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Diffstat (limited to 'netwerk/base/nsFileStreams.h')
| -rw-r--r-- | netwerk/base/nsFileStreams.h | 333 |
1 files changed, 333 insertions, 0 deletions
diff --git a/netwerk/base/nsFileStreams.h b/netwerk/base/nsFileStreams.h new file mode 100644 index 000000000..22ef91770 --- /dev/null +++ b/netwerk/base/nsFileStreams.h @@ -0,0 +1,333 @@ +// /* -*- Mode: C++; tab-width: 2; 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/. */ + +#ifndef nsFileStreams_h__ +#define nsFileStreams_h__ + +#include "nsAutoPtr.h" +#include "nsIFileStreams.h" +#include "nsIFile.h" +#include "nsIInputStream.h" +#include "nsIOutputStream.h" +#include "nsISafeOutputStream.h" +#include "nsISeekableStream.h" +#include "nsILineInputStream.h" +#include "nsCOMPtr.h" +#include "nsIIPCSerializableInputStream.h" +#include "nsReadLine.h" +#include <algorithm> + + +//////////////////////////////////////////////////////////////////////////////// + +class nsFileStreamBase : public nsISeekableStream, + public nsIFileMetadata +{ +public: + NS_DECL_THREADSAFE_ISUPPORTS + NS_DECL_NSISEEKABLESTREAM + NS_DECL_NSIFILEMETADATA + + nsFileStreamBase(); + +protected: + virtual ~nsFileStreamBase(); + + nsresult Close(); + nsresult Available(uint64_t* _retval); + nsresult Read(char* aBuf, uint32_t aCount, uint32_t* _retval); + nsresult ReadSegments(nsWriteSegmentFun aWriter, void* aClosure, + uint32_t aCount, uint32_t* _retval); + nsresult IsNonBlocking(bool* _retval); + nsresult Flush(); + nsresult Write(const char* aBuf, uint32_t aCount, uint32_t* _retval); + nsresult WriteFrom(nsIInputStream* aFromStream, uint32_t aCount, + uint32_t* _retval); + nsresult WriteSegments(nsReadSegmentFun aReader, void* aClosure, + uint32_t aCount, uint32_t* _retval); + + PRFileDesc* mFD; + + /** + * Flags describing our behavior. See the IDL file for possible values. + */ + int32_t mBehaviorFlags; + + /** + * Whether we have a pending open (see DEFER_OPEN in the IDL file). + */ + bool mDeferredOpen; + + struct OpenParams { + nsCOMPtr<nsIFile> localFile; + int32_t ioFlags; + int32_t perm; + }; + + /** + * Data we need to do an open. + */ + OpenParams mOpenParams; + + /** + * Prepares the data we need to open the file, and either does the open now + * by calling DoOpen(), or leaves it to be opened later by a call to + * DoPendingOpen(). + */ + nsresult MaybeOpen(nsIFile* aFile, int32_t aIoFlags, int32_t aPerm, + bool aDeferred); + + /** + * Cleans up data prepared in MaybeOpen. + */ + void CleanUpOpen(); + + /** + * Open the file. This is called either from MaybeOpen (during Init) + * or from DoPendingOpen (if DEFER_OPEN is used when initializing this + * stream). The default behavior of DoOpen is to open the file and save the + * file descriptor. + */ + virtual nsresult DoOpen(); + + /** + * If there is a pending open, do it now. It's important for this to be + * inline since we do it in almost every stream API call. + */ + inline nsresult DoPendingOpen(); +}; + +//////////////////////////////////////////////////////////////////////////////// + +class nsFileInputStream : public nsFileStreamBase, + public nsIFileInputStream, + public nsILineInputStream, + public nsIIPCSerializableInputStream +{ +public: + NS_DECL_ISUPPORTS_INHERITED + NS_DECL_NSIFILEINPUTSTREAM + NS_DECL_NSILINEINPUTSTREAM + NS_DECL_NSIIPCSERIALIZABLEINPUTSTREAM + + NS_IMETHOD Close() override; + NS_IMETHOD Tell(int64_t *aResult) override; + NS_IMETHOD Available(uint64_t* _retval) override; + NS_IMETHOD Read(char* aBuf, uint32_t aCount, uint32_t* _retval) override; + NS_IMETHOD ReadSegments(nsWriteSegmentFun aWriter, void *aClosure, + uint32_t aCount, uint32_t* _retval) override + { + return nsFileStreamBase::ReadSegments(aWriter, aClosure, aCount, + _retval); + } + NS_IMETHOD IsNonBlocking(bool* _retval) override + { + return nsFileStreamBase::IsNonBlocking(_retval); + } + + // Overrided from nsFileStreamBase + NS_IMETHOD Seek(int32_t aWhence, int64_t aOffset) override; + + nsFileInputStream() + : mLineBuffer(nullptr), mIOFlags(0), mPerm(0), mCachedPosition(0) + {} + + static nsresult + Create(nsISupports *aOuter, REFNSIID aIID, void **aResult); + +protected: + virtual ~nsFileInputStream() + { + Close(); + } + + nsresult SeekInternal(int32_t aWhence, int64_t aOffset, bool aClearBuf=true); + + nsAutoPtr<nsLineBuffer<char> > mLineBuffer; + + /** + * The file being opened. + */ + nsCOMPtr<nsIFile> mFile; + /** + * The IO flags passed to Init() for the file open. + */ + int32_t mIOFlags; + /** + * The permissions passed to Init() for the file open. + */ + int32_t mPerm; + + /** + * Cached position for Tell for automatically reopening streams. + */ + int64_t mCachedPosition; + +protected: + /** + * Internal, called to open a file. Parameters are the same as their + * Init() analogues. + */ + nsresult Open(nsIFile* file, int32_t ioFlags, int32_t perm); +}; + +//////////////////////////////////////////////////////////////////////////////// + +class nsPartialFileInputStream : public nsFileInputStream, + public nsIPartialFileInputStream +{ +public: + using nsFileInputStream::Init; + using nsFileInputStream::Read; + NS_DECL_ISUPPORTS_INHERITED + NS_DECL_NSIPARTIALFILEINPUTSTREAM + NS_DECL_NSIIPCSERIALIZABLEINPUTSTREAM + + nsPartialFileInputStream() + : mStart(0), mLength(0), mPosition(0), mDeferredSeek(false) + { } + + NS_IMETHOD Tell(int64_t *aResult) override; + NS_IMETHOD Available(uint64_t *aResult) override; + NS_IMETHOD Read(char* aBuf, uint32_t aCount, uint32_t* aResult) override; + NS_IMETHOD Seek(int32_t aWhence, int64_t aOffset) override; + + static nsresult + Create(nsISupports *aOuter, REFNSIID aIID, void **aResult); + +protected: + ~nsPartialFileInputStream() + { } + + inline nsresult DoPendingSeek(); + +private: + uint64_t TruncateSize(uint64_t aSize) { + return std::min<uint64_t>(mLength - mPosition, aSize); + } + + uint64_t mStart; + uint64_t mLength; + uint64_t mPosition; + bool mDeferredSeek; +}; + +//////////////////////////////////////////////////////////////////////////////// + +class nsFileOutputStream : public nsFileStreamBase, + public nsIFileOutputStream +{ +public: + NS_DECL_ISUPPORTS_INHERITED + NS_DECL_NSIFILEOUTPUTSTREAM + NS_FORWARD_NSIOUTPUTSTREAM(nsFileStreamBase::) + + static nsresult + Create(nsISupports *aOuter, REFNSIID aIID, void **aResult); + +protected: + virtual ~nsFileOutputStream() + { + Close(); + } +}; + +//////////////////////////////////////////////////////////////////////////////// + +/** + * A safe file output stream that overwrites the destination file only + * once writing is complete. This protects against incomplete writes + * due to the process or the thread being interrupted or crashed. + */ +class nsAtomicFileOutputStream : public nsFileOutputStream, + public nsISafeOutputStream +{ +public: + NS_DECL_ISUPPORTS_INHERITED + NS_DECL_NSISAFEOUTPUTSTREAM + + nsAtomicFileOutputStream() : + mTargetFileExists(true), + mWriteResult(NS_OK) {} + + virtual nsresult DoOpen() override; + + NS_IMETHOD Close() override; + NS_IMETHOD Write(const char *buf, uint32_t count, uint32_t *result) override; + NS_IMETHOD Init(nsIFile* file, int32_t ioFlags, int32_t perm, int32_t behaviorFlags) override; + +protected: + virtual ~nsAtomicFileOutputStream() + { + Close(); + } + + nsCOMPtr<nsIFile> mTargetFile; + nsCOMPtr<nsIFile> mTempFile; + + bool mTargetFileExists; + nsresult mWriteResult; // Internally set in Write() + +}; + +//////////////////////////////////////////////////////////////////////////////// + +/** + * A safe file output stream that overwrites the destination file only + * once writing + flushing is complete. This protects against more + * classes of software/hardware errors than nsAtomicFileOutputStream, + * at the expense of being more costly to the disk, OS and battery. + */ +class nsSafeFileOutputStream : public nsAtomicFileOutputStream +{ +public: + + NS_IMETHOD Finish() override; +}; + +//////////////////////////////////////////////////////////////////////////////// + +class nsFileStream : public nsFileStreamBase, + public nsIInputStream, + public nsIOutputStream, + public nsIFileStream +{ +public: + NS_DECL_ISUPPORTS_INHERITED + NS_DECL_NSIFILESTREAM + NS_FORWARD_NSIINPUTSTREAM(nsFileStreamBase::) + + // Can't use NS_FORWARD_NSIOUTPUTSTREAM due to overlapping methods + // Close() and IsNonBlocking() + NS_IMETHOD Flush() override + { + return nsFileStreamBase::Flush(); + } + NS_IMETHOD Write(const char* aBuf, uint32_t aCount, uint32_t* _retval) override + { + return nsFileStreamBase::Write(aBuf, aCount, _retval); + } + NS_IMETHOD WriteFrom(nsIInputStream* aFromStream, uint32_t aCount, + uint32_t* _retval) override + { + return nsFileStreamBase::WriteFrom(aFromStream, aCount, _retval); + } + NS_IMETHOD WriteSegments(nsReadSegmentFun aReader, void* aClosure, + uint32_t aCount, uint32_t* _retval) override + { + return nsFileStreamBase::WriteSegments(aReader, aClosure, aCount, + _retval); + } + +protected: + virtual ~nsFileStream() + { + Close(); + } +}; + +//////////////////////////////////////////////////////////////////////////////// + +#endif // nsFileStreams_h__ |