gecko-dev/netwerk/cache2/CacheFileInputStream.cpp
2017-06-14 14:44:04 -07:00

725 lines
18 KiB
C++

/* 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 "CacheLog.h"
#include "CacheFileInputStream.h"
#include "CacheFile.h"
#include "nsStreamUtils.h"
#include "nsThreadUtils.h"
#include <algorithm>
namespace mozilla {
namespace net {
NS_IMPL_ADDREF(CacheFileInputStream)
NS_IMETHODIMP_(MozExternalRefCountType)
CacheFileInputStream::Release()
{
NS_PRECONDITION(0 != mRefCnt, "dup release");
nsrefcnt count = --mRefCnt;
NS_LOG_RELEASE(this, count, "CacheFileInputStream");
if (0 == count) {
mRefCnt = 1;
delete (this);
return 0;
}
if (count == 1) {
mFile->RemoveInput(this, mStatus);
}
return count;
}
NS_INTERFACE_MAP_BEGIN(CacheFileInputStream)
NS_INTERFACE_MAP_ENTRY(nsIInputStream)
NS_INTERFACE_MAP_ENTRY(nsIAsyncInputStream)
NS_INTERFACE_MAP_ENTRY(nsISeekableStream)
NS_INTERFACE_MAP_ENTRY(mozilla::net::CacheFileChunkListener)
NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIInputStream)
NS_INTERFACE_MAP_END_THREADSAFE
CacheFileInputStream::CacheFileInputStream(CacheFile *aFile,
nsISupports *aEntry,
bool aAlternativeData)
: mFile(aFile)
, mPos(0)
, mStatus(NS_OK)
, mClosed(false)
, mInReadSegments(false)
, mWaitingForUpdate(false)
, mAlternativeData(aAlternativeData)
, mListeningForChunk(-1)
, mCallbackFlags(0)
, mCacheEntryHandle(aEntry)
{
LOG(("CacheFileInputStream::CacheFileInputStream() [this=%p]", this));
if (mAlternativeData) {
mPos = mFile->mAltDataOffset;
}
}
CacheFileInputStream::~CacheFileInputStream()
{
LOG(("CacheFileInputStream::~CacheFileInputStream() [this=%p]", this));
MOZ_ASSERT(!mInReadSegments);
}
// nsIInputStream
NS_IMETHODIMP
CacheFileInputStream::Close()
{
LOG(("CacheFileInputStream::Close() [this=%p]", this));
return CloseWithStatus(NS_OK);
}
NS_IMETHODIMP
CacheFileInputStream::Available(uint64_t *_retval)
{
CacheFileAutoLock lock(mFile);
if (mClosed) {
LOG(("CacheFileInputStream::Available() - Stream is closed. [this=%p, "
"status=0x%08" PRIx32 "]", this, static_cast<uint32_t>(mStatus)));
return NS_FAILED(mStatus) ? mStatus : NS_BASE_STREAM_CLOSED;
}
EnsureCorrectChunk(false);
if (NS_FAILED(mStatus)) {
LOG(("CacheFileInputStream::Available() - EnsureCorrectChunk failed. "
"[this=%p, status=0x%08" PRIx32 "]", this, static_cast<uint32_t>(mStatus)));
return mStatus;
}
nsresult rv = NS_OK;
*_retval = 0;
if (mChunk) {
int64_t canRead = mFile->BytesFromChunk(mChunk->Index(), mAlternativeData);
canRead -= (mPos % kChunkSize);
if (canRead > 0) {
*_retval = canRead;
} else if (canRead == 0 && !mFile->OutputStreamExists(mAlternativeData)) {
rv = NS_BASE_STREAM_CLOSED;
}
}
LOG(("CacheFileInputStream::Available() [this=%p, retval=%" PRIu64 ", rv=0x%08" PRIx32 "]",
this, *_retval, static_cast<uint32_t>(rv)));
return rv;
}
NS_IMETHODIMP
CacheFileInputStream::Read(char *aBuf, uint32_t aCount, uint32_t *_retval)
{
LOG(("CacheFileInputStream::Read() [this=%p, count=%d]", this, aCount));
return ReadSegments(NS_CopySegmentToBuffer, aBuf, aCount, _retval);
}
NS_IMETHODIMP
CacheFileInputStream::ReadSegments(nsWriteSegmentFun aWriter, void *aClosure,
uint32_t aCount, uint32_t *_retval)
{
CacheFileAutoLock lock(mFile);
LOG(("CacheFileInputStream::ReadSegments() [this=%p, count=%d]",
this, aCount));
nsresult rv;
*_retval = 0;
if (mInReadSegments) {
LOG(("CacheFileInputStream::ReadSegments() - Cannot be called while the "
"stream is in ReadSegments!"));
return NS_ERROR_UNEXPECTED;
}
if (mClosed) {
LOG(("CacheFileInputStream::ReadSegments() - Stream is closed. [this=%p, "
"status=0x%08" PRIx32 "]", this, static_cast<uint32_t>(mStatus)));
if NS_FAILED(mStatus)
return mStatus;
return NS_OK;
}
EnsureCorrectChunk(false);
while (true) {
if (NS_FAILED(mStatus))
return mStatus;
if (!mChunk) {
if (mListeningForChunk == -1) {
return NS_OK;
} else {
return NS_BASE_STREAM_WOULD_BLOCK;
}
}
CacheFileChunkReadHandle hnd = mChunk->GetReadHandle();
int64_t canRead = CanRead(&hnd);
if (NS_FAILED(mStatus)) {
return mStatus;
}
if (canRead < 0) {
// file was truncated ???
MOZ_ASSERT(false, "SetEOF is currenty not implemented?!");
rv = NS_OK;
} else if (canRead > 0) {
uint32_t toRead = std::min(static_cast<uint32_t>(canRead), aCount);
uint32_t read;
const char *buf = hnd.Buf() + (mPos - hnd.Offset());
mInReadSegments = true;
lock.Unlock();
rv = aWriter(this, aClosure, buf, *_retval, toRead, &read);
lock.Lock();
mInReadSegments = false;
if (NS_SUCCEEDED(rv)) {
MOZ_ASSERT(read <= toRead,
"writer should not write more than we asked it to write");
*_retval += read;
mPos += read;
aCount -= read;
if (!mClosed) {
if (hnd.DataSize() != mChunk->DataSize()) {
// New data was written to this chunk while the lock was released.
continue;
}
// The last chunk is released after the caller closes this stream.
EnsureCorrectChunk(false);
if (mChunk && aCount) {
// We have the next chunk! Go on.
continue;
}
}
}
if (mClosed) {
// The stream was closed from aWriter, do the cleanup.
CleanUp();
}
rv = NS_OK;
} else {
if (mFile->OutputStreamExists(mAlternativeData)) {
rv = NS_BASE_STREAM_WOULD_BLOCK;
} else {
rv = NS_OK;
}
}
break;
}
LOG(("CacheFileInputStream::ReadSegments() [this=%p, rv=0x%08" PRIx32 ", retval=%d]",
this, static_cast<uint32_t>(rv), *_retval));
return rv;
}
NS_IMETHODIMP
CacheFileInputStream::IsNonBlocking(bool *_retval)
{
*_retval = true;
return NS_OK;
}
// nsIAsyncInputStream
NS_IMETHODIMP
CacheFileInputStream::CloseWithStatus(nsresult aStatus)
{
CacheFileAutoLock lock(mFile);
LOG(("CacheFileInputStream::CloseWithStatus() [this=%p, aStatus=0x%08" PRIx32 "]",
this, static_cast<uint32_t>(aStatus)));
return CloseWithStatusLocked(aStatus);
}
nsresult
CacheFileInputStream::CloseWithStatusLocked(nsresult aStatus)
{
LOG(("CacheFileInputStream::CloseWithStatusLocked() [this=%p, "
"aStatus=0x%08" PRIx32 "]", this, static_cast<uint32_t>(aStatus)));
if (mClosed) {
// We notify listener and null out mCallback immediately after closing
// the stream. If we're in ReadSegments we postpone notification until we
// step out from ReadSegments. So if the stream is already closed the
// following assertion must be true.
MOZ_ASSERT(!mCallback || mInReadSegments);
return NS_OK;
}
mClosed = true;
mStatus = NS_FAILED(aStatus) ? aStatus : NS_BASE_STREAM_CLOSED;
if (!mInReadSegments) {
CleanUp();
}
return NS_OK;
}
void
CacheFileInputStream::CleanUp()
{
MOZ_ASSERT(!mInReadSegments);
MOZ_ASSERT(mClosed);
if (mChunk) {
ReleaseChunk();
}
// TODO propagate error from input stream to other streams ???
MaybeNotifyListener();
mFile->ReleaseOutsideLock(mCacheEntryHandle.forget());
}
NS_IMETHODIMP
CacheFileInputStream::AsyncWait(nsIInputStreamCallback *aCallback,
uint32_t aFlags,
uint32_t aRequestedCount,
nsIEventTarget *aEventTarget)
{
CacheFileAutoLock lock(mFile);
LOG(("CacheFileInputStream::AsyncWait() [this=%p, callback=%p, flags=%d, "
"requestedCount=%d, eventTarget=%p]", this, aCallback, aFlags,
aRequestedCount, aEventTarget));
if (mInReadSegments) {
LOG(("CacheFileInputStream::AsyncWait() - Cannot be called while the stream"
" is in ReadSegments!"));
MOZ_ASSERT(false, "Unexpected call. If it's a valid usage implement it. "
"Otherwise fix the caller.");
return NS_ERROR_UNEXPECTED;
}
mCallback = aCallback;
mCallbackFlags = aFlags;
mCallbackTarget = aEventTarget;
if (!mCallback) {
if (mWaitingForUpdate) {
mChunk->CancelWait(this);
mWaitingForUpdate = false;
}
return NS_OK;
}
if (mClosed) {
NotifyListener();
return NS_OK;
}
EnsureCorrectChunk(false);
MaybeNotifyListener();
return NS_OK;
}
// nsISeekableStream
NS_IMETHODIMP
CacheFileInputStream::Seek(int32_t whence, int64_t offset)
{
CacheFileAutoLock lock(mFile);
LOG(("CacheFileInputStream::Seek() [this=%p, whence=%d, offset=%" PRId64 "]",
this, whence, offset));
if (mInReadSegments) {
LOG(("CacheFileInputStream::Seek() - Cannot be called while the stream is "
"in ReadSegments!"));
return NS_ERROR_UNEXPECTED;
}
if (mClosed) {
LOG(("CacheFileInputStream::Seek() - Stream is closed. [this=%p]", this));
return NS_BASE_STREAM_CLOSED;
}
int64_t newPos = offset;
switch (whence) {
case NS_SEEK_SET:
if (mAlternativeData) {
newPos += mFile->mAltDataOffset;
}
break;
case NS_SEEK_CUR:
newPos += mPos;
break;
case NS_SEEK_END:
if (mAlternativeData) {
newPos += mFile->mDataSize;
} else {
newPos += mFile->mAltDataOffset;
}
break;
default:
NS_ERROR("invalid whence");
return NS_ERROR_INVALID_ARG;
}
mPos = newPos;
EnsureCorrectChunk(false);
LOG(("CacheFileInputStream::Seek() [this=%p, pos=%" PRId64 "]", this, mPos));
return NS_OK;
}
NS_IMETHODIMP
CacheFileInputStream::Tell(int64_t *_retval)
{
CacheFileAutoLock lock(mFile);
if (mClosed) {
LOG(("CacheFileInputStream::Tell() - Stream is closed. [this=%p]", this));
return NS_BASE_STREAM_CLOSED;
}
*_retval = mPos;
if (mAlternativeData) {
*_retval -= mFile->mAltDataOffset;
}
LOG(("CacheFileInputStream::Tell() [this=%p, retval=%" PRId64 "]", this, *_retval));
return NS_OK;
}
NS_IMETHODIMP
CacheFileInputStream::SetEOF()
{
MOZ_ASSERT(false, "Don't call SetEOF on cache input stream");
return NS_ERROR_NOT_IMPLEMENTED;
}
// CacheFileChunkListener
nsresult
CacheFileInputStream::OnChunkRead(nsresult aResult, CacheFileChunk *aChunk)
{
MOZ_CRASH("CacheFileInputStream::OnChunkRead should not be called!");
return NS_ERROR_UNEXPECTED;
}
nsresult
CacheFileInputStream::OnChunkWritten(nsresult aResult, CacheFileChunk *aChunk)
{
MOZ_CRASH("CacheFileInputStream::OnChunkWritten should not be called!");
return NS_ERROR_UNEXPECTED;
}
nsresult
CacheFileInputStream::OnChunkAvailable(nsresult aResult, uint32_t aChunkIdx,
CacheFileChunk *aChunk)
{
CacheFileAutoLock lock(mFile);
LOG(("CacheFileInputStream::OnChunkAvailable() [this=%p, result=0x%08" PRIx32 ", "
"idx=%d, chunk=%p]", this, static_cast<uint32_t>(aResult), aChunkIdx, aChunk));
MOZ_ASSERT(mListeningForChunk != -1);
if (mListeningForChunk != static_cast<int64_t>(aChunkIdx)) {
// This is not a chunk that we're waiting for
LOG(("CacheFileInputStream::OnChunkAvailable() - Notification is for a "
"different chunk. [this=%p, listeningForChunk=%" PRId64 "]",
this, mListeningForChunk));
return NS_OK;
}
MOZ_ASSERT(!mChunk);
MOZ_ASSERT(!mWaitingForUpdate);
MOZ_ASSERT(!mInReadSegments);
mListeningForChunk = -1;
if (mClosed) {
MOZ_ASSERT(!mCallback);
LOG(("CacheFileInputStream::OnChunkAvailable() - Stream is closed, "
"ignoring notification. [this=%p]", this));
return NS_OK;
}
if (NS_SUCCEEDED(aResult)) {
mChunk = aChunk;
} else if (aResult != NS_ERROR_NOT_AVAILABLE) {
// Close the stream with error. The consumer will receive this error later
// in Read(), Available() etc. We need to handle NS_ERROR_NOT_AVAILABLE
// differently since it is returned when the requested chunk is not
// available and there is no writer that could create it, i.e. it means that
// we've reached the end of the file.
CloseWithStatusLocked(aResult);
return NS_OK;
}
MaybeNotifyListener();
return NS_OK;
}
nsresult
CacheFileInputStream::OnChunkUpdated(CacheFileChunk *aChunk)
{
CacheFileAutoLock lock(mFile);
LOG(("CacheFileInputStream::OnChunkUpdated() [this=%p, idx=%d]",
this, aChunk->Index()));
if (!mWaitingForUpdate) {
LOG(("CacheFileInputStream::OnChunkUpdated() - Ignoring notification since "
"mWaitingforUpdate == false. [this=%p]", this));
return NS_OK;
}
else {
mWaitingForUpdate = false;
}
MOZ_ASSERT(mChunk == aChunk);
MaybeNotifyListener();
return NS_OK;
}
void
CacheFileInputStream::ReleaseChunk()
{
mFile->AssertOwnsLock();
LOG(("CacheFileInputStream::ReleaseChunk() [this=%p, idx=%d]",
this, mChunk->Index()));
MOZ_ASSERT(!mInReadSegments);
if (mWaitingForUpdate) {
LOG(("CacheFileInputStream::ReleaseChunk() - Canceling waiting for update. "
"[this=%p]", this));
mChunk->CancelWait(this);
mWaitingForUpdate = false;
}
mFile->ReleaseOutsideLock(mChunk.forget());
}
void
CacheFileInputStream::EnsureCorrectChunk(bool aReleaseOnly)
{
mFile->AssertOwnsLock();
LOG(("CacheFileInputStream::EnsureCorrectChunk() [this=%p, releaseOnly=%d]",
this, aReleaseOnly));
nsresult rv;
uint32_t chunkIdx = mPos / kChunkSize;
if (mInReadSegments) {
// We must have correct chunk
MOZ_ASSERT(mChunk);
MOZ_ASSERT(mChunk->Index() == chunkIdx);
return;
}
if (mChunk) {
if (mChunk->Index() == chunkIdx) {
// we have a correct chunk
LOG(("CacheFileInputStream::EnsureCorrectChunk() - Have correct chunk "
"[this=%p, idx=%d]", this, chunkIdx));
return;
} else {
ReleaseChunk();
}
}
MOZ_ASSERT(!mWaitingForUpdate);
if (aReleaseOnly)
return;
if (mListeningForChunk == static_cast<int64_t>(chunkIdx)) {
// We're already waiting for this chunk
LOG(("CacheFileInputStream::EnsureCorrectChunk() - Already listening for "
"chunk %" PRId64 " [this=%p]", mListeningForChunk, this));
return;
}
rv = mFile->GetChunkLocked(chunkIdx, CacheFile::READER, this,
getter_AddRefs(mChunk));
if (NS_FAILED(rv)) {
LOG(("CacheFileInputStream::EnsureCorrectChunk() - GetChunkLocked failed. "
"[this=%p, idx=%d, rv=0x%08" PRIx32 "]", this, chunkIdx,
static_cast<uint32_t>(rv)));
if (rv != NS_ERROR_NOT_AVAILABLE) {
// Close the stream with error. The consumer will receive this error later
// in Read(), Available() etc. We need to handle NS_ERROR_NOT_AVAILABLE
// differently since it is returned when the requested chunk is not
// available and there is no writer that could create it, i.e. it means
// that we've reached the end of the file.
CloseWithStatusLocked(rv);
return;
}
} else if (!mChunk) {
mListeningForChunk = static_cast<int64_t>(chunkIdx);
}
MaybeNotifyListener();
}
int64_t
CacheFileInputStream::CanRead(CacheFileChunkReadHandle *aHandle)
{
mFile->AssertOwnsLock();
MOZ_ASSERT(mChunk);
MOZ_ASSERT(mPos / kChunkSize == mChunk->Index());
int64_t retval = aHandle->Offset() + aHandle->DataSize() - mPos;
if (retval <= 0 && NS_FAILED(mChunk->GetStatus())) {
CloseWithStatusLocked(mChunk->GetStatus());
}
LOG(("CacheFileInputStream::CanRead() [this=%p, canRead=%" PRId64 "]",
this, retval));
return retval;
}
void
CacheFileInputStream::NotifyListener()
{
mFile->AssertOwnsLock();
LOG(("CacheFileInputStream::NotifyListener() [this=%p]", this));
MOZ_ASSERT(mCallback);
MOZ_ASSERT(!mInReadSegments);
if (!mCallbackTarget) {
mCallbackTarget = CacheFileIOManager::IOTarget();
if (!mCallbackTarget) {
LOG(("CacheFileInputStream::NotifyListener() - Cannot get Cache I/O "
"thread! Using main thread for callback."));
mCallbackTarget = GetMainThreadEventTarget();
}
}
nsCOMPtr<nsIInputStreamCallback> asyncCallback =
NS_NewInputStreamReadyEvent("CacheFileInputStream::NotifyListener",
mCallback, mCallbackTarget);
mCallback = nullptr;
mCallbackTarget = nullptr;
asyncCallback->OnInputStreamReady(this);
}
void
CacheFileInputStream::MaybeNotifyListener()
{
mFile->AssertOwnsLock();
LOG(("CacheFileInputStream::MaybeNotifyListener() [this=%p, mCallback=%p, "
"mClosed=%d, mStatus=0x%08" PRIx32 ", mChunk=%p, mListeningForChunk=%" PRId64 ", "
"mWaitingForUpdate=%d]", this, mCallback.get(), mClosed,
static_cast<uint32_t>(mStatus), mChunk.get(), mListeningForChunk,
mWaitingForUpdate));
MOZ_ASSERT(!mInReadSegments);
if (!mCallback)
return;
if (mClosed || NS_FAILED(mStatus)) {
NotifyListener();
return;
}
if (!mChunk) {
if (mListeningForChunk == -1) {
// EOF, should we notify even if mCallbackFlags == WAIT_CLOSURE_ONLY ??
NotifyListener();
}
return;
}
MOZ_ASSERT(mPos / kChunkSize == mChunk->Index());
if (mWaitingForUpdate)
return;
CacheFileChunkReadHandle hnd = mChunk->GetReadHandle();
int64_t canRead = CanRead(&hnd);
if (NS_FAILED(mStatus)) {
// CanRead() called CloseWithStatusLocked() which called
// MaybeNotifyListener() so the listener was already notified. Stop here.
MOZ_ASSERT(!mCallback);
return;
}
if (canRead > 0) {
if (!(mCallbackFlags & WAIT_CLOSURE_ONLY))
NotifyListener();
}
else if (canRead == 0) {
if (!mFile->OutputStreamExists(mAlternativeData)) {
// EOF
NotifyListener();
}
else {
mChunk->WaitForUpdate(this);
mWaitingForUpdate = true;
}
}
else {
// Output have set EOF before mPos?
MOZ_ASSERT(false, "SetEOF is currenty not implemented?!");
NotifyListener();
}
}
// Memory reporting
size_t
CacheFileInputStream::SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const
{
// Everything the stream keeps a reference to is already reported somewhere else.
// mFile reports itself.
// mChunk reported as part of CacheFile.
// mCallback is usually CacheFile or a class that is reported elsewhere.
return mallocSizeOf(this);
}
} // namespace net
} // namespace mozilla