Added --fast command to cli

3 files changed, 42 insertions, 2 deletions

diff --git a/programs/bench.c b/programs/bench.c
index 770191c..c91ce7c 100644
--- a/programs/bench.c
+++ b/programs/bench.c
@@ -407,7 +407,7 @@ static void BMK_benchCLevel(void* srcBuffer, size_t benchedSize,
     if (g_displayLevel == 1 && !g_additionalParam)
         DISPLAY("bench %s %s: input %u bytes, %u seconds, %u KB blocks\n", LZ4_VERSION_STRING, LZ4_GIT_COMMIT_STRING, (U32)benchedSize, g_nbSeconds, (U32)(g_blockSize>>10));
 
-    if (cLevelLast < cLevel) cLevelLast = cLevel;
+    // if (cLevelLast < cLevel) cLevelLast = cLevel;
 
     for (l=cLevel; l <= cLevelLast; l++) {
         BMK_benchMem(srcBuffer, benchedSize,
diff --git a/programs/lz4.1.md b/programs/lz4.1.md
index a5168e9..d4eaf8a 100644
--- a/programs/lz4.1.md
+++ b/programs/lz4.1.md
@@ -156,6 +156,13 @@ only the latest one will be applied.
 * `-BD`:
   Block Dependency (improves compression ratio on small blocks)
 
+* `--fast[=#]`:
+  switch to ultra-fast compression levels.
+  If `=#` is not present, it defaults to `1`.
+  The higher the value, the faster the compression speed, at the cost of some compression ratio.
+  This setting overwrites compression level if one was set previously.
+  Similarly, if a compression level is set after `--fast`, it overrides it.
+
 * `--[no-]frame-crc`:
   Select frame checksum (default:enabled)
 
diff --git a/programs/lz4cli.c b/programs/lz4cli.c
index ba519b4..94e3b14 100644
--- a/programs/lz4cli.c
+++ b/programs/lz4cli.c
@@ -141,6 +141,7 @@ static int usage_advanced(const char* exeName)
     DISPLAY( "--content-size : compressed frame includes original size (default:not present)\n");
     DISPLAY( "--[no-]sparse  : sparse mode (default:enabled on file, disabled on stdout)\n");
     DISPLAY( "--favor-decSpeed: compressed files decompress faster, but are less compressed \n");
+    DISPLAY( "--fast[=#]: switch to ultra fast compression level (default: %u)\n", 1);
     DISPLAY( "Benchmark arguments : \n");
     DISPLAY( " -b#    : benchmark file(s), using # compression level (default : 1) \n");
     DISPLAY( " -e#    : test all compression levels from -bX to # (default : 1)\n");
@@ -272,13 +273,28 @@ static unsigned readU32FromChar(const char** stringPtr)
     return result;
 }
 
+/** longCommandWArg() :
+ *  check if *stringPtr is the same as longCommand.
+ *  If yes, @return 1 and advances *stringPtr to the position which immediately follows longCommand.
+ * @return 0 and doesn't modify *stringPtr otherwise.
+ */
+static unsigned longCommandWArg(const char** stringPtr, const char* longCommand)
+{
+    size_t const comSize = strlen(longCommand);
+    int const result = !strncmp(*stringPtr, longCommand, comSize);
+    if (result) *stringPtr += comSize;
+    return result;
+}
+
 typedef enum { om_auto, om_compress, om_decompress, om_test, om_bench } operationMode_e;
 
+#define CLEAN_RETURN(i) { operationResult = (i); goto _cleanup; }
+
 int main(int argc, const char** argv)
 {
     int i,
         cLevel=1,
-        cLevelLast=1,
+        cLevelLast=-10000,
         legacy_format=0,
         forceStdout=0,
         main_pause=0,
@@ -363,6 +379,23 @@ int main(int argc, const char** argv)
                 if (!strcmp(argument,  "--help")) { usage_advanced(exeName); goto _cleanup; }
                 if (!strcmp(argument,  "--keep")) { LZ4IO_setRemoveSrcFile(0); continue; }   /* keep source file (default) */
                 if (!strcmp(argument,  "--rm")) { LZ4IO_setRemoveSrcFile(1); continue; }
+                if (longCommandWArg(&argument, "--fast")) {
+                        /* Parse optional window log */
+                        if (*argument == '=') {
+                            U32 fastLevel;
+                            ++argument;
+                            fastLevel = readU32FromChar(&argument);
+                            if (fastLevel) {
+                              cLevel = -(int)fastLevel;
+                            }
+                        } else if (*argument != 0) {
+                            /* Invalid character following --fast */
+                            CLEAN_RETURN(badusage(exeName));
+                        } else {
+                            cLevel = -1;  /* default for --fast */
+                        }
+                        continue;
+                    }
             }
 
             while (argument[1]!=0) {