diff options
| -rw-r--r-- | doc/zlib.n | 41 | ||||
| -rw-r--r-- | generic/tclZlib.c | 113 |
2 files changed, 99 insertions, 55 deletions
@@ -179,15 +179,24 @@ Passes a description of the gzip header to create, in the same format that . How hard to compress the data. Must be an integer from 0 (uncompressed) to 9 (maximally compressed). -'\".TP -'\"\fB\-limit\fI readaheadLimit\fR -'\". -'\"The maximum number of bytes ahead to read. -'\"\fITODO: not yet implemented!\fR +.TP +\fB\-limit\fI readaheadLimit\fR +. +The maximum number of bytes ahead to read when decompressing. This defaults to +1, which ensures that data is always decompressed correctly, but may be +increased to improve performance. This is more useful when the channel is +non-blocking. .PP Both compressing and decompressing channel transformations add extra -configuration options that may be accessed through \fBchan configure\fR. Each -option is either a read-only or a write-only option. The options are: +configuration options that may be accessed through \fBchan configure\fR. The +options are: +.TP +\fB\-checksum\fI checksum\fR +. +This read-only option gets the current checksum for the uncompressed data that +the compression engine has seen so far. It is valid for both compressing and +decompressing transforms, but not for the raw inflate and deflate formats. The +compression algorithm depends on what format is being produced or consumed. .TP \fB\-flush\fI type\fR . @@ -198,19 +207,19 @@ expensive flush respectively. Flushing degrades the compression ratio, but makes it easier for a decompressor to recover more of the file in the case of data corruption. .TP -\fB\-checksum\fR -. -This read-only option gets the current checksum for the uncompressed data -that the compression engine has seen so far. It is valid for both -compressing and decompressing transforms, but not for the raw inflate -and deflate formats. The compression algorithm depends on what -format is being produced or consumed. -.TP -\fB\-header\fR +\fB\-header\fI dictionary\fR . This read-only option, only valid for decompressing transforms that are processing gzip-format data, returns the dictionary describing the header read off the data stream. +.TP +\fB\-limit\fI readaheadLimit\fR +. +This read-write option is used by decompressing channels to control the +maximum number of bytes ahead to read from the underlying data source. This +defaults to 1, which ensures that data is always decompressed correctly, but +may be increased to improve performance. This is more useful when the channel +is non-blocking. .RE .SS "STREAMING SUBCOMMAND" .TP diff --git a/generic/tclZlib.c b/generic/tclZlib.c index a7c4453..c96594d 100644 --- a/generic/tclZlib.c +++ b/generic/tclZlib.c @@ -110,6 +110,8 @@ typedef struct { int format; /* What format of data is going on the wire. * Needed so that the correct [fconfigure] * options can be enabled. */ + int readAheadLimit; /* The maximum number of bytes to read from + * the underlying stream in one go. */ z_stream inStream; /* Structure used by zlib for decompression of * input. */ z_stream outStream; /* Structure used by zlib for compression of @@ -2958,7 +2960,7 @@ ZlibTransformInput( * reading over the border. */ - readBytes = Tcl_ReadRaw(cd->parent, cd->inBuffer, 1); + readBytes = Tcl_ReadRaw(cd->parent, cd->inBuffer, cd->readAheadLimit); /* * Three cases here: @@ -3131,8 +3133,10 @@ ZlibTransformSetOption( /* not used */ ZlibChannelData *cd = instanceData; Tcl_DriverSetOptionProc *setOptionProc = Tcl_ChannelSetOptionProc(Tcl_GetChannelType(cd->parent)); - static const char *chanOptions = "dictionary flush"; + static const char *compressChanOptions = "dictionary flush"; static const char *gzipChanOptions = "flush"; + static const char *decompressChanOptions = "dictionary limit"; + static const char *gunzipChanOptions = "flush limit"; int haveFlushOpt = (cd->mode == TCL_ZLIB_STREAM_DEFLATE); if (optionName && (strcmp(optionName, "-dictionary") == 0) @@ -3164,56 +3168,75 @@ ZlibTransformSetOption( /* not used */ return TCL_OK; } - if (haveFlushOpt && optionName && strcmp(optionName, "-flush") == 0) { - int flushType; + if (haveFlushOpt) { + if (optionName && strcmp(optionName, "-flush") == 0) { + int flushType; - if (value[0] == 'f' && strcmp(value, "full") == 0) { - flushType = Z_FULL_FLUSH; - } else if (value[0] == 's' && strcmp(value, "sync") == 0) { - flushType = Z_SYNC_FLUSH; - } else { - Tcl_AppendResult(interp, "unknown -flush type \"", value, - "\": must be full or sync", NULL); - Tcl_SetErrorCode(interp, "TCL", "VALUE", "FLUSH", NULL); - return TCL_ERROR; - } + if (value[0] == 'f' && strcmp(value, "full") == 0) { + flushType = Z_FULL_FLUSH; + } else if (value[0] == 's' && strcmp(value, "sync") == 0) { + flushType = Z_SYNC_FLUSH; + } else { + Tcl_AppendResult(interp, "unknown -flush type \"", value, + "\": must be full or sync", NULL); + Tcl_SetErrorCode(interp, "TCL", "VALUE", "FLUSH", NULL); + return TCL_ERROR; + } - /* - * Try to actually do the flush now. - */ + /* + * Try to actually do the flush now. + */ - cd->outStream.avail_in = 0; - while (1) { - int e; + cd->outStream.avail_in = 0; + while (1) { + int e; - cd->outStream.next_out = (Bytef *) cd->outBuffer; - cd->outStream.avail_out = cd->outAllocated; + cd->outStream.next_out = (Bytef *) cd->outBuffer; + cd->outStream.avail_out = cd->outAllocated; - e = deflate(&cd->outStream, flushType); - if (e == Z_BUF_ERROR) { - break; - } else if (e != Z_OK) { - ConvertError(interp, e, cd->outStream.adler); - return TCL_ERROR; - } else if (cd->outStream.avail_out == 0) { - break; + e = deflate(&cd->outStream, flushType); + if (e == Z_BUF_ERROR) { + break; + } else if (e != Z_OK) { + ConvertError(interp, e, cd->outStream.adler); + return TCL_ERROR; + } else if (cd->outStream.avail_out == 0) { + break; + } + + if (Tcl_WriteRaw(cd->parent, cd->outBuffer, + cd->outStream.next_out - (Bytef *) cd->outBuffer)<0) { + Tcl_AppendResult(interp, "problem flushing channel: ", + Tcl_PosixError(interp), NULL); + return TCL_ERROR; + } } + return TCL_OK; + } + } else { + if (optionName && strcmp(optionName, "-limit") == 0) { + int newLimit; - if (Tcl_WriteRaw(cd->parent, cd->outBuffer, - cd->outStream.next_out - (Bytef *) cd->outBuffer) < 0) { - Tcl_AppendResult(interp, "problem flushing channel: ", - Tcl_PosixError(interp), NULL); + if (Tcl_GetInt(interp, value, &newLimit) != TCL_OK) { + return TCL_ERROR; + } else if (newLimit < 1 || newLimit > 65535) { + Tcl_AppendResult(interp, "-limit must be between 1 and 65535", + NULL); + Tcl_SetErrorCode(interp, "TCL", "VALUE", "READLIMIT", NULL); return TCL_ERROR; } } - return TCL_OK; } if (setOptionProc == NULL) { if (cd->format == TCL_ZLIB_FORMAT_GZIP) { - return Tcl_BadChannelOption(interp, optionName, gzipChanOptions); + return Tcl_BadChannelOption(interp, optionName, + (cd->mode == TCL_ZLIB_STREAM_DEFLATE) + ? gzipChanOptions : gunzipChanOptions); } else { - return Tcl_BadChannelOption(interp, optionName, chanOptions); + return Tcl_BadChannelOption(interp, optionName, + (cd->mode == TCL_ZLIB_STREAM_DEFLATE) + ? compressChanOptions : decompressChanOptions); } } @@ -3246,7 +3269,10 @@ ZlibTransformGetOption( ZlibChannelData *cd = instanceData; Tcl_DriverGetOptionProc *getOptionProc = Tcl_ChannelGetOptionProc(Tcl_GetChannelType(cd->parent)); - static const char *chanOptions = "checksum dictionary header"; + static const char *compressChanOptions = "checksum dictionary"; + static const char *gzipChanOptions = "checksum"; + static const char *decompressChanOptions = "checksum dictionary limit"; + static const char *gunzipChanOptions = "checksum header limit"; /* * The "crc" option reports the current CRC (calculated with the Adler32 @@ -3331,7 +3357,15 @@ ZlibTransformGetOption( if (optionName == NULL) { return TCL_OK; } - return Tcl_BadChannelOption(interp, optionName, chanOptions); + if (cd->format == TCL_ZLIB_FORMAT_GZIP) { + return Tcl_BadChannelOption(interp, optionName, + (cd->mode == TCL_ZLIB_STREAM_DEFLATE) + ? gzipChanOptions : gunzipChanOptions); + } else { + return Tcl_BadChannelOption(interp, optionName, + (cd->mode == TCL_ZLIB_STREAM_DEFLATE) + ? compressChanOptions : decompressChanOptions); + } } /* @@ -3496,6 +3530,7 @@ ZlibStackChannelTransform( memset(cd, 0, sizeof(ZlibChannelData)); cd->mode = mode; cd->format = format; + cd->readAheadLimit = 1; if (format == TCL_ZLIB_FORMAT_GZIP || format == TCL_ZLIB_FORMAT_AUTO) { if (mode == TCL_ZLIB_STREAM_DEFLATE) { |