gecko-dev/xpcom/io/nsStreamUtils.cpp

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/* vim:set ts=4 sw=4 sts=4 et cin: */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla 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/MPL/
*
* 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.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 2002
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Darin Fisher <darin@netscape.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 MPL, 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 MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#include "nsStreamUtils.h"
#include "nsCOMPtr.h"
#include "nsIPipe.h"
#include "nsIEventTarget.h"
#include "nsAutoLock.h"
#include "nsString.h"
//-----------------------------------------------------------------------------
class nsInputStreamReadyEvent : public PLEvent
, public nsIInputStreamCallback
{
public:
NS_DECL_ISUPPORTS
nsInputStreamReadyEvent(nsIInputStreamCallback *callback,
nsIEventTarget *target)
: mCallback(callback)
, mTarget(target)
{
}
private:
~nsInputStreamReadyEvent()
{
if (mCallback) {
nsresult rv;
//
// whoa!! looks like we never posted this event. take care to
// release mCallback on the correct thread. if mTarget lives on the
// calling thread, then we are ok. otherwise, we have to try to
// proxy the Release over the right thread. if that thread is dead,
// then there's nothing we can do... better to leak than crash.
//
PRBool val;
rv = mTarget->IsOnCurrentThread(&val);
if (NS_FAILED(rv) || !val) {
nsCOMPtr<nsIInputStreamCallback> event;
NS_NewInputStreamReadyEvent(getter_AddRefs(event), mCallback, mTarget);
mCallback = 0;
if (event) {
rv = event->OnInputStreamReady(nsnull);
if (NS_FAILED(rv)) {
NS_NOTREACHED("leaking stream event");
nsISupports *sup = event;
NS_ADDREF(sup);
}
}
}
}
}
public:
NS_IMETHOD OnInputStreamReady(nsIAsyncInputStream *stream)
{
mStream = stream;
// will be released when event is handled
NS_ADDREF_THIS();
PL_InitEvent(this, nsnull, EventHandler, EventCleanup);
if (NS_FAILED(mTarget->PostEvent(this))) {
NS_WARNING("PostEvent failed");
NS_RELEASE_THIS();
return NS_ERROR_FAILURE;
}
return NS_OK;
}
private:
nsCOMPtr<nsIAsyncInputStream> mStream;
nsCOMPtr<nsIInputStreamCallback> mCallback;
nsCOMPtr<nsIEventTarget> mTarget;
PR_STATIC_CALLBACK(void *) EventHandler(PLEvent *plevent)
{
nsInputStreamReadyEvent *ev = (nsInputStreamReadyEvent *) plevent;
// bypass event delivery if this is a cleanup event...
if (ev->mCallback)
ev->mCallback->OnInputStreamReady(ev->mStream);
ev->mCallback = 0;
return NULL;
}
PR_STATIC_CALLBACK(void) EventCleanup(PLEvent *plevent)
{
nsInputStreamReadyEvent *ev = (nsInputStreamReadyEvent *) plevent;
NS_RELEASE(ev);
}
};
NS_IMPL_THREADSAFE_ISUPPORTS1(nsInputStreamReadyEvent,
nsIInputStreamCallback)
//-----------------------------------------------------------------------------
class nsOutputStreamReadyEvent : public PLEvent
, public nsIOutputStreamCallback
{
public:
NS_DECL_ISUPPORTS
nsOutputStreamReadyEvent(nsIOutputStreamCallback *callback,
nsIEventTarget *target)
: mCallback(callback)
, mTarget(target)
{
}
private:
~nsOutputStreamReadyEvent()
{
if (mCallback) {
nsresult rv;
//
// whoa!! looks like we never posted this event. take care to
// release mCallback on the correct thread. if mTarget lives on the
// calling thread, then we are ok. otherwise, we have to try to
// proxy the Release over the right thread. if that thread is dead,
// then there's nothing we can do... better to leak than crash.
//
PRBool val;
rv = mTarget->IsOnCurrentThread(&val);
if (NS_FAILED(rv) || !val) {
nsCOMPtr<nsIOutputStreamCallback> event;
NS_NewOutputStreamReadyEvent(getter_AddRefs(event), mCallback, mTarget);
mCallback = 0;
if (event) {
rv = event->OnOutputStreamReady(nsnull);
if (NS_FAILED(rv)) {
NS_NOTREACHED("leaking stream event");
nsISupports *sup = event;
NS_ADDREF(sup);
}
}
}
}
}
public:
void Init(nsIOutputStreamCallback *callback, nsIEventTarget *target)
{
mCallback = callback;
mTarget = target;
PL_InitEvent(this, nsnull, EventHandler, EventCleanup);
}
NS_IMETHOD OnOutputStreamReady(nsIAsyncOutputStream *stream)
{
mStream = stream;
// this will be released when the event is handled
NS_ADDREF_THIS();
PL_InitEvent(this, nsnull, EventHandler, EventCleanup);
if (NS_FAILED(mTarget->PostEvent(this))) {
NS_WARNING("PostEvent failed");
NS_RELEASE_THIS();
return NS_ERROR_FAILURE;
}
return NS_OK;
}
private:
nsCOMPtr<nsIAsyncOutputStream> mStream;
nsCOMPtr<nsIOutputStreamCallback> mCallback;
nsCOMPtr<nsIEventTarget> mTarget;
PR_STATIC_CALLBACK(void *) EventHandler(PLEvent *plevent)
{
nsOutputStreamReadyEvent *ev = (nsOutputStreamReadyEvent *) plevent;
if (ev->mCallback)
ev->mCallback->OnOutputStreamReady(ev->mStream);
ev->mCallback = 0;
return NULL;
}
PR_STATIC_CALLBACK(void) EventCleanup(PLEvent *ev)
{
nsOutputStreamReadyEvent *event = (nsOutputStreamReadyEvent *) ev;
NS_RELEASE(event);
}
};
NS_IMPL_THREADSAFE_ISUPPORTS1(nsOutputStreamReadyEvent,
nsIOutputStreamCallback)
//-----------------------------------------------------------------------------
NS_COM nsresult
NS_NewInputStreamReadyEvent(nsIInputStreamCallback **event,
nsIInputStreamCallback *callback,
nsIEventTarget *target)
{
nsInputStreamReadyEvent *ev = new nsInputStreamReadyEvent(callback, target);
if (!ev)
return NS_ERROR_OUT_OF_MEMORY;
NS_ADDREF(*event = ev);
return NS_OK;
}
NS_COM nsresult
NS_NewOutputStreamReadyEvent(nsIOutputStreamCallback **event,
nsIOutputStreamCallback *callback,
nsIEventTarget *target)
{
nsOutputStreamReadyEvent *ev = new nsOutputStreamReadyEvent(callback, target);
if (!ev)
return NS_ERROR_OUT_OF_MEMORY;
NS_ADDREF(*event = ev);
return NS_OK;
}
//-----------------------------------------------------------------------------
// NS_AsyncCopy implementation
// abstract stream copier...
class nsAStreamCopier : public nsIInputStreamCallback
, public nsIOutputStreamCallback
{
public:
NS_DECL_ISUPPORTS
nsAStreamCopier()
: mLock(nsnull)
, mCallback(nsnull)
, mClosure(nsnull)
, mChunkSize(0)
, mEventInProcess(PR_FALSE)
, mEventIsPending(PR_FALSE)
{
}
// virtual since subclasses call superclass Release()
virtual ~nsAStreamCopier()
{
if (mLock)
PR_DestroyLock(mLock);
}
// kick off the async copy...
nsresult Start(nsIInputStream *source,
nsIOutputStream *sink,
nsIEventTarget *target,
nsAsyncCopyCallbackFun callback,
void *closure,
PRUint32 chunksize)
{
mSource = source;
mSink = sink;
mTarget = target;
mCallback = callback;
mClosure = closure;
mChunkSize = chunksize;
mLock = PR_NewLock();
if (!mLock)
return NS_ERROR_OUT_OF_MEMORY;
mAsyncSource = do_QueryInterface(mSource);
mAsyncSink = do_QueryInterface(mSink);
return PostContinuationEvent();
}
// implemented by subclasses, returns number of bytes copied and
// sets source and sink condition before returning.
virtual PRUint32 DoCopy(nsresult *sourceCondition, nsresult *sinkCondition) = 0;
void Process()
{
if (!mSource || !mSink)
return;
nsresult sourceCondition, sinkCondition;
// ok, copy data from source to sink.
for (;;) {
PRUint32 n = DoCopy(&sourceCondition, &sinkCondition);
if (NS_FAILED(sourceCondition) || NS_FAILED(sinkCondition) || n == 0) {
if (sourceCondition == NS_BASE_STREAM_WOULD_BLOCK && mAsyncSource) {
// need to wait for more data from source. while waiting for
// more source data, be sure to observe failures on output end.
mAsyncSource->AsyncWait(this, 0, 0, nsnull);
if (mAsyncSink)
mAsyncSink->AsyncWait(this,
nsIAsyncOutputStream::WAIT_CLOSURE_ONLY,
0, nsnull);
}
else if (sinkCondition == NS_BASE_STREAM_WOULD_BLOCK && mAsyncSink) {
// need to wait for more room in the sink. while waiting for
// more room in the sink, be sure to observer failures on the
// input end.
mAsyncSink->AsyncWait(this, 0, 0, nsnull);
if (mAsyncSource)
mAsyncSource->AsyncWait(this,
nsIAsyncInputStream::WAIT_CLOSURE_ONLY,
0, nsnull);
}
else {
// close source
if (mAsyncSource)
mAsyncSource->CloseWithStatus(sinkCondition);
else
mSource->Close();
mAsyncSource = nsnull;
mSource = nsnull;
// close sink
if (mAsyncSink)
mAsyncSink->CloseWithStatus(sourceCondition);
else
mSink->Close();
mAsyncSink = nsnull;
mSink = nsnull;
// notify state complete...
if (mCallback) {
nsresult status = sourceCondition;
if (NS_SUCCEEDED(status))
status = sinkCondition;
if (status == NS_BASE_STREAM_CLOSED)
status = NS_OK;
mCallback(mClosure, status);
}
}
break;
}
}
}
NS_IMETHOD OnInputStreamReady(nsIAsyncInputStream *source)
{
PostContinuationEvent();
return NS_OK;
}
NS_IMETHOD OnOutputStreamReady(nsIAsyncOutputStream *sink)
{
PostContinuationEvent();
return NS_OK;
}
PR_STATIC_CALLBACK(void*) HandleContinuationEvent(PLEvent *event)
{
nsAStreamCopier *self = (nsAStreamCopier *) event->owner;
self->Process();
// clear "in process" flag and post any pending continuation event
nsAutoLock lock(self->mLock);
self->mEventInProcess = PR_FALSE;
if (self->mEventIsPending) {
self->mEventIsPending = PR_FALSE;
self->PostContinuationEvent_Locked();
}
return nsnull;
}
PR_STATIC_CALLBACK(void) DestroyContinuationEvent(PLEvent *event)
{
nsAStreamCopier *self = (nsAStreamCopier *) event->owner;
NS_RELEASE(self);
delete event;
}
nsresult PostContinuationEvent()
{
// we cannot post a continuation event if there is currently
// an event in process. doing so could result in Process being
// run simultaneously on multiple threads, so we mark the event
// as pending, and if an event is already in process then we
// just let that existing event take care of posting the real
// continuation event.
nsAutoLock lock(mLock);
return PostContinuationEvent_Locked();
}
nsresult PostContinuationEvent_Locked()
{
nsresult rv = NS_OK;
if (mEventInProcess)
mEventIsPending = PR_TRUE;
else {
PLEvent *event = new PLEvent;
if (!event)
rv = NS_ERROR_OUT_OF_MEMORY;
else {
NS_ADDREF_THIS();
PL_InitEvent(event, this,
HandleContinuationEvent,
DestroyContinuationEvent);
rv = mTarget->PostEvent(event);
if (NS_SUCCEEDED(rv))
mEventInProcess = PR_TRUE;
else {
NS_ERROR("unable to post continuation event");
PL_DestroyEvent(event);
}
}
}
return rv;
}
protected:
nsCOMPtr<nsIInputStream> mSource;
nsCOMPtr<nsIOutputStream> mSink;
nsCOMPtr<nsIAsyncInputStream> mAsyncSource;
nsCOMPtr<nsIAsyncOutputStream> mAsyncSink;
nsCOMPtr<nsIEventTarget> mTarget;
PRLock *mLock;
nsAsyncCopyCallbackFun mCallback;
void *mClosure;
PRUint32 mChunkSize;
PRPackedBool mEventInProcess;
PRPackedBool mEventIsPending;
};
NS_IMPL_THREADSAFE_ISUPPORTS2(nsAStreamCopier,
nsIInputStreamCallback,
nsIOutputStreamCallback)
class nsStreamCopierIB : public nsAStreamCopier
{
public:
nsStreamCopierIB() : nsAStreamCopier() {}
virtual ~nsStreamCopierIB() {}
struct ReadSegmentsState {
nsIOutputStream *mSink;
nsresult mSinkCondition;
};
static NS_METHOD ConsumeInputBuffer(nsIInputStream *inStr,
void *closure,
const char *buffer,
PRUint32 offset,
PRUint32 count,
PRUint32 *countWritten)
{
ReadSegmentsState *state = (ReadSegmentsState *) closure;
nsresult rv = state->mSink->Write(buffer, count, countWritten);
if (NS_FAILED(rv))
state->mSinkCondition = rv;
else if (*countWritten == 0)
state->mSinkCondition = NS_BASE_STREAM_CLOSED;
return state->mSinkCondition;
}
PRUint32 DoCopy(nsresult *sourceCondition, nsresult *sinkCondition)
{
ReadSegmentsState state;
state.mSink = mSink;
state.mSinkCondition = NS_OK;
PRUint32 n;
*sourceCondition =
mSource->ReadSegments(ConsumeInputBuffer, &state, mChunkSize, &n);
*sinkCondition = state.mSinkCondition;
return n;
}
};
class nsStreamCopierOB : public nsAStreamCopier
{
public:
nsStreamCopierOB() : nsAStreamCopier() {}
virtual ~nsStreamCopierOB() {}
struct WriteSegmentsState {
nsIInputStream *mSource;
nsresult mSourceCondition;
};
static NS_METHOD FillOutputBuffer(nsIOutputStream *outStr,
void *closure,
char *buffer,
PRUint32 offset,
PRUint32 count,
PRUint32 *countRead)
{
WriteSegmentsState *state = (WriteSegmentsState *) closure;
nsresult rv = state->mSource->Read(buffer, count, countRead);
if (NS_FAILED(rv))
state->mSourceCondition = rv;
else if (*countRead == 0)
state->mSourceCondition = NS_BASE_STREAM_CLOSED;
return state->mSourceCondition;
}
PRUint32 DoCopy(nsresult *sourceCondition, nsresult *sinkCondition)
{
WriteSegmentsState state;
state.mSource = mSource;
state.mSourceCondition = NS_OK;
PRUint32 n;
*sinkCondition =
mSink->WriteSegments(FillOutputBuffer, &state, mChunkSize, &n);
*sourceCondition = state.mSourceCondition;
return n;
}
};
//-----------------------------------------------------------------------------
NS_COM nsresult
NS_AsyncCopy(nsIInputStream *source,
nsIOutputStream *sink,
nsIEventTarget *target,
nsAsyncCopyMode mode,
PRUint32 chunkSize,
nsAsyncCopyCallbackFun callback,
void *closure)
{
NS_ASSERTION(target, "non-null target required");
nsresult rv;
nsAStreamCopier *copier;
if (mode == NS_ASYNCCOPY_VIA_READSEGMENTS)
copier = new nsStreamCopierIB();
else
copier = new nsStreamCopierOB();
if (!copier)
return NS_ERROR_OUT_OF_MEMORY;
// Start() takes an owning ref to the copier...
NS_ADDREF(copier);
rv = copier->Start(source, sink, target, callback, closure, chunkSize);
NS_RELEASE(copier);
return rv;
}
//-----------------------------------------------------------------------------
NS_COM nsresult
NS_ConsumeStream(nsIInputStream *stream, PRUint32 maxCount, nsACString &result)
{
nsresult rv = NS_OK;
result.Truncate();
while (maxCount) {
PRUint32 avail;
rv = stream->Available(&avail);
if (NS_FAILED(rv)) {
if (rv == NS_BASE_STREAM_CLOSED)
rv = NS_OK;
break;
}
if (avail == 0)
break;
if (avail > maxCount)
avail = maxCount;
// resize result buffer
PRUint32 length = result.Length();
result.SetLength(length + avail);
if (result.Length() != (length + avail))
return NS_ERROR_OUT_OF_MEMORY;
char *buf = result.BeginWriting() + length;
PRUint32 n;
rv = stream->Read(buf, avail, &n);
if (NS_FAILED(rv))
break;
if (n != avail)
result.SetLength(length + n);
if (n == 0)
break;
maxCount -= n;
}
return rv;
}
//-----------------------------------------------------------------------------
static NS_METHOD
TestInputStream(nsIInputStream *inStr,
void *closure,
const char *buffer,
PRUint32 offset,
PRUint32 count,
PRUint32 *countWritten)
{
PRBool *result = NS_STATIC_CAST(PRBool *, closure);
*result = PR_TRUE;
return NS_ERROR_ABORT; // don't call me anymore
}
NS_COM PRBool
NS_InputStreamIsBuffered(nsIInputStream *stream)
{
PRBool result = PR_FALSE;
PRUint32 n;
stream->ReadSegments(TestInputStream, &result, 1, &n);
return result;
}
static NS_METHOD
TestOutputStream(nsIOutputStream *outStr,
void *closure,
char *buffer,
PRUint32 offset,
PRUint32 count,
PRUint32 *countRead)
{
PRBool *result = NS_STATIC_CAST(PRBool *, closure);
*result = PR_TRUE;
return NS_ERROR_ABORT; // don't call me anymore
}
NS_COM PRBool
NS_OutputStreamIsBuffered(nsIOutputStream *stream)
{
PRBool result = PR_FALSE;
PRUint32 n;
stream->WriteSegments(TestOutputStream, &result, 1, &n);
return result;
}
//-----------------------------------------------------------------------------
NS_COM NS_METHOD
NS_CopySegmentToStream(nsIInputStream *inStr,
void *closure,
const char *buffer,
PRUint32 offset,
PRUint32 count,
PRUint32 *countWritten)
{
nsIOutputStream *outStr = NS_STATIC_CAST(nsIOutputStream *, closure);
*countWritten = 0;
while (count) {
PRUint32 n;
nsresult rv = outStr->Write(buffer, count, &n);
if (NS_FAILED(rv))
return rv;
buffer += n;
count -= n;
*countWritten += n;
}
return NS_OK;
}
NS_COM NS_METHOD
NS_CopySegmentToBuffer(nsIInputStream *inStr,
void *closure,
const char *buffer,
PRUint32 offset,
PRUint32 count,
PRUint32 *countWritten)
{
char *toBuf = NS_STATIC_CAST(char *, closure);
memcpy(&toBuf[offset], buffer, count);
*countWritten = count;
return NS_OK;
}
NS_COM NS_METHOD
NS_DiscardSegment(nsIInputStream *inStr,
void *closure,
const char *buffer,
PRUint32 offset,
PRUint32 count,
PRUint32 *countWritten)
{
*countWritten = count;
return NS_OK;
}
//-----------------------------------------------------------------------------
NS_COM NS_METHOD
NS_WriteSegmentThunk(nsIInputStream *inStr,
void *closure,
const char *buffer,
PRUint32 offset,
PRUint32 count,
PRUint32 *countWritten)
{
nsWriteSegmentThunk *thunk = NS_STATIC_CAST(nsWriteSegmentThunk *, closure);
return thunk->mFun(thunk->mStream, thunk->mClosure, buffer, offset, count,
countWritten);
}