mozglue/linker/XZStream.h

   1 /* This Source Code Form is subject to the terms of the Mozilla Public
   2  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
   3  * You can obtain one at http://mozilla.org/MPL/2.0/. */
   4
   5 #ifndef XZSTREAM_h
   6 #define XZSTREAM_h
   7
   8 #include <cstdlib>
   9 #include <stdint.h>
  10
  11 #define XZ_DEC_DYNALLOC
  12 #include "xz.h"
  13
  14 // Used to decode XZ stream buffers.
  15 class XZStream {
  16  public:
  17   // Returns whether the provided buffer is likely a XZ stream.
  18   static bool IsXZ(const void* aBuf, size_t aBufSize);
  19
  20   // Creates a XZ stream object for the given input buffer.
  21   XZStream(const void* aInBuf, size_t aInSize);
  22   ~XZStream();
  23
  24   // Initializes the decoder and returns whether decoding may commence.
  25   bool Init();
  26   // Decodes the next chunk of input into the given output buffer.
  27   size_t Decode(void* aOutBuf, size_t aOutSize);
  28   // Returns the number of yet undecoded bytes in the input buffer.
  29   size_t RemainingInput() const;
  30   // Returns the total number of bytes in the input buffer (compressed size).
  31   size_t Size() const;
  32   // Returns the expected final number of bytes in the output buffer.
  33   // Note: will return 0 before successful Init().
  34   size_t UncompressedSize() const;
  35
  36  private:
  37   // Parses the stream footer and returns the size of the index in bytes.
  38   size_t ParseIndexSize() const;
  39   // Parses the stream index and returns the expected uncompressed size in
  40   // bytes.
  41   size_t ParseUncompressedSize() const;
  42
  43   const uint8_t* mInBuf;
  44   size_t mUncompSize;
  45   xz_buf mBuffers;
  46   xz_dec* mDec;
  47 };
  48
  49 #endif  // XZSTREAM_h