diff options
Diffstat (limited to 'snappy/snappy.h')
| -rw-r--r-- | snappy/snappy.h | 163 |
1 files changed, 0 insertions, 163 deletions
diff --git a/snappy/snappy.h b/snappy/snappy.h deleted file mode 100644 index 03ef6ce5..00000000 --- a/snappy/snappy.h +++ /dev/null @@ -1,163 +0,0 @@ -// Copyright 2005 and onwards Google Inc. -// -// Redistribution and use in source and binary forms, with or without -// modification, are permitted provided that the following conditions are -// met: -// -// * Redistributions of source code must retain the above copyright -// notice, this list of conditions and the following disclaimer. -// * Redistributions in binary form must reproduce the above -// copyright notice, this list of conditions and the following disclaimer -// in the documentation and/or other materials provided with the -// distribution. -// * Neither the name of Google Inc. nor the names of its -// contributors may be used to endorse or promote products derived from -// this software without specific prior written permission. -// -// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS -// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT -// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR -// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT -// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, -// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT -// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, -// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY -// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT -// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE -// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. -// -// A light-weight compression algorithm. It is designed for speed of -// compression and decompression, rather than for the utmost in space -// savings. -// -// For getting better compression ratios when you are compressing data -// with long repeated sequences or compressing data that is similar to -// other data, while still compressing fast, you might look at first -// using BMDiff and then compressing the output of BMDiff with -// Snappy. - -#ifndef UTIL_SNAPPY_SNAPPY_H__ -#define UTIL_SNAPPY_SNAPPY_H__ - -#include <stddef.h> -#include <string> - -#include "snappy-stubs-public.h" - -namespace snappy { - class Source; - class Sink; - - // ------------------------------------------------------------------------ - // Generic compression/decompression routines. - // ------------------------------------------------------------------------ - - // Compress the bytes read from "*source" and append to "*sink". Return the - // number of bytes written. - size_t Compress(Source* source, Sink* sink); - - // Find the uncompressed length of the given stream, as given by the header. - // Note that the true length could deviate from this; the stream could e.g. - // be truncated. - // - // Also note that this leaves "*source" in a state that is unsuitable for - // further operations, such as RawUncompress(). You will need to rewind - // or recreate the source yourself before attempting any further calls. - bool GetUncompressedLength(Source* source, uint32* result); - - // ------------------------------------------------------------------------ - // Higher-level string based routines (should be sufficient for most users) - // ------------------------------------------------------------------------ - - // Sets "*output" to the compressed version of "input[0,input_length-1]". - // Original contents of *output are lost. - // - // REQUIRES: "input[]" is not an alias of "*output". - size_t Compress(const char* input, size_t input_length, string* output); - - // Decompresses "compressed[0,compressed_length-1]" to "*uncompressed". - // Original contents of "*uncompressed" are lost. - // - // REQUIRES: "compressed[]" is not an alias of "*uncompressed". - // - // returns false if the message is corrupted and could not be decompressed - bool Uncompress(const char* compressed, size_t compressed_length, - string* uncompressed); - - - // ------------------------------------------------------------------------ - // Lower-level character array based routines. May be useful for - // efficiency reasons in certain circumstances. - // ------------------------------------------------------------------------ - - // REQUIRES: "compressed" must point to an area of memory that is at - // least "MaxCompressedLength(input_length)" bytes in length. - // - // Takes the data stored in "input[0..input_length]" and stores - // it in the array pointed to by "compressed". - // - // "*compressed_length" is set to the length of the compressed output. - // - // Example: - // char* output = new char[snappy::MaxCompressedLength(input_length)]; - // size_t output_length; - // RawCompress(input, input_length, output, &output_length); - // ... Process(output, output_length) ... - // delete [] output; - void RawCompress(const char* input, - size_t input_length, - char* compressed, - size_t* compressed_length); - - // Given data in "compressed[0..compressed_length-1]" generated by - // calling the Snappy::Compress routine, this routine - // stores the uncompressed data to - // uncompressed[0..GetUncompressedLength(compressed)-1] - // returns false if the message is corrupted and could not be decrypted - bool RawUncompress(const char* compressed, size_t compressed_length, - char* uncompressed); - - // Given data from the byte source 'compressed' generated by calling - // the Snappy::Compress routine, this routine stores the uncompressed - // data to - // uncompressed[0..GetUncompressedLength(compressed,compressed_length)-1] - // returns false if the message is corrupted and could not be decrypted - bool RawUncompress(Source* compressed, char* uncompressed); - - // Returns the maximal size of the compressed representation of - // input data that is "source_bytes" bytes in length; - size_t MaxCompressedLength(size_t source_bytes); - - // REQUIRES: "compressed[]" was produced by RawCompress() or Compress() - // Returns true and stores the length of the uncompressed data in - // *result normally. Returns false on parsing error. - // This operation takes O(1) time. - bool GetUncompressedLength(const char* compressed, size_t compressed_length, - size_t* result); - - // Returns true iff the contents of "compressed[]" can be uncompressed - // successfully. Does not return the uncompressed data. Takes - // time proportional to compressed_length, but is usually at least - // a factor of four faster than actual decompression. - bool IsValidCompressedBuffer(const char* compressed, - size_t compressed_length); - - // The size of a compression block. Note that many parts of the compression - // code assumes that kBlockSize <= 65536; in particular, the hash table - // can only store 16-bit offsets, and EmitCopy() also assumes the offset - // is 65535 bytes or less. Note also that if you change this, it will - // affect the framing format (see framing_format.txt). - // - // Note that there might be older data around that is compressed with larger - // block sizes, so the decompression code should not rely on the - // non-existence of long backreferences. - static const int kBlockLog = 16; - static const size_t kBlockSize = 1 << kBlockLog; - - static const int kMaxHashTableBits = 14; - static const size_t kMaxHashTableSize = 1 << kMaxHashTableBits; - -} // end namespace snappy - - -#endif // UTIL_SNAPPY_SNAPPY_H__ |