Add CLI Support

Author: felixhandte

programs/fileio.c

@@ -308,6 +308,7 @@ FIO_prefs_t* FIO_createPreferences(void)
     ret->allowBlockDevices = 0;
     ret->asyncIO = AIO_supported();
     ret->passThrough = -1;
+    ret->constrainWindowForProtocol = ZSTD_ConstrainWindow_auto;
     return ret;
 }
 
@@ -490,6 +491,12 @@ void FIO_setMMapDict(FIO_prefs_t* const prefs, ZSTD_ParamSwitch_e value)
     prefs->mmapDict = value;
 }
 
+void FIO_setConstrainWindowForProtocol(
+        FIO_prefs_t* const prefs,
+        ZSTD_ConstrainWindow_e constraint) {
+    prefs->constrainWindowForProtocol = constraint;
+}
+
 /* FIO_ctx_t functions */
 
 void FIO_setHasStdoutOutput(FIO_ctx_t* const fCtx, int value) {
@@ -1188,6 +1195,7 @@ static cRess_t FIO_createCResources(FIO_prefs_t* const prefs,
         CHECK( ZSTD_CCtx_setParameter(ress.cctx, ZSTD_c_overlapLog, prefs->overlapLog) );
     }
     CHECK( ZSTD_CCtx_setParameter(ress.cctx, ZSTD_c_rsyncable, prefs->rsyncable) );
+    CHECK( ZSTD_CCtx_setParameter(ress.cctx, ZSTD_c_constrainWindowForProtocol, prefs->constrainWindowForProtocol) );
 #endif
     /* dictionary */
     if (prefs->patchFromMode) {

programs/fileio.h

@@ -91,6 +91,9 @@ void FIO_setTestMode(FIO_prefs_t* const prefs, int testMode);
 void FIO_setLiteralCompressionMode(
         FIO_prefs_t* const prefs,
         ZSTD_ParamSwitch_e mode);
+void FIO_setConstrainWindowForProtocol(
+        FIO_prefs_t* const prefs,
+        ZSTD_ConstrainWindow_e constraint);
 
 void FIO_setProgressSetting(FIO_progressSetting_e progressSetting);
 void FIO_setNotificationLevel(int level);

programs/fileio_types.h

@@ -54,6 +54,7 @@ typedef struct FIO_prefs_s {
     int srcSizeHint;
     int testMode;
     ZSTD_ParamSwitch_e literalCompressionMode;
+    ZSTD_ConstrainWindow_e constrainWindowForProtocol;
 
     /* IO preferences */
     int removeSrcFile;

programs/zstd.1.md

@@ -232,6 +232,11 @@ the last one takes effect.
     This parameter defines a loose target: compressed blocks will target this size "on average", but individual blocks can still be larger or smaller.
     Enabling this feature can decrease compression speed by up to ~10% at level 1.
     Higher levels will see smaller relative speed regression, becoming invisible at higher settings.
+* `--constrain-window={none,http-zstd,http-dcz}`:
+    Constrains the window size to the limits set by the indicated protocol.
+    `none` (the default) doesn't set any constraints.
+    `http-zstd` refers to the `zstd` HTTP Content-Encoding specified by RFCs 8878 and 9659.
+    `http-dcz` refers to the `dcz` HTTP Content-Encoding specified by the Compression Dictionary Transport draft.
 * `-f`, `--force`:
     disable input and output checks. Allows overwriting existing files, input
     from console, output to stdout, operating on links, block devices, etc.

programs/zstdcli.c

@@ -244,7 +244,9 @@ static void usageAdvanced(const char* programName)
     DISPLAYOUT("  --stream-size=#               Specify size of streaming input from STDIN.\n");
     DISPLAYOUT("  --size-hint=#                 Optimize compression parameters for streaming input of approximately size #.\n");
     DISPLAYOUT("  --target-compressed-block-size=#\n");
-    DISPLAYOUT("                                Generate compressed blocks of approximately # size.\n\n");
+    DISPLAYOUT("                                Generate compressed blocks of approximately # size.\n");
+    DISPLAYOUT("  --constrain-window={none,http-zstd,http-dcz}\n");
+    DISPLAYOUT("                                Constrain window size to comply with limits set by protocol. [Default: none]\n\n");
     DISPLAYOUT("  --no-dictID                   Don't write `dictID` into the header (dictionary compression only).\n");
     DISPLAYOUT("  --[no-]compress-literals      Force (un)compressed literals.\n");
     DISPLAYOUT("  --[no-]row-match-finder       Explicitly enable/disable the fast, row-based matchfinder for\n");
@@ -851,6 +853,7 @@ int main(int argCount, const char* argv[])
         removeSrcFile=0;
     ZSTD_ParamSwitch_e mmapDict=ZSTD_ps_auto;
     ZSTD_ParamSwitch_e useRowMatchFinder = ZSTD_ps_auto;
+    ZSTD_ConstrainWindow_e constrainWindowForProtocol = ZSTD_ConstrainWindow_auto;
     FIO_compressionType_t cType = FIO_zstdCompression;
     int nbWorkers = -1; /* -1 means unset */
     double compressibility = -1.0;  /* lorem ipsum generator */
@@ -1135,6 +1138,23 @@ int main(int argCount, const char* argv[])
                     continue;
                 }
 
+
+                if (longCommandWArg(&argument, "--constrain-window")) {
+                    const char* protocol;
+                    NEXT_FIELD(protocol);
+                    if (!strncmp(protocol, "none", strlen("none") + 1)) {
+                        constrainWindowForProtocol = ZSTD_ConstrainWindow_HTTP_Zstd;
+                    } else if (!strncmp(protocol, "http-zstd", strlen("http-zstd") + 1)) {
+                        constrainWindowForProtocol = ZSTD_ConstrainWindow_HTTP_Zstd;
+                    } else if (!strncmp(protocol, "http-dcz", strlen("http-dcz") + 1)) {
+                        constrainWindowForProtocol = ZSTD_ConstrainWindow_HTTP_DCZ;
+                    } else {
+                        badUsage(programName, originalArgument);
+                        CLEAN_RETURN(1);
+                    }
+                    continue;
+                }
+
                 badUsage(programName, originalArgument);
                 CLEAN_RETURN(1);
             }
@@ -1573,6 +1593,7 @@ int main(int argCount, const char* argv[])
         FIO_setSrcSizeHint(prefs, srcSizeHint);
         FIO_setLiteralCompressionMode(prefs, literalCompressionMode);
         FIO_setSparseWrite(prefs, 0);
+        FIO_setConstrainWindowForProtocol(prefs, constrainWindowForProtocol);
         if (adaptMin > cLevel) cLevel = adaptMin;
         if (adaptMax < cLevel) cLevel = adaptMax;
 
@@ -1603,6 +1624,7 @@ int main(int argCount, const char* argv[])
         (void)ultra; (void)cLevel; (void)ldmFlag; (void)literalCompressionMode;
         (void)targetCBlockSize; (void)streamSrcSize; (void)srcSizeHint;
         (void)ZSTD_strategyMap; (void)useRowMatchFinder; (void)cType;
+        (void)constrainWindowForProtocol;
         DISPLAYLEVEL(1, "Compression not supported \n");
 #endif
     } else {  /* decompression or test */