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gecko-dev/xpcom/io/nsMultiplexInputStream.cpp

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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/. */
/**
* The multiplex stream concatenates a list of input streams into a single
* stream.
*/
#include "mozilla/Attributes.h"
#include "mozilla/MathAlgorithms.h"
#include "mozilla/Mutex.h"
#include "mozilla/SystemGroup.h"
#include "base/basictypes.h"
#include "nsMultiplexInputStream.h"
#include "nsICloneableInputStream.h"
#include "nsIMultiplexInputStream.h"
#include "nsISeekableStream.h"
#include "nsCOMPtr.h"
#include "nsCOMArray.h"
#include "nsIClassInfoImpl.h"
#include "nsIIPCSerializableInputStream.h"
#include "mozilla/ipc/InputStreamUtils.h"
#include "nsIAsyncInputStream.h"
using namespace mozilla;
using namespace mozilla::ipc;
using mozilla::DeprecatedAbs;
using mozilla::Maybe;
using mozilla::Nothing;
using mozilla::Some;
class nsMultiplexInputStream final
: public nsIMultiplexInputStream
, public nsISeekableStream
, public nsIIPCSerializableInputStream
, public nsICloneableInputStream
, public nsIAsyncInputStream
, public nsIInputStreamCallback
{
public:
nsMultiplexInputStream();
NS_DECL_THREADSAFE_ISUPPORTS
NS_DECL_NSIINPUTSTREAM
NS_DECL_NSIMULTIPLEXINPUTSTREAM
NS_DECL_NSISEEKABLESTREAM
NS_DECL_NSIIPCSERIALIZABLEINPUTSTREAM
NS_DECL_NSICLONEABLEINPUTSTREAM
NS_DECL_NSIASYNCINPUTSTREAM
NS_DECL_NSIINPUTSTREAMCALLBACK
void AsyncWaitCompleted();
struct StreamData
{
void Initialize(nsIInputStream* aStream)
{
mStream = aStream;
mAsyncStream = do_QueryInterface(aStream);
mSeekableStream = do_QueryInterface(aStream);
}
nsCOMPtr<nsIInputStream> mStream;
// This can be null.
nsCOMPtr<nsIAsyncInputStream> mAsyncStream;
// This can be null.
nsCOMPtr<nsISeekableStream> mSeekableStream;
};
private:
~nsMultiplexInputStream()
{
}
nsresult
AsyncWaitInternal();
// This method updates mSeekableStreams, mIPCSerializableStreams,
// mCloneableStreams and mAsyncInputStreams values.
void UpdateQIMap(StreamData& aStream, int32_t aCount);
struct MOZ_STACK_CLASS ReadSegmentsState
{
nsCOMPtr<nsIInputStream> mThisStream;
uint32_t mOffset;
nsWriteSegmentFun mWriter;
void* mClosure;
bool mDone;
};
static nsresult ReadSegCb(nsIInputStream* aIn, void* aClosure,
const char* aFromRawSegment, uint32_t aToOffset,
uint32_t aCount, uint32_t* aWriteCount);
bool IsSeekable() const;
bool IsIPCSerializable() const;
bool IsCloneable() const;
bool IsAsyncInputStream() const;
Mutex mLock; // Protects access to all data members.
nsTArray<StreamData> mStreams;
uint32_t mCurrentStream;
bool mStartedReadingCurrent;
nsresult mStatus;
nsCOMPtr<nsIInputStreamCallback> mAsyncWaitCallback;
uint32_t mAsyncWaitFlags;
uint32_t mAsyncWaitRequestedCount;
nsCOMPtr<nsIEventTarget> mAsyncWaitEventTarget;
uint32_t mSeekableStreams;
uint32_t mIPCSerializableStreams;
uint32_t mCloneableStreams;
uint32_t mAsyncInputStreams;
};
NS_IMPL_ADDREF(nsMultiplexInputStream)
NS_IMPL_RELEASE(nsMultiplexInputStream)
NS_IMPL_CLASSINFO(nsMultiplexInputStream, nullptr, nsIClassInfo::THREADSAFE,
NS_MULTIPLEXINPUTSTREAM_CID)
NS_INTERFACE_MAP_BEGIN(nsMultiplexInputStream)
NS_INTERFACE_MAP_ENTRY(nsIMultiplexInputStream)
NS_INTERFACE_MAP_ENTRY(nsIInputStream)
NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsISeekableStream, IsSeekable())
NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIIPCSerializableInputStream,
IsIPCSerializable())
NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsICloneableInputStream,
IsCloneable())
NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIAsyncInputStream,
IsAsyncInputStream())
NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIInputStreamCallback,
IsAsyncInputStream())
NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIMultiplexInputStream)
NS_IMPL_QUERY_CLASSINFO(nsMultiplexInputStream)
NS_INTERFACE_MAP_END
NS_IMPL_CI_INTERFACE_GETTER(nsMultiplexInputStream,
nsIMultiplexInputStream,
nsIInputStream,
nsISeekableStream)
static nsresult
AvailableMaybeSeek(nsMultiplexInputStream::StreamData& aStream,
uint64_t* aResult)
{
nsresult rv = aStream.mStream->Available(aResult);
if (rv == NS_BASE_STREAM_CLOSED) {
// Blindly seek to the current position if Available() returns
// NS_BASE_STREAM_CLOSED.
// If nsIFileInputStream is closed in Read() due to CLOSE_ON_EOF flag,
// Seek() could reopen the file if REOPEN_ON_REWIND flag is set.
if (aStream.mSeekableStream) {
nsresult rvSeek =
aStream.mSeekableStream->Seek(nsISeekableStream::NS_SEEK_CUR, 0);
if (NS_SUCCEEDED(rvSeek)) {
rv = aStream.mStream->Available(aResult);
}
}
}
return rv;
}
static nsresult
TellMaybeSeek(nsISeekableStream* aSeekable, int64_t* aResult)
{
nsresult rv = aSeekable->Tell(aResult);
if (rv == NS_BASE_STREAM_CLOSED) {
// Blindly seek to the current position if Tell() returns
// NS_BASE_STREAM_CLOSED.
// If nsIFileInputStream is closed in Read() due to CLOSE_ON_EOF flag,
// Seek() could reopen the file if REOPEN_ON_REWIND flag is set.
nsresult rvSeek = aSeekable->Seek(nsISeekableStream::NS_SEEK_CUR, 0);
if (NS_SUCCEEDED(rvSeek)) {
rv = aSeekable->Tell(aResult);
}
}
return rv;
}
nsMultiplexInputStream::nsMultiplexInputStream()
: mLock("nsMultiplexInputStream lock")
, mCurrentStream(0)
, mStartedReadingCurrent(false)
, mStatus(NS_OK)
, mAsyncWaitFlags(0)
, mAsyncWaitRequestedCount(0)
, mSeekableStreams(0)
, mIPCSerializableStreams(0)
, mCloneableStreams(0)
, mAsyncInputStreams(0)
{}
NS_IMETHODIMP
nsMultiplexInputStream::GetCount(uint32_t* aCount)
{
MutexAutoLock lock(mLock);
*aCount = mStreams.Length();
return NS_OK;
}
NS_IMETHODIMP
nsMultiplexInputStream::AppendStream(nsIInputStream* aStream)
{
MutexAutoLock lock(mLock);
StreamData* streamData = mStreams.AppendElement();
if (NS_WARN_IF(!streamData)) {
return NS_ERROR_OUT_OF_MEMORY;
}
streamData->Initialize(aStream);
UpdateQIMap(*streamData, 1);
if (mStatus == NS_BASE_STREAM_CLOSED) {
// We were closed, but now we have more data to read.
mStatus = NS_OK;
}
return NS_OK;
}
NS_IMETHODIMP
nsMultiplexInputStream::GetStream(uint32_t aIndex, nsIInputStream** aResult)
{
MutexAutoLock lock(mLock);
if (aIndex >= mStreams.Length()) {
return NS_ERROR_NOT_AVAILABLE;
}
StreamData& streamData = mStreams.ElementAt(aIndex);
nsCOMPtr<nsIInputStream> stream = streamData.mStream;
stream.forget(aResult);
return NS_OK;
}
NS_IMETHODIMP
nsMultiplexInputStream::Close()
{
nsTArray<nsCOMPtr<nsIInputStream>> streams;
// Let's take a copy of the streams becuase, calling close() it could trigger
// a nsIInputStreamCallback immediately and we don't want to create a deadlock
// with mutex.
{
MutexAutoLock lock(mLock);
uint32_t len = mStreams.Length();
for (uint32_t i = 0; i < len; ++i) {
streams.AppendElement(mStreams[i].mStream);
}
mStatus = NS_BASE_STREAM_CLOSED;
}
nsresult rv = NS_OK;
uint32_t len = streams.Length();
for (uint32_t i = 0; i < len; ++i) {
nsresult rv2 = streams[i]->Close();
// We still want to close all streams, but we should return an error
if (NS_FAILED(rv2)) {
rv = rv2;
}
}
return rv;
}
NS_IMETHODIMP
nsMultiplexInputStream::Available(uint64_t* aResult)
{
*aResult = 0;
MutexAutoLock lock(mLock);
if (NS_FAILED(mStatus)) {
return mStatus;
}
uint64_t avail = 0;
nsresult rv = NS_BASE_STREAM_CLOSED;
uint32_t len = mStreams.Length();
for (uint32_t i = mCurrentStream; i < len; i++) {
uint64_t streamAvail;
rv = AvailableMaybeSeek(mStreams[i], &streamAvail);
if (rv == NS_BASE_STREAM_CLOSED) {
// If a stream is closed, we continue with the next one.
// If this is the current stream we move to the following stream.
if (mCurrentStream == i) {
++mCurrentStream;
}
// If this is the last stream, we want to return this error code.
continue;
}
if (NS_WARN_IF(NS_FAILED(rv))) {
mStatus = rv;
return mStatus;
}
// If the current stream is async, we have to return what we have so far
// without processing the following streams. This is needed because
// ::Available should return only what is currently available. In case of an
// nsIAsyncInputStream, we have to call AsyncWait() in order to read more.
if (mStreams[i].mAsyncStream) {
avail += streamAvail;
break;
}
if (streamAvail == 0) {
// Nothing to read for this stream. Let's move to the next one.
continue;
}
avail += streamAvail;
}
// We still have something to read. We don't want to return an error code yet.
if (avail) {
*aResult = avail;
return NS_OK;
}
// Let's propagate the last error message.
mStatus = rv;
return rv;
}
NS_IMETHODIMP
nsMultiplexInputStream::Read(char* aBuf, uint32_t aCount, uint32_t* aResult)
{
MutexAutoLock lock(mLock);
// It is tempting to implement this method in terms of ReadSegments, but
// that would prevent this class from being used with streams that only
// implement Read (e.g., file streams).
*aResult = 0;
if (mStatus == NS_BASE_STREAM_CLOSED) {
return NS_OK;
}
if (NS_FAILED(mStatus)) {
return mStatus;
}
nsresult rv = NS_OK;
uint32_t len = mStreams.Length();
while (mCurrentStream < len && aCount) {
uint32_t read;
rv = mStreams[mCurrentStream].mStream->Read(aBuf, aCount, &read);
// XXX some streams return NS_BASE_STREAM_CLOSED to indicate EOF.
// (This is a bug in those stream implementations)
if (rv == NS_BASE_STREAM_CLOSED) {
NS_NOTREACHED("Input stream's Read method returned NS_BASE_STREAM_CLOSED");
rv = NS_OK;
read = 0;
} else if (NS_FAILED(rv)) {
break;
}
if (read == 0) {
++mCurrentStream;
mStartedReadingCurrent = false;
} else {
NS_ASSERTION(aCount >= read, "Read more than requested");
*aResult += read;
aCount -= read;
aBuf += read;
mStartedReadingCurrent = true;
}
}
return *aResult ? NS_OK : rv;
}
NS_IMETHODIMP
nsMultiplexInputStream::ReadSegments(nsWriteSegmentFun aWriter, void* aClosure,
uint32_t aCount, uint32_t* aResult)
{
MutexAutoLock lock(mLock);
if (mStatus == NS_BASE_STREAM_CLOSED) {
*aResult = 0;
return NS_OK;
}
if (NS_FAILED(mStatus)) {
return mStatus;
}
NS_ASSERTION(aWriter, "missing aWriter");
nsresult rv = NS_OK;
ReadSegmentsState state;
state.mThisStream = this;
state.mOffset = 0;
state.mWriter = aWriter;
state.mClosure = aClosure;
state.mDone = false;
uint32_t len = mStreams.Length();
while (mCurrentStream < len && aCount) {
uint32_t read;
rv = mStreams[mCurrentStream].mStream->ReadSegments(ReadSegCb, &state,
aCount, &read);
// XXX some streams return NS_BASE_STREAM_CLOSED to indicate EOF.
// (This is a bug in those stream implementations)
if (rv == NS_BASE_STREAM_CLOSED) {
NS_NOTREACHED("Input stream's Read method returned NS_BASE_STREAM_CLOSED");
rv = NS_OK;
read = 0;
}
// if |aWriter| decided to stop reading segments...
if (state.mDone || NS_FAILED(rv)) {
break;
}
// if stream is empty, then advance to the next stream.
if (read == 0) {
++mCurrentStream;
mStartedReadingCurrent = false;
} else {
NS_ASSERTION(aCount >= read, "Read more than requested");
state.mOffset += read;
aCount -= read;
mStartedReadingCurrent = true;
}
}
// if we successfully read some data, then this call succeeded.
*aResult = state.mOffset;
return state.mOffset ? NS_OK : rv;
}
nsresult
nsMultiplexInputStream::ReadSegCb(nsIInputStream* aIn, void* aClosure,
const char* aFromRawSegment,
uint32_t aToOffset, uint32_t aCount,
uint32_t* aWriteCount)
{
nsresult rv;
ReadSegmentsState* state = (ReadSegmentsState*)aClosure;
rv = (state->mWriter)(state->mThisStream,
state->mClosure,
aFromRawSegment,
aToOffset + state->mOffset,
aCount,
aWriteCount);
if (NS_FAILED(rv)) {
state->mDone = true;
}
return rv;
}
NS_IMETHODIMP
nsMultiplexInputStream::IsNonBlocking(bool* aNonBlocking)
{
MutexAutoLock lock(mLock);
uint32_t len = mStreams.Length();
if (len == 0) {
// Claim to be non-blocking, since we won't block the caller.
*aNonBlocking = true;
return NS_OK;
}
for (uint32_t i = 0; i < len; ++i) {
nsresult rv = mStreams[i].mStream->IsNonBlocking(aNonBlocking);
if (NS_WARN_IF(NS_FAILED(rv))) {
return rv;
}
// If one is blocking the entire stream becomes blocking.
if (!*aNonBlocking) {
return NS_OK;
}
}
return NS_OK;
}
NS_IMETHODIMP
nsMultiplexInputStream::Seek(int32_t aWhence, int64_t aOffset)
{
MutexAutoLock lock(mLock);
if (NS_FAILED(mStatus)) {
return mStatus;
}
nsresult rv;
uint32_t oldCurrentStream = mCurrentStream;
bool oldStartedReadingCurrent = mStartedReadingCurrent;
if (aWhence == NS_SEEK_SET) {
int64_t remaining = aOffset;
if (aOffset == 0) {
mCurrentStream = 0;
}
for (uint32_t i = 0; i < mStreams.Length(); ++i) {
nsCOMPtr<nsISeekableStream> stream = mStreams[i].mSeekableStream;
if (!stream) {
return NS_ERROR_FAILURE;
}
// See if all remaining streams should be rewound
if (remaining == 0) {
if (i < oldCurrentStream ||
(i == oldCurrentStream && oldStartedReadingCurrent)) {
rv = stream->Seek(NS_SEEK_SET, 0);
if (NS_WARN_IF(NS_FAILED(rv))) {
return rv;
}
continue;
} else {
break;
}
}
// Get position in current stream
int64_t streamPos;
if (i > oldCurrentStream ||
(i == oldCurrentStream && !oldStartedReadingCurrent)) {
streamPos = 0;
} else {
rv = TellMaybeSeek(stream, &streamPos);
if (NS_WARN_IF(NS_FAILED(rv))) {
return rv;
}
}
// See if we need to seek current stream forward or backward
if (remaining < streamPos) {
rv = stream->Seek(NS_SEEK_SET, remaining);
if (NS_WARN_IF(NS_FAILED(rv))) {
return rv;
}
mCurrentStream = i;
mStartedReadingCurrent = remaining != 0;
remaining = 0;
} else if (remaining > streamPos) {
if (i < oldCurrentStream) {
// We're already at end so no need to seek this stream
remaining -= streamPos;
NS_ASSERTION(remaining >= 0, "Remaining invalid");
} else {
uint64_t avail;
rv = AvailableMaybeSeek(mStreams[i], &avail);
if (NS_WARN_IF(NS_FAILED(rv))) {
return rv;
}
int64_t newPos = XPCOM_MIN(remaining, streamPos + (int64_t)avail);
rv = stream->Seek(NS_SEEK_SET, newPos);
if (NS_WARN_IF(NS_FAILED(rv))) {
return rv;
}
mCurrentStream = i;
mStartedReadingCurrent = true;
remaining -= newPos;
NS_ASSERTION(remaining >= 0, "Remaining invalid");
}
} else {
NS_ASSERTION(remaining == streamPos, "Huh?");
MOZ_ASSERT(remaining != 0, "Zero remaining should be handled earlier");
remaining = 0;
mCurrentStream = i;
mStartedReadingCurrent = true;
}
}
return NS_OK;
}
if (aWhence == NS_SEEK_CUR && aOffset > 0) {
int64_t remaining = aOffset;
for (uint32_t i = mCurrentStream; remaining && i < mStreams.Length(); ++i) {
uint64_t avail;
rv = AvailableMaybeSeek(mStreams[i], &avail);
if (NS_WARN_IF(NS_FAILED(rv))) {
return rv;
}
int64_t seek = XPCOM_MIN((int64_t)avail, remaining);
rv = mStreams[i].mSeekableStream->Seek(NS_SEEK_CUR, seek);
if (NS_WARN_IF(NS_FAILED(rv))) {
return rv;
}
mCurrentStream = i;
mStartedReadingCurrent = true;
remaining -= seek;
}
return NS_OK;
}
if (aWhence == NS_SEEK_CUR && aOffset < 0) {
int64_t remaining = -aOffset;
for (uint32_t i = mCurrentStream; remaining && i != (uint32_t)-1; --i) {
int64_t pos;
rv = TellMaybeSeek(mStreams[i].mSeekableStream, &pos);
if (NS_WARN_IF(NS_FAILED(rv))) {
return rv;
}
int64_t seek = XPCOM_MIN(pos, remaining);
rv = mStreams[i].mSeekableStream->Seek(NS_SEEK_CUR, -seek);
if (NS_WARN_IF(NS_FAILED(rv))) {
return rv;
}
mCurrentStream = i;
mStartedReadingCurrent = seek != -pos;
remaining -= seek;
}
return NS_OK;
}
if (aWhence == NS_SEEK_CUR) {
NS_ASSERTION(aOffset == 0, "Should have handled all non-zero values");
return NS_OK;
}
if (aWhence == NS_SEEK_END) {
if (aOffset > 0) {
return NS_ERROR_INVALID_ARG;
}
int64_t remaining = aOffset;
for (uint32_t i = mStreams.Length() - 1; i != (uint32_t)-1; --i) {
nsCOMPtr<nsISeekableStream> stream = mStreams[i].mSeekableStream;
// See if all remaining streams should be seeked to end
if (remaining == 0) {
if (i >= oldCurrentStream) {
rv = stream->Seek(NS_SEEK_END, 0);
if (NS_WARN_IF(NS_FAILED(rv))) {
return rv;
}
} else {
break;
}
}
// Get position in current stream
int64_t streamPos;
if (i < oldCurrentStream) {
streamPos = 0;
} else {
uint64_t avail;
rv = AvailableMaybeSeek(mStreams[i], &avail);
if (NS_WARN_IF(NS_FAILED(rv))) {
return rv;
}
streamPos = avail;
}
// See if we have enough data in the current stream.
if (DeprecatedAbs(remaining) < streamPos) {
rv = stream->Seek(NS_SEEK_END, remaining);
if (NS_WARN_IF(NS_FAILED(rv))) {
return rv;
}
mCurrentStream = i;
mStartedReadingCurrent = true;
remaining = 0;
} else if (DeprecatedAbs(remaining) > streamPos) {
if (i > oldCurrentStream ||
(i == oldCurrentStream && !oldStartedReadingCurrent)) {
// We're already at start so no need to seek this stream
remaining += streamPos;
} else {
int64_t avail;
rv = TellMaybeSeek(stream, &avail);
if (NS_WARN_IF(NS_FAILED(rv))) {
return rv;
}
int64_t newPos = streamPos + XPCOM_MIN(avail, DeprecatedAbs(remaining));
rv = stream->Seek(NS_SEEK_END, -newPos);
if (NS_WARN_IF(NS_FAILED(rv))) {
return rv;
}
mCurrentStream = i;
mStartedReadingCurrent = true;
remaining += newPos;
}
} else {
NS_ASSERTION(remaining == streamPos, "Huh?");
remaining = 0;
}
}
return NS_OK;
}
// other Seeks not implemented yet
return NS_ERROR_NOT_IMPLEMENTED;
}
NS_IMETHODIMP
nsMultiplexInputStream::Tell(int64_t* aResult)
{
MutexAutoLock lock(mLock);
if (NS_FAILED(mStatus)) {
return mStatus;
}
nsresult rv;
int64_t ret64 = 0;
uint32_t i, last;
last = mStartedReadingCurrent ? mCurrentStream + 1 : mCurrentStream;
for (i = 0; i < last; ++i) {
if (NS_WARN_IF(!mStreams[i].mSeekableStream)) {
return NS_ERROR_NO_INTERFACE;
}
int64_t pos;
rv = TellMaybeSeek(mStreams[i].mSeekableStream, &pos);
if (NS_WARN_IF(NS_FAILED(rv))) {
return rv;
}
ret64 += pos;
}
*aResult = ret64;
return NS_OK;
}
NS_IMETHODIMP
nsMultiplexInputStream::SetEOF()
{
return NS_ERROR_NOT_IMPLEMENTED;
}
NS_IMETHODIMP
nsMultiplexInputStream::CloseWithStatus(nsresult aStatus)
{
return Close();
}
// This class is used to inform nsMultiplexInputStream that it's time to execute
// the asyncWait callback.
class AsyncWaitRunnable final : public CancelableRunnable
{
RefPtr<nsMultiplexInputStream> mStream;
public:
static void
Create(nsMultiplexInputStream* aStream, nsIEventTarget* aEventTarget)
{
RefPtr<AsyncWaitRunnable> runnable = new AsyncWaitRunnable(aStream);
if (aEventTarget) {
aEventTarget->Dispatch(runnable.forget(), NS_DISPATCH_NORMAL);
} else {
runnable->Run();
}
}
NS_IMETHOD
Run() override
{
mStream->AsyncWaitCompleted();
return NS_OK;
}
private:
explicit AsyncWaitRunnable(nsMultiplexInputStream* aStream)
: CancelableRunnable("AsyncWaitRunnable")
, mStream(aStream)
{
MOZ_ASSERT(aStream);
}
};
NS_IMETHODIMP
nsMultiplexInputStream::AsyncWait(nsIInputStreamCallback* aCallback,
uint32_t aFlags,
uint32_t aRequestedCount,
nsIEventTarget* aEventTarget)
{
{
MutexAutoLock lock(mLock);
// We must execute the callback also when the stream is closed.
if (NS_FAILED(mStatus) && mStatus != NS_BASE_STREAM_CLOSED) {
return mStatus;
}
if (mAsyncWaitCallback && aCallback) {
return NS_ERROR_FAILURE;
}
mAsyncWaitCallback = aCallback;
mAsyncWaitFlags = aFlags;
mAsyncWaitRequestedCount = aRequestedCount;
mAsyncWaitEventTarget = aEventTarget;
if (!mAsyncWaitCallback) {
return NS_OK;
}
}
return AsyncWaitInternal();
}
nsresult
nsMultiplexInputStream::AsyncWaitInternal()
{
nsCOMPtr<nsIAsyncInputStream> stream;
uint32_t asyncWaitFlags = 0;
uint32_t asyncWaitRequestedCount = 0;
nsCOMPtr<nsIEventTarget> asyncWaitEventTarget;
{
MutexAutoLock lock(mLock);
// Let's take the first async stream if we are not already closed, and if
// it has data to read or if it async.
if (mStatus != NS_BASE_STREAM_CLOSED) {
for (; mCurrentStream < mStreams.Length(); ++mCurrentStream) {
stream = mStreams[mCurrentStream].mAsyncStream;
if (stream) {
break;
}
uint64_t avail = 0;
nsresult rv = AvailableMaybeSeek(mStreams[mCurrentStream], &avail);
if (rv == NS_BASE_STREAM_CLOSED || (NS_SUCCEEDED(rv) && avail == 0)) {
// Nothing to read here. Let's move on.
continue;
}
if (NS_FAILED(rv)) {
return rv;
}
break;
}
}
asyncWaitFlags = mAsyncWaitFlags;
asyncWaitRequestedCount = mAsyncWaitRequestedCount;
asyncWaitEventTarget = mAsyncWaitEventTarget;
}
MOZ_ASSERT_IF(stream, NS_SUCCEEDED(mStatus));
// If we are here it's because we are already closed, or if the current stream
// is not async. In both case we have to execute the callback.
if (!stream) {
AsyncWaitRunnable::Create(this, asyncWaitEventTarget);
return NS_OK;
}
return stream->AsyncWait(this, asyncWaitFlags, asyncWaitRequestedCount,
asyncWaitEventTarget);
}
NS_IMETHODIMP
nsMultiplexInputStream::OnInputStreamReady(nsIAsyncInputStream* aStream)
{
nsCOMPtr<nsIInputStreamCallback> callback;
// When OnInputStreamReady is called, we could be in 2 scenarios:
// a. there is something to read;
// b. the stream is closed.
// But if the stream is closed and it was not the last one, we must proceed
// with the following stream in order to have something to read by the callee.
{
MutexAutoLock lock(mLock);
// The callback has been nullified in the meantime.
if (!mAsyncWaitCallback) {
return NS_OK;
}
if (NS_SUCCEEDED(mStatus)) {
uint64_t avail = 0;
nsresult rv = aStream->Available(&avail);
if (rv == NS_BASE_STREAM_CLOSED || avail == 0) {
// This stream is closed or empty, let's move to the following one.
++mCurrentStream;
MutexAutoUnlock unlock(mLock);
return AsyncWaitInternal();
}
}
mAsyncWaitCallback.swap(callback);
mAsyncWaitEventTarget = nullptr;
}
return callback->OnInputStreamReady(this);
}
void
nsMultiplexInputStream::AsyncWaitCompleted()
{
nsCOMPtr<nsIInputStreamCallback> callback;
{
MutexAutoLock lock(mLock);
// The callback has been nullified in the meantime.
if (!mAsyncWaitCallback) {
return;
}
mAsyncWaitCallback.swap(callback);
mAsyncWaitEventTarget = nullptr;
}
callback->OnInputStreamReady(this);
}
nsresult
nsMultiplexInputStreamConstructor(nsISupports* aOuter,
REFNSIID aIID,
void** aResult)
{
*aResult = nullptr;
if (aOuter) {
return NS_ERROR_NO_AGGREGATION;
}
RefPtr<nsMultiplexInputStream> inst = new nsMultiplexInputStream();
return inst->QueryInterface(aIID, aResult);
}
void
nsMultiplexInputStream::Serialize(InputStreamParams& aParams,
FileDescriptorArray& aFileDescriptors)
{
MutexAutoLock lock(mLock);
MultiplexInputStreamParams params;
uint32_t streamCount = mStreams.Length();
if (streamCount) {
InfallibleTArray<InputStreamParams>& streams = params.streams();
streams.SetCapacity(streamCount);
for (uint32_t index = 0; index < streamCount; index++) {
InputStreamParams childStreamParams;
InputStreamHelper::SerializeInputStream(mStreams[index].mStream,
childStreamParams,
aFileDescriptors);
streams.AppendElement(childStreamParams);
}
}
params.currentStream() = mCurrentStream;
params.status() = mStatus;
params.startedReadingCurrent() = mStartedReadingCurrent;
aParams = params;
}
bool
nsMultiplexInputStream::Deserialize(const InputStreamParams& aParams,
const FileDescriptorArray& aFileDescriptors)
{
if (aParams.type() !=
InputStreamParams::TMultiplexInputStreamParams) {
NS_ERROR("Received unknown parameters from the other process!");
return false;
}
const MultiplexInputStreamParams& params =
aParams.get_MultiplexInputStreamParams();
const InfallibleTArray<InputStreamParams>& streams = params.streams();
uint32_t streamCount = streams.Length();
for (uint32_t index = 0; index < streamCount; index++) {
nsCOMPtr<nsIInputStream> stream =
InputStreamHelper::DeserializeInputStream(streams[index],
aFileDescriptors);
if (!stream) {
NS_WARNING("Deserialize failed!");
return false;
}
if (NS_FAILED(AppendStream(stream))) {
NS_WARNING("AppendStream failed!");
return false;
}
}
mCurrentStream = params.currentStream();
mStatus = params.status();
mStartedReadingCurrent = params.startedReadingCurrent();
return true;
}
Maybe<uint64_t>
nsMultiplexInputStream::ExpectedSerializedLength()
{
MutexAutoLock lock(mLock);
bool lengthValueExists = false;
uint64_t expectedLength = 0;
uint32_t streamCount = mStreams.Length();
for (uint32_t index = 0; index < streamCount; index++) {
nsCOMPtr<nsIIPCSerializableInputStream> stream =
do_QueryInterface(mStreams[index].mStream);
if (!stream) {
continue;
}
Maybe<uint64_t> length = stream->ExpectedSerializedLength();
if (length.isNothing()) {
continue;
}
lengthValueExists = true;
expectedLength += length.value();
}
return lengthValueExists ? Some(expectedLength) : Nothing();
}
NS_IMETHODIMP
nsMultiplexInputStream::GetCloneable(bool* aCloneable)
{
MutexAutoLock lock(mLock);
//XXXnsm Cloning a multiplex stream which has started reading is not permitted
//right now.
if (mCurrentStream > 0 || mStartedReadingCurrent) {
*aCloneable = false;
return NS_OK;
}
uint32_t len = mStreams.Length();
for (uint32_t i = 0; i < len; ++i) {
nsCOMPtr<nsICloneableInputStream> cis =
do_QueryInterface(mStreams[i].mStream);
if (!cis || !cis->GetCloneable()) {
*aCloneable = false;
return NS_OK;
}
}
*aCloneable = true;
return NS_OK;
}
NS_IMETHODIMP
nsMultiplexInputStream::Clone(nsIInputStream** aClone)
{
MutexAutoLock lock(mLock);
//XXXnsm Cloning a multiplex stream which has started reading is not permitted
//right now.
if (mCurrentStream > 0 || mStartedReadingCurrent) {
return NS_ERROR_FAILURE;
}
RefPtr<nsMultiplexInputStream> clone = new nsMultiplexInputStream();
nsresult rv;
uint32_t len = mStreams.Length();
for (uint32_t i = 0; i < len; ++i) {
nsCOMPtr<nsICloneableInputStream> substream =
do_QueryInterface(mStreams[i].mStream);
if (NS_WARN_IF(!substream)) {
return NS_ERROR_FAILURE;
}
nsCOMPtr<nsIInputStream> clonedSubstream;
rv = substream->Clone(getter_AddRefs(clonedSubstream));
if (NS_WARN_IF(NS_FAILED(rv))) {
return rv;
}
rv = clone->AppendStream(clonedSubstream);
if (NS_WARN_IF(NS_FAILED(rv))) {
return rv;
}
}
clone.forget(aClone);
return NS_OK;
}
#define MAYBE_UPDATE_VALUE_REAL(x, y) \
if (y) { \
if (aCount == 1) { \
++x; \
} else if (x > 0) { \
--x; \
} else { \
MOZ_CRASH("A nsIInputStream changed QI map when stored in a nsMultiplexInputStream!"); \
} \
}
#define MAYBE_UPDATE_VALUE(x, y) \
{ \
nsCOMPtr<y> substream = do_QueryInterface(aStream.mStream); \
MAYBE_UPDATE_VALUE_REAL(x, substream) \
}
void
nsMultiplexInputStream::UpdateQIMap(StreamData& aStream, int32_t aCount)
{
MOZ_ASSERT(aCount == -1 || aCount == 1);
MAYBE_UPDATE_VALUE_REAL(mSeekableStreams, aStream.mSeekableStream)
MAYBE_UPDATE_VALUE(mIPCSerializableStreams, nsIIPCSerializableInputStream)
MAYBE_UPDATE_VALUE(mCloneableStreams, nsICloneableInputStream)
MAYBE_UPDATE_VALUE_REAL(mAsyncInputStreams, aStream.mAsyncStream)
}
#undef MAYBE_UPDATE_VALUE
bool
nsMultiplexInputStream::IsSeekable() const
{
return mStreams.Length() == mSeekableStreams;
}
bool
nsMultiplexInputStream::IsIPCSerializable() const
{
return mStreams.Length() == mIPCSerializableStreams;
}
bool
nsMultiplexInputStream::IsCloneable() const
{
return mStreams.Length() == mCloneableStreams;
}
bool
nsMultiplexInputStream::IsAsyncInputStream() const
{
// nsMultiplexInputStream is nsIAsyncInputStream if at least 1 of the
// substream implements that interface.
return !!mAsyncInputStreams;
}
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