gecko-dev/xpcom/io/FixedBufferOutputStream.cpp

162 строки
3.8 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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 "FixedBufferOutputStream.h"
#include "mozilla/RefPtr.h"
#include "mozilla/StreamBufferSinkImpl.h"
#include "nsStreamUtils.h"
#include "nsString.h"
namespace mozilla {
FixedBufferOutputStream::FixedBufferOutputStream(
UniquePtr<StreamBufferSink>&& aSink)
: mSink(std::move(aSink)),
mMutex("FixedBufferOutputStream::mMutex"),
mOffset(0),
mWriting(false),
mClosed(false) {}
// static
RefPtr<FixedBufferOutputStream> FixedBufferOutputStream::Create(
size_t aLength) {
MOZ_ASSERT(aLength);
return MakeRefPtr<FixedBufferOutputStream>(MakeUnique<BufferSink>(aLength));
}
// static
RefPtr<FixedBufferOutputStream> FixedBufferOutputStream::Create(
size_t aLength, const mozilla::fallible_t&) {
MOZ_ASSERT(aLength);
auto sink = BufferSink::Alloc(aLength);
if (NS_WARN_IF(!sink)) {
return nullptr;
}
return MakeRefPtr<FixedBufferOutputStream>(std::move(sink));
}
// static
RefPtr<FixedBufferOutputStream> FixedBufferOutputStream::Create(
mozilla::Span<char> aBuffer) {
return MakeRefPtr<FixedBufferOutputStream>(
MakeUnique<nsBorrowedSink>(aBuffer));
}
// static
RefPtr<FixedBufferOutputStream> FixedBufferOutputStream::Create(
UniquePtr<StreamBufferSink>&& aSink) {
return MakeRefPtr<FixedBufferOutputStream>(std::move(aSink));
}
nsDependentCSubstring FixedBufferOutputStream::WrittenData() {
MutexAutoLock autoLock(mMutex);
return mSink->Slice(mOffset);
}
NS_IMPL_ISUPPORTS(FixedBufferOutputStream, nsIOutputStream)
NS_IMETHODIMP
FixedBufferOutputStream::Close() {
MutexAutoLock autoLock(mMutex);
if (mWriting) {
return NS_ERROR_NOT_AVAILABLE;
}
mClosed = true;
return NS_OK;
}
NS_IMETHODIMP
FixedBufferOutputStream::Flush() { return NS_OK; }
NS_IMETHODIMP
FixedBufferOutputStream::StreamStatus() {
MutexAutoLock autoLock(mMutex);
return mClosed ? NS_BASE_STREAM_CLOSED : NS_OK;
}
NS_IMETHODIMP
FixedBufferOutputStream::Write(const char* aBuf, uint32_t aCount,
uint32_t* _retval) {
return WriteSegments(NS_CopyBufferToSegment, const_cast<char*>(aBuf), aCount,
_retval);
}
NS_IMETHODIMP
FixedBufferOutputStream::WriteFrom(nsIInputStream* aFromStream, uint32_t aCount,
uint32_t* _retval) {
return WriteSegments(NS_CopyStreamToSegment, aFromStream, aCount, _retval);
}
NS_IMETHODIMP
FixedBufferOutputStream::WriteSegments(nsReadSegmentFun aReader, void* aClosure,
uint32_t aCount, uint32_t* _retval) {
MOZ_ASSERT(_retval);
MutexAutoLock autoLock(mMutex);
if (mWriting) {
return NS_ERROR_NOT_AVAILABLE;
}
if (mClosed) {
return NS_BASE_STREAM_CLOSED;
}
size_t length = mSink->Data().Length();
size_t offset = mOffset;
MOZ_ASSERT(length >= offset, "Bad stream state!");
size_t maxCount = length - offset;
if (maxCount == 0) {
*_retval = 0;
return NS_OK;
}
if (aCount > maxCount) {
aCount = maxCount;
}
mWriting = true;
nsresult rv;
{
MutexAutoUnlock autoUnlock(mMutex);
rv = aReader(this, aClosure, mSink->Data().Elements() + offset, 0, aCount,
_retval);
}
mWriting = false;
if (NS_SUCCEEDED(rv)) {
MOZ_ASSERT(*_retval <= aCount,
"Reader should not read more than we asked it to read!");
mOffset += *_retval;
}
// As defined in nsIOutputStream.idl, do not pass reader func errors.
return NS_OK;
}
NS_IMETHODIMP
FixedBufferOutputStream::IsNonBlocking(bool* _retval) {
*_retval = true;
return NS_OK;
}
} // namespace mozilla