diff --git a/doc/zstd_manual.html b/doc/zstd_manual.html
index 19cd800c9..26985d1dc 100644
--- a/doc/zstd_manual.html
+++ b/doc/zstd_manual.html
@@ -503,48 +503,20 @@ size_t ZSTD_sizeof_DDict(const ZSTD_DDict* ddict);
* 9: full window; 8: w/2; 7: w/4; 6: w/8; 5:w/16; 4: w/32; 3:w/64; 2:w/128; 1:w/256;
* default value is 6 : use 1/8th of windowSize */
- /* =================================================================== */
- /* experimental parameters - no stability guaranteed */
- /* => note : should this part be exported in a different section of zstd.h ? */
- /* =================================================================== */
-
- /* compression format */
- ZSTD_p_format = 10, /* See ZSTD_format_e enum definition.
- * Cast selected format as unsigned for ZSTD_CCtx_setParameter() compatibility. */
-
- ZSTD_p_forceMaxWindow=1100, /* Force back-reference distances to remain < windowSize,
- * even when referencing into Dictionary content (default:0) */
- ZSTD_p_forceAttachDict, /* Controls whether the contents of a CDict are
- * used in place, or whether they are copied into
- * the working context.
- *
- * Accepts values from the ZSTD_dictAttachPref_e
- * enum. See the comments on that enum for an
- * explanation of the feature.
- */
-
- /* Question : should rsyncable remain experimental, or be part of candidate for stable ? */
- ZSTD_p_rsyncable, /* Enables rsyncable mode, which makes compressed
- * files more rsync friendly by adding periodic
- * synchronization points to the compressed data.
- * The target average block size is
- * ZSTD_p_jobSize / 2. You can modify the job size
- * to increase or decrease the granularity of the
- * synchronization point. Once the jobSize is
- * smaller than the window size, you will start to
- * see degraded compression ratio.
- * NOTE: This only works when multithreading is
- * enabled.
- * NOTE: You probably don't want to use this with
- * long range mode, since that will decrease the
- * effectiveness of the synchronization points,
- * but your milage may vary.
- * NOTE: Rsyncable mode will limit the maximum
- * compression speed to approximately 400 MB/s.
- * If your compression level is already running
- * significantly slower than that (< 200 MB/s),
- * the speed won't be significantly impacted.
- */
+ /* note : additional experimental parameters are also available
+ * within the experimental section of the API.
+ * At the time of this writing, they include :
+ * ZSTD_p_rsyncable
+ * ZSTD_p_format
+ * ZSTD_p_forceMaxWindow
+ * ZSTD_p_forceAttachDict
+ * Because they are not stable, it's necessary to define ZSTD_STATIC_LINKING_ONLY to access them.
+ * note : never use experimentalParam names directly
+ */
+ ZSTD_p_experimentalParam1=500,
+ ZSTD_p_experimentalParam2=10,
+ ZSTD_p_experimentalParam3=1000,
+ ZSTD_p_experimentalParam4
} ZSTD_cParameter;
typedef struct { diff --git a/lib/zstd.h b/lib/zstd.h index cd8bf34c0..2a00fcbc2 100644 --- a/lib/zstd.h +++ b/lib/zstd.h @@ -600,48 +600,20 @@ typedef enum { * 9: full window; 8: w/2; 7: w/4; 6: w/8; 5:w/16; 4: w/32; 3:w/64; 2:w/128; 1:w/256; * default value is 6 : use 1/8th of windowSize */ - /* =================================================================== */ - /* experimental parameters - no stability guaranteed */ - /* => note : should this part be exported in a different section of zstd.h ? */ - /* =================================================================== */ - - /* compression format */ - ZSTD_p_format = 10, /* See ZSTD_format_e enum definition. - * Cast selected format as unsigned for ZSTD_CCtx_setParameter() compatibility. */ - - ZSTD_p_forceMaxWindow=1100, /* Force back-reference distances to remain < windowSize, - * even when referencing into Dictionary content (default:0) */ - ZSTD_p_forceAttachDict, /* Controls whether the contents of a CDict are - * used in place, or whether they are copied into - * the working context. - * - * Accepts values from the ZSTD_dictAttachPref_e - * enum. See the comments on that enum for an - * explanation of the feature. - */ - - /* Question : should rsyncable remain experimental, or be part of candidate for stable ? */ - ZSTD_p_rsyncable, /* Enables rsyncable mode, which makes compressed - * files more rsync friendly by adding periodic - * synchronization points to the compressed data. - * The target average block size is - * ZSTD_p_jobSize / 2. You can modify the job size - * to increase or decrease the granularity of the - * synchronization point. Once the jobSize is - * smaller than the window size, you will start to - * see degraded compression ratio. - * NOTE: This only works when multithreading is - * enabled. - * NOTE: You probably don't want to use this with - * long range mode, since that will decrease the - * effectiveness of the synchronization points, - * but your milage may vary. - * NOTE: Rsyncable mode will limit the maximum - * compression speed to approximately 400 MB/s. - * If your compression level is already running - * significantly slower than that (< 200 MB/s), - * the speed won't be significantly impacted. - */ + /* note : additional experimental parameters are also available + * within the experimental section of the API. + * At the time of this writing, they include : + * ZSTD_p_rsyncable + * ZSTD_p_format + * ZSTD_p_forceMaxWindow + * ZSTD_p_forceAttachDict + * Because they are not stable, it's necessary to define ZSTD_STATIC_LINKING_ONLY to access them. + * note : never use experimentalParam names directly + */ + ZSTD_p_experimentalParam1=500, + ZSTD_p_experimentalParam2=10, + ZSTD_p_experimentalParam3=1000, + ZSTD_p_experimentalParam4 } ZSTD_cParameter; @@ -1238,6 +1210,43 @@ ZSTDLIB_API size_t ZSTD_CCtx_loadDictionary_advanced(ZSTD_CCtx* cctx, const void * how to interpret prefix content (automatic ? force raw mode (default) ? full mode only ?) */ ZSTDLIB_API size_t ZSTD_CCtx_refPrefix_advanced(ZSTD_CCtx* cctx, const void* prefix, size_t prefixSize, ZSTD_dictContentType_e dictContentType); +/* === experimental parameters === */ +/* these parameters can be used with ZSTD_setParameter() + * they are not guaranteed to remain supported in the future */ + + /* Enables rsyncable mode, + * which makes compressed files more rsync friendly + * by adding periodic synchronization points to the compressed data. + * The target average block size is ZSTD_p_jobSize / 2. + * It's possible to modify the job size to increase or decrease + * the granularity of the synchronization point. + * Once the jobSize is smaller than the window size, + * it will result in compression ratio degradation. + * NOTE 1: rsyncable mode only works when multithreading is enabled. + * NOTE 2: rsyncable performs poorly in combination with long range mode, + * since it will decrease the effectiveness of synchronization points, + * though mileage may vary. + * NOTE 3: Rsyncable mode limits maximum compression speed to ~400 MB/s. + * If the selected compression level is already running significantly slower, + * the overall speed won't be significantly impacted. + */ + #define ZSTD_p_rsyncable ZSTD_p_experimentalParam1 + +/* Select a compression format. + * The value must be of type ZSTD_format_e. + * See ZSTD_format_e enum definition for details */ +#define ZSTD_p_format ZSTD_p_experimentalParam2 + +/* Force back-reference distances to remain < windowSize, + * even when referencing into Dictionary content (default:0) */ +#define ZSTD_p_forceMaxWindow ZSTD_p_experimentalParam3 + +/* Controls whether the contents of a CDict + * are used in place, or copied into the working context. + * Accepts values from the ZSTD_dictAttachPref_e enum. + * See the comments on that enum for an explanation of the feature. */ +#define ZSTD_p_forceAttachDict ZSTD_p_experimentalParam4 + /*! ZSTD_CCtx_getParameter() : * Get the requested value of one compression parameter, selected by enum ZSTD_cParameter. * @result : 0, or an error code (which can be tested with ZSTD_isError()).