/* -*- 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/. */ /* * The storage stream provides an internal buffer that can be filled by a * client using a single output stream. One or more independent input streams * can be created to read the data out non-destructively. The implementation * uses a segmented buffer internally to avoid realloc'ing of large buffers, * with the attendant performance loss and heap fragmentation. */ #ifndef _nsStorageStream_h_ #define _nsStorageStream_h_ #include "nsIStorageStream.h" #include "nsIOutputStream.h" #include "nsMemory.h" #include "mozilla/Attributes.h" #define NS_STORAGESTREAM_CID \ { /* 669a9795-6ff7-4ed4-9150-c34ce2971b63 */ \ 0x669a9795, \ 0x6ff7, \ 0x4ed4, \ {0x91, 0x50, 0xc3, 0x4c, 0xe2, 0x97, 0x1b, 0x63} \ } #define NS_STORAGESTREAM_CONTRACTID "@mozilla.org/storagestream;1" class nsSegmentedBuffer; class nsStorageStream MOZ_FINAL : public nsIStorageStream, public nsIOutputStream { public: nsStorageStream(); NS_DECL_THREADSAFE_ISUPPORTS NS_DECL_NSISTORAGESTREAM NS_DECL_NSIOUTPUTSTREAM friend class nsStorageInputStream; private: ~nsStorageStream(); nsSegmentedBuffer* mSegmentedBuffer; uint32_t mSegmentSize; // All segments, except possibly the last, are of this size // Must be power-of-2 uint32_t mSegmentSizeLog2; // log2(mSegmentSize) bool mWriteInProgress; // true, if an un-Close'ed output stream exists int32_t mLastSegmentNum; // Last segment # in use, -1 initially char* mWriteCursor; // Pointer to next byte to be written char* mSegmentEnd; // Pointer to one byte after end of segment // containing the write cursor uint32_t mLogicalLength; // Number of bytes written to stream NS_METHOD Seek(int32_t aPosition); uint32_t SegNum(uint32_t aPosition) {return aPosition >> mSegmentSizeLog2;} uint32_t SegOffset(uint32_t aPosition) {return aPosition & (mSegmentSize - 1);} }; #endif // _nsStorageStream_h_