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/* -*- 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 <stdlib.h>
#include "mozilla/Logging.h"
#include "mozilla/Maybe.h"
#include "mozilla/Mutex.h"
#include "mozilla/Attributes.h"
#include "nsIInputStreamTee.h"
#include "nsIInputStream.h"
#include "nsIOutputStream.h"
#include "nsCOMPtr.h"
#include "nsIEventTarget.h"
#include "nsThreadUtils.h"
using namespace mozilla;
#ifdef LOG
# undef LOG
#endif
static LazyLogModule sTeeLog("nsInputStreamTee");
#define LOG(args) MOZ_LOG(sTeeLog, mozilla::LogLevel::Debug, args)
class nsInputStreamTee final : public nsIInputStreamTee {
public:
NS_DECL_THREADSAFE_ISUPPORTS
NS_DECL_NSIINPUTSTREAM
NS_DECL_NSIINPUTSTREAMTEE
nsInputStreamTee();
bool SinkIsValid();
void InvalidateSink();
private:
~nsInputStreamTee() = default;
nsresult TeeSegment(const char* aBuf, uint32_t aCount);
static nsresult WriteSegmentFun(nsIInputStream*, void*, const char*, uint32_t,
uint32_t, uint32_t*);
private:
nsCOMPtr<nsIInputStream> mSource;
nsCOMPtr<nsIOutputStream> mSink;
nsCOMPtr<nsIEventTarget> mEventTarget;
nsWriteSegmentFun mWriter; // for implementing ReadSegments
void* mClosure; // for implementing ReadSegments
Maybe<Mutex> mLock; // synchronize access to mSinkIsValid
bool mSinkIsValid; // False if TeeWriteEvent fails
};
class nsInputStreamTeeWriteEvent : public Runnable {
public:
// aTee's lock is held across construction of this object
nsInputStreamTeeWriteEvent(const char* aBuf, uint32_t aCount,
nsIOutputStream* aSink, nsInputStreamTee* aTee)
: mozilla::Runnable("nsInputStreamTeeWriteEvent") {
// copy the buffer - will be free'd by dtor
mBuf = (char*)malloc(aCount);
if (mBuf) {
memcpy(mBuf, (char*)aBuf, aCount);
}
mCount = aCount;
mSink = aSink;
bool isNonBlocking;
mSink->IsNonBlocking(&isNonBlocking);
NS_ASSERTION(isNonBlocking == false, "mSink is nonblocking");
mTee = aTee;
}
NS_IMETHOD Run() override {
if (!mBuf) {
NS_WARNING(
"nsInputStreamTeeWriteEvent::Run() "
"memory not allocated\n");
return NS_OK;
}
MOZ_ASSERT(mSink, "mSink is null!");
// The output stream could have been invalidated between when
// this event was dispatched and now, so check before writing.
if (!mTee->SinkIsValid()) {
return NS_OK;
}
LOG(
("nsInputStreamTeeWriteEvent::Run() [%p]"
"will write %u bytes to %p\n",
this, mCount, mSink.get()));
uint32_t totalBytesWritten = 0;
while (mCount) {
nsresult rv;
uint32_t bytesWritten = 0;
rv = mSink->Write(mBuf + totalBytesWritten, mCount, &bytesWritten);
if (NS_FAILED(rv)) {
LOG(("nsInputStreamTeeWriteEvent::Run[%p] error %" PRIx32 " in writing",
this, static_cast<uint32_t>(rv)));
mTee->InvalidateSink();
break;
}
totalBytesWritten += bytesWritten;
NS_ASSERTION(bytesWritten <= mCount, "wrote too much");
mCount -= bytesWritten;
}
return NS_OK;
}
protected:
virtual ~nsInputStreamTeeWriteEvent() {
if (mBuf) {
free(mBuf);
}
mBuf = nullptr;
}
private:
char* mBuf;
uint32_t mCount;
nsCOMPtr<nsIOutputStream> mSink;
// back pointer to the tee that created this runnable
RefPtr<nsInputStreamTee> mTee;
};
nsInputStreamTee::nsInputStreamTee()
: mWriter(nullptr), mClosure(nullptr), mLock(), mSinkIsValid(true) {}
bool nsInputStreamTee::SinkIsValid() {
MutexAutoLock lock(*mLock);
return mSinkIsValid;
}
void nsInputStreamTee::InvalidateSink() {
MutexAutoLock lock(*mLock);
mSinkIsValid = false;
}
nsresult nsInputStreamTee::TeeSegment(const char* aBuf, uint32_t aCount) {
if (!mSink) {
return NS_OK; // nothing to do
}
if (mLock) { // asynchronous case
NS_ASSERTION(mEventTarget, "mEventTarget is null, mLock is not null.");
if (!SinkIsValid()) {
return NS_OK; // nothing to do
}
nsCOMPtr<nsIRunnable> event =
new nsInputStreamTeeWriteEvent(aBuf, aCount, mSink, this);
LOG(("nsInputStreamTee::TeeSegment [%p] dispatching write %u bytes\n", this,
aCount));
return mEventTarget->Dispatch(event, NS_DISPATCH_NORMAL);
} else { // synchronous case
NS_ASSERTION(!mEventTarget, "mEventTarget is not null, mLock is null.");
nsresult rv;
uint32_t totalBytesWritten = 0;
while (aCount) {
uint32_t bytesWritten = 0;
rv = mSink->Write(aBuf + totalBytesWritten, aCount, &bytesWritten);
if (NS_FAILED(rv)) {
// ok, this is not a fatal error... just drop our reference to mSink
// and continue on as if nothing happened.
NS_WARNING("Write failed (non-fatal)");
// catch possible misuse of the input stream tee
NS_ASSERTION(rv != NS_BASE_STREAM_WOULD_BLOCK,
"sink must be a blocking stream");
mSink = nullptr;
break;
}
totalBytesWritten += bytesWritten;
NS_ASSERTION(bytesWritten <= aCount, "wrote too much");
aCount -= bytesWritten;
}
return NS_OK;
}
}
nsresult nsInputStreamTee::WriteSegmentFun(nsIInputStream* aIn, void* aClosure,
const char* aFromSegment,
uint32_t aOffset, uint32_t aCount,
uint32_t* aWriteCount) {
nsInputStreamTee* tee = reinterpret_cast<nsInputStreamTee*>(aClosure);
nsresult rv = tee->mWriter(aIn, tee->mClosure, aFromSegment, aOffset, aCount,
aWriteCount);
if (NS_FAILED(rv) || (*aWriteCount == 0)) {
NS_ASSERTION((NS_FAILED(rv) ? (*aWriteCount == 0) : true),
"writer returned an error with non-zero writeCount");
return rv;
}
return tee->TeeSegment(aFromSegment, *aWriteCount);
}
NS_IMPL_ISUPPORTS(nsInputStreamTee, nsIInputStreamTee, nsIInputStream)
NS_IMETHODIMP
nsInputStreamTee::Close() {
if (NS_WARN_IF(!mSource)) {
return NS_ERROR_NOT_INITIALIZED;
}
nsresult rv = mSource->Close();
mSource = nullptr;
mSink = nullptr;
return rv;
}
NS_IMETHODIMP
nsInputStreamTee::Available(uint64_t* aAvail) {
if (NS_WARN_IF(!mSource)) {
return NS_ERROR_NOT_INITIALIZED;
}
return mSource->Available(aAvail);
}
NS_IMETHODIMP
nsInputStreamTee::Read(char* aBuf, uint32_t aCount, uint32_t* aBytesRead) {
if (NS_WARN_IF(!mSource)) {
return NS_ERROR_NOT_INITIALIZED;
}
nsresult rv = mSource->Read(aBuf, aCount, aBytesRead);
if (NS_FAILED(rv) || (*aBytesRead == 0)) {
return rv;
}
return TeeSegment(aBuf, *aBytesRead);
}
NS_IMETHODIMP
nsInputStreamTee::ReadSegments(nsWriteSegmentFun aWriter, void* aClosure,
uint32_t aCount, uint32_t* aBytesRead) {
if (NS_WARN_IF(!mSource)) {
return NS_ERROR_NOT_INITIALIZED;
}
mWriter = aWriter;
mClosure = aClosure;
return mSource->ReadSegments(WriteSegmentFun, this, aCount, aBytesRead);
}
NS_IMETHODIMP
nsInputStreamTee::IsNonBlocking(bool* aResult) {
if (NS_WARN_IF(!mSource)) {
return NS_ERROR_NOT_INITIALIZED;
}
return mSource->IsNonBlocking(aResult);
}
NS_IMETHODIMP
nsInputStreamTee::SetSource(nsIInputStream* aSource) {
mSource = aSource;
return NS_OK;
}
NS_IMETHODIMP
nsInputStreamTee::GetSource(nsIInputStream** aSource) {
NS_IF_ADDREF(*aSource = mSource);
return NS_OK;
}
NS_IMETHODIMP
nsInputStreamTee::SetSink(nsIOutputStream* aSink) {
#ifdef DEBUG
if (aSink) {
bool nonBlocking;
nsresult rv = aSink->IsNonBlocking(&nonBlocking);
if (NS_FAILED(rv) || nonBlocking) {
NS_ERROR("aSink should be a blocking stream");
}
}
#endif
mSink = aSink;
return NS_OK;
}
NS_IMETHODIMP
nsInputStreamTee::GetSink(nsIOutputStream** aSink) {
NS_IF_ADDREF(*aSink = mSink);
return NS_OK;
}
NS_IMETHODIMP
nsInputStreamTee::SetEventTarget(nsIEventTarget* aEventTarget) {
mEventTarget = aEventTarget;
if (mEventTarget) {
// Only need synchronization if this is an async tee
mLock.emplace("nsInputStreamTee.mLock");
}
return NS_OK;
}
NS_IMETHODIMP
nsInputStreamTee::GetEventTarget(nsIEventTarget** aEventTarget) {
NS_IF_ADDREF(*aEventTarget = mEventTarget);
return NS_OK;
}
nsresult NS_NewInputStreamTeeAsync(nsIInputStream** aResult,
nsIInputStream* aSource,
nsIOutputStream* aSink,
nsIEventTarget* aEventTarget) {
nsresult rv;
nsCOMPtr<nsIInputStreamTee> tee = new nsInputStreamTee();
rv = tee->SetSource(aSource);
if (NS_FAILED(rv)) {
return rv;
}
rv = tee->SetSink(aSink);
if (NS_FAILED(rv)) {
return rv;
}
rv = tee->SetEventTarget(aEventTarget);
if (NS_FAILED(rv)) {
return rv;
}
tee.forget(aResult);
return rv;
}
nsresult NS_NewInputStreamTee(nsIInputStream** aResult, nsIInputStream* aSource,
nsIOutputStream* aSink) {
return NS_NewInputStreamTeeAsync(aResult, aSource, aSink, nullptr);
}
#undef LOG