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gecko-dev/xpcom/io/nsPipe3.cpp

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/* 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 "mozilla/Attributes.h"
#include "mozilla/ReentrantMonitor.h"
#include "nsIPipe.h"
#include "nsIEventTarget.h"
#include "nsISeekableStream.h"
#include "nsIProgrammingLanguage.h"
#include "nsSegmentedBuffer.h"
#include "nsStreamUtils.h"
#include "nsCOMPtr.h"
#include "nsCRT.h"
#include "prlog.h"
#include "nsIClassInfoImpl.h"
#include "nsAlgorithm.h"
#include "nsMemory.h"
#include "nsIAsyncInputStream.h"
#include "nsIAsyncOutputStream.h"
using namespace mozilla;
#ifdef LOG
#undef LOG
#endif
#if defined(PR_LOGGING)
//
// set NSPR_LOG_MODULES=nsPipe:5
//
static PRLogModuleInfo *
GetPipeLog()
{
static PRLogModuleInfo *sLog;
if (!sLog)
sLog = PR_NewLogModule("nsPipe");
return sLog;
}
#define LOG(args) PR_LOG(GetPipeLog(), PR_LOG_DEBUG, args)
#else
#define LOG(args)
#endif
#define DEFAULT_SEGMENT_SIZE 4096
#define DEFAULT_SEGMENT_COUNT 16
class nsPipe;
class nsPipeEvents;
class nsPipeInputStream;
class nsPipeOutputStream;
//-----------------------------------------------------------------------------
// this class is used to delay notifications until the end of a particular
// scope. it helps avoid the complexity of issuing callbacks while inside
// a critical section.
class nsPipeEvents
{
public:
nsPipeEvents() { }
~nsPipeEvents();
inline void NotifyInputReady(nsIAsyncInputStream *stream,
nsIInputStreamCallback *callback)
{
NS_ASSERTION(!mInputCallback, "already have an input event");
mInputStream = stream;
mInputCallback = callback;
}
inline void NotifyOutputReady(nsIAsyncOutputStream *stream,
nsIOutputStreamCallback *callback)
{
NS_ASSERTION(!mOutputCallback, "already have an output event");
mOutputStream = stream;
mOutputCallback = callback;
}
private:
nsCOMPtr<nsIAsyncInputStream> mInputStream;
nsCOMPtr<nsIInputStreamCallback> mInputCallback;
nsCOMPtr<nsIAsyncOutputStream> mOutputStream;
nsCOMPtr<nsIOutputStreamCallback> mOutputCallback;
};
//-----------------------------------------------------------------------------
// the input end of a pipe (allocated as a member of the pipe).
class nsPipeInputStream : public nsIAsyncInputStream
, public nsISeekableStream
, public nsISearchableInputStream
, public nsIClassInfo
{
public:
// since this class will be allocated as a member of the pipe, we do not
// need our own ref count. instead, we share the lifetime (the ref count)
// of the entire pipe. this macro is just convenience since it does not
// declare a mRefCount variable; however, don't let the name fool you...
// we are not inheriting from nsPipe ;-)
NS_DECL_ISUPPORTS_INHERITED
NS_DECL_NSIINPUTSTREAM
NS_DECL_NSIASYNCINPUTSTREAM
NS_DECL_NSISEEKABLESTREAM
NS_DECL_NSISEARCHABLEINPUTSTREAM
NS_DECL_NSICLASSINFO
nsPipeInputStream(nsPipe *pipe)
: mPipe(pipe)
, mReaderRefCnt(0)
, mLogicalOffset(0)
, mBlocking(true)
, mBlocked(false)
, mAvailable(0)
, mCallbackFlags(0)
{ }
nsresult Fill();
void SetNonBlocking(bool aNonBlocking) { mBlocking = !aNonBlocking; }
uint32_t Available() { return mAvailable; }
void ReduceAvailable(uint32_t avail) { mAvailable -= avail; }
// synchronously wait for the pipe to become readable.
nsresult Wait();
// these functions return true to indicate that the pipe's monitor should
// be notified, to wake up a blocked reader if any.
bool OnInputReadable(uint32_t bytesWritten, nsPipeEvents &);
bool OnInputException(nsresult, nsPipeEvents &);
private:
nsPipe *mPipe;
// separate refcnt so that we know when to close the consumer
mozilla::ThreadSafeAutoRefCnt mReaderRefCnt;
int64_t mLogicalOffset;
bool mBlocking;
// these variables can only be accessed while inside the pipe's monitor
bool mBlocked;
uint32_t mAvailable;
nsCOMPtr<nsIInputStreamCallback> mCallback;
uint32_t mCallbackFlags;
};
//-----------------------------------------------------------------------------
// the output end of a pipe (allocated as a member of the pipe).
class nsPipeOutputStream : public nsIAsyncOutputStream
, public nsIClassInfo
{
public:
// since this class will be allocated as a member of the pipe, we do not
// need our own ref count. instead, we share the lifetime (the ref count)
// of the entire pipe. this macro is just convenience since it does not
// declare a mRefCount variable; however, don't let the name fool you...
// we are not inheriting from nsPipe ;-)
NS_DECL_ISUPPORTS_INHERITED
NS_DECL_NSIOUTPUTSTREAM
NS_DECL_NSIASYNCOUTPUTSTREAM
NS_DECL_NSICLASSINFO
nsPipeOutputStream(nsPipe *pipe)
: mPipe(pipe)
, mWriterRefCnt(0)
, mLogicalOffset(0)
, mBlocking(true)
, mBlocked(false)
, mWritable(true)
, mCallbackFlags(0)
{ }
void SetNonBlocking(bool aNonBlocking) { mBlocking = !aNonBlocking; }
void SetWritable(bool writable) { mWritable = writable; }
// synchronously wait for the pipe to become writable.
nsresult Wait();
// these functions return true to indicate that the pipe's monitor should
// be notified, to wake up a blocked writer if any.
bool OnOutputWritable(nsPipeEvents &);
bool OnOutputException(nsresult, nsPipeEvents &);
private:
nsPipe *mPipe;
// separate refcnt so that we know when to close the producer
mozilla::ThreadSafeAutoRefCnt mWriterRefCnt;
int64_t mLogicalOffset;
bool mBlocking;
// these variables can only be accessed while inside the pipe's monitor
bool mBlocked;
bool mWritable;
nsCOMPtr<nsIOutputStreamCallback> mCallback;
uint32_t mCallbackFlags;
};
//-----------------------------------------------------------------------------
class nsPipe MOZ_FINAL : public nsIPipe
{
public:
friend class nsPipeInputStream;
friend class nsPipeOutputStream;
NS_DECL_THREADSAFE_ISUPPORTS
NS_DECL_NSIPIPE
// nsPipe methods:
nsPipe();
private:
~nsPipe();
public:
//
// methods below may only be called while inside the pipe's monitor
//
void PeekSegment(uint32_t n, char *&cursor, char *&limit);
//
// methods below may be called while outside the pipe's monitor
//
nsresult GetReadSegment(const char *&segment, uint32_t &segmentLen);
void AdvanceReadCursor(uint32_t count);
nsresult GetWriteSegment(char *&segment, uint32_t &segmentLen);
void AdvanceWriteCursor(uint32_t count);
void OnPipeException(nsresult reason, bool outputOnly = false);
protected:
// We can't inherit from both nsIInputStream and nsIOutputStream
// because they collide on their Close method. Consequently we nest their
// implementations to avoid the extra object allocation.
nsPipeInputStream mInput;
nsPipeOutputStream mOutput;
ReentrantMonitor mReentrantMonitor;
nsSegmentedBuffer mBuffer;
char* mReadCursor;
char* mReadLimit;
int32_t mWriteSegment;
char* mWriteCursor;
char* mWriteLimit;
nsresult mStatus;
bool mInited;
};
//
// NOTES on buffer architecture:
//
// +-----------------+ - - mBuffer.GetSegment(0)
// | |
// + - - - - - - - - + - - mReadCursor
// |/////////////////|
// |/////////////////|
// |/////////////////|
// |/////////////////|
// +-----------------+ - - mReadLimit
// |
// +-----------------+
// |/////////////////|
// |/////////////////|
// |/////////////////|
// |/////////////////|
// |/////////////////|
// |/////////////////|
// +-----------------+
// |
// +-----------------+ - - mBuffer.GetSegment(mWriteSegment)
// |/////////////////|
// |/////////////////|
// |/////////////////|
// + - - - - - - - - + - - mWriteCursor
// | |
// | |
// +-----------------+ - - mWriteLimit
//
// (shaded region contains data)
//
// NOTE: on some systems (notably OS/2), the heap allocator uses an arena for
// small allocations (e.g., 64 byte allocations). this means that buffers may
// be allocated back-to-back. in the diagram above, for example, mReadLimit
// would actually be pointing at the beginning of the next segment. when
// making changes to this file, please keep this fact in mind.
//
//-----------------------------------------------------------------------------
// nsPipe methods:
//-----------------------------------------------------------------------------
nsPipe::nsPipe()
: mInput(MOZ_THIS_IN_INITIALIZER_LIST())
, mOutput(MOZ_THIS_IN_INITIALIZER_LIST())
, mReentrantMonitor("nsPipe.mReentrantMonitor")
, mReadCursor(nullptr)
, mReadLimit(nullptr)
, mWriteSegment(-1)
, mWriteCursor(nullptr)
, mWriteLimit(nullptr)
, mStatus(NS_OK)
, mInited(false)
{
}
nsPipe::~nsPipe()
{
}
NS_IMPL_ISUPPORTS1(nsPipe, nsIPipe)
NS_IMETHODIMP
nsPipe::Init(bool nonBlockingIn,
bool nonBlockingOut,
uint32_t segmentSize,
uint32_t segmentCount)
{
mInited = true;
if (segmentSize == 0)
segmentSize = DEFAULT_SEGMENT_SIZE;
if (segmentCount == 0)
segmentCount = DEFAULT_SEGMENT_COUNT;
// protect against overflow
uint32_t maxCount = uint32_t(-1) / segmentSize;
if (segmentCount > maxCount)
segmentCount = maxCount;
nsresult rv = mBuffer.Init(segmentSize, segmentSize * segmentCount);
if (NS_FAILED(rv))
return rv;
mInput.SetNonBlocking(nonBlockingIn);
mOutput.SetNonBlocking(nonBlockingOut);
return NS_OK;
}
NS_IMETHODIMP
nsPipe::GetInputStream(nsIAsyncInputStream **aInputStream)
{
NS_ADDREF(*aInputStream = &mInput);
return NS_OK;
}
NS_IMETHODIMP
nsPipe::GetOutputStream(nsIAsyncOutputStream **aOutputStream)
{
if (NS_WARN_IF(!mInited))
return NS_ERROR_NOT_INITIALIZED;
NS_ADDREF(*aOutputStream = &mOutput);
return NS_OK;
}
void
nsPipe::PeekSegment(uint32_t index, char *&cursor, char *&limit)
{
if (index == 0) {
NS_ASSERTION(!mReadCursor || mBuffer.GetSegmentCount(), "unexpected state");
cursor = mReadCursor;
limit = mReadLimit;
}
else {
uint32_t numSegments = mBuffer.GetSegmentCount();
if (index >= numSegments)
cursor = limit = nullptr;
else {
cursor = mBuffer.GetSegment(index);
if (mWriteSegment == (int32_t) index)
limit = mWriteCursor;
else
limit = cursor + mBuffer.GetSegmentSize();
}
}
}
nsresult
nsPipe::GetReadSegment(const char *&segment, uint32_t &segmentLen)
{
ReentrantMonitorAutoEnter mon(mReentrantMonitor);
if (mReadCursor == mReadLimit)
return NS_FAILED(mStatus) ? mStatus : NS_BASE_STREAM_WOULD_BLOCK;
segment = mReadCursor;
segmentLen = mReadLimit - mReadCursor;
return NS_OK;
}
void
nsPipe::AdvanceReadCursor(uint32_t bytesRead)
{
NS_ASSERTION(bytesRead, "don't call if no bytes read");
nsPipeEvents events;
{
ReentrantMonitorAutoEnter mon(mReentrantMonitor);
LOG(("III advancing read cursor by %u\n", bytesRead));
NS_ASSERTION(bytesRead <= mBuffer.GetSegmentSize(), "read too much");
mReadCursor += bytesRead;
NS_ASSERTION(mReadCursor <= mReadLimit, "read cursor exceeds limit");
mInput.ReduceAvailable(bytesRead);
if (mReadCursor == mReadLimit) {
// we've reached the limit of how much we can read from this segment.
// if at the end of this segment, then we must discard this segment.
// if still writing in this segment then bail because we're not done
// with the segment and have to wait for now...
if (mWriteSegment == 0 && mWriteLimit > mWriteCursor) {
NS_ASSERTION(mReadLimit == mWriteCursor, "unexpected state");
return;
}
// shift write segment index (-1 indicates an empty buffer).
--mWriteSegment;
// done with this segment
mBuffer.DeleteFirstSegment();
LOG(("III deleting first segment\n"));
if (mWriteSegment == -1) {
// buffer is completely empty
mReadCursor = nullptr;
mReadLimit = nullptr;
mWriteCursor = nullptr;
mWriteLimit = nullptr;
}
else {
// advance read cursor and limit to next buffer segment
mReadCursor = mBuffer.GetSegment(0);
if (mWriteSegment == 0)
mReadLimit = mWriteCursor;
else
mReadLimit = mReadCursor + mBuffer.GetSegmentSize();
}
// we've free'd up a segment, so notify output stream that pipe has
// room for a new segment.
if (mOutput.OnOutputWritable(events))
mon.Notify();
}
}
}
nsresult
nsPipe::GetWriteSegment(char *&segment, uint32_t &segmentLen)
{
ReentrantMonitorAutoEnter mon(mReentrantMonitor);
if (NS_FAILED(mStatus))
return mStatus;
// write cursor and limit may both be null indicating an empty buffer.
if (mWriteCursor == mWriteLimit) {
char *seg = mBuffer.AppendNewSegment();
// pipe is full
if (seg == nullptr)
return NS_BASE_STREAM_WOULD_BLOCK;
LOG(("OOO appended new segment\n"));
mWriteCursor = seg;
mWriteLimit = mWriteCursor + mBuffer.GetSegmentSize();
++mWriteSegment;
}
// make sure read cursor is initialized
if (mReadCursor == nullptr) {
NS_ASSERTION(mWriteSegment == 0, "unexpected null read cursor");
mReadCursor = mReadLimit = mWriteCursor;
}
// check to see if we can roll-back our read and write cursors to the
// beginning of the current/first segment. this is purely an optimization.
if (mReadCursor == mWriteCursor && mWriteSegment == 0) {
char *head = mBuffer.GetSegment(0);
LOG(("OOO rolling back write cursor %u bytes\n", mWriteCursor - head));
mWriteCursor = mReadCursor = mReadLimit = head;
}
segment = mWriteCursor;
segmentLen = mWriteLimit - mWriteCursor;
return NS_OK;
}
void
nsPipe::AdvanceWriteCursor(uint32_t bytesWritten)
{
NS_ASSERTION(bytesWritten, "don't call if no bytes written");
nsPipeEvents events;
{
ReentrantMonitorAutoEnter mon(mReentrantMonitor);
LOG(("OOO advancing write cursor by %u\n", bytesWritten));
char *newWriteCursor = mWriteCursor + bytesWritten;
NS_ASSERTION(newWriteCursor <= mWriteLimit, "write cursor exceeds limit");
// update read limit if reading in the same segment
if (mWriteSegment == 0 && mReadLimit == mWriteCursor)
mReadLimit = newWriteCursor;
mWriteCursor = newWriteCursor;
// The only way mReadCursor == mWriteCursor is if:
//
// - mReadCursor is at the start of a segment (which, based on how
// nsSegmentedBuffer works, means that this segment is the "first"
// segment)
// - mWriteCursor points at the location past the end of the current
// write segment (so the current write filled the current write
// segment, so we've incremented mWriteCursor to point past the end
// of it)
// - the segment to which data has just been written is located
// exactly one segment's worth of bytes before the first segment
// where mReadCursor is located
//
// Consequently, the byte immediately after the end of the current
// write segment is the first byte of the first segment, so
// mReadCursor == mWriteCursor. (Another way to think about this is
// to consider the buffer architecture diagram above, but consider it
// with an arena allocator which allocates from the *end* of the
// arena to the *beginning* of the arena.)
NS_ASSERTION(mReadCursor != mWriteCursor ||
(mBuffer.GetSegment(0) == mReadCursor &&
mWriteCursor == mWriteLimit),
"read cursor is bad");
// update the writable flag on the output stream
if (mWriteCursor == mWriteLimit) {
if (mBuffer.GetSize() >= mBuffer.GetMaxSize())
mOutput.SetWritable(false);
}
// notify input stream that pipe now contains additional data
if (mInput.OnInputReadable(bytesWritten, events))
mon.Notify();
}
}
void
nsPipe::OnPipeException(nsresult reason, bool outputOnly)
{
LOG(("PPP nsPipe::OnPipeException [reason=%x output-only=%d]\n",
reason, outputOnly));
nsPipeEvents events;
{
ReentrantMonitorAutoEnter mon(mReentrantMonitor);
// if we've already hit an exception, then ignore this one.
if (NS_FAILED(mStatus))
return;
mStatus = reason;
// an output-only exception applies to the input end if the pipe has
// zero bytes available.
if (outputOnly && !mInput.Available())
outputOnly = false;
if (!outputOnly)
if (mInput.OnInputException(reason, events))
mon.Notify();
if (mOutput.OnOutputException(reason, events))
mon.Notify();
}
}
//-----------------------------------------------------------------------------
// nsPipeEvents methods:
//-----------------------------------------------------------------------------
nsPipeEvents::~nsPipeEvents()
{
// dispatch any pending events
if (mInputCallback) {
mInputCallback->OnInputStreamReady(mInputStream);
mInputCallback = 0;
mInputStream = 0;
}
if (mOutputCallback) {
mOutputCallback->OnOutputStreamReady(mOutputStream);
mOutputCallback = 0;
mOutputStream = 0;
}
}
//-----------------------------------------------------------------------------
// nsPipeInputStream methods:
//-----------------------------------------------------------------------------
NS_IMPL_QUERY_INTERFACE5(nsPipeInputStream,
nsIInputStream,
nsIAsyncInputStream,
nsISeekableStream,
nsISearchableInputStream,
nsIClassInfo)
NS_IMPL_CI_INTERFACE_GETTER4(nsPipeInputStream,
nsIInputStream,
nsIAsyncInputStream,
nsISeekableStream,
nsISearchableInputStream)
NS_IMPL_THREADSAFE_CI(nsPipeInputStream)
nsresult
nsPipeInputStream::Wait()
{
NS_ASSERTION(mBlocking, "wait on non-blocking pipe input stream");
ReentrantMonitorAutoEnter mon(mPipe->mReentrantMonitor);
while (NS_SUCCEEDED(mPipe->mStatus) && (mAvailable == 0)) {
LOG(("III pipe input: waiting for data\n"));
mBlocked = true;
mon.Wait();
mBlocked = false;
LOG(("III pipe input: woke up [pipe-status=%x available=%u]\n",
mPipe->mStatus, mAvailable));
}
return mPipe->mStatus == NS_BASE_STREAM_CLOSED ? NS_OK : mPipe->mStatus;
}
bool
nsPipeInputStream::OnInputReadable(uint32_t bytesWritten, nsPipeEvents &events)
{
bool result = false;
mAvailable += bytesWritten;
if (mCallback && !(mCallbackFlags & WAIT_CLOSURE_ONLY)) {
events.NotifyInputReady(this, mCallback);
mCallback = 0;
mCallbackFlags = 0;
}
else if (mBlocked)
result = true;
return result;
}
bool
nsPipeInputStream::OnInputException(nsresult reason, nsPipeEvents &events)
{
LOG(("nsPipeInputStream::OnInputException [this=%x reason=%x]\n",
this, reason));
bool result = false;
NS_ASSERTION(NS_FAILED(reason), "huh? successful exception");
// force count of available bytes to zero.
mAvailable = 0;
if (mCallback) {
events.NotifyInputReady(this, mCallback);
mCallback = 0;
mCallbackFlags = 0;
}
else if (mBlocked)
result = true;
return result;
}
NS_IMETHODIMP_(MozExternalRefCountType)
nsPipeInputStream::AddRef(void)
{
++mReaderRefCnt;
return mPipe->AddRef();
}
NS_IMETHODIMP_(MozExternalRefCountType)
nsPipeInputStream::Release(void)
{
if (--mReaderRefCnt == 0)
Close();
return mPipe->Release();
}
NS_IMETHODIMP
nsPipeInputStream::CloseWithStatus(nsresult reason)
{
LOG(("III CloseWithStatus [this=%x reason=%x]\n", this, reason));
if (NS_SUCCEEDED(reason))
reason = NS_BASE_STREAM_CLOSED;
mPipe->OnPipeException(reason);
return NS_OK;
}
NS_IMETHODIMP
nsPipeInputStream::Close()
{
return CloseWithStatus(NS_BASE_STREAM_CLOSED);
}
NS_IMETHODIMP
nsPipeInputStream::Available(uint64_t *result)
{
// nsPipeInputStream supports under 4GB stream only
ReentrantMonitorAutoEnter mon(mPipe->mReentrantMonitor);
// return error if pipe closed
if (!mAvailable && NS_FAILED(mPipe->mStatus))
return mPipe->mStatus;
*result = (uint64_t)mAvailable;
return NS_OK;
}
NS_IMETHODIMP
nsPipeInputStream::ReadSegments(nsWriteSegmentFun writer,
void *closure,
uint32_t count,
uint32_t *readCount)
{
LOG(("III ReadSegments [this=%x count=%u]\n", this, count));
nsresult rv = NS_OK;
const char *segment;
uint32_t segmentLen;
*readCount = 0;
while (count) {
rv = mPipe->GetReadSegment(segment, segmentLen);
if (NS_FAILED(rv)) {
// ignore this error if we've already read something.
if (*readCount > 0) {
rv = NS_OK;
break;
}
if (rv == NS_BASE_STREAM_WOULD_BLOCK) {
// pipe is empty
if (!mBlocking)
break;
// wait for some data to be written to the pipe
rv = Wait();
if (NS_SUCCEEDED(rv))
continue;
}
// ignore this error, just return.
if (rv == NS_BASE_STREAM_CLOSED) {
rv = NS_OK;
break;
}
mPipe->OnPipeException(rv);
break;
}
// read no more than count
if (segmentLen > count)
segmentLen = count;
uint32_t writeCount, originalLen = segmentLen;
while (segmentLen) {
writeCount = 0;
rv = writer(this, closure, segment, *readCount, segmentLen, &writeCount);
if (NS_FAILED(rv) || writeCount == 0) {
count = 0;
// any errors returned from the writer end here: do not
// propagate to the caller of ReadSegments.
rv = NS_OK;
break;
}
NS_ASSERTION(writeCount <= segmentLen, "wrote more than expected");
segment += writeCount;
segmentLen -= writeCount;
count -= writeCount;
*readCount += writeCount;
mLogicalOffset += writeCount;
}
if (segmentLen < originalLen)
mPipe->AdvanceReadCursor(originalLen - segmentLen);
}
return rv;
}
NS_IMETHODIMP
nsPipeInputStream::Read(char* toBuf, uint32_t bufLen, uint32_t *readCount)
{
return ReadSegments(NS_CopySegmentToBuffer, toBuf, bufLen, readCount);
}
NS_IMETHODIMP
nsPipeInputStream::IsNonBlocking(bool *aNonBlocking)
{
*aNonBlocking = !mBlocking;
return NS_OK;
}
NS_IMETHODIMP
nsPipeInputStream::AsyncWait(nsIInputStreamCallback *callback,
uint32_t flags,
uint32_t requestedCount,
nsIEventTarget *target)
{
LOG(("III AsyncWait [this=%x]\n", this));
nsPipeEvents pipeEvents;
{
ReentrantMonitorAutoEnter mon(mPipe->mReentrantMonitor);
// replace a pending callback
mCallback = 0;
mCallbackFlags = 0;
if (!callback)
return NS_OK;
nsCOMPtr<nsIInputStreamCallback> proxy;
if (target) {
proxy = NS_NewInputStreamReadyEvent(callback, target);
callback = proxy;
}
if (NS_FAILED(mPipe->mStatus) ||
(mAvailable && !(flags & WAIT_CLOSURE_ONLY))) {
// stream is already closed or readable; post event.
pipeEvents.NotifyInputReady(this, callback);
}
else {
// queue up callback object to be notified when data becomes available
mCallback = callback;
mCallbackFlags = flags;
}
}
return NS_OK;
}
NS_IMETHODIMP
nsPipeInputStream::Seek(int32_t whence, int64_t offset)
{
NS_NOTREACHED("nsPipeInputStream::Seek");
return NS_ERROR_NOT_IMPLEMENTED;
}
NS_IMETHODIMP
nsPipeInputStream::Tell(int64_t *offset)
{
ReentrantMonitorAutoEnter mon(mPipe->mReentrantMonitor);
// return error if pipe closed
if (!mAvailable && NS_FAILED(mPipe->mStatus))
return mPipe->mStatus;
*offset = mLogicalOffset;
return NS_OK;
}
NS_IMETHODIMP
nsPipeInputStream::SetEOF()
{
NS_NOTREACHED("nsPipeInputStream::SetEOF");
return NS_ERROR_NOT_IMPLEMENTED;
}
#define COMPARE(s1, s2, i) \
(ignoreCase \
? nsCRT::strncasecmp((const char *)s1, (const char *)s2, (uint32_t)i) \
: nsCRT::strncmp((const char *)s1, (const char *)s2, (uint32_t)i))
NS_IMETHODIMP
nsPipeInputStream::Search(const char *forString,
bool ignoreCase,
bool *found,
uint32_t *offsetSearchedTo)
{
LOG(("III Search [for=%s ic=%u]\n", forString, ignoreCase));
ReentrantMonitorAutoEnter mon(mPipe->mReentrantMonitor);
char *cursor1, *limit1;
uint32_t index = 0, offset = 0;
uint32_t strLen = strlen(forString);
mPipe->PeekSegment(0, cursor1, limit1);
if (cursor1 == limit1) {
*found = false;
*offsetSearchedTo = 0;
LOG((" result [found=%u offset=%u]\n", *found, *offsetSearchedTo));
return NS_OK;
}
while (true) {
uint32_t i, len1 = limit1 - cursor1;
// check if the string is in the buffer segment
for (i = 0; i < len1 - strLen + 1; i++) {
if (COMPARE(&cursor1[i], forString, strLen) == 0) {
*found = true;
*offsetSearchedTo = offset + i;
LOG((" result [found=%u offset=%u]\n", *found, *offsetSearchedTo));
return NS_OK;
}
}
// get the next segment
char *cursor2, *limit2;
uint32_t len2;
index++;
offset += len1;
mPipe->PeekSegment(index, cursor2, limit2);
if (cursor2 == limit2) {
*found = false;
*offsetSearchedTo = offset - strLen + 1;
LOG((" result [found=%u offset=%u]\n", *found, *offsetSearchedTo));
return NS_OK;
}
len2 = limit2 - cursor2;
// check if the string is straddling the next buffer segment
uint32_t lim = XPCOM_MIN(strLen, len2 + 1);
for (i = 0; i < lim; ++i) {
uint32_t strPart1Len = strLen - i - 1;
uint32_t strPart2Len = strLen - strPart1Len;
const char* strPart2 = &forString[strLen - strPart2Len];
uint32_t bufSeg1Offset = len1 - strPart1Len;
if (COMPARE(&cursor1[bufSeg1Offset], forString, strPart1Len) == 0 &&
COMPARE(cursor2, strPart2, strPart2Len) == 0) {
*found = true;
*offsetSearchedTo = offset - strPart1Len;
LOG((" result [found=%u offset=%u]\n", *found, *offsetSearchedTo));
return NS_OK;
}
}
// finally continue with the next buffer
cursor1 = cursor2;
limit1 = limit2;
}
NS_NOTREACHED("can't get here");
return NS_ERROR_UNEXPECTED; // keep compiler happy
}
//-----------------------------------------------------------------------------
// nsPipeOutputStream methods:
//-----------------------------------------------------------------------------
NS_IMPL_QUERY_INTERFACE3(nsPipeOutputStream,
nsIOutputStream,
nsIAsyncOutputStream,
nsIClassInfo)
NS_IMPL_CI_INTERFACE_GETTER2(nsPipeOutputStream,
nsIOutputStream,
nsIAsyncOutputStream)
NS_IMPL_THREADSAFE_CI(nsPipeOutputStream)
nsresult
nsPipeOutputStream::Wait()
{
NS_ASSERTION(mBlocking, "wait on non-blocking pipe output stream");
ReentrantMonitorAutoEnter mon(mPipe->mReentrantMonitor);
if (NS_SUCCEEDED(mPipe->mStatus) && !mWritable) {
LOG(("OOO pipe output: waiting for space\n"));
mBlocked = true;
mon.Wait();
mBlocked = false;
LOG(("OOO pipe output: woke up [pipe-status=%x writable=%u]\n",
mPipe->mStatus, mWritable));
}
return mPipe->mStatus == NS_BASE_STREAM_CLOSED ? NS_OK : mPipe->mStatus;
}
bool
nsPipeOutputStream::OnOutputWritable(nsPipeEvents &events)
{
bool result = false;
mWritable = true;
if (mCallback && !(mCallbackFlags & WAIT_CLOSURE_ONLY)) {
events.NotifyOutputReady(this, mCallback);
mCallback = 0;
mCallbackFlags = 0;
}
else if (mBlocked)
result = true;
return result;
}
bool
nsPipeOutputStream::OnOutputException(nsresult reason, nsPipeEvents &events)
{
LOG(("nsPipeOutputStream::OnOutputException [this=%x reason=%x]\n",
this, reason));
bool result = false;
NS_ASSERTION(NS_FAILED(reason), "huh? successful exception");
mWritable = false;
if (mCallback) {
events.NotifyOutputReady(this, mCallback);
mCallback = 0;
mCallbackFlags = 0;
}
else if (mBlocked)
result = true;
return result;
}
NS_IMETHODIMP_(MozExternalRefCountType)
nsPipeOutputStream::AddRef()
{
++mWriterRefCnt;
return mPipe->AddRef();
}
NS_IMETHODIMP_(MozExternalRefCountType)
nsPipeOutputStream::Release()
{
if (--mWriterRefCnt == 0)
Close();
return mPipe->Release();
}
NS_IMETHODIMP
nsPipeOutputStream::CloseWithStatus(nsresult reason)
{
LOG(("OOO CloseWithStatus [this=%x reason=%x]\n", this, reason));
if (NS_SUCCEEDED(reason))
reason = NS_BASE_STREAM_CLOSED;
// input stream may remain open
mPipe->OnPipeException(reason, true);
return NS_OK;
}
NS_IMETHODIMP
nsPipeOutputStream::Close()
{
return CloseWithStatus(NS_BASE_STREAM_CLOSED);
}
NS_IMETHODIMP
nsPipeOutputStream::WriteSegments(nsReadSegmentFun reader,
void* closure,
uint32_t count,
uint32_t *writeCount)
{
LOG(("OOO WriteSegments [this=%x count=%u]\n", this, count));
nsresult rv = NS_OK;
char *segment;
uint32_t segmentLen;
*writeCount = 0;
while (count) {
rv = mPipe->GetWriteSegment(segment, segmentLen);
if (NS_FAILED(rv)) {
if (rv == NS_BASE_STREAM_WOULD_BLOCK) {
// pipe is full
if (!mBlocking) {
// ignore this error if we've already written something
if (*writeCount > 0)
rv = NS_OK;
break;
}
// wait for the pipe to have an empty segment.
rv = Wait();
if (NS_SUCCEEDED(rv))
continue;
}
mPipe->OnPipeException(rv);
break;
}
// write no more than count
if (segmentLen > count)
segmentLen = count;
uint32_t readCount, originalLen = segmentLen;
while (segmentLen) {
readCount = 0;
rv = reader(this, closure, segment, *writeCount, segmentLen, &readCount);
if (NS_FAILED(rv) || readCount == 0) {
count = 0;
// any errors returned from the reader end here: do not
// propagate to the caller of WriteSegments.
rv = NS_OK;
break;
}
NS_ASSERTION(readCount <= segmentLen, "read more than expected");
segment += readCount;
segmentLen -= readCount;
count -= readCount;
*writeCount += readCount;
mLogicalOffset += readCount;
}
if (segmentLen < originalLen)
mPipe->AdvanceWriteCursor(originalLen - segmentLen);
}
return rv;
}
static NS_METHOD
nsReadFromRawBuffer(nsIOutputStream* outStr,
void* closure,
char* toRawSegment,
uint32_t offset,
uint32_t count,
uint32_t *readCount)
{
const char* fromBuf = (const char*)closure;
memcpy(toRawSegment, &fromBuf[offset], count);
*readCount = count;
return NS_OK;
}
NS_IMETHODIMP
nsPipeOutputStream::Write(const char* fromBuf,
uint32_t bufLen,
uint32_t *writeCount)
{
return WriteSegments(nsReadFromRawBuffer, (void*)fromBuf, bufLen, writeCount);
}
NS_IMETHODIMP
nsPipeOutputStream::Flush(void)
{
// nothing to do
return NS_OK;
}
static NS_METHOD
nsReadFromInputStream(nsIOutputStream* outStr,
void* closure,
char* toRawSegment,
uint32_t offset,
uint32_t count,
uint32_t *readCount)
{
nsIInputStream* fromStream = (nsIInputStream*)closure;
return fromStream->Read(toRawSegment, count, readCount);
}
NS_IMETHODIMP
nsPipeOutputStream::WriteFrom(nsIInputStream* fromStream,
uint32_t count,
uint32_t *writeCount)
{
return WriteSegments(nsReadFromInputStream, fromStream, count, writeCount);
}
NS_IMETHODIMP
nsPipeOutputStream::IsNonBlocking(bool *aNonBlocking)
{
*aNonBlocking = !mBlocking;
return NS_OK;
}
NS_IMETHODIMP
nsPipeOutputStream::AsyncWait(nsIOutputStreamCallback *callback,
uint32_t flags,
uint32_t requestedCount,
nsIEventTarget *target)
{
LOG(("OOO AsyncWait [this=%x]\n", this));
nsPipeEvents pipeEvents;
{
ReentrantMonitorAutoEnter mon(mPipe->mReentrantMonitor);
// replace a pending callback
mCallback = 0;
mCallbackFlags = 0;
if (!callback)
return NS_OK;
nsCOMPtr<nsIOutputStreamCallback> proxy;
if (target) {
proxy = NS_NewOutputStreamReadyEvent(callback, target);
callback = proxy;
}
if (NS_FAILED(mPipe->mStatus) ||
(mWritable && !(flags & WAIT_CLOSURE_ONLY))) {
// stream is already closed or writable; post event.
pipeEvents.NotifyOutputReady(this, callback);
}
else {
// queue up callback object to be notified when data becomes available
mCallback = callback;
mCallbackFlags = flags;
}
}
return NS_OK;
}
////////////////////////////////////////////////////////////////////////////////
nsresult
NS_NewPipe(nsIInputStream **pipeIn,
nsIOutputStream **pipeOut,
uint32_t segmentSize,
uint32_t maxSize,
bool nonBlockingInput,
bool nonBlockingOutput)
{
if (segmentSize == 0)
segmentSize = DEFAULT_SEGMENT_SIZE;
// Handle maxSize of UINT32_MAX as a special case
uint32_t segmentCount;
if (maxSize == UINT32_MAX)
segmentCount = UINT32_MAX;
else
segmentCount = maxSize / segmentSize;
nsIAsyncInputStream *in;
nsIAsyncOutputStream *out;
nsresult rv = NS_NewPipe2(&in, &out, nonBlockingInput, nonBlockingOutput,
segmentSize, segmentCount);
if (NS_FAILED(rv)) return rv;
*pipeIn = in;
*pipeOut = out;
return NS_OK;
}
nsresult
NS_NewPipe2(nsIAsyncInputStream **pipeIn,
nsIAsyncOutputStream **pipeOut,
bool nonBlockingInput,
bool nonBlockingOutput,
uint32_t segmentSize,
uint32_t segmentCount)
{
nsresult rv;
nsPipe *pipe = new nsPipe();
if (!pipe)
return NS_ERROR_OUT_OF_MEMORY;
rv = pipe->Init(nonBlockingInput,
nonBlockingOutput,
segmentSize,
segmentCount);
if (NS_FAILED(rv)) {
NS_ADDREF(pipe);
NS_RELEASE(pipe);
return rv;
}
pipe->GetInputStream(pipeIn);
pipe->GetOutputStream(pipeOut);
return NS_OK;
}
nsresult
nsPipeConstructor(nsISupports *outer, REFNSIID iid, void **result)
{
if (outer)
return NS_ERROR_NO_AGGREGATION;
nsPipe *pipe = new nsPipe();
if (!pipe)
return NS_ERROR_OUT_OF_MEMORY;
NS_ADDREF(pipe);
nsresult rv = pipe->QueryInterface(iid, result);
NS_RELEASE(pipe);
return rv;
}
////////////////////////////////////////////////////////////////////////////////
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