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gecko-dev/netwerk/base/nsFileStreams.cpp

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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* 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 "ipc/IPCMessageUtils.h"
#if defined(XP_UNIX) || defined(XP_BEOS)
#include <unistd.h>
#elif defined(XP_WIN)
#include <windows.h>
#include "nsILocalFileWin.h"
#else
// XXX add necessary include file for ftruncate (or equivalent)
#endif
#include "private/pprio.h"
#include "nsFileStreams.h"
#include "nsIFile.h"
#include "nsReadLine.h"
#include "nsIClassInfoImpl.h"
#include "mozilla/ipc/InputStreamUtils.h"
#include "mozilla/Unused.h"
#include "mozilla/FileUtils.h"
#include "nsNetCID.h"
#include "nsXULAppAPI.h"
typedef mozilla::ipc::FileDescriptor::PlatformHandleType FileHandleType;
using namespace mozilla::ipc;
using mozilla::DebugOnly;
using mozilla::Maybe;
using mozilla::Nothing;
using mozilla::Some;
////////////////////////////////////////////////////////////////////////////////
// nsFileStreamBase
nsFileStreamBase::nsFileStreamBase()
: mFD(nullptr)
, mBehaviorFlags(0)
, mState(eUnitialized)
, mErrorValue(NS_ERROR_FAILURE)
{
}
nsFileStreamBase::~nsFileStreamBase()
{
// We don't want to try to rewrind the stream when shutting down.
mBehaviorFlags &= ~nsIFileInputStream::REOPEN_ON_REWIND;
Close();
}
NS_IMPL_ISUPPORTS(nsFileStreamBase,
nsISeekableStream,
nsIFileMetadata)
NS_IMETHODIMP
nsFileStreamBase::Seek(int32_t whence, int64_t offset)
{
nsresult rv = DoPendingOpen();
NS_ENSURE_SUCCESS(rv, rv);
int64_t cnt = PR_Seek64(mFD, offset, (PRSeekWhence)whence);
if (cnt == int64_t(-1)) {
return NS_ErrorAccordingToNSPR();
}
return NS_OK;
}
NS_IMETHODIMP
nsFileStreamBase::Tell(int64_t *result)
{
nsresult rv = DoPendingOpen();
NS_ENSURE_SUCCESS(rv, rv);
int64_t cnt = PR_Seek64(mFD, 0, PR_SEEK_CUR);
if (cnt == int64_t(-1)) {
return NS_ErrorAccordingToNSPR();
}
*result = cnt;
return NS_OK;
}
NS_IMETHODIMP
nsFileStreamBase::SetEOF()
{
nsresult rv = DoPendingOpen();
NS_ENSURE_SUCCESS(rv, rv);
#if defined(XP_UNIX) || defined(XP_BEOS)
// Some system calls require an EOF offset.
int64_t offset;
rv = Tell(&offset);
if (NS_FAILED(rv)) return rv;
#endif
#if defined(XP_UNIX) || defined(XP_BEOS)
if (ftruncate(PR_FileDesc2NativeHandle(mFD), offset) != 0) {
NS_ERROR("ftruncate failed");
return NS_ERROR_FAILURE;
}
#elif defined(XP_WIN)
if (!SetEndOfFile((HANDLE) PR_FileDesc2NativeHandle(mFD))) {
NS_ERROR("SetEndOfFile failed");
return NS_ERROR_FAILURE;
}
#else
// XXX not implemented
#endif
return NS_OK;
}
NS_IMETHODIMP
nsFileStreamBase::GetSize(int64_t* _retval)
{
nsresult rv = DoPendingOpen();
NS_ENSURE_SUCCESS(rv, rv);
PRFileInfo64 info;
if (PR_GetOpenFileInfo64(mFD, &info) == PR_FAILURE) {
return NS_BASE_STREAM_OSERROR;
}
*_retval = int64_t(info.size);
return NS_OK;
}
NS_IMETHODIMP
nsFileStreamBase::GetLastModified(int64_t* _retval)
{
nsresult rv = DoPendingOpen();
NS_ENSURE_SUCCESS(rv, rv);
PRFileInfo64 info;
if (PR_GetOpenFileInfo64(mFD, &info) == PR_FAILURE) {
return NS_BASE_STREAM_OSERROR;
}
int64_t modTime = int64_t(info.modifyTime);
if (modTime == 0) {
*_retval = 0;
}
else {
*_retval = modTime / int64_t(PR_USEC_PER_MSEC);
}
return NS_OK;
}
NS_IMETHODIMP
nsFileStreamBase::GetFileDescriptor(PRFileDesc** _retval)
{
nsresult rv = DoPendingOpen();
NS_ENSURE_SUCCESS(rv, rv);
*_retval = mFD;
return NS_OK;
}
nsresult
nsFileStreamBase::Close()
{
CleanUpOpen();
nsresult rv = NS_OK;
if (mFD) {
if (PR_Close(mFD) == PR_FAILURE)
rv = NS_BASE_STREAM_OSERROR;
mFD = nullptr;
mState = eClosed;
}
return rv;
}
nsresult
nsFileStreamBase::Available(uint64_t* aResult)
{
nsresult rv = DoPendingOpen();
NS_ENSURE_SUCCESS(rv, rv);
// PR_Available with files over 4GB returns an error, so we have to
// use the 64-bit version of PR_Available.
int64_t avail = PR_Available64(mFD);
if (avail == -1) {
return NS_ErrorAccordingToNSPR();
}
// If available is greater than 4GB, return 4GB
*aResult = (uint64_t)avail;
return NS_OK;
}
nsresult
nsFileStreamBase::Read(char* aBuf, uint32_t aCount, uint32_t* aResult)
{
nsresult rv = DoPendingOpen();
if (rv == NS_BASE_STREAM_CLOSED) {
*aResult = 0;
return NS_OK;
}
if (NS_FAILED(rv)) {
return rv;
}
int32_t bytesRead = PR_Read(mFD, aBuf, aCount);
if (bytesRead == -1) {
return NS_ErrorAccordingToNSPR();
}
*aResult = bytesRead;
return NS_OK;
}
nsresult
nsFileStreamBase::ReadSegments(nsWriteSegmentFun aWriter, void* aClosure,
uint32_t aCount, uint32_t* aResult)
{
// ReadSegments is not implemented because it would be inefficient when
// the writer does not consume all data. If you want to call ReadSegments,
// wrap a BufferedInputStream around the file stream. That will call
// Read().
return NS_ERROR_NOT_IMPLEMENTED;
}
nsresult
nsFileStreamBase::IsNonBlocking(bool *aNonBlocking)
{
*aNonBlocking = false;
return NS_OK;
}
nsresult
nsFileStreamBase::Flush(void)
{
nsresult rv = DoPendingOpen();
NS_ENSURE_SUCCESS(rv, rv);
int32_t cnt = PR_Sync(mFD);
if (cnt == -1) {
return NS_ErrorAccordingToNSPR();
}
return NS_OK;
}
nsresult
nsFileStreamBase::Write(const char *buf, uint32_t count, uint32_t *result)
{
nsresult rv = DoPendingOpen();
NS_ENSURE_SUCCESS(rv, rv);
int32_t cnt = PR_Write(mFD, buf, count);
if (cnt == -1) {
return NS_ErrorAccordingToNSPR();
}
*result = cnt;
return NS_OK;
}
nsresult
nsFileStreamBase::WriteFrom(nsIInputStream *inStr, uint32_t count, uint32_t *_retval)
{
NS_NOTREACHED("WriteFrom (see source comment)");
return NS_ERROR_NOT_IMPLEMENTED;
// File streams intentionally do not support this method.
// If you need something like this, then you should wrap
// the file stream using nsIBufferedOutputStream
}
nsresult
nsFileStreamBase::WriteSegments(nsReadSegmentFun reader, void * closure, uint32_t count, uint32_t *_retval)
{
return NS_ERROR_NOT_IMPLEMENTED;
// File streams intentionally do not support this method.
// If you need something like this, then you should wrap
// the file stream using nsIBufferedOutputStream
}
nsresult
nsFileStreamBase::MaybeOpen(nsIFile* aFile, int32_t aIoFlags,
int32_t aPerm, bool aDeferred)
{
NS_ENSURE_STATE(aFile);
mOpenParams.ioFlags = aIoFlags;
mOpenParams.perm = aPerm;
if (aDeferred) {
// Clone the file, as it may change between now and the deferred open
nsCOMPtr<nsIFile> file;
nsresult rv = aFile->Clone(getter_AddRefs(file));
NS_ENSURE_SUCCESS(rv, rv);
mOpenParams.localFile = do_QueryInterface(file);
NS_ENSURE_TRUE(mOpenParams.localFile, NS_ERROR_UNEXPECTED);
mState = eDeferredOpen;
return NS_OK;
}
mOpenParams.localFile = aFile;
// Following call open() at main thread.
// Main thread might be blocked, while open a remote file.
return DoOpen();
}
void
nsFileStreamBase::CleanUpOpen()
{
mOpenParams.localFile = nullptr;
}
nsresult
nsFileStreamBase::DoOpen()
{
MOZ_ASSERT(mState == eDeferredOpen || mState == eUnitialized ||
mState == eClosed);
NS_ASSERTION(!mFD, "Already have a file descriptor!");
NS_ASSERTION(mOpenParams.localFile, "Must have a file to open");
PRFileDesc* fd;
nsresult rv;
if (mOpenParams.ioFlags & PR_CREATE_FILE) {
nsCOMPtr<nsIFile> parent;
mOpenParams.localFile->GetParent(getter_AddRefs(parent));
// Result doesn't need to be checked. If the file's parent path does not
// exist, make it. If it does exist, do nothing.
if (parent) {
Unused << parent->Create(nsIFile::DIRECTORY_TYPE, 0755);
}
}
#ifdef XP_WIN
if (mBehaviorFlags & nsIFileInputStream::SHARE_DELETE) {
nsCOMPtr<nsILocalFileWin> file = do_QueryInterface(mOpenParams.localFile);
MOZ_ASSERT(file);
rv = file->OpenNSPRFileDescShareDelete(mOpenParams.ioFlags,
mOpenParams.perm,
&fd);
} else
#endif // XP_WIN
{
rv = mOpenParams.localFile->OpenNSPRFileDesc(mOpenParams.ioFlags,
mOpenParams.perm,
&fd);
}
CleanUpOpen();
if (NS_FAILED(rv)) {
mState = eError;
mErrorValue = rv;
return rv;
}
mFD = fd;
mState = eOpened;
return NS_OK;
}
nsresult
nsFileStreamBase::DoPendingOpen()
{
switch (mState) {
case eUnitialized:
MOZ_CRASH("This should not happen.");
return NS_ERROR_FAILURE;
case eDeferredOpen:
return DoOpen();
case eOpened:
MOZ_ASSERT(mFD);
if (NS_WARN_IF(!mFD)) {
return NS_ERROR_FAILURE;
}
return NS_OK;
case eClosed:
MOZ_ASSERT(!mFD);
return NS_BASE_STREAM_CLOSED;
case eError:
return mErrorValue;
}
MOZ_CRASH("Invalid mState value.");
return NS_ERROR_FAILURE;
}
////////////////////////////////////////////////////////////////////////////////
// nsFileInputStream
NS_IMPL_ADDREF_INHERITED(nsFileInputStream, nsFileStreamBase)
NS_IMPL_RELEASE_INHERITED(nsFileInputStream, nsFileStreamBase)
NS_IMPL_CLASSINFO(nsFileInputStream, nullptr, nsIClassInfo::THREADSAFE,
NS_LOCALFILEINPUTSTREAM_CID)
NS_INTERFACE_MAP_BEGIN(nsFileInputStream)
NS_INTERFACE_MAP_ENTRY(nsIInputStream)
NS_INTERFACE_MAP_ENTRY(nsIFileInputStream)
NS_INTERFACE_MAP_ENTRY(nsILineInputStream)
NS_INTERFACE_MAP_ENTRY(nsIIPCSerializableInputStream)
NS_IMPL_QUERY_CLASSINFO(nsFileInputStream)
NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsICloneableInputStream, IsCloneable())
NS_INTERFACE_MAP_END_INHERITING(nsFileStreamBase)
NS_IMPL_CI_INTERFACE_GETTER(nsFileInputStream,
nsIInputStream,
nsIFileInputStream,
nsISeekableStream,
nsILineInputStream)
nsresult
nsFileInputStream::Create(nsISupports *aOuter, REFNSIID aIID, void **aResult)
{
NS_ENSURE_NO_AGGREGATION(aOuter);
nsFileInputStream* stream = new nsFileInputStream();
if (stream == nullptr)
return NS_ERROR_OUT_OF_MEMORY;
NS_ADDREF(stream);
nsresult rv = stream->QueryInterface(aIID, aResult);
NS_RELEASE(stream);
return rv;
}
nsresult
nsFileInputStream::Open(nsIFile* aFile, int32_t aIOFlags, int32_t aPerm)
{
nsresult rv = NS_OK;
// If the previous file is open, close it
if (mFD) {
rv = Close();
if (NS_FAILED(rv)) return rv;
}
// Open the file
if (aIOFlags == -1)
aIOFlags = PR_RDONLY;
if (aPerm == -1)
aPerm = 0;
return MaybeOpen(aFile, aIOFlags, aPerm,
mBehaviorFlags & nsIFileInputStream::DEFER_OPEN);
}
NS_IMETHODIMP
nsFileInputStream::Init(nsIFile* aFile, int32_t aIOFlags, int32_t aPerm,
int32_t aBehaviorFlags)
{
NS_ENSURE_TRUE(!mFD, NS_ERROR_ALREADY_INITIALIZED);
NS_ENSURE_TRUE(mState == eUnitialized || mState == eClosed,
NS_ERROR_ALREADY_INITIALIZED);
mBehaviorFlags = aBehaviorFlags;
mState = eUnitialized;
mFile = aFile;
mIOFlags = aIOFlags;
mPerm = aPerm;
return Open(aFile, aIOFlags, aPerm);
}
NS_IMETHODIMP
nsFileInputStream::Close()
{
// Get the cache position at the time the file was close. This allows
// NS_SEEK_CUR on a closed file that has been opened with
// REOPEN_ON_REWIND.
if (mBehaviorFlags & REOPEN_ON_REWIND) {
// Get actual position. Not one modified by subclasses
nsFileStreamBase::Tell(&mCachedPosition);
}
// null out mLineBuffer in case Close() is called again after failing
mLineBuffer = nullptr;
return nsFileStreamBase::Close();
}
NS_IMETHODIMP
nsFileInputStream::Read(char* aBuf, uint32_t aCount, uint32_t* _retval)
{
nsresult rv = nsFileStreamBase::Read(aBuf, aCount, _retval);
if (rv == NS_ERROR_FILE_NOT_FOUND) {
// Don't warn if this is a deffered file not found.
return rv;
}
NS_ENSURE_SUCCESS(rv, rv);
// Check if we're at the end of file and need to close
if (mBehaviorFlags & CLOSE_ON_EOF && *_retval == 0) {
Close();
}
return NS_OK;
}
NS_IMETHODIMP
nsFileInputStream::ReadLine(nsACString& aLine, bool* aResult)
{
if (!mLineBuffer) {
mLineBuffer = new nsLineBuffer<char>;
}
return NS_ReadLine(this, mLineBuffer.get(), aLine, aResult);
}
NS_IMETHODIMP
nsFileInputStream::Seek(int32_t aWhence, int64_t aOffset)
{
return SeekInternal(aWhence, aOffset);
}
nsresult
nsFileInputStream::SeekInternal(int32_t aWhence, int64_t aOffset, bool aClearBuf)
{
nsresult rv = DoPendingOpen();
if (rv != NS_OK && rv != NS_BASE_STREAM_CLOSED) {
return rv;
}
if (aClearBuf) {
mLineBuffer = nullptr;
}
if (rv == NS_BASE_STREAM_CLOSED) {
if (mBehaviorFlags & REOPEN_ON_REWIND) {
rv = Open(mFile, mIOFlags, mPerm);
NS_ENSURE_SUCCESS(rv, rv);
// If the file was closed, and we do a relative seek, use the
// position we cached when we closed the file to seek to the right
// location.
if (aWhence == NS_SEEK_CUR) {
aWhence = NS_SEEK_SET;
aOffset += mCachedPosition;
}
} else {
return NS_BASE_STREAM_CLOSED;
}
}
return nsFileStreamBase::Seek(aWhence, aOffset);
}
NS_IMETHODIMP
nsFileInputStream::Tell(int64_t *aResult)
{
return nsFileStreamBase::Tell(aResult);
}
NS_IMETHODIMP
nsFileInputStream::Available(uint64_t *aResult)
{
return nsFileStreamBase::Available(aResult);
}
void
nsFileInputStream::Serialize(InputStreamParams& aParams,
FileDescriptorArray& aFileDescriptors)
{
FileInputStreamParams params;
if (NS_SUCCEEDED(DoPendingOpen())) {
MOZ_ASSERT(mFD);
FileHandleType fd = FileHandleType(PR_FileDesc2NativeHandle(mFD));
NS_ASSERTION(fd, "This should never be null!");
DebugOnly<FileDescriptor*> dbgFD = aFileDescriptors.AppendElement(fd);
NS_ASSERTION(dbgFD->IsValid(), "Sending an invalid file descriptor!");
params.fileDescriptorIndex() = aFileDescriptors.Length() - 1;
Close();
} else {
NS_WARNING("This file has not been opened (or could not be opened). "
"Sending an invalid file descriptor to the other process!");
params.fileDescriptorIndex() = UINT32_MAX;
}
int32_t behaviorFlags = mBehaviorFlags;
// The receiving process (or thread) is going to have an open file
// descriptor automatically so transferring this flag is meaningless.
behaviorFlags &= ~nsIFileInputStream::DEFER_OPEN;
params.behaviorFlags() = behaviorFlags;
params.ioFlags() = mIOFlags;
aParams = params;
}
bool
nsFileInputStream::Deserialize(const InputStreamParams& aParams,
const FileDescriptorArray& aFileDescriptors)
{
NS_ASSERTION(!mFD, "Already have a file descriptor?!");
NS_ASSERTION(mState == nsFileStreamBase::eUnitialized, "Deferring open?!");
NS_ASSERTION(!mFile, "Should never have a file here!");
NS_ASSERTION(!mPerm, "This should always be 0!");
if (aParams.type() != InputStreamParams::TFileInputStreamParams) {
NS_WARNING("Received unknown parameters from the other process!");
return false;
}
const FileInputStreamParams& params = aParams.get_FileInputStreamParams();
uint32_t fileDescriptorIndex = params.fileDescriptorIndex();
FileDescriptor fd;
if (fileDescriptorIndex < aFileDescriptors.Length()) {
fd = aFileDescriptors[fileDescriptorIndex];
NS_WARNING_ASSERTION(fd.IsValid(),
"Received an invalid file descriptor!");
} else {
NS_WARNING("Received a bad file descriptor index!");
}
if (fd.IsValid()) {
auto rawFD = fd.ClonePlatformHandle();
PRFileDesc* fileDesc = PR_ImportFile(PROsfd(rawFD.release()));
if (!fileDesc) {
NS_WARNING("Failed to import file handle!");
return false;
}
mFD = fileDesc;
mState = eOpened;
} else {
mState = eError;
mErrorValue = NS_ERROR_FILE_NOT_FOUND;
}
mBehaviorFlags = params.behaviorFlags();
if (!XRE_IsParentProcess()) {
// A child process shouldn't close when it reads the end because it will
// not be able to reopen the file later.
mBehaviorFlags &= ~nsIFileInputStream::CLOSE_ON_EOF;
// A child process will not be able to reopen the file so this flag is
// meaningless.
mBehaviorFlags &= ~nsIFileInputStream::REOPEN_ON_REWIND;
}
mIOFlags = params.ioFlags();
return true;
}
Maybe<uint64_t>
nsFileInputStream::ExpectedSerializedLength()
{
return Nothing();
}
bool
nsFileInputStream::IsCloneable() const
{
// This inputStream is cloneable only if has been created using Init() and
// it owns a nsIFile. This is not true when it is deserialized from IPC.
return XRE_IsParentProcess() && mFile;
}
NS_IMETHODIMP
nsFileInputStream::GetCloneable(bool* aCloneable)
{
*aCloneable = IsCloneable();
return NS_OK;
}
NS_IMETHODIMP
nsFileInputStream::Clone(nsIInputStream** aResult)
{
MOZ_ASSERT(IsCloneable());
return NS_NewLocalFileInputStream(aResult, mFile, mIOFlags, mPerm,
mBehaviorFlags);
}
////////////////////////////////////////////////////////////////////////////////
// nsFileOutputStream
NS_IMPL_ISUPPORTS_INHERITED(nsFileOutputStream,
nsFileStreamBase,
nsIOutputStream,
nsIFileOutputStream)
nsresult
nsFileOutputStream::Create(nsISupports *aOuter, REFNSIID aIID, void **aResult)
{
NS_ENSURE_NO_AGGREGATION(aOuter);
nsFileOutputStream* stream = new nsFileOutputStream();
if (stream == nullptr)
return NS_ERROR_OUT_OF_MEMORY;
NS_ADDREF(stream);
nsresult rv = stream->QueryInterface(aIID, aResult);
NS_RELEASE(stream);
return rv;
}
NS_IMETHODIMP
nsFileOutputStream::Init(nsIFile* file, int32_t ioFlags, int32_t perm,
int32_t behaviorFlags)
{
NS_ENSURE_TRUE(mFD == nullptr, NS_ERROR_ALREADY_INITIALIZED);
NS_ENSURE_TRUE(mState == eUnitialized || mState == eClosed,
NS_ERROR_ALREADY_INITIALIZED);
mBehaviorFlags = behaviorFlags;
mState = eUnitialized;
if (ioFlags == -1)
ioFlags = PR_WRONLY | PR_CREATE_FILE | PR_TRUNCATE;
if (perm <= 0)
perm = 0664;
return MaybeOpen(file, ioFlags, perm,
mBehaviorFlags & nsIFileOutputStream::DEFER_OPEN);
}
NS_IMETHODIMP
nsFileOutputStream::Preallocate(int64_t aLength)
{
if (!mFD) {
return NS_ERROR_NOT_INITIALIZED;
}
if (!mozilla::fallocate(mFD, aLength)) {
return NS_ERROR_FAILURE;
}
return NS_OK;
}
////////////////////////////////////////////////////////////////////////////////
// nsAtomicFileOutputStream
NS_IMPL_ISUPPORTS_INHERITED(nsAtomicFileOutputStream,
nsFileOutputStream,
nsISafeOutputStream,
nsIOutputStream,
nsIFileOutputStream)
NS_IMETHODIMP
nsAtomicFileOutputStream::Init(nsIFile* file, int32_t ioFlags, int32_t perm,
int32_t behaviorFlags)
{
// While `PR_APPEND` is not supported, `-1` is used as `ioFlags` parameter
// in some places, and `PR_APPEND | PR_TRUNCATE` does not require appending
// to existing file. So, throw an exception only if `PR_APPEND` is
// explicitly specified without `PR_TRUNCATE`.
if ((ioFlags & PR_APPEND) && !(ioFlags & PR_TRUNCATE)) {
return NS_ERROR_INVALID_ARG;
}
return nsFileOutputStream::Init(file, ioFlags, perm, behaviorFlags);
}
nsresult
nsAtomicFileOutputStream::DoOpen()
{
// Make sure mOpenParams.localFile will be empty if we bail somewhere in
// this function
nsCOMPtr<nsIFile> file;
file.swap(mOpenParams.localFile);
if (!file) {
return NS_ERROR_NOT_INITIALIZED;
}
nsresult rv = file->Exists(&mTargetFileExists);
if (NS_FAILED(rv)) {
NS_ERROR("Can't tell if target file exists");
mTargetFileExists = true; // Safer to assume it exists - we just do more work.
}
// follow symlinks, for two reasons:
// 1) if a user has deliberately set up a profile file as a symlink, we honor it
// 2) to make the MoveToNative() in Finish() an atomic operation (which may not
// be the case if moving across directories on different filesystems).
nsCOMPtr<nsIFile> tempResult;
rv = file->Clone(getter_AddRefs(tempResult));
if (NS_SUCCEEDED(rv)) {
tempResult->SetFollowLinks(true);
// XP_UNIX ignores SetFollowLinks(), so we have to normalize.
if (mTargetFileExists) {
tempResult->Normalize();
}
}
if (NS_SUCCEEDED(rv) && mTargetFileExists) {
// Abort if |file| is not writable; it won't work as an output stream.
bool isWritable;
if (NS_SUCCEEDED(file->IsWritable(&isWritable)) && !isWritable) {
return NS_ERROR_FILE_ACCESS_DENIED;
}
uint32_t origPerm;
if (NS_FAILED(file->GetPermissions(&origPerm))) {
NS_ERROR("Can't get permissions of target file");
origPerm = mOpenParams.perm;
}
// XXX What if |perm| is more restrictive then |origPerm|?
// This leaves the user supplied permissions as they were.
rv = tempResult->CreateUnique(nsIFile::NORMAL_FILE_TYPE, origPerm);
}
if (NS_SUCCEEDED(rv)) {
// nsFileOutputStream::DoOpen will work on the temporary file, so we
// prepare it and place it in mOpenParams.localFile.
mOpenParams.localFile = tempResult;
mTempFile = tempResult;
mTargetFile = file;
rv = nsFileOutputStream::DoOpen();
}
return rv;
}
NS_IMETHODIMP
nsAtomicFileOutputStream::Close()
{
nsresult rv = nsFileOutputStream::Close();
// the consumer doesn't want the original file overwritten -
// so clean up by removing the temp file.
if (mTempFile) {
mTempFile->Remove(false);
mTempFile = nullptr;
}
return rv;
}
NS_IMETHODIMP
nsAtomicFileOutputStream::Finish()
{
nsresult rv = nsFileOutputStream::Close();
// if there is no temp file, don't try to move it over the original target.
// It would destroy the targetfile if close() is called twice.
if (!mTempFile)
return rv;
// Only overwrite if everything was ok, and the temp file could be closed.
if (NS_SUCCEEDED(mWriteResult) && NS_SUCCEEDED(rv)) {
NS_ENSURE_STATE(mTargetFile);
if (!mTargetFileExists) {
// If the target file did not exist when we were initialized, then the
// temp file we gave out was actually a reference to the target file.
// since we succeeded in writing to the temp file (and hence succeeded
// in writing to the target file), there is nothing more to do.
#ifdef DEBUG
bool equal;
if (NS_FAILED(mTargetFile->Equals(mTempFile, &equal)) || !equal)
NS_WARNING("mTempFile not equal to mTargetFile");
#endif
}
else {
nsAutoString targetFilename;
rv = mTargetFile->GetLeafName(targetFilename);
if (NS_SUCCEEDED(rv)) {
// This will replace target.
rv = mTempFile->MoveTo(nullptr, targetFilename);
if (NS_FAILED(rv))
mTempFile->Remove(false);
}
}
}
else {
mTempFile->Remove(false);
// if writing failed, propagate the failure code to the caller.
if (NS_FAILED(mWriteResult))
rv = mWriteResult;
}
mTempFile = nullptr;
return rv;
}
NS_IMETHODIMP
nsAtomicFileOutputStream::Write(const char *buf, uint32_t count, uint32_t *result)
{
nsresult rv = nsFileOutputStream::Write(buf, count, result);
if (NS_SUCCEEDED(mWriteResult)) {
if (NS_FAILED(rv))
mWriteResult = rv;
else if (count != *result)
mWriteResult = NS_ERROR_LOSS_OF_SIGNIFICANT_DATA;
if (NS_FAILED(mWriteResult) && count > 0)
NS_WARNING("writing to output stream failed! data may be lost");
}
return rv;
}
////////////////////////////////////////////////////////////////////////////////
// nsSafeFileOutputStream
NS_IMETHODIMP
nsSafeFileOutputStream::Finish()
{
(void) Flush();
return nsAtomicFileOutputStream::Finish();
}
////////////////////////////////////////////////////////////////////////////////
// nsFileStream
NS_IMPL_ISUPPORTS_INHERITED(nsFileStream,
nsFileStreamBase,
nsIInputStream,
nsIOutputStream,
nsIFileStream)
NS_IMETHODIMP
nsFileStream::Init(nsIFile* file, int32_t ioFlags, int32_t perm,
int32_t behaviorFlags)
{
NS_ENSURE_TRUE(mFD == nullptr, NS_ERROR_ALREADY_INITIALIZED);
NS_ENSURE_TRUE(mState == eUnitialized || mState == eClosed,
NS_ERROR_ALREADY_INITIALIZED);
mBehaviorFlags = behaviorFlags;
mState = eUnitialized;
if (ioFlags == -1)
ioFlags = PR_RDWR;
if (perm <= 0)
perm = 0;
return MaybeOpen(file, ioFlags, perm,
mBehaviorFlags & nsIFileStream::DEFER_OPEN);
}
////////////////////////////////////////////////////////////////////////////////
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