summaryrefslogtreecommitdiffstats
path: root/Doc/libzlib.tex
diff options
context:
space:
mode:
authorGuido van Rossum <guido@python.org>1997-04-30 18:12:27 (GMT)
committerGuido van Rossum <guido@python.org>1997-04-30 18:12:27 (GMT)
commit04bc9d6e67016d0968d86744fd4379870f5a6c6e (patch)
tree075d48538da4b2d30dd825ab572e778e27668bde /Doc/libzlib.tex
parent1526219431c3db4fcdc54cc207d99459f886249d (diff)
downloadcpython-04bc9d6e67016d0968d86744fd4379870f5a6c6e.zip
cpython-04bc9d6e67016d0968d86744fd4379870f5a6c6e.tar.gz
cpython-04bc9d6e67016d0968d86744fd4379870f5a6c6e.tar.bz2
zlib by AMK
Diffstat (limited to 'Doc/libzlib.tex')
-rw-r--r--Doc/libzlib.tex107
1 files changed, 107 insertions, 0 deletions
diff --git a/Doc/libzlib.tex b/Doc/libzlib.tex
new file mode 100644
index 0000000..c0ab117
--- /dev/null
+++ b/Doc/libzlib.tex
@@ -0,0 +1,107 @@
+% zlib compression module version A.01.02
+% Alpha test release.
+% Written by A.M. Kuchling (amk@magnet.com)
+% Comments are welcomed.
+%
+% Can you think of a better name than zlib? (The module's purpose isn't
+% really obvious from the name)
+
+\section{Built-in Module \sectcode{zlib}}
+\bimodindex{zlib}
+
+For applications that require data compression, the functions in this
+module allow compression and decompression, using a library based on
+GNU zip. The library is available at
+\code{ftp://godzilli.cs.sunysb.edu/pub/ngf/zlib-1.00.tar.gz},
+and is mirrored at
+\code{ftp://ftp.uu.net/graphics/png/src/zlib-1.00.tar.gz}. Version
+1.00 is the most recent version as of March 18, 1996; use a later
+version if one is available.
+
+The available functions in this module are:
+
+\renewcommand{\indexsubitem}{(in module zlib)}
+\begin{funcdesc}{adler32}{string\optional{\, value}}
+ Computes a Adler-32 checksum of \var{string}. (An Adler-32
+ checksum is almost as reliable as a CRC32 but can be computed much
+ more quickly.) If \var{value} is present, it is used as the
+ starting value of the checksum; otherwise, a fixed default value is
+ used. This allows computing a running checksum over the
+ concatenation of several input strings. The algorithm is not
+ cryptographically strong, and should not be used for
+ authentication or digital signatures.
+\end{funcdesc}
+
+\begin{funcdesc}{compress}{string\optional{\, level}}
+Compresses the data in \var{string}, returning a string contained
+compressed data. \var{level} is an integer from 1 to 9 controlling
+the level of compression; 1 is fastest and produces the least
+compression, 9 is slowest and produces the most. The default value is
+6, which . Raises the \code{zlib.error} exception if any error occurs.
+\end{funcdesc}
+
+\begin{funcdesc}{compressobj}{\optional{level}}
+Returns a compression object, to be used for compressing data streams
+ that won't fit into memory at once. \var{level} is an integer from
+ 1 to 9 controlling the level of compression; 1 is fastest and
+ produces the least compression, 9 is slowest and produces the most.
+ The default value is 6.
+\end{funcdesc}
+
+\begin{funcdesc}{crc32}{string\optional{\, value}}
+ Computes a CRC (Cyclic Redundancy Check) sum of \var{string}. If
+ \var{value} is present, it is used as the starting value of the
+ checksum; otherwise, a fixed default value is used. This allows
+ computing a running checksum over the concatenation of several
+ input strings. The algorithm is not cryptographically strong, and
+ should not be used for authentication or digital signatures.
+\end{funcdesc}
+
+\begin{funcdesc}{decompress}{string}
+Decompresses the data in \var{string}, returning a string containing
+the uncompressed data. Raises the \code{zlib.error} exception if any
+error occurs.
+\end{funcdesc}
+
+\begin{funcdesc}{decompressobj}{\optional{wbits}}
+Returns a compression object, to be used for decompressing data streams
+ that won't fit into memory at once. The \var{wbits} parameter controls the size of the window buffer; usually this can be left alone.
+\end{funcdesc}
+
+Compression objects support the following methods:
+
+\begin{funcdesc}{compress}{string}
+Compress \var{string}, returning a string containing compressed data
+for at least part of the data in \var{string}. This data should be
+concatenated to the output produced by any preceding calls to the
+\code{compress()} method. Some input may be kept in internal buffers
+for later processing.
+\end{funcdesc}
+
+\begin{funcdesc}{flush}{}
+All pending input is processed, and an string containing the remaining
+compressed output is returned. After calling \code{flush()}, the
+\code{compress()} method cannot be called again; the only realistic
+action is to delete the object.
+\end{funcdesc}
+
+Decompression objects support the following methods:
+
+\begin{funcdesc}{decompress}{string}
+Decompress \var{string}, returning a string containing the
+uncompressed data corresponding to at least part of the data in
+\var{string}. This data should be concatenated to the output produced
+by any preceding calls to the
+\code{decompress()} method. Some of the input data may be preserved in internal buffers
+for later processing.
+\end{funcdesc}
+
+\begin{funcdesc}{flush}{}
+All pending input is processed, and a string containing the remaining
+uncompressed output is returned. After calling \code{flush()}, the
+\code{decompress()} method cannot be called again; the only realistic
+action is to delete the object.
+\end{funcdesc}
+
+
+