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authorYann Collet <cyan@fb.com>2017-08-30 23:09:10 (GMT)
committerYann Collet <cyan@fb.com>2017-08-30 23:09:10 (GMT)
commit3d260f352293d5cddc8e7f7464b93308d47ed176 (patch)
tree685de13ba1a81f3128f8a9efb2dc248b3582a5f1
parente3c71584ff3242ce0a42e1cdeb183756b2c47da4 (diff)
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complementary information for #394
-rw-r--r--doc/lz4_manual.html24
-rw-r--r--lib/lz4.h22
2 files changed, 29 insertions, 17 deletions
diff --git a/doc/lz4_manual.html b/doc/lz4_manual.html
index e3f6681..32d98e2 100644
--- a/doc/lz4_manual.html
+++ b/doc/lz4_manual.html
@@ -158,24 +158,29 @@ int LZ4_freeStream (LZ4_stream_t* streamPtr);
<pre><b>void LZ4_resetStream (LZ4_stream_t* streamPtr);
</b><p> An LZ4_stream_t structure can be allocated once and re-used multiple times.
- Use this function to init an allocated `LZ4_stream_t` structure and start a new compression.
+ Use this function to start compressing a new stream.
</p></pre><BR>
<pre><b>int LZ4_loadDict (LZ4_stream_t* streamPtr, const char* dictionary, int dictSize);
-</b><p> Use this function to load a static dictionary into LZ4_stream.
+</b><p> Use this function to load a static dictionary into LZ4_stream_t.
Any previous data will be forgotten, only 'dictionary' will remain in memory.
- Loading a size of 0 is allowed.
- Return : dictionary size, in bytes (necessarily <= 64 KB)
+ Loading a size of 0 is allowed, and is the same as reset.
+ @return : dictionary size, in bytes (necessarily <= 64 KB)
</p></pre><BR>
<pre><b>int LZ4_compress_fast_continue (LZ4_stream_t* streamPtr, const char* src, char* dst, int srcSize, int dstCapacity, int acceleration);
-</b><p> Compress buffer content 'src', using data from previously compressed blocks as dictionary to improve compression ratio.
- Important : Previous data blocks are assumed to remain present and unmodified !
+</b><p> Compress content into 'src' using data from previously compressed blocks, improving compression ratio.
'dst' buffer must be already allocated.
If dstCapacity >= LZ4_compressBound(srcSize), compression is guaranteed to succeed, and runs faster.
- If not, and if compressed data cannot fit into 'dst' buffer size, compression stops, and function @return==0.
+
+ Important : Up to 64KB of previously compressed data is assumed to remain present and unmodified in memory !
+ Special 1 : If input buffer is a double-buffer, it can have any size, including < 64 KB.
+ Special 2 : If input buffer is a ring-buffer, it can have any size, including < 64 KB.
+
+ @return : size of compressed block
+ or 0 if there is an error (typically, compressed data cannot fit into 'dst')
After an error, the stream status is invalid, it can only be reset or freed.
</p></pre><BR>
@@ -198,7 +203,8 @@ int LZ4_freeStreamDecode (LZ4_streamDecode_t* LZ4_stream);
</p></pre><BR>
<pre><b>int LZ4_setStreamDecode (LZ4_streamDecode_t* LZ4_streamDecode, const char* dictionary, int dictSize);
-</b><p> Use this function to start decompression of a new stream of blocks.
+</b><p> An LZ4_streamDecode_t structure can be allocated once and re-used multiple times.
+ Use this function to start decompression of a new stream of blocks.
A dictionary can optionnally be set. Use NULL or size 0 for a simple reset order.
@return : 1 if OK, 0 if error
@@ -222,7 +228,7 @@ int LZ4_decompress_fast_continue (LZ4_streamDecode_t* LZ4_streamDecode, const ch
In which case, encoding and decoding buffers do not need to be synchronized,
and encoding ring buffer can have any size, including larger than decoding buffer.
Whenever these conditions are not possible, save the last 64KB of decoded data into a safe buffer,
- and indicate where it is saved using LZ4_setStreamDecode() before decompressin next block.
+ and indicate where it is saved using LZ4_setStreamDecode() before decompressing next block.
</p></pre><BR>
<pre><b>int LZ4_decompress_safe_usingDict (const char* source, char* dest, int compressedSize, int maxDecompressedSize, const char* dictStart, int dictSize);
diff --git a/lib/lz4.h b/lib/lz4.h
index 3564a1d..d284d63 100644
--- a/lib/lz4.h
+++ b/lib/lz4.h
@@ -242,24 +242,29 @@ LZ4LIB_API int LZ4_freeStream (LZ4_stream_t* streamPtr);
/*! LZ4_resetStream() :
* An LZ4_stream_t structure can be allocated once and re-used multiple times.
- * Use this function to init an allocated `LZ4_stream_t` structure and start a new compression.
+ * Use this function to start compressing a new stream.
*/
LZ4LIB_API void LZ4_resetStream (LZ4_stream_t* streamPtr);
/*! LZ4_loadDict() :
- * Use this function to load a static dictionary into LZ4_stream.
+ * Use this function to load a static dictionary into LZ4_stream_t.
* Any previous data will be forgotten, only 'dictionary' will remain in memory.
- * Loading a size of 0 is allowed.
- * Return : dictionary size, in bytes (necessarily <= 64 KB)
+ * Loading a size of 0 is allowed, and is the same as reset.
+ * @return : dictionary size, in bytes (necessarily <= 64 KB)
*/
LZ4LIB_API int LZ4_loadDict (LZ4_stream_t* streamPtr, const char* dictionary, int dictSize);
/*! LZ4_compress_fast_continue() :
- * Compress buffer content 'src', using data from previously compressed blocks as dictionary to improve compression ratio.
- * Important : Previous data blocks are assumed to remain present and unmodified !
+ * Compress content into 'src' using data from previously compressed blocks, improving compression ratio.
* 'dst' buffer must be already allocated.
* If dstCapacity >= LZ4_compressBound(srcSize), compression is guaranteed to succeed, and runs faster.
- * If not, and if compressed data cannot fit into 'dst' buffer size, compression stops, and function @return==0.
+ *
+ * Important : Up to 64KB of previously compressed data is assumed to remain present and unmodified in memory !
+ * Special 1 : If input buffer is a double-buffer, it can have any size, including < 64 KB.
+ * Special 2 : If input buffer is a ring-buffer, it can have any size, including < 64 KB.
+ *
+ * @return : size of compressed block
+ * or 0 if there is an error (typically, compressed data cannot fit into 'dst')
* After an error, the stream status is invalid, it can only be reset or freed.
*/
LZ4LIB_API int LZ4_compress_fast_continue (LZ4_stream_t* streamPtr, const char* src, char* dst, int srcSize, int dstCapacity, int acceleration);
@@ -286,6 +291,7 @@ LZ4LIB_API LZ4_streamDecode_t* LZ4_createStreamDecode(void);
LZ4LIB_API int LZ4_freeStreamDecode (LZ4_streamDecode_t* LZ4_stream);
/*! LZ4_setStreamDecode() :
+ * An LZ4_streamDecode_t structure can be allocated once and re-used multiple times.
* Use this function to start decompression of a new stream of blocks.
* A dictionary can optionnally be set. Use NULL or size 0 for a simple reset order.
* @return : 1 if OK, 0 if error
@@ -309,7 +315,7 @@ LZ4LIB_API int LZ4_setStreamDecode (LZ4_streamDecode_t* LZ4_streamDecode, const
* In which case, encoding and decoding buffers do not need to be synchronized,
* and encoding ring buffer can have any size, including larger than decoding buffer.
* Whenever these conditions are not possible, save the last 64KB of decoded data into a safe buffer,
- * and indicate where it is saved using LZ4_setStreamDecode() before decompressin next block.
+ * and indicate where it is saved using LZ4_setStreamDecode() before decompressing next block.
*/
LZ4LIB_API int LZ4_decompress_safe_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* source, char* dest, int compressedSize, int maxDecompressedSize);
LZ4LIB_API int LZ4_decompress_fast_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* source, char* dest, int originalSize);