gecko-dev/mozglue/baseprofiler/core/ProfileJSONWriter.cpp

121 строка
3.6 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "BaseProfiler.h"
#ifdef MOZ_BASE_PROFILER
# include "BaseProfileJSONWriter.h"
# include "mozilla/HashFunctions.h"
void ChunkedJSONWriteFunc::Write(const char* aStr) {
MOZ_ASSERT(mChunkPtr >= mChunkList.back().get() && mChunkPtr <= mChunkEnd);
MOZ_ASSERT(mChunkEnd >= mChunkList.back().get() + mChunkLengths.back());
MOZ_ASSERT(*mChunkPtr == '\0');
size_t len = strlen(aStr);
// Most strings to be written are small, but subprocess profiles (e.g.,
// from the content process in e10s) may be huge. If the string is larger
// than a chunk, allocate its own chunk.
char* newPtr;
if (len >= kChunkSize) {
AllocChunk(len + 1);
newPtr = mChunkPtr + len;
} else {
newPtr = mChunkPtr + len;
if (newPtr >= mChunkEnd) {
AllocChunk(kChunkSize);
newPtr = mChunkPtr + len;
}
}
memcpy(mChunkPtr, aStr, len);
*newPtr = '\0';
mChunkPtr = newPtr;
mChunkLengths.back() += len;
}
size_t ChunkedJSONWriteFunc::GetTotalLength() const {
MOZ_ASSERT(mChunkLengths.length() == mChunkList.length());
size_t totalLen = 1;
for (size_t i = 0; i < mChunkLengths.length(); i++) {
MOZ_ASSERT(strlen(mChunkList[i].get()) == mChunkLengths[i]);
totalLen += mChunkLengths[i];
}
return totalLen;
}
void ChunkedJSONWriteFunc::CopyDataIntoLazilyAllocatedBuffer(
const std::function<char*(size_t)>& aAllocator) const {
size_t totalLen = GetTotalLength();
char* ptr = aAllocator(totalLen);
for (size_t i = 0; i < mChunkList.length(); i++) {
size_t len = mChunkLengths[i];
memcpy(ptr, mChunkList[i].get(), len);
ptr += len;
}
*ptr = '\0';
}
mozilla::UniquePtr<char[]> ChunkedJSONWriteFunc::CopyData() const {
mozilla::UniquePtr<char[]> c;
CopyDataIntoLazilyAllocatedBuffer([&](size_t allocationSize) {
c = mozilla::MakeUnique<char[]>(allocationSize);
return c.get();
});
return c;
}
void ChunkedJSONWriteFunc::Take(ChunkedJSONWriteFunc&& aOther) {
for (size_t i = 0; i < aOther.mChunkList.length(); i++) {
MOZ_ALWAYS_TRUE(mChunkLengths.append(aOther.mChunkLengths[i]));
MOZ_ALWAYS_TRUE(mChunkList.append(std::move(aOther.mChunkList[i])));
}
mChunkPtr = mChunkList.back().get() + mChunkLengths.back();
mChunkEnd = mChunkPtr;
aOther.mChunkPtr = nullptr;
aOther.mChunkEnd = nullptr;
aOther.mChunkList.clear();
aOther.mChunkLengths.clear();
}
void ChunkedJSONWriteFunc::AllocChunk(size_t aChunkSize) {
MOZ_ASSERT(mChunkLengths.length() == mChunkList.length());
mozilla::UniquePtr<char[]> newChunk = mozilla::MakeUnique<char[]>(aChunkSize);
mChunkPtr = newChunk.get();
mChunkEnd = mChunkPtr + aChunkSize;
*mChunkPtr = '\0';
MOZ_ALWAYS_TRUE(mChunkLengths.append(0));
MOZ_ALWAYS_TRUE(mChunkList.append(std::move(newChunk)));
}
void SpliceableJSONWriter::TakeAndSplice(ChunkedJSONWriteFunc* aFunc) {
Separator();
for (size_t i = 0; i < aFunc->mChunkList.length(); i++) {
WriteFunc()->Write(aFunc->mChunkList[i].get());
}
aFunc->mChunkPtr = nullptr;
aFunc->mChunkEnd = nullptr;
aFunc->mChunkList.clear();
aFunc->mChunkLengths.clear();
mNeedComma[mDepth] = true;
}
void SpliceableJSONWriter::Splice(const char* aStr) {
Separator();
WriteFunc()->Write(aStr);
mNeedComma[mDepth] = true;
}
void SpliceableChunkedJSONWriter::TakeAndSplice(ChunkedJSONWriteFunc* aFunc) {
Separator();
WriteFunc()->Take(std::move(*aFunc));
mNeedComma[mDepth] = true;
}
#endif // MOZ_BASE_PROFILER