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gecko-dev/xpcom/io/nsPipe2.cpp

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: NPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Netscape Public License
* Version 1.1 (the "License"); you may not use this file except in
* compliance with the License. You may obtain a copy of the License at
* http://www.mozilla.org/NPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is mozilla.org code.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Pierre Phaneuf <pp@ludusdesign.com>
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the NPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the NPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#include "nsIPipe.h"
#include "nsIInputStream.h"
#include "nsIOutputStream.h"
#include "nsSegmentedBuffer.h"
#include "nsAutoLock.h"
#include "nsIServiceManager.h"
#ifdef PAGE_MANAGER
#include "nsIPageManager.h"
#endif
#include "nsCRT.h"
#include "nsCOMPtr.h"
// define to include temporary code which prevents a common startup crash
// (Bugzilla bug 46267) without addressing the unerlying issue.
#define MASK_PREMATURE_STREAM_RELEASE
////////////////////////////////////////////////////////////////////////////////
#define GET_INPUTSTREAM_PIPE(_this) \
((nsPipe*)((char*)(_this) - offsetof(nsPipe, mInput)))
#define GET_OUTPUTSTREAM_PIPE(_this) \
((nsPipe*)((char*)(_this) - offsetof(nsPipe, mOutput)))
////////////////////////////////////////////////////////////////////////////////
class nsPipe : public nsIPipe
{
public:
// 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, and speed up method
// invocation between them and the nsPipe's buffer manipulation methods.
class nsPipeInputStream : public nsIInputStream, public nsISearchableInputStream {
public:
NS_IMETHOD QueryInterface(const nsIID& aIID, void** aInstancePtr);
NS_IMETHOD_(nsrefcnt) AddRef(void);
NS_IMETHOD_(nsrefcnt) Release(void);
// nsIBaseStream methods:
NS_IMETHOD Close(void);
// nsIInputStream methods:
NS_IMETHOD Available(PRUint32 *result);
NS_IMETHOD Read(char* toBuf, PRUint32 bufLen, PRUint32 *readCount);
// nsIInputStream methods:
NS_IMETHOD ReadSegments(nsWriteSegmentFun writer, void* closure, PRUint32 count,
PRUint32 *readCount);
NS_IMETHOD Search(const char *forString, PRBool ignoreCase, PRBool *found,
PRUint32 *offsetSearchedTo);
NS_IMETHOD GetNonBlocking(PRBool *aNonBlocking);
NS_IMETHOD SetNonBlocking(PRBool aNonBlocking);
NS_IMETHOD GetObserver(nsIInputStreamObserver* *result) {
*result = mObserver;
NS_IF_ADDREF(*result);
return NS_OK;
}
NS_IMETHOD SetObserver(nsIInputStreamObserver* obs) {
mObserver = obs;
return NS_OK;
}
nsPipeInputStream() : mReaderRefCnt(0), mBlocking(PR_TRUE) {}
nsresult Fill();
protected:
nsrefcnt mReaderRefCnt; // separate refcnt so that we know when to close the consumer
PRBool mBlocking;
nsCOMPtr<nsIInputStreamObserver> mObserver;
};
class nsPipeOutputStream : public nsIOutputStream {
public:
NS_IMETHOD QueryInterface(const nsIID& aIID, void** aInstancePtr);
NS_IMETHOD_(nsrefcnt) AddRef(void);
NS_IMETHOD_(nsrefcnt) Release(void);
// nsIBaseStream methods:
NS_IMETHOD Close(void);
NS_IMETHOD Write(const char* fromBuf, PRUint32 bufLen, PRUint32 *writeCount);
NS_IMETHOD Flush(void);
// nsIOutputStream methods:
NS_IMETHOD WriteSegments(nsReadSegmentFun reader, void* closure, PRUint32 count,
PRUint32 *writeCount);
NS_IMETHOD WriteFrom(nsIInputStream* fromStream, PRUint32 count, PRUint32 *writeCount);
NS_IMETHOD GetNonBlocking(PRBool *aNonBlocking);
NS_IMETHOD SetNonBlocking(PRBool aNonBlocking);
NS_IMETHOD GetObserver(nsIOutputStreamObserver* *result) {
*result = mObserver;
NS_IF_ADDREF(*result);
return NS_OK;
}
NS_IMETHOD SetObserver(nsIOutputStreamObserver* obs) {
mObserver = obs;
return NS_OK;
}
nsPipeOutputStream() : mWriterRefCnt(0), mBlocking(PR_TRUE) {}
protected:
nsrefcnt mWriterRefCnt; // separate refcnt so that we know when to close the producer
PRBool mBlocking;
nsCOMPtr<nsIOutputStreamObserver> mObserver;
};
friend class nsPipeInputStream;
friend class nsPipeOutputStream;
NS_DECL_ISUPPORTS
// nsIPipe methods:
NS_IMETHOD Initialize(PRUint32 segmentSize, PRUint32 maxSize,
PRBool nonBlockingIn, PRBool nonBlockingOut,
nsIMemory *segmentAllocator) {
nsresult rv;
mMonitor = PR_NewMonitor();
if (mMonitor == nsnull)
return NS_ERROR_OUT_OF_MEMORY;
rv = mBuffer.Init(segmentSize, maxSize, segmentAllocator);
GetInputStream()->SetNonBlocking(nonBlockingIn);
GetOutputStream()->SetNonBlocking(nonBlockingOut);
return NS_OK;
}
NS_IMETHOD GetInputStream(nsIInputStream * *aInputStream) {
*aInputStream = &mInput;
NS_IF_ADDREF(*aInputStream);
return NS_OK;
}
NS_IMETHOD GetOutputStream(nsIOutputStream * *aOutputStream) {
*aOutputStream = &mOutput;
NS_IF_ADDREF(*aOutputStream);
return NS_OK;
}
// nsPipe methods:
nsPipe();
virtual ~nsPipe();
PRMonitor* GetMonitor() { return mMonitor; }
nsPipeInputStream* GetInputStream() { return &mInput; }
nsPipeOutputStream* GetOutputStream() { return &mOutput; }
nsresult GetReadSegment(PRUint32 segmentLogicalOffset,
const char* *resultSegment,
PRUint32 *resultSegmentLen);
nsresult GetWriteSegment(char* *resultSegment,
PRUint32 *resultSegmentLen);
protected:
PRMonitor* mMonitor;
nsPipeInputStream mInput;
nsPipeOutputStream mOutput;
nsSegmentedBuffer mBuffer;
char* mReadCursor;
char* mReadLimit;
char* mWriteCursor;
char* mWriteLimit;
nsresult mCondition;
};
////////////////////////////////////////////////////////////////////////////////
// nsPipe methods:
nsPipe::nsPipe()
: mMonitor(nsnull),
mReadCursor(nsnull),
mReadLimit(nsnull),
mWriteCursor(nsnull),
mWriteLimit(nsnull),
mCondition(NS_OK)
{
NS_INIT_REFCNT();
}
nsPipe::~nsPipe()
{
if (mMonitor) PR_DestroyMonitor(mMonitor);
}
NS_IMPL_THREADSAFE_ADDREF(nsPipe);
NS_IMPL_THREADSAFE_RELEASE(nsPipe);
NS_IMETHODIMP
nsPipe::QueryInterface(const nsIID& aIID, void** aInstancePtr)
{
if (aInstancePtr == nsnull)
return NS_ERROR_NULL_POINTER;
if (aIID.Equals(NS_GET_IID(nsIInputStream))) {
nsIInputStream* in = GetInputStream();
NS_ADDREF(in);
*aInstancePtr = in;
return NS_OK;
}
if (aIID.Equals(NS_GET_IID(nsIOutputStream))) {
nsIOutputStream* out = GetOutputStream();
NS_ADDREF(out);
*aInstancePtr = out;
return NS_OK;
}
if (aIID.Equals(NS_GET_IID(nsIPipe)) ||
aIID.Equals(NS_GET_IID(nsISupports))) {
*aInstancePtr = this;
NS_ADDREF_THIS();
return NS_OK;
}
return NS_NOINTERFACE;
}
nsresult
nsPipe::GetReadSegment(PRUint32 segmentLogicalOffset,
const char* *resultSegment,
PRUint32 *resultSegmentLen)
{
nsAutoMonitor mon(mMonitor);
PRInt32 offset = (PRInt32)segmentLogicalOffset;
PRInt32 segCount = mBuffer.GetSegmentCount();
for (PRInt32 i = 0; i < segCount; i++) {
char* segStart = mBuffer.GetSegment(i);
char* segEnd = segStart + mBuffer.GetSegmentSize();
if (mReadCursor == nsnull) {
mReadCursor = segStart;
mReadLimit = segEnd;
}
else if (segStart <= mReadCursor && mReadCursor < segEnd) {
segStart = mReadCursor;
NS_ASSERTION(i == 0, "read cursor not in first segment");
}
if (segStart <= mWriteCursor && mWriteCursor < segEnd) {
segEnd = mWriteCursor;
NS_ASSERTION(i == segCount - 1, "write cursor not in last segment");
}
PRInt32 amt = segEnd - segStart;
if (offset < amt) {
// segmentLogicalOffset is in this segment, so read up to its end
*resultSegmentLen = amt - offset;
*resultSegment = segStart + offset;
return *resultSegmentLen == 0 ? mCondition : NS_OK;
}
offset -= amt;
}
*resultSegmentLen = 0;
*resultSegment = nsnull;
return *resultSegmentLen == 0 ? mCondition : NS_OK;
}
nsresult
nsPipe::GetWriteSegment(char* *resultSegment,
PRUint32 *resultSegmentLen)
{
nsAutoMonitor mon(mMonitor);
*resultSegment = nsnull;
*resultSegmentLen = 0;
if (mWriteCursor == nsnull ||
mWriteCursor == mWriteLimit) {
char* seg = mBuffer.AppendNewSegment();
if (seg == nsnull) {
// buffer is full
return NS_OK;
}
mWriteCursor = seg;
mWriteLimit = seg + mBuffer.GetSegmentSize();
}
*resultSegment = mWriteCursor;
*resultSegmentLen = mWriteLimit - mWriteCursor;
return NS_OK;
}
////////////////////////////////////////////////////////////////////////////////
// nsPipeInputStream methods:
NS_IMETHODIMP
nsPipe::nsPipeInputStream::QueryInterface(const nsIID& aIID, void** aInstancePtr)
{
if (aIID.Equals(NS_GET_IID(nsISearchableInputStream)))
{
nsISearchableInputStream* in = NS_STATIC_CAST(nsISearchableInputStream *, this);
NS_ADDREF(in);
*aInstancePtr = in;
return NS_OK;
}
else
return GET_INPUTSTREAM_PIPE(this)->QueryInterface(aIID, aInstancePtr);
}
NS_IMETHODIMP_(nsrefcnt)
nsPipe::nsPipeInputStream::AddRef(void)
{
mReaderRefCnt++;
return GET_INPUTSTREAM_PIPE(this)->AddRef();
}
NS_IMETHODIMP_(nsrefcnt)
nsPipe::nsPipeInputStream::Release(void)
{
if (--mReaderRefCnt == 0)
Close();
return GET_INPUTSTREAM_PIPE(this)->Release();
}
NS_IMETHODIMP
nsPipe::nsPipeInputStream::Close(void)
{
nsPipe* pipe = GET_INPUTSTREAM_PIPE(this);
nsAutoMonitor mon(pipe->GetMonitor());
pipe->mCondition = NS_BASE_STREAM_CLOSED;
pipe->mBuffer.Empty();
pipe->mWriteCursor = nsnull;
pipe->mWriteLimit = nsnull;
if (mObserver) {
nsCOMPtr<nsIInputStreamObserver> obs = mObserver;
mon.Exit(); // XXXbe avoid deadlock better
nsresult rv = obs->OnClose(this);
mon.Enter();
NS_ASSERTION(NS_SUCCEEDED(rv), "OnClose failed");
// don't return error from OnClose -- its not our problem
mObserver = nsnull; // so we don't call OnClose again
}
return NS_OK;
}
NS_IMETHODIMP
nsPipe::nsPipeInputStream::Available(PRUint32 *result)
{
nsPipe* pipe = GET_INPUTSTREAM_PIPE(this);
nsAutoMonitor mon(pipe->GetMonitor());
PRUint32 len = pipe->mBuffer.GetSize();
if (pipe->mReadCursor)
len -= pipe->mBuffer.GetSegmentSize() - (pipe->mReadLimit - pipe->mReadCursor);
if (pipe->mWriteCursor)
len -= pipe->mWriteLimit - pipe->mWriteCursor;
*result = len;
return NS_OK;
}
NS_IMETHODIMP
nsPipe::nsPipeInputStream::ReadSegments(nsWriteSegmentFun writer,
void* closure,
PRUint32 count,
PRUint32 *readCount)
{
nsPipe* pipe = GET_INPUTSTREAM_PIPE(this);
nsAutoMonitor mon(pipe->GetMonitor());
nsresult rv = NS_OK;
PRUint32 readBufferLen;
const char* readBuffer;
*readCount = 0;
PRUint32 amt = count;
while (amt > 0) {
rv = pipe->GetReadSegment(0, &readBuffer, &readBufferLen);
if (NS_FAILED(rv))
goto done;
if (readBufferLen == 0) {
rv = pipe->mCondition;
if (*readCount > 0 || NS_FAILED(rv))
goto done; // don't Fill if we've got something
if (mObserver) {
mon.Exit(); // XXXbe avoid deadlock better
rv = mObserver->OnEmpty(this);
mon.Enter();
if (NS_FAILED(rv)) goto done;
}
rv = Fill();
if (/*rv == NS_BASE_STREAM_WOULD_BLOCK || */NS_FAILED(rv))
goto done;
// else we filled the pipe, so go around again
continue;
}
readBufferLen = PR_MIN(readBufferLen, amt);
while (readBufferLen > 0) {
PRUint32 writeCount = 0;
mon.Exit(); // XXX avoid deadlock better
rv = writer(this, closure, readBuffer, *readCount, readBufferLen, &writeCount);
mon.Enter();
if (NS_FAILED(rv) && rv != NS_BASE_STREAM_WOULD_BLOCK)
goto done;
NS_ASSERTION(writeCount <= readBufferLen, "writer returned bad writeCount");
#ifdef DEBUG
if (writeCount > 0 && rv == NS_BASE_STREAM_WOULD_BLOCK)
NS_WARNING("Invalid writer implementation: cannot write data and return WOULD_BLOCK");
#endif
readBuffer += writeCount;
readBufferLen -= writeCount;
*readCount += writeCount;
amt -= writeCount;
pipe->mReadCursor += writeCount;
if (writeCount == 0 || rv == NS_BASE_STREAM_WOULD_BLOCK) {
rv = pipe->mCondition;
if (*readCount > 0 || NS_FAILED(rv))
goto done; // don't Fill if we've got something
rv = Fill();
if (/*rv == NS_BASE_STREAM_WOULD_BLOCK || */NS_FAILED(rv))
goto done;
// else we filled the pipe, so go around again
continue;
}
}
if (pipe->mReadCursor == pipe->mReadLimit) {
pipe->mReadCursor = nsnull;
pipe->mReadLimit = nsnull;
PRBool empty = pipe->mBuffer.DeleteFirstSegment();
if (empty && mObserver) {
mon.Exit(); // XXXbe avoid deadlock better
rv = mObserver->OnEmpty(this);
mon.Enter();
mon.Notify(); // wake up writer
if (NS_FAILED(rv))
goto done;
}
}
else if (pipe->mReadCursor == pipe->mWriteCursor) {
if (mObserver) {
mon.Exit(); // XXXbe avoid deadlock better
rv = mObserver->OnEmpty(this);
mon.Enter();
if (NS_FAILED(rv))
goto done;
}
}
}
done:
if (mBlocking && rv == NS_BASE_STREAM_WOULD_BLOCK && *readCount > 0) {
mon.Notify(); // wake up writer
}
if (rv == NS_BASE_STREAM_CLOSED) { // EOF
if (mObserver) {
nsCOMPtr<nsIInputStreamObserver> obs = mObserver;
mon.Exit(); // XXXbe avoid deadlock better
nsresult rv2 = obs->OnClose(this);
mon.Enter();
NS_ASSERTION(NS_SUCCEEDED(rv2), "OnClose failed");
// don't return error from OnClose -- its not our problem
mObserver = nsnull; // so we don't call OnClose again
}
rv = NS_OK;
}
NS_ASSERTION(*readCount <= count, "read more than expected");
return *readCount == 0 ? rv : NS_OK;
}
nsresult
nsPipe::nsPipeInputStream::Fill()
{
nsPipe* pipe = GET_INPUTSTREAM_PIPE(this);
nsAutoMonitor mon(pipe->GetMonitor());
nsresult rv;
while (PR_TRUE) {
// check read buffer again while in the monitor
PRUint32 amt;
const char* buf;
rv = pipe->GetReadSegment(0, &buf, &amt);
if (NS_FAILED(rv) || amt > 0) return rv;
// else notify the writer and wait
rv = mon.Notify();
if (NS_FAILED(rv)) return rv; // interrupted
if (mBlocking) {
rv = mon.Wait();
if (NS_FAILED(rv)) return rv; // interrupted
}
else {
return NS_BASE_STREAM_WOULD_BLOCK;
}
// loop again so that we end up exiting on EOF with
// the right error
}
return NS_OK;
}
static NS_METHOD
nsWriteToRawBuffer(nsIInputStream* inStr,
void* closure,
const char* fromRawSegment,
PRUint32 offset,
PRUint32 count,
PRUint32 *writeCount)
{
char* toBuf = (char*)closure;
memcpy(&toBuf[offset], fromRawSegment, count);
*writeCount = count;
return NS_OK;
}
NS_IMETHODIMP
nsPipe::nsPipeInputStream::Read(char* toBuf, PRUint32 bufLen, PRUint32 *readCount)
{
return ReadSegments(nsWriteToRawBuffer, toBuf, bufLen, readCount);
}
#define COMPARE(s1, s2, i) \
(ignoreCase \
? nsCRT::strncasecmp((const char *)s1, (const char *)s2, (PRUint32)i) \
: nsCRT::strncmp((const char *)s1, (const char *)s2, (PRUint32)i))
NS_IMETHODIMP
nsPipe::nsPipeInputStream::Search(const char *forString,
PRBool ignoreCase,
PRBool *found,
PRUint32 *offsetSearchedTo)
{
nsPipe* pipe = GET_INPUTSTREAM_PIPE(this);
nsresult rv;
const char* bufSeg1;
PRUint32 bufSegLen1;
PRUint32 segmentPos = 0;
PRUint32 strLen = nsCRT::strlen(forString);
rv = pipe->GetReadSegment(segmentPos, &bufSeg1, &bufSegLen1);
if (NS_FAILED(rv) || bufSegLen1 == 0) {
*found = PR_FALSE;
*offsetSearchedTo = segmentPos;
return NS_OK;
}
while (PR_TRUE) {
PRUint32 i;
// check if the string is in the buffer segment
for (i = 0; i < bufSegLen1 - strLen + 1; i++) {
if (COMPARE(&bufSeg1[i], forString, strLen) == 0) {
*found = PR_TRUE;
*offsetSearchedTo = segmentPos + i;
return NS_OK;
}
}
// get the next segment
const char* bufSeg2;
PRUint32 bufSegLen2;
segmentPos += bufSegLen1;
rv = pipe->GetReadSegment(segmentPos, &bufSeg2, &bufSegLen2);
if (NS_FAILED(rv) || bufSegLen2 == 0) {
*found = PR_FALSE;
if (NS_FAILED(pipe->mCondition))
*offsetSearchedTo = segmentPos;
else
*offsetSearchedTo = segmentPos - strLen + 1;
return NS_OK;
}
// check if the string is straddling the next buffer segment
PRUint32 limit = PR_MIN(strLen, bufSegLen2 + 1);
for (i = 0; i < limit; i++) {
PRUint32 strPart1Len = strLen - i - 1;
PRUint32 strPart2Len = strLen - strPart1Len;
const char* strPart2 = &forString[strLen - strPart2Len];
PRUint32 bufSeg1Offset = bufSegLen1 - strPart1Len;
if (COMPARE(&bufSeg1[bufSeg1Offset], forString, strPart1Len) == 0 &&
COMPARE(bufSeg2, strPart2, strPart2Len) == 0) {
*found = PR_TRUE;
*offsetSearchedTo = segmentPos - strPart1Len;
return NS_OK;
}
}
// finally continue with the next buffer
bufSeg1 = bufSeg2;
bufSegLen1 = bufSegLen2;
}
NS_NOTREACHED("can't get here");
return NS_ERROR_FAILURE; // keep compiler happy
}
NS_IMETHODIMP
nsPipe::nsPipeInputStream::GetNonBlocking(PRBool *aNonBlocking)
{
*aNonBlocking = !mBlocking;
return NS_OK;
}
NS_IMETHODIMP
nsPipe::nsPipeInputStream::SetNonBlocking(PRBool aNonBlocking)
{
mBlocking = !aNonBlocking;
return NS_OK;
}
////////////////////////////////////////////////////////////////////////////////
// nsPipeOutputStream methods:
NS_IMETHODIMP
nsPipe::nsPipeOutputStream::QueryInterface(const nsIID& aIID, void** aInstancePtr)
{
return GET_OUTPUTSTREAM_PIPE(this)->QueryInterface(aIID, aInstancePtr);
}
NS_IMETHODIMP_(nsrefcnt)
nsPipe::nsPipeOutputStream::AddRef(void)
{
mWriterRefCnt++;
return GET_OUTPUTSTREAM_PIPE(this)->AddRef();
}
NS_IMETHODIMP_(nsrefcnt)
nsPipe::nsPipeOutputStream::Release(void)
{
if (--mWriterRefCnt == 0)
Close();
return GET_OUTPUTSTREAM_PIPE(this)->Release();
}
NS_IMETHODIMP
nsPipe::nsPipeOutputStream::Close(void)
{
nsPipe* pipe = GET_OUTPUTSTREAM_PIPE(this);
nsAutoMonitor mon(pipe->GetMonitor());
if (pipe->mCondition == NS_OK)
pipe->mCondition = NS_BASE_STREAM_CLOSED;
nsresult rv = mon.Notify(); // wake up the writer
if (NS_FAILED(rv))
return rv;
return NS_OK;
}
NS_IMETHODIMP
nsPipe::nsPipeOutputStream::WriteSegments(nsReadSegmentFun reader,
void* closure,
PRUint32 count,
PRUint32 *writeCount)
{
nsresult rv = NS_OK;
#ifdef MASK_PREMATURE_STREAM_RELEASE
nsCOMPtr<nsIOutputStream> kungFuDeathGrip(this);
#endif
nsPipe* pipe = GET_OUTPUTSTREAM_PIPE(this);
PRUint32 amt = count;
{
nsAutoMonitor mon(pipe->GetMonitor());
*writeCount = 0;
if (NS_FAILED(pipe->mCondition)
&& pipe->mCondition != NS_BASE_STREAM_CLOSED) {
rv = pipe->mCondition;
goto done;
}
while (amt > 0) {
PRUint32 writeBufLen;
char* writeBuf;
rv = pipe->GetWriteSegment(&writeBuf, &writeBufLen);
if (NS_FAILED(rv))
goto done;
if (writeBufLen == 0) {
if (*writeCount > 0 && !mBlocking)
goto done;
if (mObserver/* && *writeCount == 0*/) {
mon.Exit(); // XXXbe avoid deadlock better
rv = mObserver->OnFull(this);
mon.Enter();
if (NS_FAILED(rv)) goto done;
}
rv = Flush();
if (/*rv == NS_BASE_STREAM_WOULD_BLOCK || */NS_FAILED(rv))
goto done;
// else we flushed, so go around again
continue;
}
writeBufLen = PR_MIN(writeBufLen, amt);
while (writeBufLen > 0) {
PRUint32 readCount = 0;
mon.Exit(); // XXX avoid deadlock better
rv = reader(this, closure, writeBuf, *writeCount, writeBufLen, &readCount);
mon.Enter();
if (rv == NS_BASE_STREAM_WOULD_BLOCK) {
NS_ASSERTION(readCount <= writeBufLen, "reader returned bad readCount");
// XXX should not update counters if reader returned WOULD_BLOCK!!
writeBuf += readCount;
writeBufLen -= readCount;
*writeCount += readCount;
amt -= readCount;
pipe->mWriteCursor += readCount;
// The reader didn't have anything else to put in the buffer, so
// call flush to notify the guy downstream, hoping that he'll somehow
// wake up the guy upstream to eventually produce more data for us.
nsresult rv2 = Flush();
if (NS_FAILED(rv2)) {
if (rv2 == NS_BASE_STREAM_WOULD_BLOCK)
rv = pipe->mCondition;
goto done;
}
// else we flushed, so go around again
continue;
}
if (NS_FAILED(rv)) {
// save the failure condition so that we can get it again later
pipe->mCondition = rv;
goto done;
}
if (readCount == 0) { // EOF
pipe->mCondition = NS_BASE_STREAM_CLOSED;
goto done;
}
NS_ASSERTION(readCount <= writeBufLen, "reader returned bad readCount");
writeBuf += readCount;
writeBufLen -= readCount;
*writeCount += readCount;
amt -= readCount;
pipe->mWriteCursor += readCount;
}
if (pipe->mWriteCursor == pipe->mWriteLimit) {
pipe->mWriteCursor = nsnull;
pipe->mWriteLimit = nsnull;
}
}
done:
if (mBlocking && rv == NS_BASE_STREAM_WOULD_BLOCK && *writeCount > 0) {
mon.Notify(); // wake up reader
}
;
} // exit monitor
if (mObserver && *writeCount > 0) {
mObserver->OnWrite(this, *writeCount);
}
NS_ASSERTION(*writeCount <= count, "wrote more than expected");
return *writeCount == 0 ? rv : NS_OK;
}
static NS_METHOD
nsReadFromRawBuffer(nsIOutputStream* outStr,
void* closure,
char* toRawSegment,
PRUint32 offset,
PRUint32 count,
PRUint32 *readCount)
{
const char* fromBuf = (const char*)closure;
memcpy(toRawSegment, &fromBuf[offset], count);
*readCount = count;
return NS_OK;
}
NS_IMETHODIMP
nsPipe::nsPipeOutputStream::Write(const char* fromBuf,
PRUint32 bufLen,
PRUint32 *writeCount)
{
return WriteSegments(nsReadFromRawBuffer, (void*)fromBuf, bufLen, writeCount);
}
NS_IMETHODIMP
nsPipe::nsPipeOutputStream::Flush(void)
{
nsPipe* pipe = GET_OUTPUTSTREAM_PIPE(this);
nsAutoMonitor mon(pipe->GetMonitor());
nsresult rv = NS_OK;
PRBool firstTime = PR_TRUE;
while (PR_TRUE) {
// check write buffer again while in the monitor
PRUint32 amt;
const char* buf;
rv = pipe->GetReadSegment(0, &buf, &amt);
if (firstTime && amt == 0) {
// If we think we needed to flush, yet there's nothing
// in the buffer to read, we must have not been able to
// allocate any segments.
return NS_BASE_STREAM_WOULD_BLOCK;
}
if (NS_FAILED(rv) || amt == 0) return rv;
firstTime = PR_FALSE;
// else notify the reader and wait
rv = mon.Notify();
if (NS_FAILED(rv)) return rv; // interrupted
if (mBlocking) {
rv = mon.Wait();
if (NS_FAILED(rv)) return rv; // interrupted
}
else {
return NS_BASE_STREAM_WOULD_BLOCK;
}
}
return NS_OK;
}
static NS_METHOD
nsReadFromInputStream(nsIOutputStream* outStr,
void* closure,
char* toRawSegment,
PRUint32 offset,
PRUint32 count,
PRUint32 *readCount)
{
nsIInputStream* fromStream = (nsIInputStream*)closure;
return fromStream->Read(toRawSegment, count, readCount);
}
NS_IMETHODIMP
nsPipe::nsPipeOutputStream::WriteFrom(nsIInputStream* fromStream,
PRUint32 count,
PRUint32 *writeCount)
{
return WriteSegments(nsReadFromInputStream, fromStream, count, writeCount);
}
NS_IMETHODIMP
nsPipe::nsPipeOutputStream::GetNonBlocking(PRBool *aNonBlocking)
{
*aNonBlocking = !mBlocking;
return NS_OK;
}
NS_IMETHODIMP
nsPipe::nsPipeOutputStream::SetNonBlocking(PRBool aNonBlocking)
{
mBlocking = !aNonBlocking;
return NS_OK;
}
////////////////////////////////////////////////////////////////////////////////
#ifdef PAGE_MANAGER
static NS_DEFINE_CID(kPageManagerCID, NS_PAGEMANAGER_CID);
#endif
static NS_DEFINE_CID(kMemoryCID, NS_MEMORY_CID);
NS_COM nsresult
NS_NewPipe(nsIInputStream* *inStrResult,
nsIOutputStream* *outStrResult,
PRUint32 segmentSize,
PRUint32 maxSize,
PRBool nonBlockingInput,
PRBool nonBlockingOutput,
nsIMemory* memory)
{
nsresult rv;
NS_ASSERTION(segmentSize > 0, "need to supply segmentSize for buffer");
NS_ASSERTION(maxSize > 0, "need to supply maxSize for buffer");
const nsCID* cid = &kMemoryCID;
#ifdef PAGE_MANAGER
// Take the page manager out altogether because some unices don't
// know how to reserve VM -- only preallocate it which takes up a lot
// of space.
#ifndef XP_MAC
// Don't use page buffers on the mac because we don't really have
// VM there, and they end up being more wasteful:
if (segmentSize >= NS_PAGEMGR_PAGE_SIZE) {
cid = &kPageManagerCID;
}
#endif
#endif
nsCOMPtr<nsIMemory> alloc = memory;
if (alloc == nsnull) {
alloc = do_GetService(*cid, &rv);
if (NS_FAILED(rv)) return rv;
}
nsPipe* pipe = new nsPipe();
if (pipe == nsnull)
return NS_ERROR_OUT_OF_MEMORY;
rv = pipe->Initialize(segmentSize, maxSize,
nonBlockingInput, nonBlockingOutput,
alloc);
if (NS_FAILED(rv)) {
delete pipe;
return rv;
}
*inStrResult = pipe->GetInputStream();
*outStrResult = pipe->GetOutputStream();
NS_ADDREF(*inStrResult);
NS_ADDREF(*outStrResult);
return NS_OK;
}
////////////////////////////////////////////////////////////////////////////////
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