Files
Mozilla/mozilla/netwerk/base/src/nsIncrementalDownload.cpp
darin%meer.net df6db9b6dd fixes bug 291910 "Provide utility for incremental download" r=biesi,dougt sr=bzbarsky a=shaver
git-svn-id: svn://10.0.0.236/trunk@173941 18797224-902f-48f8-a5cc-f745e15eee43
2005-06-01 18:05:36 +00:00

645 lines
16 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* ***** 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.org code.
*
* The Initial Developer of the Original Code is Google Inc.
* Portions created by the Initial Developer are Copyright (C) 2005
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Darin Fisher <darin@meer.net>
*
* 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 "nsIIncrementalDownload.h"
#include "nsIRequestObserver.h"
#include "nsIProgressEventSink.h"
#include "nsIObserverService.h"
#include "nsIObserver.h"
#include "nsIServiceManager.h"
#include "nsILocalFile.h"
#include "nsITimer.h"
#include "nsInt64.h"
#include "nsNetUtil.h"
#include "nsAutoPtr.h"
#include "nsWeakReference.h"
#include "prio.h"
#include "prprf.h"
// Error code used internally by the incremental downloader to cancel the
// network channel when the download is already complete.
#define NS_ERROR_DOWNLOAD_COMPLETE \
NS_ERROR_GENERATE_FAILURE(NS_ERROR_MODULE_GENERAL, 1)
// Default values used to initialize a nsIncrementalDownload object.
#define DEFAULT_CHUNK_SIZE (4096 * 16) // bytes
#define DEFAULT_INTERVAL 60 // seconds
//-----------------------------------------------------------------------------
static nsresult
WriteToFile(nsILocalFile *lf, const char *data, PRUint32 len, PRInt32 flags)
{
PRFileDesc *fd;
nsresult rv = lf->OpenNSPRFileDesc(flags, 0600, &fd);
if (NS_FAILED(rv))
return rv;
rv = PR_Write(fd, data, len) == len ? NS_OK : NS_ERROR_FAILURE;
PR_Close(fd);
return rv;
}
static nsresult
AppendToFile(nsILocalFile *lf, const char *data, PRUint32 len)
{
PRInt32 flags = PR_WRONLY | PR_CREATE_FILE | PR_APPEND;
return WriteToFile(lf, data, len, flags);
}
// maxSize may be -1 if unknown
static void
MakeRangeSpec(const nsInt64 &size, const nsInt64 &maxSize, PRInt32 chunkSize,
PRBool fetchRemaining, nsCString &rangeSpec)
{
rangeSpec.AssignLiteral("bytes=");
rangeSpec.AppendInt(PRInt64(size));
rangeSpec.Append('-');
if (fetchRemaining)
return;
nsInt64 end = size + nsInt64(chunkSize);
if (maxSize != nsInt64(-1) && end > maxSize)
end = maxSize;
end -= 1;
rangeSpec.AppendInt(PRInt64(end));
}
//-----------------------------------------------------------------------------
class nsIncrementalDownload : public nsIIncrementalDownload
, public nsIStreamListener
, public nsIObserver
, public nsSupportsWeakReference
{
public:
NS_DECL_ISUPPORTS
NS_DECL_NSIREQUEST
NS_DECL_NSIINCREMENTALDOWNLOAD
NS_DECL_NSIREQUESTOBSERVER
NS_DECL_NSISTREAMLISTENER
NS_DECL_NSIOBSERVER
nsIncrementalDownload();
private:
~nsIncrementalDownload() {}
nsresult FlushChunk();
nsresult CallOnStartRequest();
void CallOnStopRequest();
nsresult StartTimer(PRInt32 interval);
nsresult ProcessTimeout();
nsresult ReadCurrentSize();
nsCOMPtr<nsIRequestObserver> mObserver;
nsCOMPtr<nsISupports> mObserverContext;
nsCOMPtr<nsIProgressEventSink> mProgressSink;
nsCOMPtr<nsIURI> mURI;
nsCOMPtr<nsIURI> mFinalURI;
nsCOMPtr<nsILocalFile> mDest;
nsCOMPtr<nsIChannel> mChannel;
nsCOMPtr<nsITimer> mTimer;
nsAutoArrayPtr<char> mChunk;
PRInt32 mChunkLen;
PRInt32 mChunkSize;
PRInt32 mInterval;
nsInt64 mTotalSize;
nsInt64 mCurrentSize;
PRUint32 mLoadFlags;
nsresult mStatus;
PRPackedBool mIsPending;
PRPackedBool mDidOnStartRequest;
};
nsIncrementalDownload::nsIncrementalDownload()
: mChunkLen(0)
, mChunkSize(DEFAULT_CHUNK_SIZE)
, mInterval(DEFAULT_INTERVAL)
, mTotalSize(-1)
, mCurrentSize(-1)
, mLoadFlags(LOAD_NORMAL)
, mStatus(NS_OK)
, mIsPending(PR_FALSE)
, mDidOnStartRequest(PR_FALSE)
{
}
nsresult
nsIncrementalDownload::FlushChunk()
{
NS_ASSERTION(mTotalSize != nsInt64(-1), "total size should be known");
if (mChunkLen == 0)
return NS_OK;
nsresult rv = AppendToFile(mDest, mChunk, mChunkLen);
if (NS_FAILED(rv))
return rv;
mCurrentSize += nsInt64(mChunkLen);
mChunkLen = 0;
if (mProgressSink)
mProgressSink->OnProgress(this, mObserverContext,
PRUint64(PRInt64(mCurrentSize)),
PRUint64(PRInt64(mTotalSize)));
return NS_OK;
}
nsresult
nsIncrementalDownload::CallOnStartRequest()
{
if (!mObserver || mDidOnStartRequest)
return NS_OK;
mDidOnStartRequest = PR_TRUE;
return mObserver->OnStartRequest(this, mObserverContext);
}
void
nsIncrementalDownload::CallOnStopRequest()
{
if (!mObserver)
return;
// Ensure that OnStartRequest is always called once before OnStopRequest.
nsresult rv = CallOnStartRequest();
if (NS_SUCCEEDED(mStatus))
mStatus = rv;
mIsPending = PR_FALSE;
mObserver->OnStopRequest(this, mObserverContext, mStatus);
mObserver = nsnull;
mObserverContext = nsnull;
}
nsresult
nsIncrementalDownload::StartTimer(PRInt32 interval)
{
nsresult rv;
mTimer = do_CreateInstance(NS_TIMER_CONTRACTID, &rv);
if (NS_FAILED(rv))
return rv;
return mTimer->Init(this, interval * 1000, nsITimer::TYPE_ONE_SHOT);
}
nsresult
nsIncrementalDownload::ProcessTimeout()
{
NS_ASSERTION(!mChannel, "how can we have a channel?");
// Handle existing error conditions
if (NS_FAILED(mStatus)) {
CallOnStopRequest();
return NS_OK;
}
// Fetch next chunk
nsCOMPtr<nsIChannel> channel;
nsresult rv = NS_NewChannel(getter_AddRefs(channel), mFinalURI);
if (NS_FAILED(rv))
return rv;
nsCOMPtr<nsIHttpChannel> http = do_QueryInterface(channel, &rv);
if (NS_FAILED(rv))
return rv;
NS_ASSERTION(mCurrentSize != nsInt64(-1),
"we should know the current file size by now");
nsCAutoString range;
MakeRangeSpec(mCurrentSize, mTotalSize, mChunkSize, mInterval == 0, range);
rv = http->SetRequestHeader(NS_LITERAL_CSTRING("Range"), range, PR_FALSE);
if (NS_FAILED(rv))
return rv;
rv = channel->AsyncOpen(this, nsnull);
if (NS_FAILED(rv))
return rv;
// Wait to assign mChannel when we know we are going to succeed. This is
// important because we don't want to introduce a reference cycle between
// mChannel and this until we know for a fact that AsyncOpen has succeeded,
// thus ensuring that our stream listener methods will be invoked.
mChannel = channel;
return NS_OK;
}
// Reads the current file size and validates it.
nsresult
nsIncrementalDownload::ReadCurrentSize()
{
nsInt64 size;
nsresult rv = mDest->GetFileSize((PRInt64 *) &size);
if (rv == NS_ERROR_FILE_NOT_FOUND) {
mCurrentSize = 0;
return NS_OK;
}
if (NS_FAILED(rv))
return rv;
mCurrentSize = size;
return NS_OK;
}
// nsISupports
NS_IMPL_ISUPPORTS6(nsIncrementalDownload,
nsIIncrementalDownload,
nsIRequest,
nsIStreamListener,
nsIRequestObserver,
nsIObserver,
nsISupportsWeakReference)
// nsIRequest
NS_IMETHODIMP
nsIncrementalDownload::GetName(nsACString &name)
{
NS_ENSURE_TRUE(mURI, NS_ERROR_NOT_INITIALIZED);
return mURI->GetSpec(name);
}
NS_IMETHODIMP
nsIncrementalDownload::IsPending(PRBool *isPending)
{
*isPending = mIsPending;
return NS_OK;
}
NS_IMETHODIMP
nsIncrementalDownload::GetStatus(nsresult *status)
{
*status = mStatus;
return NS_OK;
}
NS_IMETHODIMP
nsIncrementalDownload::Cancel(nsresult status)
{
NS_ENSURE_ARG(NS_FAILED(status));
// Ignore this cancelation if we're already canceled.
if (NS_FAILED(mStatus))
return NS_OK;
mStatus = status;
// Nothing more to do if callbacks aren't pending.
if (!mIsPending)
return NS_OK;
if (mChannel) {
mChannel->Cancel(mStatus);
NS_ASSERTION(!mTimer, "what is this timer object doing here?");
}
else {
// dispatch a timer callback event to drive invoking our listener's
// OnStopRequest.
if (mTimer)
mTimer->Cancel();
StartTimer(0);
}
return NS_OK;
}
NS_IMETHODIMP
nsIncrementalDownload::Suspend()
{
return NS_ERROR_NOT_IMPLEMENTED;
}
NS_IMETHODIMP
nsIncrementalDownload::Resume()
{
return NS_ERROR_NOT_IMPLEMENTED;
}
NS_IMETHODIMP
nsIncrementalDownload::GetLoadFlags(nsLoadFlags *loadFlags)
{
*loadFlags = mLoadFlags;
return NS_OK;
}
NS_IMETHODIMP
nsIncrementalDownload::SetLoadFlags(nsLoadFlags loadFlags)
{
mLoadFlags = loadFlags;
return NS_OK;
}
NS_IMETHODIMP
nsIncrementalDownload::GetLoadGroup(nsILoadGroup **loadGroup)
{
return NS_ERROR_NOT_IMPLEMENTED;
}
NS_IMETHODIMP
nsIncrementalDownload::SetLoadGroup(nsILoadGroup *loadGroup)
{
return NS_ERROR_NOT_IMPLEMENTED;
}
// nsIIncrementalDownload
NS_IMETHODIMP
nsIncrementalDownload::Init(nsIURI *uri, nsIFile *dest,
PRInt32 chunkSize, PRInt32 interval)
{
// Keep it simple: only allow initialization once
NS_ENSURE_FALSE(mURI, NS_ERROR_ALREADY_INITIALIZED);
mDest = do_QueryInterface(dest);
NS_ENSURE_ARG(mDest);
mURI = uri;
mFinalURI = uri;
if (chunkSize != -1)
mChunkSize = chunkSize;
if (interval != -1)
mInterval = interval;
return NS_OK;
}
NS_IMETHODIMP
nsIncrementalDownload::GetURI(nsIURI **result)
{
NS_IF_ADDREF(*result = mURI);
return NS_OK;
}
NS_IMETHODIMP
nsIncrementalDownload::GetFinalURI(nsIURI **result)
{
NS_IF_ADDREF(*result = mFinalURI);
return NS_OK;
}
NS_IMETHODIMP
nsIncrementalDownload::GetDestination(nsIFile **result)
{
NS_IF_ADDREF(*result = mDest);
return NS_OK;
}
NS_IMETHODIMP
nsIncrementalDownload::GetTotalSize(PRInt64 *result)
{
*result = mTotalSize;
return NS_OK;
}
NS_IMETHODIMP
nsIncrementalDownload::GetCurrentSize(PRInt64 *result)
{
*result = mCurrentSize;
return NS_OK;
}
NS_IMETHODIMP
nsIncrementalDownload::Start(nsIRequestObserver *observer,
nsISupports *context)
{
NS_ENSURE_ARG(observer);
NS_ENSURE_FALSE(mIsPending, NS_ERROR_IN_PROGRESS);
// Observe system shutdown so we can be sure to release any reference held
// between ourselves and the timer. We have the observer service hold a weak
// reference to us, so that we don't have to worry about calling
// RemoveObserver. XXX(darin): The timer code should do this for us.
nsCOMPtr<nsIObserverService> obs =
do_GetService("@mozilla.org/observer-service;1");
if (obs)
obs->AddObserver(this, NS_XPCOM_SHUTDOWN_OBSERVER_ID, PR_TRUE);
nsresult rv = ReadCurrentSize();
if (NS_FAILED(rv))
return rv;
rv = StartTimer(0);
if (NS_FAILED(rv))
return rv;
mObserver = observer;
mObserverContext = context;
mProgressSink = do_QueryInterface(observer); // ok if null
mIsPending = PR_TRUE;
return NS_OK;
}
// nsIRequestObserver
NS_IMETHODIMP
nsIncrementalDownload::OnStartRequest(nsIRequest *request,
nsISupports *context)
{
nsresult rv;
nsCOMPtr<nsIHttpChannel> http = do_QueryInterface(request, &rv);
if (NS_FAILED(rv))
return rv;
// Ensure that we are receiving a 206 response.
PRUint32 code;
rv = http->GetResponseStatus(&code);
if (NS_FAILED(rv))
return rv;
if (code != 206) {
// We may already have the entire file downloaded, in which case
// our request for a range beyond the end of the file would have
// been met with an error response code.
if (code == 416 && mTotalSize == nsInt64(-1)) {
mTotalSize = mCurrentSize;
// Return an error code here to suppress OnDataAvailable.
return NS_ERROR_DOWNLOAD_COMPLETE;
}
NS_WARNING("server response was unexpected");
return NS_ERROR_UNEXPECTED;
}
// Do special processing after the first response.
if (mTotalSize == nsInt64(-1)) {
// Update knowledge of mFinalURI
rv = http->GetURI(getter_AddRefs(mFinalURI));
if (NS_FAILED(rv))
return rv;
// OK, read the Content-Range header to determine the total size of this
// download file.
nsCAutoString buf;
rv = http->GetResponseHeader(NS_LITERAL_CSTRING("Content-Range"), buf);
if (NS_FAILED(rv))
return rv;
PRInt32 slash = buf.FindChar('/');
if (slash == kNotFound) {
NS_WARNING("server returned invalid Content-Range header!");
return NS_ERROR_UNEXPECTED;
}
if (PR_sscanf(buf.get() + slash + 1, "%lld", (PRInt64 *) &mTotalSize) != 1)
return NS_ERROR_UNEXPECTED;
// Notify observer that we are starting...
rv = CallOnStartRequest();
if (NS_FAILED(rv))
return rv;
}
// Adjust mChunkSize accordingly if mCurrentSize is close to mTotalSize.
nsInt64 diff = mTotalSize - mCurrentSize;
if (diff < nsInt64(mChunkSize))
mChunkSize = PRUint32(diff);
mChunk = new char[mChunkSize];
if (!mChunk)
rv = NS_ERROR_OUT_OF_MEMORY;
return rv;
}
NS_IMETHODIMP
nsIncrementalDownload::OnStopRequest(nsIRequest *request,
nsISupports *context,
nsresult status)
{
// Not a real error; just a trick used to suppress OnDataAvailable calls.
if (status == NS_ERROR_DOWNLOAD_COMPLETE)
status = NS_OK;
if (NS_SUCCEEDED(mStatus))
mStatus = status;
if (mChunk) {
if (NS_SUCCEEDED(mStatus))
mStatus = FlushChunk();
mChunk = nsnull; // deletes memory
mChunkLen = 0;
}
mChannel = nsnull;
// Notify listener if we hit an error or finished
if (NS_FAILED(mStatus) || mCurrentSize == mTotalSize) {
CallOnStopRequest();
return NS_OK;
}
return StartTimer(mInterval); // Do next chunk
}
// nsIStreamListener
NS_IMETHODIMP
nsIncrementalDownload::OnDataAvailable(nsIRequest *request,
nsISupports *context,
nsIInputStream *input,
PRUint32 offset,
PRUint32 count)
{
while (count) {
PRUint32 space = mChunkSize - mChunkLen;
PRUint32 n, len = PR_MIN(space, count);
nsresult rv = input->Read(mChunk + mChunkLen, len, &n);
if (NS_FAILED(rv))
return rv;
if (n != len)
return NS_ERROR_UNEXPECTED;
count -= n;
mChunkLen += n;
if (mChunkLen == mChunkSize)
FlushChunk();
}
return NS_OK;
}
// nsIObserver
NS_IMETHODIMP
nsIncrementalDownload::Observe(nsISupports *subject, const char *topic,
const PRUnichar *data)
{
if (strcmp(topic, NS_XPCOM_SHUTDOWN_OBSERVER_ID) == 0) {
Cancel(NS_ERROR_ABORT);
// Since the app is shutting down, we need to go ahead and notify our
// observer here. Otherwise, we would notify them after XPCOM has been
// shutdown or not at all.
CallOnStopRequest();
}
else if (strcmp(topic, NS_TIMER_CALLBACK_TOPIC) == 0) {
mTimer = nsnull;
nsresult rv = ProcessTimeout();
if (NS_FAILED(rv))
Cancel(rv);
}
return NS_OK;
}
extern NS_METHOD
net_NewIncrementalDownload(nsISupports *outer, const nsIID &iid, void **result)
{
if (outer)
return NS_ERROR_NO_AGGREGATION;
nsIncrementalDownload *d = new nsIncrementalDownload();
if (!d)
return NS_ERROR_OUT_OF_MEMORY;
NS_ADDREF(d);
nsresult rv = d->QueryInterface(iid, result);
NS_RELEASE(d);
return rv;
}