NS_IMETHODIMP
nsOutputStreamTransport::OpenOutputStream(PRUint32 flags,
PRUint32 segsize,
PRUint32 segcount,
nsIOutputStream **result)
{
NS_ENSURE_TRUE(!mInProgress, NS_ERROR_IN_PROGRESS);
nsresult rv;
nsCOMPtr<nsIEventTarget> target =
do_GetService(NS_STREAMTRANSPORTSERVICE_CONTRACTID, &rv);
if (NS_FAILED(rv)) return rv;
// XXX if the caller requests an unbuffered stream, then perhaps
// we'd want to simply return mSink; however, then we would
// not be writing to mSink on a background thread. is this ok?
PRBool nonblocking = !(flags & OPEN_BLOCKING);
net_ResolveSegmentParams(segsize, segcount);
nsIMemory *segalloc = net_GetSegmentAlloc(segsize);
nsCOMPtr<nsIAsyncInputStream> pipeIn;
rv = NS_NewPipe2(getter_AddRefs(pipeIn),
getter_AddRefs(mPipeOut),
PR_TRUE, nonblocking,
segsize, segcount, segalloc);
if (NS_FAILED(rv)) return rv;
mInProgress = PR_TRUE;
// startup async copy process...
rv = NS_AsyncCopy(pipeIn, this, target,
NS_ASYNCCOPY_VIA_READSEGMENTS, segsize);
if (NS_SUCCEEDED(rv))
NS_ADDREF(*result = mPipeOut);
return rv;
}
NS_IMETHODIMP
nsInputStreamTransport::OpenInputStream(uint32_t flags,
uint32_t segsize,
uint32_t segcount,
nsIInputStream **result)
{
NS_ENSURE_TRUE(!mInProgress, NS_ERROR_IN_PROGRESS);
nsresult rv;
nsCOMPtr<nsIEventTarget> target =
do_GetService(NS_STREAMTRANSPORTSERVICE_CONTRACTID, &rv);
if (NS_FAILED(rv)) return rv;
// XXX if the caller requests an unbuffered stream, then perhaps
// we'd want to simply return mSource; however, then we would
// not be reading mSource on a background thread. is this ok?
bool nonblocking = !(flags & OPEN_BLOCKING);
net_ResolveSegmentParams(segsize, segcount);
nsCOMPtr<nsIAsyncOutputStream> pipeOut;
rv = NS_NewPipe2(getter_AddRefs(mPipeIn),
getter_AddRefs(pipeOut),
nonblocking, true,
segsize, segcount);
if (NS_FAILED(rv)) return rv;
mInProgress = true;
// startup async copy process...
rv = NS_AsyncCopy(this, pipeOut, target,
NS_ASYNCCOPY_VIA_WRITESEGMENTS, segsize);
if (NS_SUCCEEDED(rv))
NS_ADDREF(*result = mPipeIn);
return rv;
}
// Called on the worker thread.
nsresult
BackgroundFileSaver::ProcessStateChange()
{
nsresult rv;
// We might have been notified because the operation is complete, verify.
if (CheckCompletion()) {
return NS_OK;
}
// Get a copy of the current shared state for the worker thread.
nsCOMPtr<nsIFile> initialTarget;
bool initialTargetKeepPartial;
nsCOMPtr<nsIFile> renamedTarget;
bool renamedTargetKeepPartial;
bool sha256Enabled;
bool append;
{
MutexAutoLock lock(mLock);
initialTarget = mInitialTarget;
initialTargetKeepPartial = mInitialTargetKeepPartial;
renamedTarget = mRenamedTarget;
renamedTargetKeepPartial = mRenamedTargetKeepPartial;
sha256Enabled = mSha256Enabled;
append = mAppend;
// From now on, another attention event needs to be posted if state changes.
mWorkerThreadAttentionRequested = false;
}
// The initial target can only be null if it has never been assigned. In this
// case, there is nothing to do since we never created any output file.
if (!initialTarget) {
return NS_OK;
}
// Determine if we are processing the attention request for the first time.
bool isContinuation = !!mActualTarget;
if (!isContinuation) {
// Assign the target file for the first time.
mActualTarget = initialTarget;
mActualTargetKeepPartial = initialTargetKeepPartial;
}
// Verify whether we have actually been instructed to use a different file.
// This may happen the first time this function is executed, if SetTarget was
// called two times before the worker thread processed the attention request.
bool equalToCurrent = false;
if (renamedTarget) {
rv = mActualTarget->Equals(renamedTarget, &equalToCurrent);
NS_ENSURE_SUCCESS(rv, rv);
if (!equalToCurrent)
{
// If we were asked to rename the file but the initial file did not exist,
// we simply create the file in the renamed location. We avoid this check
// if we have already started writing the output file ourselves.
bool exists = true;
if (!isContinuation) {
rv = mActualTarget->Exists(&exists);
NS_ENSURE_SUCCESS(rv, rv);
}
if (exists) {
// We are moving the previous target file to a different location.
nsCOMPtr<nsIFile> renamedTargetParentDir;
rv = renamedTarget->GetParent(getter_AddRefs(renamedTargetParentDir));
NS_ENSURE_SUCCESS(rv, rv);
nsAutoString renamedTargetName;
rv = renamedTarget->GetLeafName(renamedTargetName);
NS_ENSURE_SUCCESS(rv, rv);
// We must delete any existing target file before moving the current
// one.
rv = renamedTarget->Exists(&exists);
NS_ENSURE_SUCCESS(rv, rv);
if (exists) {
rv = renamedTarget->Remove(false);
NS_ENSURE_SUCCESS(rv, rv);
}
// Move the file. If this fails, we still reference the original file
// in mActualTarget, so that it is deleted if requested. If this
// succeeds, the nsIFile instance referenced by mActualTarget mutates
// and starts pointing to the new file, but we'll discard the reference.
rv = mActualTarget->MoveTo(renamedTargetParentDir, renamedTargetName);
NS_ENSURE_SUCCESS(rv, rv);
}
// Now we can update the actual target file name.
mActualTarget = renamedTarget;
mActualTargetKeepPartial = renamedTargetKeepPartial;
}
}
// Notify if the target file name actually changed.
if (!equalToCurrent) {
// We must clone the nsIFile instance because mActualTarget is not
// immutable, it may change if the target is renamed later.
nsCOMPtr<nsIFile> actualTargetToNotify;
rv = mActualTarget->Clone(getter_AddRefs(actualTargetToNotify));
NS_ENSURE_SUCCESS(rv, rv);
RefPtr<NotifyTargetChangeRunnable> event =
new NotifyTargetChangeRunnable(this, actualTargetToNotify);
NS_ENSURE_TRUE(event, NS_ERROR_FAILURE);
rv = mControlThread->Dispatch(event, NS_DISPATCH_NORMAL);
NS_ENSURE_SUCCESS(rv, rv);
}
if (isContinuation) {
// The pending rename operation might be the last task before finishing. We
// may return here only if we have already created the target file.
if (CheckCompletion()) {
return NS_OK;
}
// Even if the operation did not complete, the pipe input stream may be
// empty and may have been closed already. We detect this case using the
// Available property, because it never returns an error if there is more
// data to be consumed. If the pipe input stream is closed, we just exit
// and wait for more calls like SetTarget or Finish to be invoked on the
// control thread. However, we still truncate the file or create the
// initial digest context if we are expected to do that.
uint64_t available;
rv = mPipeInputStream->Available(&available);
if (NS_FAILED(rv)) {
return NS_OK;
}
}
// Create the digest context if requested and NSS hasn't been shut down.
if (sha256Enabled && !mDigestContext) {
nsNSSShutDownPreventionLock lock;
if (!isAlreadyShutDown()) {
mDigestContext = UniquePK11Context(
PK11_CreateDigestContext(SEC_OID_SHA256));
NS_ENSURE_TRUE(mDigestContext, NS_ERROR_OUT_OF_MEMORY);
}
}
// When we are requested to append to an existing file, we should read the
// existing data and ensure we include it as part of the final hash.
if (mDigestContext && append && !isContinuation) {
nsCOMPtr<nsIInputStream> inputStream;
rv = NS_NewLocalFileInputStream(getter_AddRefs(inputStream),
mActualTarget,
PR_RDONLY | nsIFile::OS_READAHEAD);
if (rv != NS_ERROR_FILE_NOT_FOUND) {
NS_ENSURE_SUCCESS(rv, rv);
char buffer[BUFFERED_IO_SIZE];
while (true) {
uint32_t count;
rv = inputStream->Read(buffer, BUFFERED_IO_SIZE, &count);
NS_ENSURE_SUCCESS(rv, rv);
if (count == 0) {
// We reached the end of the file.
break;
}
nsNSSShutDownPreventionLock lock;
if (isAlreadyShutDown()) {
return NS_ERROR_NOT_AVAILABLE;
}
nsresult rv = MapSECStatus(PK11_DigestOp(mDigestContext.get(),
uint8_t_ptr_cast(buffer),
count));
NS_ENSURE_SUCCESS(rv, rv);
}
rv = inputStream->Close();
NS_ENSURE_SUCCESS(rv, rv);
}
}
// We will append to the initial target file only if it was requested by the
// caller, but we'll always append on subsequent accesses to the target file.
int32_t creationIoFlags;
if (isContinuation) {
creationIoFlags = PR_APPEND;
} else {
creationIoFlags = (append ? PR_APPEND : PR_TRUNCATE) | PR_CREATE_FILE;
}
// Create the target file, or append to it if we already started writing it.
// The 0600 permissions are used while the file is being downloaded, and for
// interrupted downloads. Those may be located in the system temporary
// directory, as well as the target directory, and generally have a ".part"
// extension. Those part files should never be group or world-writable even
// if the umask allows it.
nsCOMPtr<nsIOutputStream> outputStream;
rv = NS_NewLocalFileOutputStream(getter_AddRefs(outputStream),
mActualTarget,
PR_WRONLY | creationIoFlags, 0600);
NS_ENSURE_SUCCESS(rv, rv);
outputStream = NS_BufferOutputStream(outputStream, BUFFERED_IO_SIZE);
if (!outputStream) {
return NS_ERROR_FAILURE;
}
// Wrap the output stream so that it feeds the digest context if needed.
if (mDigestContext) {
// No need to acquire the NSS lock here, DigestOutputStream must acquire it
// in any case before each asynchronous write. Constructing the
// DigestOutputStream cannot fail. Passing mDigestContext to
// DigestOutputStream is safe, because BackgroundFileSaver always outlives
// the outputStream. BackgroundFileSaver is reference-counted before the
// call to AsyncCopy, and mDigestContext is never destroyed before
// AsyncCopyCallback.
outputStream = new DigestOutputStream(outputStream, mDigestContext.get());
}
// Start copying our input to the target file. No errors can be raised past
// this point if the copy starts, since they should be handled by the thread.
{
MutexAutoLock lock(mLock);
rv = NS_AsyncCopy(mPipeInputStream, outputStream, mWorkerThread,
NS_ASYNCCOPY_VIA_READSEGMENTS, 4096, AsyncCopyCallback,
this, false, true, getter_AddRefs(mAsyncCopyContext),
GetProgressCallback());
if (NS_FAILED(rv)) {
NS_WARNING("NS_AsyncCopy failed.");
mAsyncCopyContext = nullptr;
return rv;
}
}
// If the operation succeeded, we must ensure that we keep this object alive
// for the entire duration of the copy, since only the raw pointer will be
// provided as the argument of the AsyncCopyCallback function. We can add the
// reference now, after NS_AsyncCopy returned, because it always starts
// processing asynchronously, and there is no risk that the callback is
// invoked before we reach this point. If the operation failed instead, then
// AsyncCopyCallback will never be called.
NS_ADDREF_THIS();
return NS_OK;
}
