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Increase maximum window size

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* Maximum window size in 32-bit mode is 1GB, since allocations for 2GB fail
  on my Mac.
* Maximum window size in 64-bit mode is 2GB, since that is the largest
  power of 2 that works with the overflow prevention.
* Allow `--long=windowLog` to set the window log, along with
  `--zstd=wlog=#`. These options also set the window size during
  decompression, but don't override `--memory=#` if it is set.
* Present a helpful error message when the window size is too large during
  decompression.
* The long range matcher defaults to a hash log 7 less than the window log,
  which keeps it at 20 for window log 27.
* Keep the default long range matcher window size and the default maximum
  window size at 27 for the API and CLI.
* Add tests that use the maximum window size and hash size for compression
  and decompression.
This commit is contained in:
Nick Terrell
2017-09-22 14:04:39 -07:00
parent 8a4d0abc1c
commit c233bdbaee
12 changed files with 139 additions and 40 deletions
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27
programs/zstdcli.c
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@ -72,6 +72,7 @@ static const char* g_defaultDictName = "dictionary";
static const unsigned g_defaultMaxDictSize = 110 KB;
static const int g_defaultDictCLevel = 3;
static const unsigned g_defaultSelectivityLevel = 9;
static const unsigned g_defaultMaxWindowLog = 27;
#define OVERLAP_LOG_DEFAULT 9999
#define LDM_PARAM_DEFAULT 9999 /* Default for parameters where 0 is valid */
static U32 g_overlapLog = OVERLAP_LOG_DEFAULT;
@ -129,7 +130,7 @@ static int usage_advanced(const char* programName)
DISPLAY( " -l : print information about zstd compressed files \n");
#ifndef ZSTD_NOCOMPRESS
DISPLAY( "--ultra : enable levels beyond %i, up to %i (requires more memory)\n", ZSTDCLI_CLEVEL_MAX, ZSTD_maxCLevel());
DISPLAY( "--long : enable long distance matching (requires more memory)\n");
DISPLAY( "--long[=#] : enable long distance matching with given window log (default : %u)\n", g_defaultMaxWindowLog);
#ifdef ZSTD_MULTITHREAD
DISPLAY( " -T# : use # threads for compression (default:1) \n");
DISPLAY( " -B# : select size of each job (default:0==automatic) \n");
@ -459,7 +460,6 @@ int main(int argCount, const char* argv[])
if (!strcmp(argument, "--quiet")) { g_displayLevel--; continue; }
if (!strcmp(argument, "--stdout")) { forceStdout=1; outFileName=stdoutmark; g_displayLevel-=(g_displayLevel==2); continue; }
if (!strcmp(argument, "--ultra")) { ultra=1; continue; }
if (!strcmp(argument, "--long")) { ldmFlag = 1; continue; }
if (!strcmp(argument, "--check")) { FIO_setChecksumFlag(2); continue; }
if (!strcmp(argument, "--no-check")) { FIO_setChecksumFlag(0); continue; }
if (!strcmp(argument, "--sparse")) { FIO_setSparseWrite(2); continue; }
@ -514,6 +514,22 @@ int main(int argCount, const char* argv[])
if (longCommandWArg(&argument, "--maxdict=")) { maxDictSize = readU32FromChar(&argument); continue; }
if (longCommandWArg(&argument, "--dictID=")) { dictID = readU32FromChar(&argument); continue; }
if (longCommandWArg(&argument, "--zstd=")) { if (!parseCompressionParameters(argument, &compressionParams)) CLEAN_RETURN(badusage(programName)); continue; }
if (longCommandWArg(&argument, "--long")) {
unsigned ldmWindowLog = 0;
ldmFlag = 1;
/* Parse optional window log */
if (*argument == '=') {
++argument;
ldmWindowLog = readU32FromChar(&argument);
} else if (*argument != 0) {
/* Invalid character following --long */
CLEAN_RETURN(badusage(programName));
}
/* Only set windowLog if not already set by --zstd */
if (compressionParams.windowLog == 0)
compressionParams.windowLog = ldmWindowLog;
continue;
}
/* fall-through, will trigger bad_usage() later on */
}
@ -830,6 +846,13 @@ int main(int argCount, const char* argv[])
#endif
} else { /* decompression or test */
#ifndef ZSTD_NODECOMPRESS
if (memLimit == 0) {
if (compressionParams.windowLog == 0)
memLimit = (U32)1 << g_defaultMaxWindowLog;
else {
memLimit = (U32)1 << (compressionParams.windowLog & 31);
}
}
FIO_setMemLimit(memLimit);
if (filenameIdx==1 && outFileName)
operationResult = FIO_decompressFilename(outFileName, filenameTable[0], dictFileName);