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-rw-r--r--doc/lz4_manual.html18
-rw-r--r--doc/lz4frame_manual.html75
2 files changed, 61 insertions, 32 deletions
diff --git a/doc/lz4_manual.html b/doc/lz4_manual.html
index ff6e149..4c4174d 100644
--- a/doc/lz4_manual.html
+++ b/doc/lz4_manual.html
@@ -1,10 +1,10 @@
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
-<title>lz4 1.7.5 Manual</title>
+<title>1.7.6 Manual</title>
</head>
<body>
-<h1>lz4 1.7.5 Manual</h1>
+<h1>1.7.6 Manual</h1>
<hr>
<a name="Contents"></a><h2>Contents</h2>
<ol>
@@ -170,21 +170,21 @@ int LZ4_freeStream (LZ4_stream_t* streamPtr);
</p></pre><BR>
-<pre><b>int LZ4_compress_fast_continue (LZ4_stream_t* streamPtr, const char* src, char* dst, int srcSize, int maxDstSize, int acceleration);
+<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 still be present and unmodified !
+ Important : Previous data blocks are assumed to remain present and unmodified !
'dst' buffer must be already allocated.
- If maxDstSize >= LZ4_compressBound(srcSize), compression is guaranteed to succeed, and runs faster.
+ 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 returns a zero.
+ After an error, the stream status is invalid, and it can only be reset or freed.
</p></pre><BR>
<pre><b>int LZ4_saveDict (LZ4_stream_t* streamPtr, char* safeBuffer, int dictSize);
-</b><p> If previously compressed data block is not guaranteed to remain available at its memory location,
+</b><p> If previously compressed data block is not guaranteed to remain available at its current memory location,
save it into a safer place (char* safeBuffer).
- Note : you don't need to call LZ4_loadDict() afterwards,
- dictionary is immediately usable, you can therefore call LZ4_compress_fast_continue().
- Return : saved dictionary size in bytes (necessarily <= dictSize), or 0 if error.
+ Note : it's not necessary to call LZ4_loadDict() after LZ4_saveDict(), dictionary is immediately usable.
+ @return : saved dictionary size in bytes (necessarily <= dictSize), or 0 if error.
</p></pre><BR>
diff --git a/doc/lz4frame_manual.html b/doc/lz4frame_manual.html
index f76ec3d..5d553ed 100644
--- a/doc/lz4frame_manual.html
+++ b/doc/lz4frame_manual.html
@@ -1,19 +1,23 @@
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
-<title>lz4frame 1.7.5 Manual</title>
+<title>1.7.6 Manual</title>
</head>
<body>
-<h1>lz4frame 1.7.5 Manual</h1>
+<h1>1.7.6 Manual</h1>
<hr>
<a name="Contents"></a><h2>Contents</h2>
<ol>
<li><a href="#Chapter1">Introduction</a></li>
-<li><a href="#Chapter2">Error management</a></li>
-<li><a href="#Chapter3">Frame compression types</a></li>
-<li><a href="#Chapter4">Simple compression function</a></li>
-<li><a href="#Chapter5">Advanced compression functions</a></li>
-<li><a href="#Chapter6">Decompression functions</a></li>
+<li><a href="#Chapter2">Compiler specifics</a></li>
+<li><a href="#Chapter3">Error management</a></li>
+<li><a href="#Chapter4">Frame compression types</a></li>
+<li><a href="#Chapter5">Simple compression function</a></li>
+<li><a href="#Chapter6">Advanced compression functions</a></li>
+<li><a href="#Chapter7">Resource Management</a></li>
+<li><a href="#Chapter8">Compression</a></li>
+<li><a href="#Chapter9">Decompression functions</a></li>
+<li><a href="#Chapter10">Streaming decompression functions</a></li>
</ol>
<hr>
<a name="Chapter1"></a><h2>Introduction</h2><pre>
@@ -22,13 +26,15 @@
of encoding standard metadata alongside LZ4-compressed blocks.
<BR></pre>
-<a name="Chapter2"></a><h2>Error management</h2><pre></pre>
+<a name="Chapter2"></a><h2>Compiler specifics</h2><pre></pre>
+
+<a name="Chapter3"></a><h2>Error management</h2><pre></pre>
<pre><b>unsigned LZ4F_isError(LZ4F_errorCode_t code); </b>/**< tells if a `LZ4F_errorCode_t` function result is an error code */<b>
</b></pre><BR>
<pre><b>const char* LZ4F_getErrorName(LZ4F_errorCode_t code); </b>/**< return error code string; useful for debugging */<b>
</b></pre><BR>
-<a name="Chapter3"></a><h2>Frame compression types</h2><pre></pre>
+<a name="Chapter4"></a><h2>Frame compression types</h2><pre></pre>
<pre><b>typedef enum {
LZ4F_default=0,
@@ -77,7 +83,7 @@
<pre><b>typedef struct {
LZ4F_frameInfo_t frameInfo;
- int compressionLevel; </b>/* 0 == default (fast mode); values above 16 count as 16; values below 0 count as 0 */<b>
+ int compressionLevel; </b>/* 0 == default (fast mode); values above LZ4HC_CLEVEL_MAX count as LZ4HC_CLEVEL_MAX; values below 0 trigger "fast acceleration", proportional to value */<b>
unsigned autoFlush; </b>/* 1 == always flush (reduce usage of tmp buffer) */<b>
unsigned reserved[4]; </b>/* must be zero for forward compatibility */<b>
} LZ4F_preferences_t;
@@ -86,7 +92,7 @@
All reserved fields must be set to zero.
</p></pre><BR>
-<a name="Chapter4"></a><h2>Simple compression function</h2><pre></pre>
+<a name="Chapter5"></a><h2>Simple compression function</h2><pre></pre>
<pre><b>size_t LZ4F_compressFrameBound(size_t srcSize, const LZ4F_preferences_t* preferencesPtr);
</b><p> Returns the maximum possible size of a frame compressed with LZ4F_compressFrame() given srcSize content and preferences.
@@ -105,17 +111,19 @@
</p></pre><BR>
-<a name="Chapter5"></a><h2>Advanced compression functions</h2><pre></pre>
+<a name="Chapter6"></a><h2>Advanced compression functions</h2><pre></pre>
<pre><b>typedef struct {
unsigned stableSrc; </b>/* 1 == src content will remain present on future calls to LZ4F_compress(); skip copying src content within tmp buffer */<b>
unsigned reserved[3];
} LZ4F_compressOptions_t;
</b></pre><BR>
+<a name="Chapter7"></a><h2>Resource Management</h2><pre></pre>
+
<pre><b>LZ4F_errorCode_t LZ4F_createCompressionContext(LZ4F_cctx** cctxPtr, unsigned version);
LZ4F_errorCode_t LZ4F_freeCompressionContext(LZ4F_cctx* cctx);
</b><p> The first thing to do is to create a compressionContext object, which will be used in all compression operations.
- This is achieved using LZ4F_createCompressionContext(), which takes as argument a version and an LZ4F_preferences_t structure.
+ This is achieved using LZ4F_createCompressionContext(), which takes as argument a version.
The version provided MUST be LZ4F_VERSION. It is intended to track potential version mismatch, notably when using DLL.
The function will provide a pointer to a fully allocated LZ4F_cctx object.
If @return != zero, there was an error during context creation.
@@ -123,6 +131,8 @@ LZ4F_errorCode_t LZ4F_freeCompressionContext(LZ4F_cctx* cctx);
</p></pre><BR>
+<a name="Chapter8"></a><h2>Compression</h2><pre></pre>
+
<pre><b>size_t LZ4F_compressBegin(LZ4F_cctx* cctx, void* dstBuffer, size_t dstCapacity, const LZ4F_preferences_t* prefsPtr);
</b><p> will write the frame header into dstBuffer.
dstCapacity must be large enough to store the header. Maximum header size is LZ4F_HEADER_SIZE_MAX bytes.
@@ -173,7 +183,7 @@ LZ4F_errorCode_t LZ4F_freeCompressionContext(LZ4F_cctx* cctx);
</p></pre><BR>
-<a name="Chapter6"></a><h2>Decompression functions</h2><pre></pre>
+<a name="Chapter9"></a><h2>Decompression functions</h2><pre></pre>
<pre><b>typedef struct {
unsigned stableDst; </b>/* guarantee that decompressed data will still be there on next function calls (avoid storage into tmp buffers) */<b>
@@ -181,7 +191,7 @@ LZ4F_errorCode_t LZ4F_freeCompressionContext(LZ4F_cctx* cctx);
} LZ4F_decompressOptions_t;
</b></pre><BR>
<pre><b>LZ4F_errorCode_t LZ4F_createDecompressionContext(LZ4F_dctx** dctxPtr, unsigned version);
-LZ4F_errorCode_t LZ4F_freeDecompressionContext(LZ4F_dctx* const dctx);
+LZ4F_errorCode_t LZ4F_freeDecompressionContext(LZ4F_dctx* dctx);
</b><p> Create an LZ4F_decompressionContext_t object, which will be used to track all decompression operations.
The version provided MUST be LZ4F_VERSION. It is intended to track potential breaking differences between different versions.
The function will provide a pointer to a fully allocated and initialized LZ4F_decompressionContext_t object.
@@ -192,19 +202,27 @@ LZ4F_errorCode_t LZ4F_freeDecompressionContext(LZ4F_dctx* const dctx);
</p></pre><BR>
+<a name="Chapter10"></a><h2>Streaming decompression functions</h2><pre></pre>
+
<pre><b>size_t LZ4F_getFrameInfo(LZ4F_dctx* dctx,
LZ4F_frameInfo_t* frameInfoPtr,
const void* srcBuffer, size_t* srcSizePtr);
-</b><p> This function decodes frame header information (such as max blockSize, frame checksum, etc.).
- Its usage is optional. The objective is to extract frame header information, typically for allocation purposes.
- A header size is variable and can length from 7 to 15 bytes. It's possible to provide more input bytes than that.
+</b><p> This function extracts frame parameters (such as max blockSize, frame checksum, etc.).
+ Its usage is optional. Extracted information can be useful for allocation purposes, typically.
+ This function works in 2 situations :
+ - At the beginning of a new frame, in which case it will decode this information from `srcBuffer`, and start the decoding process.
+ Input size must be large enough to successfully decode the entire frame header.
+ Frame header size is variable, but is guaranteed to be <= LZ4F_HEADER_SIZE_MAX bytes.
+ It's allowed to provide more input data than this minimum.
+ - After decoding has been started.
+ In which case, no input is read, frame parameters are extracted from dctx.
+ If decoding has just started, but not yet extracted information from header, LZ4F_getFrameInfo() will fail.
The number of bytes consumed from srcBuffer will be updated within *srcSizePtr (necessarily <= original value).
- Decompression must resume from this point (srcBuffer + *srcSizePtr).
- Note that LZ4F_getFrameInfo() can also be used anytime *after* decompression is started, in which case 0 input byte can be enough.
- Frame header info is *copied into* an already allocated LZ4F_frameInfo_t structure.
+ Decompression must resume from (srcBuffer + *srcSizePtr).
@return : an hint about how many srcSize bytes LZ4F_decompress() expects for next call,
or an error code which can be tested using LZ4F_isError()
- (typically, when there is not enough src bytes to fully decode the frame header)
+ note 1 : in case of error, dctx is not modified. Decoding operations can resume from where they stopped.
+ note 2 : frame parameters are *copied into* an already allocated LZ4F_frameInfo_t structure.
</p></pre><BR>
@@ -227,14 +245,25 @@ LZ4F_errorCode_t LZ4F_freeDecompressionContext(LZ4F_dctx* const dctx);
@return is an hint of how many `srcSize` bytes LZ4F_decompress() expects for next call.
Schematically, it's the size of the current (or remaining) compressed block + header of next block.
- Respecting the hint provides some boost to performance, since it does skip intermediate buffers.
+ Respecting the hint provides some small speed benefit, because it skips intermediate buffers.
This is just a hint though, it's always possible to provide any srcSize.
When a frame is fully decoded, @return will be 0 (no more data expected).
If decompression failed, @return is an error code, which can be tested using LZ4F_isError().
After a frame is fully decoded, dctx can be used again to decompress another frame.
+ After a decompression error, use LZ4F_resetDecompressionContext() before re-using dctx, to return to clean state.
</p></pre><BR>
+<pre><b>LZ4F_errorCode_t LZ4F_resetDecompressionContext(LZ4F_dctx* dctx);
+</b><p> When decompression ends successfully,
+ it's possible to start a new decompression immediately
+ re-using the same context.
+ However, in case of an error, the context is left in "undefined" state.
+ In which case, it's necessary to reset it, before re-using it.
+ This method can also be used to abruptly stop an unfinished decompression,
+ and start a new on the same context.
+</p></pre><BR>
+
</html>
</body>