MCL/sf/adapt/qemu: symbian-qemu-0.9.1-12/zlib-1.2.3/examples/zlib

1 2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	1	<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	2	"http://www.w3.org/TR/REC-html40/loose.dtd">
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	3	<html>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	4	<head>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	5	<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	6	<title>zlib Usage Example</title>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	7	<!-- Copyright (c) 2004 Mark Adler. -->
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	8	</head>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	9	<body bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#00A000">
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	10	<h2 align="center"> zlib Usage Example </h2>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	11	We often get questions about how the <tt>deflate()</tt> and <tt>inflate()</tt> functions should be used.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	12	Users wonder when they should provide more input, when they should use more output,
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	13	what to do with a <tt>Z_BUF_ERROR</tt>, how to make sure the process terminates properly, and
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	14	so on. So for those who have read <tt>zlib.h</tt> (a few times), and
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	15	would like further edification, below is an annotated example in C of simple routines to compress and decompress
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	16	from an input file to an output file using <tt>deflate()</tt> and <tt>inflate()</tt> respectively. The
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	17	annotations are interspersed between lines of the code. So please read between the lines.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	18	We hope this helps explain some of the intricacies of <em>zlib</em>.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	19	<p>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	20	Without further adieu, here is the program <a href="zpipe.c"><tt>zpipe.c</tt></a>:
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	21	<pre><b>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	22	/* zpipe.c: example of proper use of zlib's inflate() and deflate()
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	23	Not copyrighted -- provided to the public domain
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	24	Version 1.2 9 November 2004 Mark Adler */
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	25
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	26	/* Version history:
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	27	1.0 30 Oct 2004 First version
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	28	1.1 8 Nov 2004 Add void casting for unused return values
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	29	Use switch statement for inflate() return values
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	30	1.2 9 Nov 2004 Add assertions to document zlib guarantees
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	31	*/
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	32	</b></pre><!-- -->
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	33	We now include the header files for the required definitions. From
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	34	<tt>stdio.h</tt> we use <tt>fopen()</tt>, <tt>fread()</tt>, <tt>fwrite()</tt>,
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	35	<tt>feof()</tt>, <tt>ferror()</tt>, and <tt>fclose()</tt> for file i/o, and
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	36	<tt>fputs()</tt> for error messages. From <tt>string.h</tt> we use
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	37	<tt>strcmp()</tt> for command line argument processing.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	38	From <tt>assert.h</tt> we use the <tt>assert()</tt> macro.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	39	From <tt>zlib.h</tt>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	40	we use the basic compression functions <tt>deflateInit()</tt>,
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	41	<tt>deflate()</tt>, and <tt>deflateEnd()</tt>, and the basic decompression
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	42	functions <tt>inflateInit()</tt>, <tt>inflate()</tt>, and
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	43	<tt>inflateEnd()</tt>.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	44	<pre><b>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	45	#include <stdio.h>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	46	#include <string.h>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	47	#include <assert.h>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	48	#include "zlib.h"
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	49	</b></pre><!-- -->
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	50	<tt>CHUNK</tt> is simply the buffer size for feeding data to and pulling data
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	51	from the <em>zlib</em> routines. Larger buffer sizes would be more efficient,
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	52	especially for <tt>inflate()</tt>. If the memory is available, buffers sizes
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	53	on the order of 128K or 256K bytes should be used.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	54	<pre><b>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	55	#define CHUNK 16384
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	56	</b></pre><!-- -->
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	57	The <tt>def()</tt> routine compresses data from an input file to an output file. The output data
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	58	will be in the <em>zlib</em> format, which is different from the <em>gzip</em> or <em>zip</em>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	59	formats. The <em>zlib</em> format has a very small header of only two bytes to identify it as
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	60	a <em>zlib</em> stream and to provide decoding information, and a four-byte trailer with a fast
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	61	check value to verify the integrity of the uncompressed data after decoding.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	62	<pre><b>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	63	/* Compress from file source to file dest until EOF on source.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	64	def() returns Z_OK on success, Z_MEM_ERROR if memory could not be
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	65	allocated for processing, Z_STREAM_ERROR if an invalid compression
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	66	level is supplied, Z_VERSION_ERROR if the version of zlib.h and the
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	67	version of the library linked do not match, or Z_ERRNO if there is
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	68	an error reading or writing the files. */
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	69	int def(FILE source, FILE dest, int level)
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	70	{
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	71	</b></pre>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	72	Here are the local variables for <tt>def()</tt>. <tt>ret</tt> will be used for <em>zlib</em>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	73	return codes. <tt>flush</tt> will keep track of the current flushing state for <tt>deflate()</tt>,
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	74	which is either no flushing, or flush to completion after the end of the input file is reached.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	75	<tt>have</tt> is the amount of data returned from <tt>deflate()</tt>. The <tt>strm</tt> structure
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	76	is used to pass information to and from the <em>zlib</em> routines, and to maintain the
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	77	<tt>deflate()</tt> state. <tt>in</tt> and <tt>out</tt> are the input and output buffers for
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	78	<tt>deflate()</tt>.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	79	<pre><b>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	80	int ret, flush;
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	81	unsigned have;
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	82	z_stream strm;
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	83	char in[CHUNK];
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	84	char out[CHUNK];
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	85	</b></pre><!-- -->
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	86	The first thing we do is to initialize the <em>zlib</em> state for compression using
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	87	<tt>deflateInit()</tt>. This must be done before the first use of <tt>deflate()</tt>.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	88	The <tt>zalloc</tt>, <tt>zfree</tt>, and <tt>opaque</tt> fields in the <tt>strm</tt>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	89	structure must be initialized before calling <tt>deflateInit()</tt>. Here they are
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	90	set to the <em>zlib</em> constant <tt>Z_NULL</tt> to request that <em>zlib</em> use
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	91	the default memory allocation routines. An application may also choose to provide
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	92	custom memory allocation routines here. <tt>deflateInit()</tt> will allocate on the
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	93	order of 256K bytes for the internal state.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	94	(See <a href="zlib_tech.html"><em>zlib Technical Details</em></a>.)
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	95	<p>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	96	<tt>deflateInit()</tt> is called with a pointer to the structure to be initialized and
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	97	the compression level, which is an integer in the range of -1 to 9. Lower compression
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	98	levels result in faster execution, but less compression. Higher levels result in
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	99	greater compression, but slower execution. The <em>zlib</em> constant Z_DEFAULT_COMPRESSION,
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	100	equal to -1,
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	101	provides a good compromise between compression and speed and is equivalent to level 6.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	102	Level 0 actually does no compression at all, and in fact expands the data slightly to produce
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	103	the <em>zlib</em> format (it is not a byte-for-byte copy of the input).
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	104	More advanced applications of <em>zlib</em>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	105	may use <tt>deflateInit2()</tt> here instead. Such an application may want to reduce how
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	106	much memory will be used, at some price in compression. Or it may need to request a
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	107	<em>gzip</em> header and trailer instead of a <em>zlib</em> header and trailer, or raw
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	108	encoding with no header or trailer at all.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	109	<p>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	110	We must check the return value of <tt>deflateInit()</tt> against the <em>zlib</em> constant
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	111	<tt>Z_OK</tt> to make sure that it was able to
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	112	allocate memory for the internal state, and that the provided arguments were valid.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	113	<tt>deflateInit()</tt> will also check that the version of <em>zlib</em> that the <tt>zlib.h</tt>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	114	file came from matches the version of <em>zlib</em> actually linked with the program. This
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	115	is especially important for environments in which <em>zlib</em> is a shared library.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	116	<p>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	117	Note that an application can initialize multiple, independent <em>zlib</em> streams, which can
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	118	operate in parallel. The state information maintained in the structure allows the <em>zlib</em>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	119	routines to be reentrant.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	120	<pre><b>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	121	/* allocate deflate state */
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	122	strm.zalloc = Z_NULL;
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	123	strm.zfree = Z_NULL;
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	124	strm.opaque = Z_NULL;
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	125	ret = deflateInit(&strm, level);
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	126	if (ret != Z_OK)
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	127	return ret;
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	128	</b></pre><!-- -->
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	129	With the pleasantries out of the way, now we can get down to business. The outer <tt>do</tt>-loop
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	130	reads all of the input file and exits at the bottom of the loop once end-of-file is reached.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	131	This loop contains the only call of <tt>deflate()</tt>. So we must make sure that all of the
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	132	input data has been processed and that all of the output data has been generated and consumed
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	133	before we fall out of the loop at the bottom.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	134	<pre><b>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	135	/* compress until end of file */
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	136	do {
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	137	</b></pre>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	138	We start off by reading data from the input file. The number of bytes read is put directly
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	139	into <tt>avail_in</tt>, and a pointer to those bytes is put into <tt>next_in</tt>. We also
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	140	check to see if end-of-file on the input has been reached. If we are at the end of file, then <tt>flush</tt> is set to the
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	141	<em>zlib</em> constant <tt>Z_FINISH</tt>, which is later passed to <tt>deflate()</tt> to
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	142	indicate that this is the last chunk of input data to compress. We need to use <tt>feof()</tt>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	143	to check for end-of-file as opposed to seeing if fewer than <tt>CHUNK</tt> bytes have been read. The
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	144	reason is that if the input file length is an exact multiple of <tt>CHUNK</tt>, we will miss
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	145	the fact that we got to the end-of-file, and not know to tell <tt>deflate()</tt> to finish
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	146	up the compressed stream. If we are not yet at the end of the input, then the <em>zlib</em>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	147	constant <tt>Z_NO_FLUSH</tt> will be passed to <tt>deflate</tt> to indicate that we are still
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	148	in the middle of the uncompressed data.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	149	<p>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	150	If there is an error in reading from the input file, the process is aborted with
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	151	<tt>deflateEnd()</tt> being called to free the allocated <em>zlib</em> state before returning
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	152	the error. We wouldn't want a memory leak, now would we? <tt>deflateEnd()</tt> can be called
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	153	at any time after the state has been initialized. Once that's done, <tt>deflateInit()</tt> (or
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	154	<tt>deflateInit2()</tt>) would have to be called to start a new compression process. There is
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	155	no point here in checking the <tt>deflateEnd()</tt> return code. The deallocation can't fail.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	156	<pre><b>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	157	strm.avail_in = fread(in, 1, CHUNK, source);
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	158	if (ferror(source)) {
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	159	(void)deflateEnd(&strm);
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	160	return Z_ERRNO;
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	161	}
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	162	flush = feof(source) ? Z_FINISH : Z_NO_FLUSH;
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	163	strm.next_in = in;
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	164	</b></pre><!-- -->
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	165	The inner <tt>do</tt>-loop passes our chunk of input data to <tt>deflate()</tt>, and then
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	166	keeps calling <tt>deflate()</tt> until it is done producing output. Once there is no more
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	167	new output, <tt>deflate()</tt> is guaranteed to have consumed all of the input, i.e.,
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	168	<tt>avail_in</tt> will be zero.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	169	<pre><b>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	170	/* run deflate() on input until output buffer not full, finish
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	171	compression if all of source has been read in */
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	172	do {
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	173	</b></pre>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	174	Output space is provided to <tt>deflate()</tt> by setting <tt>avail_out</tt> to the number
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	175	of available output bytes and <tt>next_out</tt> to a pointer to that space.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	176	<pre><b>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	177	strm.avail_out = CHUNK;
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	178	strm.next_out = out;
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	179	</b></pre>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	180	Now we call the compression engine itself, <tt>deflate()</tt>. It takes as many of the
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	181	<tt>avail_in</tt> bytes at <tt>next_in</tt> as it can process, and writes as many as
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	182	<tt>avail_out</tt> bytes to <tt>next_out</tt>. Those counters and pointers are then
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	183	updated past the input data consumed and the output data written. It is the amount of
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	184	output space available that may limit how much input is consumed.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	185	Hence the inner loop to make sure that
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	186	all of the input is consumed by providing more output space each time. Since <tt>avail_in</tt>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	187	and <tt>next_in</tt> are updated by <tt>deflate()</tt>, we don't have to mess with those
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	188	between <tt>deflate()</tt> calls until it's all used up.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	189	<p>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	190	The parameters to <tt>deflate()</tt> are a pointer to the <tt>strm</tt> structure containing
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	191	the input and output information and the internal compression engine state, and a parameter
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	192	indicating whether and how to flush data to the output. Normally <tt>deflate</tt> will consume
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	193	several K bytes of input data before producing any output (except for the header), in order
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	194	to accumulate statistics on the data for optimum compression. It will then put out a burst of
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	195	compressed data, and proceed to consume more input before the next burst. Eventually,
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	196	<tt>deflate()</tt>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	197	must be told to terminate the stream, complete the compression with provided input data, and
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	198	write out the trailer check value. <tt>deflate()</tt> will continue to compress normally as long
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	199	as the flush parameter is <tt>Z_NO_FLUSH</tt>. Once the <tt>Z_FINISH</tt> parameter is provided,
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	200	<tt>deflate()</tt> will begin to complete the compressed output stream. However depending on how
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	201	much output space is provided, <tt>deflate()</tt> may have to be called several times until it
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	202	has provided the complete compressed stream, even after it has consumed all of the input. The flush
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	203	parameter must continue to be <tt>Z_FINISH</tt> for those subsequent calls.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	204	<p>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	205	There are other values of the flush parameter that are used in more advanced applications. You can
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	206	force <tt>deflate()</tt> to produce a burst of output that encodes all of the input data provided
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	207	so far, even if it wouldn't have otherwise, for example to control data latency on a link with
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	208	compressed data. You can also ask that <tt>deflate()</tt> do that as well as erase any history up to
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	209	that point so that what follows can be decompressed independently, for example for random access
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	210	applications. Both requests will degrade compression by an amount depending on how often such
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	211	requests are made.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	212	<p>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	213	<tt>deflate()</tt> has a return value that can indicate errors, yet we do not check it here. Why
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	214	not? Well, it turns out that <tt>deflate()</tt> can do no wrong here. Let's go through
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	215	<tt>deflate()</tt>'s return values and dispense with them one by one. The possible values are
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	216	<tt>Z_OK</tt>, <tt>Z_STREAM_END</tt>, <tt>Z_STREAM_ERROR</tt>, or <tt>Z_BUF_ERROR</tt>. <tt>Z_OK</tt>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	217	is, well, ok. <tt>Z_STREAM_END</tt> is also ok and will be returned for the last call of
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	218	<tt>deflate()</tt>. This is already guaranteed by calling <tt>deflate()</tt> with <tt>Z_FINISH</tt>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	219	until it has no more output. <tt>Z_STREAM_ERROR</tt> is only possible if the stream is not
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	220	initialized properly, but we did initialize it properly. There is no harm in checking for
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	221	<tt>Z_STREAM_ERROR</tt> here, for example to check for the possibility that some
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	222	other part of the application inadvertently clobbered the memory containing the <em>zlib</em> state.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	223	<tt>Z_BUF_ERROR</tt> will be explained further below, but
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	224	suffice it to say that this is simply an indication that <tt>deflate()</tt> could not consume
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	225	more input or produce more output. <tt>deflate()</tt> can be called again with more output space
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	226	or more available input, which it will be in this code.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	227	<pre><b>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	228	ret = deflate(&strm, flush); /* no bad return value */
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	229	assert(ret != Z_STREAM_ERROR); /* state not clobbered */
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	230	</b></pre>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	231	Now we compute how much output <tt>deflate()</tt> provided on the last call, which is the
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	232	difference between how much space was provided before the call, and how much output space
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	233	is still available after the call. Then that data, if any, is written to the output file.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	234	We can then reuse the output buffer for the next call of <tt>deflate()</tt>. Again if there
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	235	is a file i/o error, we call <tt>deflateEnd()</tt> before returning to avoid a memory leak.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	236	<pre><b>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	237	have = CHUNK - strm.avail_out;
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	238	if (fwrite(out, 1, have, dest) != have \|\| ferror(dest)) {
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	239	(void)deflateEnd(&strm);
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	240	return Z_ERRNO;
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	241	}
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	242	</b></pre>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	243	The inner <tt>do</tt>-loop is repeated until the last <tt>deflate()</tt> call fails to fill the
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	244	provided output buffer. Then we know that <tt>deflate()</tt> has done as much as it can with
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	245	the provided input, and that all of that input has been consumed. We can then fall out of this
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	246	loop and reuse the input buffer.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	247	<p>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	248	The way we tell that <tt>deflate()</tt> has no more output is by seeing that it did not fill
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	249	the output buffer, leaving <tt>avail_out</tt> greater than zero. However suppose that
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	250	<tt>deflate()</tt> has no more output, but just so happened to exactly fill the output buffer!
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	251	<tt>avail_out</tt> is zero, and we can't tell that <tt>deflate()</tt> has done all it can.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	252	As far as we know, <tt>deflate()</tt>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	253	has more output for us. So we call it again. But now <tt>deflate()</tt> produces no output
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	254	at all, and <tt>avail_out</tt> remains unchanged as <tt>CHUNK</tt>. That <tt>deflate()</tt> call
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	255	wasn't able to do anything, either consume input or produce output, and so it returns
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	256	<tt>Z_BUF_ERROR</tt>. (See, I told you I'd cover this later.) However this is not a problem at
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	257	all. Now we finally have the desired indication that <tt>deflate()</tt> is really done,
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	258	and so we drop out of the inner loop to provide more input to <tt>deflate()</tt>.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	259	<p>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	260	With <tt>flush</tt> set to <tt>Z_FINISH</tt>, this final set of <tt>deflate()</tt> calls will
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	261	complete the output stream. Once that is done, subsequent calls of <tt>deflate()</tt> would return
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	262	<tt>Z_STREAM_ERROR</tt> if the flush parameter is not <tt>Z_FINISH</tt>, and do no more processing
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	263	until the state is reinitialized.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	264	<p>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	265	Some applications of <em>zlib</em> have two loops that call <tt>deflate()</tt>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	266	instead of the single inner loop we have here. The first loop would call
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	267	without flushing and feed all of the data to <tt>deflate()</tt>. The second loop would call
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	268	<tt>deflate()</tt> with no more
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	269	data and the <tt>Z_FINISH</tt> parameter to complete the process. As you can see from this
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	270	example, that can be avoided by simply keeping track of the current flush state.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	271	<pre><b>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	272	} while (strm.avail_out == 0);
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	273	assert(strm.avail_in == 0); /* all input will be used */
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	274	</b></pre><!-- -->
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	275	Now we check to see if we have already processed all of the input file. That information was
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	276	saved in the <tt>flush</tt> variable, so we see if that was set to <tt>Z_FINISH</tt>. If so,
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	277	then we're done and we fall out of the outer loop. We're guaranteed to get <tt>Z_STREAM_END</tt>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	278	from the last <tt>deflate()</tt> call, since we ran it until the last chunk of input was
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	279	consumed and all of the output was generated.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	280	<pre><b>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	281	/* done when last data in file processed */
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	282	} while (flush != Z_FINISH);
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	283	assert(ret == Z_STREAM_END); /* stream will be complete */
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	284	</b></pre><!-- -->
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	285	The process is complete, but we still need to deallocate the state to avoid a memory leak
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	286	(or rather more like a memory hemorrhage if you didn't do this). Then
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	287	finally we can return with a happy return value.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	288	<pre><b>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	289	/* clean up and return */
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	290	(void)deflateEnd(&strm);
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	291	return Z_OK;
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	292	}
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	293	</b></pre><!-- -->
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	294	Now we do the same thing for decompression in the <tt>inf()</tt> routine. <tt>inf()</tt>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	295	decompresses what is hopefully a valid <em>zlib</em> stream from the input file and writes the
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	296	uncompressed data to the output file. Much of the discussion above for <tt>def()</tt>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	297	applies to <tt>inf()</tt> as well, so the discussion here will focus on the differences between
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	298	the two.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	299	<pre><b>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	300	/* Decompress from file source to file dest until stream ends or EOF.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	301	inf() returns Z_OK on success, Z_MEM_ERROR if memory could not be
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	302	allocated for processing, Z_DATA_ERROR if the deflate data is
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	303	invalid or incomplete, Z_VERSION_ERROR if the version of zlib.h and
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	304	the version of the library linked do not match, or Z_ERRNO if there
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	305	is an error reading or writing the files. */
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	306	int inf(FILE source, FILE dest)
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	307	{
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	308	</b></pre>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	309	The local variables have the same functionality as they do for <tt>def()</tt>. The
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	310	only difference is that there is no <tt>flush</tt> variable, since <tt>inflate()</tt>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	311	can tell from the <em>zlib</em> stream itself when the stream is complete.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	312	<pre><b>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	313	int ret;
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	314	unsigned have;
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	315	z_stream strm;
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	316	char in[CHUNK];
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	317	char out[CHUNK];
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	318	</b></pre><!-- -->
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	319	The initialization of the state is the same, except that there is no compression level,
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	320	of course, and two more elements of the structure are initialized. <tt>avail_in</tt>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	321	and <tt>next_in</tt> must be initialized before calling <tt>inflateInit()</tt>. This
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	322	is because the application has the option to provide the start of the zlib stream in
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	323	order for <tt>inflateInit()</tt> to have access to information about the compression
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	324	method to aid in memory allocation. In the current implementation of <em>zlib</em>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	325	(up through versions 1.2.x), the method-dependent memory allocations are deferred to the first call of
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	326	<tt>inflate()</tt> anyway. However those fields must be initialized since later versions
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	327	of <em>zlib</em> that provide more compression methods may take advantage of this interface.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	328	In any case, no decompression is performed by <tt>inflateInit()</tt>, so the
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	329	<tt>avail_out</tt> and <tt>next_out</tt> fields do not need to be initialized before calling.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	330	<p>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	331	Here <tt>avail_in</tt> is set to zero and <tt>next_in</tt> is set to <tt>Z_NULL</tt> to
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	332	indicate that no input data is being provided.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	333	<pre><b>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	334	/* allocate inflate state */
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	335	strm.zalloc = Z_NULL;
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	336	strm.zfree = Z_NULL;
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	337	strm.opaque = Z_NULL;
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	338	strm.avail_in = 0;
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	339	strm.next_in = Z_NULL;
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	340	ret = inflateInit(&strm);
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	341	if (ret != Z_OK)
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	342	return ret;
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	343	</b></pre><!-- -->
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	344	The outer <tt>do</tt>-loop decompresses input until <tt>inflate()</tt> indicates
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	345	that it has reached the end of the compressed data and has produced all of the uncompressed
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	346	output. This is in contrast to <tt>def()</tt> which processes all of the input file.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	347	If end-of-file is reached before the compressed data self-terminates, then the compressed
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	348	data is incomplete and an error is returned.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	349	<pre><b>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	350	/* decompress until deflate stream ends or end of file */
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	351	do {
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	352	</b></pre>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	353	We read input data and set the <tt>strm</tt> structure accordingly. If we've reached the
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	354	end of the input file, then we leave the outer loop and report an error, since the
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	355	compressed data is incomplete. Note that we may read more data than is eventually consumed
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	356	by <tt>inflate()</tt>, if the input file continues past the <em>zlib</em> stream.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	357	For applications where <em>zlib</em> streams are embedded in other data, this routine would
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	358	need to be modified to return the unused data, or at least indicate how much of the input
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	359	data was not used, so the application would know where to pick up after the <em>zlib</em> stream.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	360	<pre><b>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	361	strm.avail_in = fread(in, 1, CHUNK, source);
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	362	if (ferror(source)) {
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	363	(void)inflateEnd(&strm);
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	364	return Z_ERRNO;
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	365	}
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	366	if (strm.avail_in == 0)
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	367	break;
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	368	strm.next_in = in;
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	369	</b></pre><!-- -->
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	370	The inner <tt>do</tt>-loop has the same function it did in <tt>def()</tt>, which is to
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	371	keep calling <tt>inflate()</tt> until has generated all of the output it can with the
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	372	provided input.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	373	<pre><b>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	374	/* run inflate() on input until output buffer not full */
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	375	do {
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	376	</b></pre>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	377	Just like in <tt>def()</tt>, the same output space is provided for each call of <tt>inflate()</tt>.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	378	<pre><b>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	379	strm.avail_out = CHUNK;
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	380	strm.next_out = out;
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	381	</b></pre>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	382	Now we run the decompression engine itself. There is no need to adjust the flush parameter, since
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	383	the <em>zlib</em> format is self-terminating. The main difference here is that there are
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	384	return values that we need to pay attention to. <tt>Z_DATA_ERROR</tt>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	385	indicates that <tt>inflate()</tt> detected an error in the <em>zlib</em> compressed data format,
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	386	which means that either the data is not a <em>zlib</em> stream to begin with, or that the data was
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	387	corrupted somewhere along the way since it was compressed. The other error to be processed is
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	388	<tt>Z_MEM_ERROR</tt>, which can occur since memory allocation is deferred until <tt>inflate()</tt>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	389	needs it, unlike <tt>deflate()</tt>, whose memory is allocated at the start by <tt>deflateInit()</tt>.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	390	<p>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	391	Advanced applications may use
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	392	<tt>deflateSetDictionary()</tt> to prime <tt>deflate()</tt> with a set of likely data to improve the
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	393	first 32K or so of compression. This is noted in the <em>zlib</em> header, so <tt>inflate()</tt>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	394	requests that that dictionary be provided before it can start to decompress. Without the dictionary,
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	395	correct decompression is not possible. For this routine, we have no idea what the dictionary is,
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	396	so the <tt>Z_NEED_DICT</tt> indication is converted to a <tt>Z_DATA_ERROR</tt>.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	397	<p>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	398	<tt>inflate()</tt> can also return <tt>Z_STREAM_ERROR</tt>, which should not be possible here,
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	399	but could be checked for as noted above for <tt>def()</tt>. <tt>Z_BUF_ERROR</tt> does not need to be
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	400	checked for here, for the same reasons noted for <tt>def()</tt>. <tt>Z_STREAM_END</tt> will be
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	401	checked for later.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	402	<pre><b>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	403	ret = inflate(&strm, Z_NO_FLUSH);
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	404	assert(ret != Z_STREAM_ERROR); /* state not clobbered */
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	405	switch (ret) {
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	406	case Z_NEED_DICT:
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	407	ret = Z_DATA_ERROR; /* and fall through */
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	408	case Z_DATA_ERROR:
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	409	case Z_MEM_ERROR:
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	410	(void)inflateEnd(&strm);
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	411	return ret;
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	412	}
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	413	</b></pre>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	414	The output of <tt>inflate()</tt> is handled identically to that of <tt>deflate()</tt>.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	415	<pre><b>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	416	have = CHUNK - strm.avail_out;
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	417	if (fwrite(out, 1, have, dest) != have \|\| ferror(dest)) {
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	418	(void)inflateEnd(&strm);
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	419	return Z_ERRNO;
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	420	}
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	421	</b></pre>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	422	The inner <tt>do</tt>-loop ends when <tt>inflate()</tt> has no more output as indicated
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	423	by not filling the output buffer, just as for <tt>deflate()</tt>. In this case, we cannot
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	424	assert that <tt>strm.avail_in</tt> will be zero, since the deflate stream may end before the file
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	425	does.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	426	<pre><b>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	427	} while (strm.avail_out == 0);
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	428	</b></pre><!-- -->
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	429	The outer <tt>do</tt>-loop ends when <tt>inflate()</tt> reports that it has reached the
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	430	end of the input <em>zlib</em> stream, has completed the decompression and integrity
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	431	check, and has provided all of the output. This is indicated by the <tt>inflate()</tt>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	432	return value <tt>Z_STREAM_END</tt>. The inner loop is guaranteed to leave <tt>ret</tt>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	433	equal to <tt>Z_STREAM_END</tt> if the last chunk of the input file read contained the end
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	434	of the <em>zlib</em> stream. So if the return value is not <tt>Z_STREAM_END</tt>, the
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	435	loop continues to read more input.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	436	<pre><b>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	437	/* done when inflate() says it's done */
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	438	} while (ret != Z_STREAM_END);
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	439	</b></pre><!-- -->
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	440	At this point, decompression successfully completed, or we broke out of the loop due to no
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	441	more data being available from the input file. If the last <tt>inflate()</tt> return value
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	442	is not <tt>Z_STREAM_END</tt>, then the <em>zlib</em> stream was incomplete and a data error
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	443	is returned. Otherwise, we return with a happy return value. Of course, <tt>inflateEnd()</tt>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	444	is called first to avoid a memory leak.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	445	<pre><b>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	446	/* clean up and return */
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	447	(void)inflateEnd(&strm);
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	448	return ret == Z_STREAM_END ? Z_OK : Z_DATA_ERROR;
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	449	}
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	450	</b></pre><!-- -->
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	451	That ends the routines that directly use <em>zlib</em>. The following routines make this
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	452	a command-line program by running data through the above routines from <tt>stdin</tt> to
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	453	<tt>stdout</tt>, and handling any errors reported by <tt>def()</tt> or <tt>inf()</tt>.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	454	<p>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	455	<tt>zerr()</tt> is used to interpret the possible error codes from <tt>def()</tt>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	456	and <tt>inf()</tt>, as detailed in their comments above, and print out an error message.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	457	Note that these are only a subset of the possible return values from <tt>deflate()</tt>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	458	and <tt>inflate()</tt>.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	459	<pre><b>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	460	/* report a zlib or i/o error */
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	461	void zerr(int ret)
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	462	{
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	463	fputs("zpipe: ", stderr);
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	464	switch (ret) {
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	465	case Z_ERRNO:
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	466	if (ferror(stdin))
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	467	fputs("error reading stdin\n", stderr);
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	468	if (ferror(stdout))
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	469	fputs("error writing stdout\n", stderr);
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	470	break;
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	471	case Z_STREAM_ERROR:
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	472	fputs("invalid compression level\n", stderr);
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	473	break;
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	474	case Z_DATA_ERROR:
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	475	fputs("invalid or incomplete deflate data\n", stderr);
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	476	break;
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	477	case Z_MEM_ERROR:
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	478	fputs("out of memory\n", stderr);
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	479	break;
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	480	case Z_VERSION_ERROR:
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	481	fputs("zlib version mismatch!\n", stderr);
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	482	}
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	483	}
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	484	</b></pre><!-- -->
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	485	Here is the <tt>main()</tt> routine used to test <tt>def()</tt> and <tt>inf()</tt>. The
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	486	<tt>zpipe</tt> command is simply a compression pipe from <tt>stdin</tt> to <tt>stdout</tt>, if
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	487	no arguments are given, or it is a decompression pipe if <tt>zpipe -d</tt> is used. If any other
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	488	arguments are provided, no compression or decompression is performed. Instead a usage
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	489	message is displayed. Examples are <tt>zpipe < foo.txt > foo.txt.z</tt> to compress, and
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	490	<tt>zpipe -d < foo.txt.z > foo.txt</tt> to decompress.
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	491	<pre><b>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	492	/* compress or decompress from stdin to stdout */
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	493	int main(int argc, char **argv)
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	494	{
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	495	int ret;
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	496
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	497	/* do compression if no arguments */
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	498	if (argc == 1) {
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	499	ret = def(stdin, stdout, Z_DEFAULT_COMPRESSION);
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	500	if (ret != Z_OK)
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	501	zerr(ret);
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	502	return ret;
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	503	}
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	504
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	505	/* do decompression if -d specified */
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	506	else if (argc == 2 && strcmp(argv[1], "-d") == 0) {
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	507	ret = inf(stdin, stdout);
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	508	if (ret != Z_OK)
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	509	zerr(ret);
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	510	return ret;
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	511	}
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	512
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	513	/* otherwise, report usage */
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	514	else {
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	515	fputs("zpipe usage: zpipe [-d] < source > dest\n", stderr);
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	516	return 1;
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	517	}
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	518	}
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	519	</b></pre>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	520	<hr>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	521	<i>Copyright (c) 2004 by Mark Adler<br>Last modified 13 November 2004</i>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	522	</body>
2fb8b9db1c86 Initial QEMU (symbian-qemu-0.9.1-12) import martin.trojer@nokia.com parents: diff changeset	523	</html>

author	martin.trojer@nokia.com
	Fri, 31 Jul 2009 15:01:17 +0100
changeset 1	2fb8b9db1c86
permissions	-rw-r--r--