summaryrefslogtreecommitdiffstats
path: root/lib/lz4hc.h
diff options
context:
space:
mode:
authorYann Collet <yann.collet.73@gmail.com>2014-11-30 22:32:12 (GMT)
committerYann Collet <yann.collet.73@gmail.com>2014-11-30 22:32:12 (GMT)
commitd008c87151abf8c36a9f98d28461bf6f3dfdc6ae (patch)
treef9cbf5a95577a4bbbe610b1dca00e1f332e56623 /lib/lz4hc.h
parent80030c16fff7a8a5dae18cf2b1ab5da508137847 (diff)
downloadlz4-d008c87151abf8c36a9f98d28461bf6f3dfdc6ae.zip
lz4-d008c87151abf8c36a9f98d28461bf6f3dfdc6ae.tar.gz
lz4-d008c87151abf8c36a9f98d28461bf6f3dfdc6ae.tar.bz2
New directory structure : library source files into /lib directory
Diffstat (limited to 'lib/lz4hc.h')
-rw-r--r--lib/lz4hc.h223
1 files changed, 223 insertions, 0 deletions
diff --git a/lib/lz4hc.h b/lib/lz4hc.h
new file mode 100644
index 0000000..26ba6d3
--- /dev/null
+++ b/lib/lz4hc.h
@@ -0,0 +1,223 @@
+/*
+ LZ4 HC - High Compression Mode of LZ4
+ Header File
+ Copyright (C) 2011-2014, Yann Collet.
+ BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
+
+ 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.
+
+ 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.
+
+ You can contact the author at :
+ - LZ4 homepage : http://fastcompression.blogspot.com/p/lz4.html
+ - LZ4 source repository : http://code.google.com/p/lz4/
+*/
+#pragma once
+
+
+#if defined (__cplusplus)
+extern "C" {
+#endif
+
+
+int LZ4_compressHC (const char* source, char* dest, int inputSize);
+/*
+LZ4_compressHC :
+ return : the number of bytes in compressed buffer dest
+ or 0 if compression fails.
+ note : destination buffer must be already allocated.
+ To avoid any problem, size it to handle worst cases situations (input data not compressible)
+ Worst case size evaluation is provided by function LZ4_compressBound() (see "lz4.h")
+*/
+
+int LZ4_compressHC_limitedOutput (const char* source, char* dest, int inputSize, int maxOutputSize);
+/*
+LZ4_compress_limitedOutput() :
+ Compress 'inputSize' bytes from 'source' into an output buffer 'dest' of maximum size 'maxOutputSize'.
+ If it cannot achieve it, compression will stop, and result of the function will be zero.
+ This function never writes outside of provided output buffer.
+
+ inputSize : Max supported value is 1 GB
+ maxOutputSize : is maximum allowed size into the destination buffer (which must be already allocated)
+ return : the number of output bytes written in buffer 'dest'
+ or 0 if compression fails.
+*/
+
+
+int LZ4_compressHC2 (const char* source, char* dest, int inputSize, int compressionLevel);
+int LZ4_compressHC2_limitedOutput (const char* source, char* dest, int inputSize, int maxOutputSize, int compressionLevel);
+/*
+ Same functions as above, but with programmable 'compressionLevel'.
+ Recommended values are between 4 and 9, although any value between 0 and 16 will work.
+ 'compressionLevel'==0 means use default 'compressionLevel' value.
+ Values above 16 behave the same as 16.
+ Equivalent variants exist for all other compression functions below.
+*/
+
+/* Note :
+ Decompression functions are provided within LZ4 source code (see "lz4.h") (BSD license)
+*/
+
+
+/**************************************
+ Using an external allocation
+**************************************/
+int LZ4_sizeofStateHC(void);
+int LZ4_compressHC_withStateHC (void* state, const char* source, char* dest, int inputSize);
+int LZ4_compressHC_limitedOutput_withStateHC (void* state, const char* source, char* dest, int inputSize, int maxOutputSize);
+
+int LZ4_compressHC2_withStateHC (void* state, const char* source, char* dest, int inputSize, int compressionLevel);
+int LZ4_compressHC2_limitedOutput_withStateHC(void* state, const char* source, char* dest, int inputSize, int maxOutputSize, int compressionLevel);
+
+/*
+These functions are provided should you prefer to allocate memory for compression tables with your own allocation methods.
+To know how much memory must be allocated for the compression tables, use :
+int LZ4_sizeofStateHC();
+
+Note that tables must be aligned for pointer (32 or 64 bits), otherwise compression will fail (return code 0).
+
+The allocated memory can be provided to the compression functions using 'void* state' parameter.
+LZ4_compress_withStateHC() and LZ4_compress_limitedOutput_withStateHC() are equivalent to previously described functions.
+They just use the externally allocated memory for state instead of allocating their own (on stack, or on heap).
+*/
+
+
+
+/**************************************
+ Experimental Streaming Functions
+**************************************/
+#define LZ4_STREAMHCSIZE_U64 32774
+#define LZ4_STREAMHCSIZE (LZ4_STREAMHCSIZE_U64 * sizeof(unsigned long long))
+typedef struct { unsigned long long table[LZ4_STREAMHCSIZE_U64]; } LZ4_streamHC_t;
+
+/*
+This structure allows static allocation of LZ4 HC streaming state.
+State must then be initialized using LZ4_resetStreamHC() before first use.
+
+If you prefer dynamic allocation, please refer to functions below.
+*/
+
+LZ4_streamHC_t* LZ4_createStreamHC(void);
+int LZ4_freeStreamHC (LZ4_streamHC_t* LZ4_streamHCPtr);
+
+/*
+These functions create and release memory for LZ4 HC streaming state.
+Newly created states are already initialized.
+Existing state space can be re-used anytime using LZ4_resetStreamHC().
+*/
+
+void LZ4_resetStreamHC (LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel);
+int LZ4_loadDictHC (LZ4_streamHC_t* LZ4_streamHCPtr, const char* dictionary, int dictSize);
+
+int LZ4_compressHC_continue (LZ4_streamHC_t* LZ4_streamHCPtr, const char* source, char* dest, int inputSize);
+int LZ4_compressHC_limitedOutput_continue (LZ4_streamHC_t* LZ4_streamHCPtr, const char* source, char* dest, int inputSize, int maxOutputSize);
+
+int LZ4_saveDictHC (LZ4_streamHC_t* LZ4_streamHCPtr, char* safeBuffer, int maxDictSize);
+
+/*
+These functions compress data in successive blocks of any size, using previous blocks as dictionary.
+One key assumption is that each previous block will remain read-accessible while compressing next block.
+
+Before starting compression, state must be properly initialized, using LZ4_resetStreamHC().
+A first "fictional block" can then be designated as initial dictionary, using LZ4_loadDictHC() (Optional).
+
+Then, use LZ4_compressHC_continue() or LZ4_compressHC_limitedOutput_continue() to compress each successive block.
+They work like usual LZ4_compressHC() or LZ4_compressHC_limitedOutput(), but use previous memory blocks to improve compression.
+Previous memory blocks (including initial dictionary when present) must remain accessible and unmodified during compression.
+
+If, for any reason, previous data block can't be preserved in memory during next compression block,
+you must save it to a safer memory space,
+using LZ4_saveDictHC().
+*/
+
+
+
+/**************************************
+ Deprecated Streaming Functions
+**************************************/
+/* Note : these streaming functions still follows the older model */
+void* LZ4_createHC (const char* inputBuffer);
+//int LZ4_compressHC_continue (void* LZ4HC_Data, const char* source, char* dest, int inputSize);
+//int LZ4_compressHC_limitedOutput_continue (void* LZ4HC_Data, const char* source, char* dest, int inputSize, int maxOutputSize);
+char* LZ4_slideInputBufferHC (void* LZ4HC_Data);
+int LZ4_freeHC (void* LZ4HC_Data);
+
+int LZ4_compressHC2_continue (void* LZ4HC_Data, const char* source, char* dest, int inputSize, int compressionLevel);
+int LZ4_compressHC2_limitedOutput_continue (void* LZ4HC_Data, const char* source, char* dest, int inputSize, int maxOutputSize, int compressionLevel);
+
+/*
+These functions allow the compression of dependent blocks, where each block benefits from prior 64 KB within preceding blocks.
+In order to achieve this, it is necessary to start creating the LZ4HC Data Structure, thanks to the function :
+
+void* LZ4_createHC (const char* inputBuffer);
+The result of the function is the (void*) pointer on the LZ4HC Data Structure.
+This pointer will be needed in all other functions.
+If the pointer returned is NULL, then the allocation has failed, and compression must be aborted.
+The only parameter 'const char* inputBuffer' must, obviously, point at the beginning of input buffer.
+The input buffer must be already allocated, and size at least 192KB.
+'inputBuffer' will also be the 'const char* source' of the first block.
+
+All blocks are expected to lay next to each other within the input buffer, starting from 'inputBuffer'.
+To compress each block, use either LZ4_compressHC_continue() or LZ4_compressHC_limitedOutput_continue().
+Their behavior are identical to LZ4_compressHC() or LZ4_compressHC_limitedOutput(),
+but require the LZ4HC Data Structure as their first argument, and check that each block starts right after the previous one.
+If next block does not begin immediately after the previous one, the compression will fail (return 0).
+
+When it's no longer possible to lay the next block after the previous one (not enough space left into input buffer), a call to :
+char* LZ4_slideInputBufferHC(void* LZ4HC_Data);
+must be performed. It will typically copy the latest 64KB of input at the beginning of input buffer.
+Note that, for this function to work properly, minimum size of an input buffer must be 192KB.
+==> The memory position where the next input data block must start is provided as the result of the function.
+
+Compression can then resume, using LZ4_compressHC_continue() or LZ4_compressHC_limitedOutput_continue(), as usual.
+
+When compression is completed, a call to LZ4_freeHC() will release the memory used by the LZ4HC Data Structure.
+*/
+
+int LZ4_sizeofStreamStateHC(void);
+int LZ4_resetStreamStateHC(void* state, const char* inputBuffer);
+
+/*
+These functions achieve the same result as :
+void* LZ4_createHC (const char* inputBuffer);
+
+They are provided here to allow the user program to allocate memory using its own routines.
+
+To know how much space must be allocated, use LZ4_sizeofStreamStateHC();
+Note also that space must be aligned for pointers (32 or 64 bits).
+
+Once space is allocated, you must initialize it using : LZ4_resetStreamStateHC(void* state, const char* inputBuffer);
+void* state is a pointer to the space allocated.
+It must be aligned for pointers (32 or 64 bits), and be large enough.
+The parameter 'const char* inputBuffer' must, obviously, point at the beginning of input buffer.
+The input buffer must be already allocated, and size at least 192KB.
+'inputBuffer' will also be the 'const char* source' of the first block.
+
+The same space can be re-used multiple times, just by initializing it each time with LZ4_resetStreamState().
+return value of LZ4_resetStreamStateHC() must be 0 is OK.
+Any other value means there was an error (typically, state is not aligned for pointers (32 or 64 bits)).
+*/
+
+
+#if defined (__cplusplus)
+}
+#endif