diff options
| -rw-r--r-- | runtime/zlibw.c | 10 | ||||
| -rw-r--r-- | runtime/zlibw.h | 1 | ||||
| -rw-r--r-- | tools/omfile.c | 30 |
3 files changed, 36 insertions, 5 deletions
diff --git a/runtime/zlibw.c b/runtime/zlibw.c index 95ac9138..2b386213 100644 --- a/runtime/zlibw.c +++ b/runtime/zlibw.c @@ -51,9 +51,9 @@ static int myDeflateInit(z_streamp strm, int level) return deflateInit(strm, level); } -static int myDeflate(z_streamp strm, int flush) +static int myDeflateInit2(z_streamp strm, int level, int method, int windowBits, int memLevel, int strategy) { - return deflate(strm, flush); + return deflateInit2(strm, level, method, windowBits, memLevel, strategy); } static int myDeflateEnd(z_streamp strm) @@ -61,6 +61,11 @@ static int myDeflateEnd(z_streamp strm) return deflateEnd(strm); } +static int myDeflate(z_streamp strm, int flush) +{ + return deflate(strm, flush); +} + /* queryInterface function * rgerhards, 2008-03-05 @@ -77,6 +82,7 @@ CODESTARTobjQueryInterface(zlibw) * of course, also affects the "if" above). */ pIf->DeflateInit = myDeflateInit; + pIf->DeflateInit2 = myDeflateInit2; pIf->Deflate = myDeflate; pIf->DeflateEnd = myDeflateEnd; finalize_it: diff --git a/runtime/zlibw.h b/runtime/zlibw.h index 01e0b054..63d8f386 100644 --- a/runtime/zlibw.h +++ b/runtime/zlibw.h @@ -30,6 +30,7 @@ /* interfaces */ BEGINinterface(zlibw) /* name must also be changed in ENDinterface macro! */ int (*DeflateInit)(z_streamp strm, int); + int (*DeflateInit2)(z_streamp strm, int level, int method, int windowBits, int memLevel, int strategy); int (*Deflate)(z_streamp strm, int); int (*DeflateEnd)(z_streamp strm); ENDinterface(zlibw) diff --git a/tools/omfile.c b/tools/omfile.c index 62a044d8..08c33a7f 100644 --- a/tools/omfile.c +++ b/tools/omfile.c @@ -14,6 +14,29 @@ * * Copyright 2007-2009 Rainer Gerhards and Adiscon GmbH. * + * An important note on writing gzip format via zlib (kept anonymous + * by request): + * + * -------------------------------------------------------------------------- + * We'd like to make sure the output file is in full gzip format + * (compatible with gzip -d/zcat etc). There is a flag in how the output + * is initialized within zlib to properly add the gzip wrappers to the + * output. (gzip is effectively a small metadata wrapper around raw + * zstream output.) + * + * I had written an old bit of code to do this - the documentation on + * deflatInit2() was pretty tricky to nail down on this specific feature: + * + * int deflateInit2 (z_streamp strm, int level, int method, int windowBits, + * int memLevel, int strategy); + * + * I believe "31" would be the value for the "windowBits" field that you'd + * want to try: + * + * deflateInit2(zstrmptr, 6, Z_DEFLATED, 31, 9, Z_DEFAULT_STRATEGY); + * -------------------------------------------------------------------------- + * + * * This file is part of rsyslog. * * Rsyslog is free software: you can redistribute it and/or modify @@ -698,12 +721,13 @@ doZipWrite(instanceData *pData) strm.zalloc = Z_NULL; strm.zfree = Z_NULL; strm.opaque = Z_NULL; - zRet = zlibw.DeflateInit(&strm, 9); + /* see note in file header for the params we use with deflateInit2() */ + zRet = zlibw.DeflateInit2(&strm, 9, Z_DEFLATED, 31, 9, Z_DEFAULT_STRATEGY); if(zRet != Z_OK) { - dbgprintf("error %d returned from zlib/deflateInit()\n", zRet); + dbgprintf("error %d returned from zlib/deflateInit2()\n", zRet); ABORT_FINALIZE(RS_RET_ZLIB_ERR); } -RUNLOG_STR("deflateInit() done successfully\n"); +RUNLOG_STR("deflateInit2() done successfully\n"); /* now doing the compression */ strm.avail_in = poBuf->iBuf; |