_stream << val;
76 14 : real = convert_stream.str();
77 : // Ensure that the number has a .0 if there's no decimal or 'e'. This
78 : // makes sure that when we read the JSON back, it's interpreted as a
79 : // real rather than an int.
80 42 : if (real.find('.') == std::string::npos &&
81 21 : real.find('e') == std::string::npos &&
82 7 : real.find('E') == std::string::npos) {
83 : real += ".0";
84 14 : }
85 21 : } else if (std::isnan(val)) {
86 : // The JSON spec doesn't allow NaN and Infinity (since these are
87 : // objects in EcmaScript). Use strings instead.
88 : real = "\"NaN\"";
89 14 : } else if (val < 0) {
90 : real = "\"-Infinity\"";
91 : } else {
92 : real = "\"Infinity\"";
93 : }
94 35 : stream_ << real;
95 : break;
96 : }
97 : case TRACE_VALUE_TYPE_POINTER:
98 : // JSON only supports double and int numbers.
99 : // So as not to lose bits from a 64-bit pointer, output as a hex string.
100 14 : stream_ << "\"" << value.as_pointer << "\"";
101 7 : break;
102 : case TRACE_VALUE_TYPE_STRING:
103 : case TRACE_VALUE_TYPE_COPY_STRING:
104 49 : if (value.as_string == nullptr) {
105 0 : stream_ << "\"NULL\"";
106 : } else {
107 49 : WriteJSONStringToStream(value.as_string, stream_);
108 : }
109 : break;
110 : default:
111 0 : UNREACHABLE();
112 : break;
113 : }
114 168 : }
115 :
116 21 : void JSONTraceWriter::AppendArgValue(ConvertableToTraceFormat* value) {
117 : std::string arg_stringified;
118 21 : value->AppendAsTraceFormat(&arg_stringified);
119 21 : stream_ << arg_stringified;
120 21 : }
121 :
122 14 : JSONTraceWriter::JSONTraceWriter(std::ostream& stream) : stream_(stream) {
123 14 : stream_ << "{\"traceEvents\":[";
124 0 : }
125 :
126 28 : JSONTraceWriter::~JSONTraceWriter() { stream_ << "]}"; }
127 :
128 1113 : void JSONTraceWriter::AppendTraceEvent(TraceObject* trace_event) {
129 182 : if (append_comma_) stream_ << ",";
130 182 : append_comma_ = true;
131 182 : stream_ << "{\"pid\":" << trace_event->pid()
132 182 : << ",\"tid\":" << trace_event->tid()
133 182 : << ",\"ts\":" << trace_event->ts()
134 364 : << ",\"tts\":" << trace_event->tts() << ",\"ph\":\""
135 182 : << trace_event->phase() << "\",\"cat\":\""
136 : << TracingController::GetCategoryGroupName(
137 364 : trace_event->category_enabled_flag())
138 182 : << "\",\"name\":\"" << trace_event->name()
139 182 : << "\",\"dur\":" << trace_event->duration()
140 182 : << ",\"tdur\":" << trace_event->cpu_duration();
141 182 : if (trace_event->flags() & TRACE_EVENT_FLAG_HAS_ID) {
142 7 : if (trace_event->scope() != nullptr) {
143 0 : stream_ << ",\"scope\":\"" << trace_event->scope() << "\"";
144 : }
145 : // So as not to lose bits from a 64-bit integer, output as a hex string.
146 14 : stream_ << ",\"id\":\"0x" << std::hex << trace_event->id() << "\""
147 : << std::dec;
148 : }
149 182 : stream_ << ",\"args\":{";
150 182 : const char** arg_names = trace_event->arg_names();
151 182 : const uint8_t* arg_types = trace_event->arg_types();
152 182 : TraceObject::ArgValue* arg_values = trace_event->arg_values();
153 : std::unique_ptr<v8::ConvertableToTraceFormat>* arg_convertables =
154 182 : trace_event->arg_convertables();
155 742 : for (int i = 0; i < trace_event->num_args(); ++i) {
156 189 : if (i > 0) stream_ << ",";
157 189 : stream_ << "\"" << arg_names[i] << "\":";
158 189 : if (arg_types[i] == TRACE_VALUE_TYPE_CONVERTABLE) {
159 42 : AppendArgValue(arg_convertables[i].get());
160 : } else {
161 168 : AppendArgValue(arg_types[i], arg_values[i]);
162 : }
163 : }
164 182 : stream_ << "}}";
165 : // TODO(fmeawad): Add support for Flow Events.
166 182 : }
167 :
168 14 : void JSONTraceWriter::Flush() {}
169 :
170 14 : TraceWriter* TraceWriter::CreateJSONTraceWriter(std::ostream& stream) {
171 28 : return new JSONTraceWriter(stream);
172 : }
173 :
174 : } // namespace tracing
175 : } // namespace platform
176 : } // namespace v8
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