diff options
Diffstat (limited to 'netwerk/base/nsBufferedStreams.cpp')
| -rw-r--r-- | netwerk/base/nsBufferedStreams.cpp | 1197 |
1 files changed, 1197 insertions, 0 deletions
diff --git a/netwerk/base/nsBufferedStreams.cpp b/netwerk/base/nsBufferedStreams.cpp new file mode 100644 index 0000000000..2606352cc4 --- /dev/null +++ b/netwerk/base/nsBufferedStreams.cpp @@ -0,0 +1,1197 @@ +/* -*- 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 "nsBufferedStreams.h" +#include "nsStreamUtils.h" +#include "nsNetCID.h" +#include "nsIClassInfoImpl.h" +#include "nsIEventTarget.h" +#include "nsThreadUtils.h" +#include "mozilla/DebugOnly.h" +#include "mozilla/ipc/InputStreamUtils.h" +#include <algorithm> + +#ifdef DEBUG_brendan +# define METERING +#endif + +#ifdef METERING +# include <stdio.h> +# define METER(x) x +# define MAX_BIG_SEEKS 20 + +static struct { + uint32_t mSeeksWithinBuffer; + uint32_t mSeeksOutsideBuffer; + uint32_t mBufferReadUponSeek; + uint32_t mBufferUnreadUponSeek; + uint32_t mBytesReadFromBuffer; + uint32_t mBigSeekIndex; + struct { + int64_t mOldOffset; + int64_t mNewOffset; + } mBigSeek[MAX_BIG_SEEKS]; +} bufstats; +#else +# define METER(x) /* nothing */ +#endif + +using namespace mozilla::ipc; +using namespace mozilla; + +//////////////////////////////////////////////////////////////////////////////// +// nsBufferedStream + +nsBufferedStream::~nsBufferedStream() { Close(); } + +NS_IMPL_ADDREF(nsBufferedStream) +NS_IMPL_RELEASE(nsBufferedStream) + +NS_INTERFACE_MAP_BEGIN(nsBufferedStream) + NS_INTERFACE_MAP_ENTRY(nsISupports) + NS_INTERFACE_MAP_ENTRY(nsITellableStream) + NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsISeekableStream, mSeekable) +NS_INTERFACE_MAP_END + +nsresult nsBufferedStream::Init(nsISupports* aStream, uint32_t bufferSize) { + NS_ASSERTION(aStream, "need to supply a stream"); + NS_ASSERTION(mStream == nullptr, "already inited"); + mStream = aStream; // we keep a reference until nsBufferedStream::Close + mBufferSize = bufferSize; + mBufferStartOffset = 0; + mCursor = 0; + nsCOMPtr<nsISeekableStream> seekable = do_QueryInterface(mStream); + mSeekable = seekable; + RecursiveMutexAutoLock lock(mBufferMutex); + mBuffer = new (mozilla::fallible) char[bufferSize]; + if (mBuffer == nullptr) { + return NS_ERROR_OUT_OF_MEMORY; + } + return NS_OK; +} + +void nsBufferedStream::Close() { + // Drop the reference from nsBufferedStream::Init() + mStream = nullptr; + RecursiveMutexAutoLock lock(mBufferMutex); + if (mBuffer) { + delete[] mBuffer; + mBuffer = nullptr; + mBufferSize = 0; + mBufferStartOffset = 0; + mCursor = 0; + mFillPoint = 0; + } +#ifdef METERING + { + static FILE* tfp; + if (!tfp) { + tfp = fopen("/tmp/bufstats", "w"); + if (tfp) { + setvbuf(tfp, nullptr, _IOLBF, 0); + } + } + if (tfp) { + fprintf(tfp, "seeks within buffer: %u\n", bufstats.mSeeksWithinBuffer); + fprintf(tfp, "seeks outside buffer: %u\n", + bufstats.mSeeksOutsideBuffer); + fprintf(tfp, "buffer read on seek: %u\n", + bufstats.mBufferReadUponSeek); + fprintf(tfp, "buffer unread on seek: %u\n", + bufstats.mBufferUnreadUponSeek); + fprintf(tfp, "bytes read from buffer: %u\n", + bufstats.mBytesReadFromBuffer); + for (uint32_t i = 0; i < bufstats.mBigSeekIndex; i++) { + fprintf(tfp, "bigseek[%u] = {old: %u, new: %u}\n", i, + bufstats.mBigSeek[i].mOldOffset, + bufstats.mBigSeek[i].mNewOffset); + } + } + } +#endif +} + +NS_IMETHODIMP +nsBufferedStream::Seek(int32_t whence, int64_t offset) { + if (mStream == nullptr) { + return NS_BASE_STREAM_CLOSED; + } + + // If the underlying stream isn't a random access store, then fail early. + // We could possibly succeed for the case where the seek position denotes + // something that happens to be read into the buffer, but that would make + // the failure data-dependent. + nsresult rv; + nsCOMPtr<nsISeekableStream> ras = do_QueryInterface(mStream, &rv); + if (NS_FAILED(rv)) { + NS_WARNING("mStream doesn't QI to nsISeekableStream"); + return rv; + } + + int64_t absPos = 0; + switch (whence) { + case nsISeekableStream::NS_SEEK_SET: + absPos = offset; + break; + case nsISeekableStream::NS_SEEK_CUR: + absPos = mBufferStartOffset; + absPos += mCursor; + absPos += offset; + break; + case nsISeekableStream::NS_SEEK_END: + absPos = -1; + break; + default: + MOZ_ASSERT_UNREACHABLE("bogus seek whence parameter"); + return NS_ERROR_UNEXPECTED; + } + + // Let mCursor point into the existing buffer if the new position is + // between the current cursor and the mFillPoint "fencepost" -- the + // client may never get around to a Read or Write after this Seek. + // Read and Write worry about flushing and filling in that event. + // But if we're at EOF, make sure to pass the seek through to the + // underlying stream, because it may have auto-closed itself and + // needs to reopen. + uint32_t offsetInBuffer = uint32_t(absPos - mBufferStartOffset); + if (offsetInBuffer <= mFillPoint && !mEOF) { + METER(bufstats.mSeeksWithinBuffer++); + mCursor = offsetInBuffer; + return NS_OK; + } + + METER(bufstats.mSeeksOutsideBuffer++); + METER(bufstats.mBufferReadUponSeek += mCursor); + METER(bufstats.mBufferUnreadUponSeek += mFillPoint - mCursor); + rv = Flush(); + if (NS_FAILED(rv)) { +#ifdef DEBUG + NS_WARNING( + "(debug) Flush returned error within nsBufferedStream::Seek, so we " + "exit early."); +#endif + return rv; + } + + rv = ras->Seek(whence, offset); + if (NS_FAILED(rv)) { +#ifdef DEBUG + NS_WARNING( + "(debug) Error: ras->Seek() returned error within " + "nsBufferedStream::Seek, so we exit early."); +#endif + return rv; + } + + mEOF = false; + + // Recompute whether the offset we're seeking to is in our buffer. + // Note that we need to recompute because Flush() might have + // changed mBufferStartOffset. + offsetInBuffer = uint32_t(absPos - mBufferStartOffset); + if (offsetInBuffer <= mFillPoint) { + // It's safe to just set mCursor to offsetInBuffer. In particular, we + // want to avoid calling Fill() here since we already have the data that + // was seeked to and calling Fill() might auto-close our underlying + // stream in some cases. + mCursor = offsetInBuffer; + return NS_OK; + } + + METER(if (bufstats.mBigSeekIndex < MAX_BIG_SEEKS) + bufstats.mBigSeek[bufstats.mBigSeekIndex] + .mOldOffset = mBufferStartOffset + int64_t(mCursor)); + const int64_t minus1 = -1; + if (absPos == minus1) { + // then we had the SEEK_END case, above + int64_t tellPos; + rv = ras->Tell(&tellPos); + mBufferStartOffset = tellPos; + if (NS_FAILED(rv)) { + return rv; + } + } else { + mBufferStartOffset = absPos; + } + METER(if (bufstats.mBigSeekIndex < MAX_BIG_SEEKS) + bufstats.mBigSeek[bufstats.mBigSeekIndex++] + .mNewOffset = mBufferStartOffset); + + mFillPoint = mCursor = 0; + + // If we seeked back to the start, then don't fill the buffer + // right now in case this is a lazily-opened file stream. + // We'll fill on the first read, like we did initially. + if (whence == nsISeekableStream::NS_SEEK_SET && offset == 0) { + return NS_OK; + } + return Fill(); +} + +NS_IMETHODIMP +nsBufferedStream::Tell(int64_t* result) { + if (mStream == nullptr) { + return NS_BASE_STREAM_CLOSED; + } + + int64_t result64 = mBufferStartOffset; + result64 += mCursor; + *result = result64; + return NS_OK; +} + +NS_IMETHODIMP +nsBufferedStream::SetEOF() { + if (mStream == nullptr) { + return NS_BASE_STREAM_CLOSED; + } + + nsresult rv; + nsCOMPtr<nsISeekableStream> ras = do_QueryInterface(mStream, &rv); + if (NS_FAILED(rv)) { + return rv; + } + + rv = ras->SetEOF(); + if (NS_SUCCEEDED(rv)) { + mEOF = true; + } + + return rv; +} + +nsresult nsBufferedStream::GetData(nsISupports** aResult) { + nsCOMPtr<nsISupports> stream(mStream); + stream.forget(aResult); + return NS_OK; +} + +//////////////////////////////////////////////////////////////////////////////// +// nsBufferedInputStream + +NS_IMPL_ADDREF_INHERITED(nsBufferedInputStream, nsBufferedStream) +NS_IMPL_RELEASE_INHERITED(nsBufferedInputStream, nsBufferedStream) + +NS_IMPL_CLASSINFO(nsBufferedInputStream, nullptr, nsIClassInfo::THREADSAFE, + NS_BUFFEREDINPUTSTREAM_CID) + +NS_INTERFACE_MAP_BEGIN(nsBufferedInputStream) + // Unfortunately there isn't a macro that combines ambiguous and conditional, + // and as far as I can tell, no other class would need such a macro. + if (mIsAsyncInputStream && aIID.Equals(NS_GET_IID(nsIInputStream))) { + foundInterface = + static_cast<nsIInputStream*>(static_cast<nsIAsyncInputStream*>(this)); + } else if (!mIsAsyncInputStream && aIID.Equals(NS_GET_IID(nsIInputStream))) { + foundInterface = static_cast<nsIInputStream*>( + static_cast<nsIBufferedInputStream*>(this)); + } else + NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIBufferedInputStream) + NS_INTERFACE_MAP_ENTRY(nsIBufferedInputStream) + NS_INTERFACE_MAP_ENTRY(nsIStreamBufferAccess) + NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIIPCSerializableInputStream, + mIsIPCSerializable) + NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIAsyncInputStream, mIsAsyncInputStream) + NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIInputStreamCallback, + mIsAsyncInputStream) + NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsICloneableInputStream, + mIsCloneableInputStream) + NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIInputStreamLength, mIsInputStreamLength) + NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIAsyncInputStreamLength, + mIsAsyncInputStreamLength) + NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIInputStreamLengthCallback, + mIsAsyncInputStreamLength) + NS_IMPL_QUERY_CLASSINFO(nsBufferedInputStream) +NS_INTERFACE_MAP_END_INHERITING(nsBufferedStream) + +NS_IMPL_CI_INTERFACE_GETTER(nsBufferedInputStream, nsIInputStream, + nsIBufferedInputStream, nsISeekableStream, + nsITellableStream, nsIStreamBufferAccess) + +nsresult nsBufferedInputStream::Create(REFNSIID aIID, void** aResult) { + RefPtr<nsBufferedInputStream> stream = new nsBufferedInputStream(); + return stream->QueryInterface(aIID, aResult); +} + +NS_IMETHODIMP +nsBufferedInputStream::Init(nsIInputStream* stream, uint32_t bufferSize) { + nsresult rv = nsBufferedStream::Init(stream, bufferSize); + NS_ENSURE_SUCCESS(rv, rv); + + { + nsCOMPtr<nsIIPCSerializableInputStream> stream = do_QueryInterface(mStream); + mIsIPCSerializable = !!stream; + } + + { + nsCOMPtr<nsIAsyncInputStream> stream = do_QueryInterface(mStream); + mIsAsyncInputStream = !!stream; + } + + { + nsCOMPtr<nsICloneableInputStream> stream = do_QueryInterface(mStream); + mIsCloneableInputStream = !!stream; + } + + { + nsCOMPtr<nsIInputStreamLength> stream = do_QueryInterface(mStream); + mIsInputStreamLength = !!stream; + } + + { + nsCOMPtr<nsIAsyncInputStreamLength> stream = do_QueryInterface(mStream); + mIsAsyncInputStreamLength = !!stream; + } + + return NS_OK; +} + +already_AddRefed<nsIInputStream> nsBufferedInputStream::GetInputStream() { + // A non-null mStream implies Init() has been called. + MOZ_ASSERT(mStream); + + nsIInputStream* out = nullptr; + DebugOnly<nsresult> rv = QueryInterface(NS_GET_IID(nsIInputStream), + reinterpret_cast<void**>(&out)); + MOZ_ASSERT(NS_SUCCEEDED(rv)); + MOZ_ASSERT(out); + + return already_AddRefed<nsIInputStream>(out); +} + +NS_IMETHODIMP +nsBufferedInputStream::Close() { + nsresult rv = NS_OK; + if (mStream) { + rv = Source()->Close(); + if (NS_FAILED(rv)) { + NS_WARNING( + "(debug) Error: Source()->Close() returned error in " + "bsBuffedInputStream::Close()."); + } + } + + nsBufferedStream::Close(); + return rv; +} + +NS_IMETHODIMP +nsBufferedInputStream::Available(uint64_t* result) { + *result = 0; + + if (!mStream) { + return NS_OK; + } + + uint64_t avail = mFillPoint - mCursor; + + uint64_t tmp; + nsresult rv = Source()->Available(&tmp); + if (NS_SUCCEEDED(rv)) { + avail += tmp; + } + + if (avail) { + *result = avail; + return NS_OK; + } + + return rv; +} + +NS_IMETHODIMP +nsBufferedInputStream::StreamStatus() { + if (!mStream) { + return NS_OK; + } + + if (mFillPoint - mCursor) { + return NS_OK; + } + + return Source()->StreamStatus(); +} + +NS_IMETHODIMP +nsBufferedInputStream::Read(char* buf, uint32_t count, uint32_t* result) { + if (mBufferDisabled) { + if (!mStream) { + *result = 0; + return NS_OK; + } + nsresult rv = Source()->Read(buf, count, result); + if (NS_SUCCEEDED(rv)) { + mBufferStartOffset += *result; // so nsBufferedStream::Tell works + if (*result == 0) { + mEOF = true; + } + } + return rv; + } + + return ReadSegments(NS_CopySegmentToBuffer, buf, count, result); +} + +NS_IMETHODIMP +nsBufferedInputStream::ReadSegments(nsWriteSegmentFun writer, void* closure, + uint32_t count, uint32_t* result) { + *result = 0; + + if (!mStream) { + return NS_OK; + } + + nsresult rv = NS_OK; + RecursiveMutexAutoLock lock(mBufferMutex); + while (count > 0) { + uint32_t amt = std::min(count, mFillPoint - mCursor); + if (amt > 0) { + uint32_t read = 0; + rv = writer(static_cast<nsIBufferedInputStream*>(this), closure, + mBuffer + mCursor, *result, amt, &read); + if (NS_FAILED(rv)) { + // errors returned from the writer end here! + rv = NS_OK; + break; + } + *result += read; + count -= read; + mCursor += read; + } else { + rv = Fill(); + if (rv == NS_BASE_STREAM_WOULD_BLOCK) { + break; + } + if (NS_FAILED(rv)) { + return rv; + } + if (mFillPoint == mCursor) { + break; + } + } + } + return (*result > 0) ? NS_OK : rv; +} + +NS_IMETHODIMP +nsBufferedInputStream::IsNonBlocking(bool* aNonBlocking) { + if (mStream) { + return Source()->IsNonBlocking(aNonBlocking); + } + return NS_ERROR_NOT_INITIALIZED; +} + +NS_IMETHODIMP +nsBufferedInputStream::Fill() { + if (mBufferDisabled) { + return NS_OK; + } + NS_ENSURE_TRUE(mStream, NS_ERROR_NOT_INITIALIZED); + + RecursiveMutexAutoLock lock(mBufferMutex); + + nsresult rv; + int32_t rem = int32_t(mFillPoint - mCursor); + if (rem > 0) { + // slide the remainder down to the start of the buffer + // |<------------->|<--rem-->|<--->| + // b c f s + memcpy(mBuffer, mBuffer + mCursor, rem); + } + mBufferStartOffset += mCursor; + mFillPoint = rem; + mCursor = 0; + + uint32_t amt; + rv = Source()->Read(mBuffer + mFillPoint, mBufferSize - mFillPoint, &amt); + if (NS_FAILED(rv)) { + return rv; + } + + if (amt == 0) { + mEOF = true; + } + + mFillPoint += amt; + return NS_OK; +} + +NS_IMETHODIMP_(char*) +nsBufferedInputStream::GetBuffer(uint32_t aLength, uint32_t aAlignMask) { + NS_ASSERTION(mGetBufferCount == 0, "nested GetBuffer!"); + if (mGetBufferCount != 0) { + return nullptr; + } + + if (mBufferDisabled) { + return nullptr; + } + + RecursiveMutexAutoLock lock(mBufferMutex); + char* buf = mBuffer + mCursor; + uint32_t rem = mFillPoint - mCursor; + if (rem == 0) { + if (NS_FAILED(Fill())) { + return nullptr; + } + buf = mBuffer + mCursor; + rem = mFillPoint - mCursor; + } + + uint32_t mod = (NS_PTR_TO_INT32(buf) & aAlignMask); + if (mod) { + uint32_t pad = aAlignMask + 1 - mod; + if (pad > rem) { + return nullptr; + } + + memset(buf, 0, pad); + mCursor += pad; + buf += pad; + rem -= pad; + } + + if (aLength > rem) { + return nullptr; + } + mGetBufferCount++; + return buf; +} + +NS_IMETHODIMP_(void) +nsBufferedInputStream::PutBuffer(char* aBuffer, uint32_t aLength) { + NS_ASSERTION(mGetBufferCount == 1, "stray PutBuffer!"); + if (--mGetBufferCount != 0) { + return; + } + + NS_ASSERTION(mCursor + aLength <= mFillPoint, "PutBuffer botch"); + mCursor += aLength; +} + +NS_IMETHODIMP +nsBufferedInputStream::DisableBuffering() { + NS_ASSERTION(!mBufferDisabled, "redundant call to DisableBuffering!"); + NS_ASSERTION(mGetBufferCount == 0, + "DisableBuffer call between GetBuffer and PutBuffer!"); + if (mGetBufferCount != 0) { + return NS_ERROR_UNEXPECTED; + } + + // Empty the buffer so nsBufferedStream::Tell works. + mBufferStartOffset += mCursor; + mFillPoint = mCursor = 0; + mBufferDisabled = true; + return NS_OK; +} + +NS_IMETHODIMP +nsBufferedInputStream::EnableBuffering() { + NS_ASSERTION(mBufferDisabled, "gratuitous call to EnableBuffering!"); + mBufferDisabled = false; + return NS_OK; +} + +NS_IMETHODIMP +nsBufferedInputStream::GetUnbufferedStream(nsISupports** aStream) { + // Empty the buffer so subsequent i/o trumps any buffered data. + mBufferStartOffset += mCursor; + mFillPoint = mCursor = 0; + + nsCOMPtr<nsISupports> stream = mStream; + stream.forget(aStream); + return NS_OK; +} + +void nsBufferedInputStream::SerializedComplexity(uint32_t aMaxSize, + uint32_t* aSizeUsed, + uint32_t* aPipes, + uint32_t* aTransferables) { + if (mStream) { + nsCOMPtr<nsIInputStream> stream = do_QueryInterface(mStream); + MOZ_ASSERT(stream); + + InputStreamHelper::SerializedComplexity(stream, aMaxSize, aSizeUsed, aPipes, + aTransferables); + } +} + +void nsBufferedInputStream::Serialize(InputStreamParams& aParams, + uint32_t aMaxSize, uint32_t* aSizeUsed) { + MOZ_ASSERT(aSizeUsed); + *aSizeUsed = 0; + + BufferedInputStreamParams params; + + if (mStream) { + nsCOMPtr<nsIInputStream> stream = do_QueryInterface(mStream); + MOZ_ASSERT(stream); + + InputStreamParams wrappedParams; + InputStreamHelper::SerializeInputStream(stream, wrappedParams, aMaxSize, + aSizeUsed); + + params.optionalStream().emplace(wrappedParams); + } + + params.bufferSize() = mBufferSize; + + aParams = params; +} + +bool nsBufferedInputStream::Deserialize(const InputStreamParams& aParams) { + if (aParams.type() != InputStreamParams::TBufferedInputStreamParams) { + NS_ERROR("Received unknown parameters from the other process!"); + return false; + } + + const BufferedInputStreamParams& params = + aParams.get_BufferedInputStreamParams(); + const Maybe<InputStreamParams>& wrappedParams = params.optionalStream(); + + nsCOMPtr<nsIInputStream> stream; + if (wrappedParams.isSome()) { + stream = InputStreamHelper::DeserializeInputStream(wrappedParams.ref()); + if (!stream) { + NS_WARNING("Failed to deserialize wrapped stream!"); + return false; + } + } + + nsresult rv = Init(stream, params.bufferSize()); + NS_ENSURE_SUCCESS(rv, false); + + return true; +} + +NS_IMETHODIMP +nsBufferedInputStream::CloseWithStatus(nsresult aStatus) { return Close(); } + +NS_IMETHODIMP +nsBufferedInputStream::AsyncWait(nsIInputStreamCallback* aCallback, + uint32_t aFlags, uint32_t aRequestedCount, + nsIEventTarget* aEventTarget) { + nsCOMPtr<nsIAsyncInputStream> stream = do_QueryInterface(mStream); + if (!stream) { + // Stream is probably closed. Callback, if not nullptr, can be executed + // immediately + if (!aCallback) { + return NS_OK; + } + + if (aEventTarget) { + nsCOMPtr<nsIInputStreamCallback> callable = NS_NewInputStreamReadyEvent( + "nsBufferedInputStream::OnInputStreamReady", aCallback, aEventTarget); + return callable->OnInputStreamReady(this); + } + + aCallback->OnInputStreamReady(this); + return NS_OK; + } + + nsCOMPtr<nsIInputStreamCallback> callback = aCallback ? this : nullptr; + { + MutexAutoLock lock(mMutex); + + if (NS_WARN_IF(mAsyncWaitCallback && aCallback && + mAsyncWaitCallback != aCallback)) { + return NS_ERROR_FAILURE; + } + + mAsyncWaitCallback = aCallback; + } + + return stream->AsyncWait(callback, aFlags, aRequestedCount, aEventTarget); +} + +NS_IMETHODIMP +nsBufferedInputStream::OnInputStreamReady(nsIAsyncInputStream* aStream) { + nsCOMPtr<nsIInputStreamCallback> callback; + { + MutexAutoLock lock(mMutex); + + // We have been canceled in the meanwhile. + if (!mAsyncWaitCallback) { + return NS_OK; + } + + callback.swap(mAsyncWaitCallback); + } + + MOZ_ASSERT(callback); + return callback->OnInputStreamReady(this); +} + +NS_IMETHODIMP +nsBufferedInputStream::GetData(nsIInputStream** aResult) { + nsCOMPtr<nsISupports> stream; + nsBufferedStream::GetData(getter_AddRefs(stream)); + nsCOMPtr<nsIInputStream> inputStream = do_QueryInterface(stream); + inputStream.forget(aResult); + return NS_OK; +} + +// nsICloneableInputStream interface + +NS_IMETHODIMP +nsBufferedInputStream::GetCloneable(bool* aCloneable) { + *aCloneable = false; + + RecursiveMutexAutoLock lock(mBufferMutex); + + // If we don't have the buffer, the inputStream has been already closed. + // If mBufferStartOffset is not 0, the stream has been seeked or read. + // In both case the cloning is not supported. + if (!mBuffer || mBufferStartOffset) { + return NS_OK; + } + + nsCOMPtr<nsICloneableInputStream> stream = do_QueryInterface(mStream); + + // GetCloneable is infallible. + NS_ENSURE_TRUE(stream, NS_OK); + + return stream->GetCloneable(aCloneable); +} + +NS_IMETHODIMP +nsBufferedInputStream::Clone(nsIInputStream** aResult) { + RecursiveMutexAutoLock lock(mBufferMutex); + + if (!mBuffer || mBufferStartOffset) { + return NS_ERROR_FAILURE; + } + + nsCOMPtr<nsICloneableInputStream> stream = do_QueryInterface(mStream); + NS_ENSURE_TRUE(stream, NS_ERROR_FAILURE); + + nsCOMPtr<nsIInputStream> clonedStream; + nsresult rv = stream->Clone(getter_AddRefs(clonedStream)); + NS_ENSURE_SUCCESS(rv, rv); + + nsCOMPtr<nsIBufferedInputStream> bis = new nsBufferedInputStream(); + rv = bis->Init(clonedStream, mBufferSize); + NS_ENSURE_SUCCESS(rv, rv); + + *aResult = + static_cast<nsBufferedInputStream*>(bis.get())->GetInputStream().take(); + + return NS_OK; +} + +// nsIInputStreamLength + +NS_IMETHODIMP +nsBufferedInputStream::Length(int64_t* aLength) { + nsCOMPtr<nsIInputStreamLength> stream = do_QueryInterface(mStream); + NS_ENSURE_TRUE(stream, NS_ERROR_FAILURE); + + return stream->Length(aLength); +} + +// nsIAsyncInputStreamLength + +NS_IMETHODIMP +nsBufferedInputStream::AsyncLengthWait(nsIInputStreamLengthCallback* aCallback, + nsIEventTarget* aEventTarget) { + nsCOMPtr<nsIAsyncInputStreamLength> stream = do_QueryInterface(mStream); + if (!stream) { + // Stream is probably closed. Callback, if not nullptr, can be executed + // immediately + if (aCallback) { + const RefPtr<nsBufferedInputStream> self = this; + const nsCOMPtr<nsIInputStreamLengthCallback> callback = aCallback; + nsCOMPtr<nsIRunnable> runnable = NS_NewRunnableFunction( + "nsBufferedInputStream::OnInputStreamLengthReady", + [self, callback] { callback->OnInputStreamLengthReady(self, -1); }); + + if (aEventTarget) { + aEventTarget->Dispatch(runnable, NS_DISPATCH_NORMAL); + } else { + runnable->Run(); + } + } + return NS_OK; + } + + nsCOMPtr<nsIInputStreamLengthCallback> callback = aCallback ? this : nullptr; + { + MutexAutoLock lock(mMutex); + mAsyncInputStreamLengthCallback = aCallback; + } + + MOZ_ASSERT(stream); + return stream->AsyncLengthWait(callback, aEventTarget); +} + +// nsIInputStreamLengthCallback + +NS_IMETHODIMP +nsBufferedInputStream::OnInputStreamLengthReady( + nsIAsyncInputStreamLength* aStream, int64_t aLength) { + nsCOMPtr<nsIInputStreamLengthCallback> callback; + { + MutexAutoLock lock(mMutex); + // We have been canceled in the meanwhile. + if (!mAsyncInputStreamLengthCallback) { + return NS_OK; + } + + callback.swap(mAsyncInputStreamLengthCallback); + } + + MOZ_ASSERT(callback); + return callback->OnInputStreamLengthReady(this, aLength); +} + +//////////////////////////////////////////////////////////////////////////////// +// nsBufferedOutputStream + +NS_IMPL_ADDREF_INHERITED(nsBufferedOutputStream, nsBufferedStream) +NS_IMPL_RELEASE_INHERITED(nsBufferedOutputStream, nsBufferedStream) +// This QI uses NS_INTERFACE_MAP_ENTRY_CONDITIONAL to check for +// non-nullness of mSafeStream. +NS_INTERFACE_MAP_BEGIN(nsBufferedOutputStream) + NS_INTERFACE_MAP_ENTRY(nsIOutputStream) + NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsISafeOutputStream, mSafeStream) + NS_INTERFACE_MAP_ENTRY(nsIBufferedOutputStream) + NS_INTERFACE_MAP_ENTRY(nsIStreamBufferAccess) +NS_INTERFACE_MAP_END_INHERITING(nsBufferedStream) + +nsresult nsBufferedOutputStream::Create(REFNSIID aIID, void** aResult) { + RefPtr<nsBufferedOutputStream> stream = new nsBufferedOutputStream(); + return stream->QueryInterface(aIID, aResult); +} + +NS_IMETHODIMP +nsBufferedOutputStream::Init(nsIOutputStream* stream, uint32_t bufferSize) { + // QI stream to an nsISafeOutputStream, to see if we should support it + mSafeStream = do_QueryInterface(stream); + + return nsBufferedStream::Init(stream, bufferSize); +} + +NS_IMETHODIMP +nsBufferedOutputStream::Close() { + if (!mStream) { + return NS_OK; + } + + nsresult rv1, rv2 = NS_OK; + + rv1 = Flush(); + +#ifdef DEBUG + if (NS_FAILED(rv1)) { + NS_WARNING( + "(debug) Flush() inside nsBufferedOutputStream::Close() returned error " + "(rv1)."); + } +#endif + + // If we fail to Flush all the data, then we close anyway and drop the + // remaining data in the buffer. We do this because it's what Unix does + // for fclose and close. However, we report the error from Flush anyway. + if (mStream) { + rv2 = Sink()->Close(); +#ifdef DEBUG + if (NS_FAILED(rv2)) { + NS_WARNING( + "(debug) Sink->Close() inside nsBufferedOutputStream::Close() " + "returned error (rv2)."); + } +#endif + } + nsBufferedStream::Close(); + + if (NS_FAILED(rv1)) { + return rv1; + } + if (NS_FAILED(rv2)) { + return rv2; + } + return NS_OK; +} + +NS_IMETHODIMP +nsBufferedOutputStream::StreamStatus() { + return mStream ? Sink()->StreamStatus() : NS_BASE_STREAM_CLOSED; +} + +NS_IMETHODIMP +nsBufferedOutputStream::Write(const char* buf, uint32_t count, + uint32_t* result) { + nsresult rv = NS_OK; + uint32_t written = 0; + *result = 0; + if (!mStream) { + // We special case this situation. + // We should catch the failure, NS_BASE_STREAM_CLOSED ASAP, here. + // If we don't, eventually Flush() is called in the while loop below + // after so many writes. + // However, Flush() returns NS_OK when mStream is null (!!), + // and we don't get a meaningful error, NS_BASE_STREAM_CLOSED, + // soon enough when we use buffered output. +#ifdef DEBUG + NS_WARNING( + "(info) nsBufferedOutputStream::Write returns NS_BASE_STREAM_CLOSED " + "immediately (mStream==null)."); +#endif + return NS_BASE_STREAM_CLOSED; + } + + RecursiveMutexAutoLock lock(mBufferMutex); + while (count > 0) { + uint32_t amt = std::min(count, mBufferSize - mCursor); + if (amt > 0) { + memcpy(mBuffer + mCursor, buf + written, amt); + written += amt; + count -= amt; + mCursor += amt; + if (mFillPoint < mCursor) mFillPoint = mCursor; + } else { + NS_ASSERTION(mFillPoint, "loop in nsBufferedOutputStream::Write!"); + rv = Flush(); + if (NS_FAILED(rv)) { +#ifdef DEBUG + NS_WARNING( + "(debug) Flush() returned error in nsBufferedOutputStream::Write."); +#endif + break; + } + } + } + *result = written; + return (written > 0) ? NS_OK : rv; +} + +NS_IMETHODIMP +nsBufferedOutputStream::Flush() { + nsresult rv; + uint32_t amt; + if (!mStream) { + // Stream already cancelled/flushed; probably because of previous error. + return NS_OK; + } + // optimize : some code within C-C needs to call Seek -> Flush() often. + if (mFillPoint == 0) { + return NS_OK; + } + RecursiveMutexAutoLock lock(mBufferMutex); + rv = Sink()->Write(mBuffer, mFillPoint, &amt); + if (NS_FAILED(rv)) { + return rv; + } + mBufferStartOffset += amt; + if (amt == mFillPoint) { + mFillPoint = mCursor = 0; + return NS_OK; // flushed everything + } + + // slide the remainder down to the start of the buffer + // |<-------------->|<---|----->| + // b a c s + uint32_t rem = mFillPoint - amt; + memmove(mBuffer, mBuffer + amt, rem); + mFillPoint = mCursor = rem; + return NS_ERROR_FAILURE; // didn't flush all +} + +// nsISafeOutputStream +NS_IMETHODIMP +nsBufferedOutputStream::Finish() { + // flush the stream, to write out any buffered data... + nsresult rv1 = nsBufferedOutputStream::Flush(); + nsresult rv2 = NS_OK; + + if (NS_FAILED(rv1)) { + NS_WARNING( + "(debug) nsBufferedOutputStream::Flush() failed in " + "nsBufferedOutputStream::Finish()! Possible dataloss."); + + rv2 = Sink()->Close(); + if (NS_FAILED(rv2)) { + NS_WARNING( + "(debug) Sink()->Close() failed in nsBufferedOutputStream::Finish()! " + "Possible dataloss."); + } + } else { + rv2 = mSafeStream->Finish(); + if (NS_FAILED(rv2)) { + NS_WARNING( + "(debug) mSafeStream->Finish() failed within " + "nsBufferedOutputStream::Flush()! Possible dataloss."); + } + } + + // ... and close the buffered stream, so any further attempts to flush/close + // the buffered stream won't cause errors. + nsBufferedStream::Close(); + + // We want to return the errors precisely from Finish() + // and mimick the existing error handling in + // nsBufferedOutputStream::Close() as reference. + + if (NS_FAILED(rv1)) { + return rv1; + } + if (NS_FAILED(rv2)) { + return rv2; + } + return NS_OK; +} + +NS_IMETHODIMP +nsBufferedOutputStream::WriteFrom(nsIInputStream* inStr, uint32_t count, + uint32_t* _retval) { + return WriteSegments(NS_CopyStreamToSegment, inStr, count, _retval); +} + +NS_IMETHODIMP +nsBufferedOutputStream::WriteSegments(nsReadSegmentFun reader, void* closure, + uint32_t count, uint32_t* _retval) { + *_retval = 0; + nsresult rv; + RecursiveMutexAutoLock lock(mBufferMutex); + while (count > 0) { + uint32_t left = std::min(count, mBufferSize - mCursor); + if (left == 0) { + rv = Flush(); + if (NS_FAILED(rv)) { + return (*_retval > 0) ? NS_OK : rv; + } + + continue; + } + + uint32_t read = 0; + rv = reader(this, closure, mBuffer + mCursor, *_retval, left, &read); + + if (NS_FAILED(rv)) { // If we have read some data, return ok + return (*_retval > 0) ? NS_OK : rv; + } + mCursor += read; + *_retval += read; + count -= read; + mFillPoint = std::max(mFillPoint, mCursor); + } + return NS_OK; +} + +NS_IMETHODIMP +nsBufferedOutputStream::IsNonBlocking(bool* aNonBlocking) { + if (mStream) { + return Sink()->IsNonBlocking(aNonBlocking); + } + return NS_ERROR_NOT_INITIALIZED; +} + +NS_IMETHODIMP_(char*) +nsBufferedOutputStream::GetBuffer(uint32_t aLength, uint32_t aAlignMask) { + NS_ASSERTION(mGetBufferCount == 0, "nested GetBuffer!"); + if (mGetBufferCount != 0) { + return nullptr; + } + + if (mBufferDisabled) { + return nullptr; + } + + RecursiveMutexAutoLock lock(mBufferMutex); + char* buf = mBuffer + mCursor; + uint32_t rem = mBufferSize - mCursor; + if (rem == 0) { + if (NS_FAILED(Flush())) { + return nullptr; + } + buf = mBuffer + mCursor; + rem = mBufferSize - mCursor; + } + + uint32_t mod = (NS_PTR_TO_INT32(buf) & aAlignMask); + if (mod) { + uint32_t pad = aAlignMask + 1 - mod; + if (pad > rem) { + return nullptr; + } + + memset(buf, 0, pad); + mCursor += pad; + buf += pad; + rem -= pad; + } + + if (aLength > rem) { + return nullptr; + } + mGetBufferCount++; + return buf; +} + +NS_IMETHODIMP_(void) +nsBufferedOutputStream::PutBuffer(char* aBuffer, uint32_t aLength) { + NS_ASSERTION(mGetBufferCount == 1, "stray PutBuffer!"); + if (--mGetBufferCount != 0) { + return; + } + + NS_ASSERTION(mCursor + aLength <= mBufferSize, "PutBuffer botch"); + mCursor += aLength; + if (mFillPoint < mCursor) { + mFillPoint = mCursor; + } +} + +NS_IMETHODIMP +nsBufferedOutputStream::DisableBuffering() { + NS_ASSERTION(!mBufferDisabled, "redundant call to DisableBuffering!"); + NS_ASSERTION(mGetBufferCount == 0, + "DisableBuffer call between GetBuffer and PutBuffer!"); + if (mGetBufferCount != 0) { + return NS_ERROR_UNEXPECTED; + } + + // Empty the buffer so nsBufferedStream::Tell works. + nsresult rv = Flush(); + if (NS_FAILED(rv)) { + return rv; + } + + mBufferDisabled = true; + return NS_OK; +} + +NS_IMETHODIMP +nsBufferedOutputStream::EnableBuffering() { + NS_ASSERTION(mBufferDisabled, "gratuitous call to EnableBuffering!"); + mBufferDisabled = false; + return NS_OK; +} + +NS_IMETHODIMP +nsBufferedOutputStream::GetUnbufferedStream(nsISupports** aStream) { + // Empty the buffer so subsequent i/o trumps any buffered data. + if (mFillPoint) { + nsresult rv = Flush(); + if (NS_FAILED(rv)) { + return rv; + } + } + + nsCOMPtr<nsISupports> stream = mStream; + stream.forget(aStream); + return NS_OK; +} + +NS_IMETHODIMP +nsBufferedOutputStream::GetData(nsIOutputStream** aResult) { + nsCOMPtr<nsISupports> stream; + nsBufferedStream::GetData(getter_AddRefs(stream)); + nsCOMPtr<nsIOutputStream> outputStream = do_QueryInterface(stream); + outputStream.forget(aResult); + return NS_OK; +} +#undef METER + +//////////////////////////////////////////////////////////////////////////////// |