forked from mirrors/gecko-dev
300 lines
9 KiB
C++
300 lines
9 KiB
C++
// /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
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/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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#ifndef nsFileStreams_h__
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#define nsFileStreams_h__
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#include "nsAutoPtr.h"
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#include "nsIFileStreams.h"
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#include "nsIFile.h"
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#include "nsICloneableInputStream.h"
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#include "nsIInputStream.h"
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#include "nsIOutputStream.h"
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#include "nsISafeOutputStream.h"
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#include "nsISeekableStream.h"
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#include "nsILineInputStream.h"
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#include "nsCOMPtr.h"
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#include "nsIIPCSerializableInputStream.h"
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#include "nsReadLine.h"
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#include <algorithm>
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////////////////////////////////////////////////////////////////////////////////
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class nsFileStreamBase : public nsISeekableStream,
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public nsIFileMetadata
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{
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public:
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NS_DECL_THREADSAFE_ISUPPORTS
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NS_DECL_NSISEEKABLESTREAM
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NS_DECL_NSIFILEMETADATA
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nsFileStreamBase();
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protected:
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virtual ~nsFileStreamBase();
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nsresult Close();
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nsresult Available(uint64_t* _retval);
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nsresult Read(char* aBuf, uint32_t aCount, uint32_t* _retval);
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nsresult ReadSegments(nsWriteSegmentFun aWriter, void* aClosure,
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uint32_t aCount, uint32_t* _retval);
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nsresult IsNonBlocking(bool* _retval);
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nsresult Flush();
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nsresult Write(const char* aBuf, uint32_t aCount, uint32_t* _retval);
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nsresult WriteFrom(nsIInputStream* aFromStream, uint32_t aCount,
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uint32_t* _retval);
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nsresult WriteSegments(nsReadSegmentFun aReader, void* aClosure,
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uint32_t aCount, uint32_t* _retval);
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PRFileDesc* mFD;
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/**
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* Flags describing our behavior. See the IDL file for possible values.
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*/
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int32_t mBehaviorFlags;
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enum {
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// This is the default value. It will be changed by Deserialize or Init.
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eUnitialized,
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// The opening has been deferred. See DEFER_OPEN.
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eDeferredOpen,
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// The file has been opened. mFD is not null.
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eOpened,
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// The file has been closed. mFD is null.
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eClosed,
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// Something bad happen in the Open() or in Deserialize(). The actual
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// error value is stored in mErrorValue.
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eError
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} mState;
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struct OpenParams {
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nsCOMPtr<nsIFile> localFile;
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int32_t ioFlags;
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int32_t perm;
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};
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/**
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* Data we need to do an open.
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*/
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OpenParams mOpenParams;
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nsresult mErrorValue;
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/**
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* Prepares the data we need to open the file, and either does the open now
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* by calling DoOpen(), or leaves it to be opened later by a call to
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* DoPendingOpen().
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*/
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nsresult MaybeOpen(nsIFile* aFile, int32_t aIoFlags, int32_t aPerm,
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bool aDeferred);
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/**
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* Cleans up data prepared in MaybeOpen.
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*/
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void CleanUpOpen();
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/**
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* Open the file. This is called either from MaybeOpen (during Init)
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* or from DoPendingOpen (if DEFER_OPEN is used when initializing this
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* stream). The default behavior of DoOpen is to open the file and save the
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* file descriptor.
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*/
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virtual nsresult DoOpen();
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/**
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* Based on mState, this method does the opening, return an error, or do
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* nothing. If the return value is not NS_OK, please, return it back to the
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* callee.
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*/
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inline nsresult DoPendingOpen();
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};
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////////////////////////////////////////////////////////////////////////////////
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// nsFileInputStream is cloneable only on the parent process because only there
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// it can open the same file multiple times.
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class nsFileInputStream : public nsFileStreamBase
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, public nsIFileInputStream
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, public nsILineInputStream
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, public nsIIPCSerializableInputStream
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, public nsICloneableInputStream
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{
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public:
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NS_DECL_ISUPPORTS_INHERITED
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NS_DECL_NSIFILEINPUTSTREAM
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NS_DECL_NSILINEINPUTSTREAM
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NS_DECL_NSIIPCSERIALIZABLEINPUTSTREAM
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NS_DECL_NSICLONEABLEINPUTSTREAM
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NS_IMETHOD Close() override;
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NS_IMETHOD Tell(int64_t *aResult) override;
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NS_IMETHOD Available(uint64_t* _retval) override;
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NS_IMETHOD Read(char* aBuf, uint32_t aCount, uint32_t* _retval) override;
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NS_IMETHOD ReadSegments(nsWriteSegmentFun aWriter, void *aClosure,
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uint32_t aCount, uint32_t* _retval) override
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{
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return nsFileStreamBase::ReadSegments(aWriter, aClosure, aCount,
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_retval);
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}
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NS_IMETHOD IsNonBlocking(bool* _retval) override
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{
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return nsFileStreamBase::IsNonBlocking(_retval);
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}
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// Overrided from nsFileStreamBase
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NS_IMETHOD Seek(int32_t aWhence, int64_t aOffset) override;
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nsFileInputStream()
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: mLineBuffer(nullptr), mIOFlags(0), mPerm(0), mCachedPosition(0)
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{}
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static nsresult
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Create(nsISupports *aOuter, REFNSIID aIID, void **aResult);
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protected:
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virtual ~nsFileInputStream() = default;
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nsresult SeekInternal(int32_t aWhence, int64_t aOffset, bool aClearBuf=true);
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nsAutoPtr<nsLineBuffer<char> > mLineBuffer;
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/**
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* The file being opened.
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*/
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nsCOMPtr<nsIFile> mFile;
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/**
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* The IO flags passed to Init() for the file open.
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*/
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int32_t mIOFlags;
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/**
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* The permissions passed to Init() for the file open.
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*/
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int32_t mPerm;
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/**
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* Cached position for Tell for automatically reopening streams.
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*/
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int64_t mCachedPosition;
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protected:
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/**
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* Internal, called to open a file. Parameters are the same as their
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* Init() analogues.
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*/
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nsresult Open(nsIFile* file, int32_t ioFlags, int32_t perm);
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bool IsCloneable() const;
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};
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////////////////////////////////////////////////////////////////////////////////
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class nsFileOutputStream : public nsFileStreamBase,
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public nsIFileOutputStream
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{
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public:
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NS_DECL_ISUPPORTS_INHERITED
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NS_DECL_NSIFILEOUTPUTSTREAM
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NS_FORWARD_NSIOUTPUTSTREAM(nsFileStreamBase::)
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static nsresult
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Create(nsISupports *aOuter, REFNSIID aIID, void **aResult);
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protected:
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virtual ~nsFileOutputStream() = default;
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};
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////////////////////////////////////////////////////////////////////////////////
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/**
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* A safe file output stream that overwrites the destination file only
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* once writing is complete. This protects against incomplete writes
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* due to the process or the thread being interrupted or crashed.
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*/
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class nsAtomicFileOutputStream : public nsFileOutputStream,
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public nsISafeOutputStream
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{
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public:
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NS_DECL_ISUPPORTS_INHERITED
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NS_DECL_NSISAFEOUTPUTSTREAM
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nsAtomicFileOutputStream() :
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mTargetFileExists(true),
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mWriteResult(NS_OK) {}
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virtual nsresult DoOpen() override;
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NS_IMETHOD Close() override;
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NS_IMETHOD Write(const char *buf, uint32_t count, uint32_t *result) override;
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NS_IMETHOD Init(nsIFile* file, int32_t ioFlags, int32_t perm, int32_t behaviorFlags) override;
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protected:
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virtual ~nsAtomicFileOutputStream() = default;
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nsCOMPtr<nsIFile> mTargetFile;
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nsCOMPtr<nsIFile> mTempFile;
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bool mTargetFileExists;
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nsresult mWriteResult; // Internally set in Write()
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};
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////////////////////////////////////////////////////////////////////////////////
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/**
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* A safe file output stream that overwrites the destination file only
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* once writing + flushing is complete. This protects against more
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* classes of software/hardware errors than nsAtomicFileOutputStream,
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* at the expense of being more costly to the disk, OS and battery.
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*/
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class nsSafeFileOutputStream : public nsAtomicFileOutputStream
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{
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public:
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NS_IMETHOD Finish() override;
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};
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////////////////////////////////////////////////////////////////////////////////
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class nsFileStream : public nsFileStreamBase,
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public nsIInputStream,
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public nsIOutputStream,
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public nsIFileStream
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{
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public:
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NS_DECL_ISUPPORTS_INHERITED
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NS_DECL_NSIFILESTREAM
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NS_FORWARD_NSIINPUTSTREAM(nsFileStreamBase::)
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// Can't use NS_FORWARD_NSIOUTPUTSTREAM due to overlapping methods
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// Close() and IsNonBlocking()
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NS_IMETHOD Flush() override
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{
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return nsFileStreamBase::Flush();
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}
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NS_IMETHOD Write(const char* aBuf, uint32_t aCount, uint32_t* _retval) override
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{
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return nsFileStreamBase::Write(aBuf, aCount, _retval);
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}
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NS_IMETHOD WriteFrom(nsIInputStream* aFromStream, uint32_t aCount,
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uint32_t* _retval) override
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{
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return nsFileStreamBase::WriteFrom(aFromStream, aCount, _retval);
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}
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NS_IMETHOD WriteSegments(nsReadSegmentFun aReader, void* aClosure,
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uint32_t aCount, uint32_t* _retval) override
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{
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return nsFileStreamBase::WriteSegments(aReader, aClosure, aCount,
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_retval);
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}
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protected:
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virtual ~nsFileStream() = default;
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};
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////////////////////////////////////////////////////////////////////////////////
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#endif // nsFileStreams_h__
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