updated comment on parameters that can be changed during compression

This commit is contained in:
Yann Collet 2018-04-09 17:39:07 -07:00
parent 1da629f2ad
commit ad5ba6cdcf

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@ -912,7 +912,6 @@ ZSTDLIB_API ZSTD_nextInputType_e ZSTD_nextInputType(ZSTD_DCtx* dctx);
* When no parameter is ever provided, CCtx is created with compression level ZSTD_CLEVEL_DEFAULT.
*
* This API is intended to replace all others advanced / experimental API entry points.
* But it stands a reasonable chance to become "stable", after a reasonable testing period.
*/
/* note on naming convention :
@ -1069,10 +1068,13 @@ typedef enum {
/*! ZSTD_CCtx_setParameter() :
* Set one compression parameter, selected by enum ZSTD_cParameter.
* Setting a parameter is generally only possible during frame initialization (before starting compression),
* except for a few exceptions which can be updated during compression: compressionLevel, hashLog, chainLog, searchLog, minMatch, targetLength and strategy.
* Note : when `value` is an enum, cast it to unsigned for proper type checking.
* @result : informational value (typically, value being set clamped correctly),
* Setting a parameter is generally only possible during frame initialization (before starting compression).
* Exception : when using multi-threading mode (nbThreads >= 1),
* following parameters can be updated _during_ compression (within same frame):
* => compressionLevel, hashLog, chainLog, searchLog, minMatch, targetLength and strategy.
* new parameters will be active on next job, or after a flush().
* Note : when `value` type is not unsigned (int, or enum), cast it to unsigned for proper type checking.
* @result : informational value (typically, value being set, correctly clamped),
* or an error code (which can be tested with ZSTD_isError()). */
ZSTDLIB_API size_t ZSTD_CCtx_setParameter(ZSTD_CCtx* cctx, ZSTD_cParameter param, unsigned value);