blob: 86e69ef2fa83464a107a0fc7b11b0d033f530810 [file] [log] [blame]
// Copyright 2016 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/libplatform/tracing/trace-writer.h"
#include <cmath>
#include "v8/src/tracing/trace_event_common.h"
#include "include/v8-platform.h"
#include "src/base/platform/platform.h"
namespace v8 {
namespace platform {
namespace tracing {
// Writes the given string to a stream, taking care to escape characters
// when necessary.
V8_INLINE static void WriteJSONStringToStream(const char* str,
std::ostream& stream) {
size_t len = strlen(str);
stream << "\"";
for (size_t i = 0; i < len; ++i) {
// All of the permitted escape sequences in JSON strings, as per
// https://mathiasbynens.be/notes/javascript-escapes
switch (str[i]) {
case '\b':
stream << "\\b";
break;
case '\f':
stream << "\\f";
break;
case '\n':
stream << "\\n";
break;
case '\r':
stream << "\\r";
break;
case '\t':
stream << "\\t";
break;
case '\"':
stream << "\\\"";
break;
case '\\':
stream << "\\\\";
break;
// Note that because we use double quotes for JSON strings,
// we don't need to escape single quotes.
default:
stream << str[i];
break;
}
}
stream << "\"";
}
void JSONTraceWriter::AppendArgValue(uint8_t type,
TraceObject::ArgValue value) {
switch (type) {
case TRACE_VALUE_TYPE_BOOL:
stream_ << (value.as_bool ? "true" : "false");
break;
case TRACE_VALUE_TYPE_UINT:
stream_ << value.as_uint;
break;
case TRACE_VALUE_TYPE_INT:
stream_ << value.as_int;
break;
case TRACE_VALUE_TYPE_DOUBLE: {
std::string real;
double val = value.as_double;
if (std::isfinite(val)) {
std::ostringstream convert_stream;
convert_stream << val;
real = convert_stream.str();
// Ensure that the number has a .0 if there's no decimal or 'e'. This
// makes sure that when we read the JSON back, it's interpreted as a
// real rather than an int.
if (real.find('.') == std::string::npos &&
real.find('e') == std::string::npos &&
real.find('E') == std::string::npos) {
real += ".0";
}
} else if (std::isnan(val)) {
// The JSON spec doesn't allow NaN and Infinity (since these are
// objects in EcmaScript). Use strings instead.
real = "\"NaN\"";
} else if (val < 0) {
real = "\"-Infinity\"";
} else {
real = "\"Infinity\"";
}
stream_ << real;
break;
}
case TRACE_VALUE_TYPE_POINTER:
// JSON only supports double and int numbers.
// So as not to lose bits from a 64-bit pointer, output as a hex string.
stream_ << "\"" << value.as_pointer << "\"";
break;
case TRACE_VALUE_TYPE_STRING:
case TRACE_VALUE_TYPE_COPY_STRING:
if (value.as_string == nullptr) {
stream_ << "\"NULL\"";
} else {
WriteJSONStringToStream(value.as_string, stream_);
}
break;
default:
UNREACHABLE();
break;
}
}
void JSONTraceWriter::AppendArgValue(ConvertableToTraceFormat* value) {
std::string arg_stringified;
value->AppendAsTraceFormat(&arg_stringified);
stream_ << arg_stringified;
}
JSONTraceWriter::JSONTraceWriter(std::ostream& stream) : stream_(stream) {
stream_ << "{\"traceEvents\":[";
}
JSONTraceWriter::~JSONTraceWriter() { stream_ << "]}"; }
void JSONTraceWriter::AppendTraceEvent(TraceObject* trace_event) {
if (append_comma_) stream_ << ",";
append_comma_ = true;
stream_ << "{\"pid\":" << trace_event->pid()
<< ",\"tid\":" << trace_event->tid()
<< ",\"ts\":" << trace_event->ts()
<< ",\"tts\":" << trace_event->tts() << ",\"ph\":\""
<< trace_event->phase() << "\",\"cat\":\""
<< TracingController::GetCategoryGroupName(
trace_event->category_enabled_flag())
<< "\",\"name\":\"" << trace_event->name()
<< "\",\"dur\":" << trace_event->duration()
<< ",\"tdur\":" << trace_event->cpu_duration();
if (trace_event->flags() & TRACE_EVENT_FLAG_HAS_ID) {
if (trace_event->scope() != nullptr) {
stream_ << ",\"scope\":\"" << trace_event->scope() << "\"";
}
// So as not to lose bits from a 64-bit integer, output as a hex string.
stream_ << ",\"id\":\"0x" << std::hex << trace_event->id() << "\""
<< std::dec;
}
stream_ << ",\"args\":{";
const char** arg_names = trace_event->arg_names();
const uint8_t* arg_types = trace_event->arg_types();
TraceObject::ArgValue* arg_values = trace_event->arg_values();
std::unique_ptr<v8::ConvertableToTraceFormat>* arg_convertables =
trace_event->arg_convertables();
for (int i = 0; i < trace_event->num_args(); ++i) {
if (i > 0) stream_ << ",";
stream_ << "\"" << arg_names[i] << "\":";
if (arg_types[i] == TRACE_VALUE_TYPE_CONVERTABLE) {
AppendArgValue(arg_convertables[i].get());
} else {
AppendArgValue(arg_types[i], arg_values[i]);
}
}
stream_ << "}}";
// TODO(fmeawad): Add support for Flow Events.
}
void JSONTraceWriter::Flush() {}
TraceWriter* TraceWriter::CreateJSONTraceWriter(std::ostream& stream) {
return new JSONTraceWriter(stream);
}
} // namespace tracing
} // namespace platform
} // namespace v8