diff options
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/zlib.n | 75 |
1 files changed, 58 insertions, 17 deletions
@@ -1,5 +1,5 @@ '\" -'\" Copyright (c) 2008 Donal K. Fellows +'\" Copyright (c) 2008-2012 Donal K. Fellows '\" '\" See the file "license.terms" for information on usage and redistribution '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. @@ -222,39 +222,53 @@ command works, see \fBSTREAMING INSTANCE COMMAND\fR below. The following modes are supported: .RS .TP -\fBzlib stream compress\fR ?\fIlevel\fR? +\fBzlib stream compress\fR ?\fB\-dictionary \fIbindata\fR? ?\fB\-level \fIlevel\fR? . The stream will be a compressing stream that produces zlib-format output, using compression level \fIlevel\fR (if specified) which will be an integer -from 0 to 9. +from 0 to 9, +.VS +and the compression dictionary \fIbindata\fR (if specified). +.VE .TP -\fBzlib stream decompress\fR +\fBzlib stream decompress\fR ?\fB\-dictionary \fIbindata\fR? . The stream will be a decompressing stream that takes zlib-format input and produces uncompressed output. +.VS +If \fIbindata\fR is supplied, it is a compression dictionary to use if +required. +.VE .TP -\fBzlib stream deflate\fR ?\fIlevel\fR? +\fBzlib stream deflate\fR ?\fB\-dictionary \fIbindata\fR? ?\fB\-level \fIlevel\fR? . The stream will be a compressing stream that produces raw output, using compression level \fIlevel\fR (if specified) which will be an integer from 0 -to 9. +to 9, +.VS +and the compression dictionary \fIbindata\fR (if specified). Note that +the raw compressed data includes no metadata about what compression +dictionary was used, if any; that is a feature of the zlib-format data. +.VE .TP -\fBzlib stream gunzip\fR +\fBzlib stream gunzip\fR ?\fIlevel\fR? . The stream will be a decompressing stream that takes gzip-format input and produces uncompressed output. .TP -\fBzlib stream gzip\fR ?\fIlevel\fR? +\fBzlib stream gzip\fR ?\fB\-header \fIheader\fR? ?\fB\-level \fIlevel\fR? . The stream will be a compressing stream that produces gzip-format output, using compression level \fIlevel\fR (if specified) which will be an integer -from 0 to 9. -'\" TODO: Header dictionary! +from 0 to 9, and the header descriptor dictionary \fIheader\fR (if specified; +for keys see \fBzlib gzip\fR). .TP -\fBzlib stream inflate\fR +\fBzlib stream inflate\fR ?\fB\-dictionary \fIbindata\fR? . The stream will be a decompressing stream that takes raw compressed input and -produces uncompressed output. +produces uncompressed output. If \fIbindata\fR is supplied, it is a +compression dictionary to use. Note that there are no checks in place +to determine whether the compression dictionary is correct. .RE .SS "CHECKSUMMING SUBCOMMANDS" .TP @@ -277,10 +291,10 @@ the transformed data. The full set of subcommands supported by a streaming instance command, \fIstream\fR, is as follows: .TP -\fIstream \fBadd\fR ?\fIoption\fR? \fIdata\fR +\fIstream \fBadd\fR ?\fIoption...\fR? \fIdata\fR . A short-cut for -.QW "\fIstream \fBput \fIoption data\fR" +.QW "\fIstream \fBput \fR?\fIoption...\fR? \fIdata\fR" followed by .QW "\fIstream \fBget\fR" . .TP @@ -318,15 +332,27 @@ A short-cut for Return up to \fIcount\fR bytes from \fIstream\fR's internal buffers with the transformation applied. If \fIcount\fR is omitted, the entire contents of the buffers are returned. +. +\fIstream \fBheader\fR +. +Return the gzip header description dictionary extracted from the stream. Only +supported for streams created with their \fImode\fR parameter set to +\fBgunzip\fR. .TP -\fIstream \fBput\fR ?\fIoption\fR? \fIdata\fR +\fIstream \fBput\fR ?\fIoption...\fR? \fIdata\fR . Append the contents of the binary string \fIdata\fR to \fIstream\fR's internal -buffers while applying the transformation. If present, \fIoption\fR must be -one of the following (or an unambiguous prefix) which are used to modify the +buffers while applying the transformation. The following \fIoption\fRs are +supported (or an unambiguous prefix of them), which are used to modify the way in which the transformation is applied: .RS .TP +\fB\-dictionary\fI compressionDictionary\fR +.VS "TIP 400" +Sets a compression dictionary to use when working with compressing or +decompressing the data. +.VE +.TP \fB\-finalize\fR . Mark the stream as finished, ensuring that all bytes have been wholly @@ -334,12 +360,22 @@ compressed or decompressed. For gzip streams, this also ensures that the footer is written to the stream. The stream will need to be reset before having more data written to it after this, though data can still be read out of the stream with the \fBget\fR subcommand. +.RS +.PP +This option is mutually exclusive with the \fB\-flush\fR and \fB\-fullflush\fR +options. +.RE .TP \fB\-flush\fR . Ensure that a decompressor consuming the bytes that the current (compressing) stream is producing will be able to produce all the bytes that have been compressed so far, at some performance penalty. +.RS +.PP +This option is mutually exclusive with the \fB\-finalize\fR and +\fB\-fullflush\fR options. +.RE .TP \fB\-fullflush\fR . @@ -347,6 +383,11 @@ Ensure that not only can a decompressor handle all the bytes produced so far (as with \fB\-flush\fR above) but also that it can restart from this point if it detects that the stream is partially corrupt. This incurs a substantial performance penalty. +.RS +.PP +This option is mutually exclusive with the \fB\-finalize\fR and \fB\-flush\fR +options. +.RE .RE .TP \fIstream \fBreset\fR |