benchmark more can test targetCBlockSize

programs/benchzstd.c

@@ -200,6 +200,7 @@ BMK_advancedParams_t BMK_initAdvancedParams(void)
         BMK_both,               /* mode */
         BMK_TIMETEST_DEFAULT_S, /* nbSeconds */
         0,                      /* blockSize */
+        0,               /* targetCBlockSize */
         0,                      /* nbWorkers */
         0,                      /* realTime */
         0,                      /* additionalParam */
@@ -275,6 +276,8 @@ static void BMK_initCCtx(
             (int)adv->literalCompressionMode));
     CHECK_Z(ZSTD_CCtx_setParameter(
             ctx, ZSTD_c_strategy, (int)comprParams->strategy));
+    CHECK_Z(ZSTD_CCtx_setParameter(
+            ctx, ZSTD_c_targetCBlockSize, (int)adv->targetCBlockSize));
     CHECK_Z(ZSTD_CCtx_loadDictionary(ctx, dictBuffer, dictBufferSize));
 }
 

programs/benchzstd.h

@@ -100,6 +100,7 @@ typedef struct {
     BMK_mode_t mode;        /* 0: all, 1: compress only 2: decode only */
     unsigned nbSeconds;     /* default timing is in nbSeconds */
     size_t blockSize;       /* Maximum size of each block*/
+    size_t targetCBlockSize;/* Approximative size of compressed blocks */
     int nbWorkers;          /* multithreading */
     unsigned realTime;      /* real time priority */
     int additionalParam;    /* used by python speed benchmark */

programs/zstd.1.md

@@ -218,6 +218,10 @@ the last one takes effect.
     expected. This feature allows for controlling the guess when needed.
     Exact guesses result in better compression ratios. Overestimates result in slightly
     degraded compression ratios, while underestimates may result in significant degradation.
+* `--target-compressed-block-size=#`:
+    Attempt to produce compressed blocks of approximately this size.
+    This will split larger blocks in order to approach this target.
+    Notably useful to improve latency when the receiver can make use of early data sooner.
 * `-o FILE`:
     save result into `FILE`.
 * `-f`, `--force`:

programs/zstdcli.c

@@ -1374,6 +1374,7 @@ int main(int argCount, const char* argv[])
             CLEAN_RETURN(1);
         }
         benchParams.blockSize = blockSize;
+        benchParams.targetCBlockSize = targetCBlockSize;
         benchParams.nbWorkers = (int)nbWorkers;
         benchParams.realTime = (unsigned)setRealTimePrio;
         benchParams.nbSeconds = bench_nbSeconds;