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libisofs/libisofs/filters/gzip.c

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/*
* Copyright (c) 2009 Thomas Schmitt
*
* This file is part of the libisofs project; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version 2
* or later as published by the Free Software Foundation.
* See COPYING file for details.
*
* It implements a filter facility which can pipe a IsoStream into gzip
* compression resp. uncompression, read its output and forward it as IsoStream
* output to an IsoFile.
* The gzip compression is done via zlib by Jean-loup Gailly and Mark Adler
* who state in <zlib.h>:
* "The data format used by the zlib library is described by RFCs (Request for
* Comments) 1950 to 1952 in the files http://www.ietf.org/rfc/rfc1950.txt
* (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format)."
*
*/
#ifdef HAVE_CONFIG_H
#include "../config.h"
#endif
#include "../libisofs.h"
#include "../filter.h"
#include "../fsource.h"
#include "../util.h"
#include <sys/types.h>
#include <sys/time.h>
#include <sys/wait.h>
#include <unistd.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#ifdef Libisofs_with_zliB
#include <zlib.h>
#else
/* If zlib is not available then this code is a dummy */
#endif
/*
* A filter that encodes or decodes the content of gzip compressed files.
*/
/* --------------------------- GzipFilterRuntime ------------------------- */
/* Individual runtime properties exist only as long as the stream is opened.
*/
typedef struct
{
#ifdef Libisofs_with_zliB
z_stream strm; /* The zlib processing context */
#endif
char *in_buffer;
char *out_buffer;
int in_buffer_size;
int out_buffer_size;
char *rpt; /* out_buffer + read_bytes */
off_t in_counter;
off_t out_counter;
int do_flush; /* flush mode for deflate() changes at end of input */
int error_ret;
} GzipFilterRuntime;
#ifdef Libisofs_with_zliB
static
int gzip_running_destroy(GzipFilterRuntime **running, int flag)
{
GzipFilterRuntime *o= *running;
if (o == NULL)
return 0;
if (o->in_buffer != NULL)
free(o->in_buffer);
if (o->out_buffer != NULL)
free(o->out_buffer);
free((char *) o);
*running = NULL;
return 1;
}
static
int gzip_running_new(GzipFilterRuntime **running, int flag)
{
GzipFilterRuntime *o;
*running = o = calloc(sizeof(GzipFilterRuntime), 1);
if (o == NULL) {
return ISO_OUT_OF_MEM;
}
memset(&(o->strm), 0, sizeof(o->strm));
o->in_buffer = NULL;
o->out_buffer = NULL;
o->in_buffer_size = 0;
o->out_buffer_size = 0;
o->rpt = NULL;
o->in_counter = 0;
o->out_counter = 0;
o->do_flush = Z_NO_FLUSH;
o->error_ret = 1;
o->in_buffer_size= 2048;
o->out_buffer_size= 2048;
o->in_buffer = calloc(o->in_buffer_size, 1);
o->out_buffer = calloc(o->out_buffer_size, 1);
if (o->in_buffer == NULL || o->out_buffer == NULL)
goto failed;
o->rpt = o->out_buffer;
return 1;
failed:
gzip_running_destroy(running, 0);
return -1;
}
#endif /* Libisofs_with_zliB */
/* ---------------------------- GzipFilterStreamData --------------------- */
/* Counts the number of active compression filters */
static off_t gzip_ref_count = 0;
/* Counts the number of active uncompression filters */
static off_t gunzip_ref_count = 0;
#ifdef Libisofs_with_zliB
/* Parameter for deflateInit2() , see <zlib.h> */
/* ??? get this from zisofs.c ziso_compression_level ?
* ??? have an own global parameter API ?
* For now level 6 seems to be a fine compromise between speed and size.
*/
static int gzip_compression_level = 6;
#endif /* Libisofs_with_zliB */
/*
* The data payload of an individual Gzip Filter IsoStream
*/
typedef struct
{
IsoStream *orig;
off_t size; /* -1 means that the size is unknown yet */
GzipFilterRuntime *running; /* is non-NULL when open */
ino_t id;
} GzipFilterStreamData;
#ifdef Libisofs_with_zliB
/* Each individual GzipFilterStreamData needs a unique id number. */
/* >>> This is very suboptimal:
The counter can rollover.
*/
static ino_t gzip_ino_id = 0;
#endif /* Libisofs_with_zliB */
static
int gzip_stream_uncompress(IsoStream *stream, void *buf, size_t desired);
/*
* Methods for the IsoStreamIface of a Gzip Filter object.
*/
/*
* @param flag bit0= original stream is not open
*/
static
int gzip_stream_close_flag(IsoStream *stream, int flag)
{
#ifdef Libisofs_with_zliB
GzipFilterStreamData *data;
if (stream == NULL) {
return ISO_NULL_POINTER;
}
data = stream->data;
if (data->running == NULL) {
return 1;
}
if (stream->class->read == &gzip_stream_uncompress) {
inflateEnd(&(data->running->strm));
} else {
deflateEnd(&(data->running->strm));
}
gzip_running_destroy(&(data->running), 0);
if (flag & 1)
return 1;
return iso_stream_close(data->orig);
#else
return ISO_ZLIB_NOT_ENABLED;
#endif
}
static
int gzip_stream_close(IsoStream *stream)
{
return gzip_stream_close_flag(stream, 0);
}
/*
* @param flag bit0= do not run .get_size() if size is < 0
*/
static
int gzip_stream_open_flag(IsoStream *stream, int flag)
{
#ifdef Libisofs_with_zliB
GzipFilterStreamData *data;
GzipFilterRuntime *running = NULL;
int ret;
z_stream *strm;
if (stream == NULL) {
return ISO_NULL_POINTER;
}
data = (GzipFilterStreamData*) stream->data;
if (data->running != NULL) {
return ISO_FILE_ALREADY_OPENED;
}
if (data->size < 0 && !(flag & 1)) {
/* Do the size determination run now, so that the size gets cached
and .get_size() will not fail on an opened stream.
*/
stream->class->get_size(stream);
}
ret = gzip_running_new(&running,
stream->class->read == &gzip_stream_uncompress);
if (ret < 0) {
return ret;
}
data->running = running;
/* Start up zlib compression context */
strm = &(running->strm);
strm->zalloc = Z_NULL;
strm->zfree = Z_NULL;
strm->opaque = Z_NULL;
if (stream->class->read == &gzip_stream_uncompress) {
ret = inflateInit2(strm, 15 | 16);
} else {
ret = deflateInit2(strm, gzip_compression_level, Z_DEFLATED,
15 | 16, 8, Z_DEFAULT_STRATEGY);
}
if (ret != Z_OK)
return ISO_ZLIB_COMPR_ERR;
strm->next_out = (Bytef *) running->out_buffer;
strm->avail_out = running->out_buffer_size;
/* Open input stream */
ret = iso_stream_open(data->orig);
if (ret < 0) {
return ret;
}
return 1;
#else
return ISO_ZLIB_NOT_ENABLED;
#endif
}
static
int gzip_stream_open(IsoStream *stream)
{
return gzip_stream_open_flag(stream, 0);
}
/*
* @param flag bit1= uncompress rather than compress
*/
static
int gzip_stream_convert(IsoStream *stream, void *buf, size_t desired, int flag)
{
#ifdef Libisofs_with_zliB
int ret, todo, cnv_ret, c_bytes;
GzipFilterStreamData *data;
GzipFilterRuntime *rng;
size_t fill = 0;
z_stream *strm;
if (stream == NULL) {
return ISO_NULL_POINTER;
}
data = stream->data;
rng= data->running;
if (rng == NULL) {
return ISO_FILE_NOT_OPENED;
}
strm = &(rng->strm);
if (rng->error_ret < 0) {
return rng->error_ret;
} else if (rng->error_ret == 0) {
if (rng->out_buffer_size - strm->avail_out
- (rng->rpt - rng->out_buffer) <= 0)
return 0;
}
while (1) {
/* Transfer eventual converted bytes from strm to buf */
c_bytes = rng->out_buffer_size - strm->avail_out
- (rng->rpt - rng->out_buffer);
if (c_bytes > 0) {
todo = desired - fill;
if (todo > c_bytes)
todo = c_bytes;
memcpy(((char *) buf) + fill, rng->rpt, todo);
rng->rpt += todo;
fill += todo;
rng->out_counter += todo;
}
if (fill >= desired || rng->error_ret == 0)
return fill;
/* All buffered out data are consumed now */
rng->rpt = rng->out_buffer;
strm->next_out = (Bytef *) rng->out_buffer;
strm->avail_out = rng->out_buffer_size;
if (strm->avail_in == 0) {
/* All pending input is consumed. Get new input. */
ret = iso_stream_read(data->orig, rng->in_buffer,
rng->in_buffer_size);
if (ret < 0)
return (rng->error_ret = ret);
if (ret == 0) {
if (flag & 2) {
/* Early input EOF */
return (rng->error_ret = ISO_ZLIB_EARLY_EOF);
} else {
/* Tell zlib by the next call that it is over */
rng->do_flush = Z_FINISH;
}
}
strm->next_in = (Bytef *) rng->in_buffer;
strm->avail_in = ret;
rng->in_counter += ret;
}
/* Submit input and fetch output until input is consumed */
while (1) {
if (flag & 2) {
cnv_ret = inflate(strm, rng->do_flush);
} else {
cnv_ret = deflate(strm, rng->do_flush);
}
if (cnv_ret == Z_STREAM_ERROR || cnv_ret == Z_BUF_ERROR) {
return (rng->error_ret = ISO_ZLIB_COMPR_ERR);
}
if (strm->avail_out < rng->out_buffer_size)
break; /* output is available */
if (strm->avail_in == 0) /* all pending input consumed */
break;
}
if (cnv_ret == Z_STREAM_END)
rng->error_ret = 0;
}
return fill;
#else
return ISO_ZLIB_NOT_ENABLED;
#endif
}
static
int gzip_stream_compress(IsoStream *stream, void *buf, size_t desired)
{
return gzip_stream_convert(stream, buf, desired, 0);
}
static
int gzip_stream_uncompress(IsoStream *stream, void *buf, size_t desired)
{
return gzip_stream_convert(stream, buf, desired, 2);
}
static
off_t gzip_stream_get_size(IsoStream *stream)
{
int ret, ret_close;
off_t count = 0;
GzipFilterStreamData *data;
char buf[64 * 1024];
size_t bufsize = 64 * 1024;
if (stream == NULL) {
return ISO_NULL_POINTER;
}
data = stream->data;
if (data->size >= 0) {
return data->size;
}
/* Run filter command and count output bytes */
ret = gzip_stream_open_flag(stream, 1);
if (ret < 0) {
return ret;
}
while (1) {
ret = stream->class->read(stream, buf, bufsize);
if (ret <= 0)
break;
count += ret;
}
ret_close = gzip_stream_close(stream);
if (ret < 0)
return ret;
if (ret_close < 0)
return ret_close;
data->size = count;
return count;
}
static
int gzip_stream_is_repeatable(IsoStream *stream)
{
/* Only repeatable streams are accepted as orig */
return 1;
}
static
void gzip_stream_get_id(IsoStream *stream, unsigned int *fs_id,
dev_t *dev_id, ino_t *ino_id)
{
GzipFilterStreamData *data;
data = stream->data;
*fs_id = ISO_FILTER_FS_ID;
*dev_id = ISO_FILTER_GZIP_DEV_ID;
*ino_id = data->id;
}
static
void gzip_stream_free(IsoStream *stream)
{
GzipFilterStreamData *data;
if (stream == NULL) {
return;
}
data = stream->data;
if (data->running != NULL) {
gzip_stream_close(stream);
}
if (stream->class->read == &gzip_stream_uncompress) {
if (--gunzip_ref_count < 0)
gunzip_ref_count = 0;
} else {
if (--gzip_ref_count < 0)
gzip_ref_count = 0;
}
iso_stream_unref(data->orig);
free(data);
}
static
int gzip_update_size(IsoStream *stream)
{
/* By principle size is determined only once */
return 1;
}
static
IsoStream *gzip_get_input_stream(IsoStream *stream, int flag)
{
GzipFilterStreamData *data;
if (stream == NULL) {
return NULL;
}
data = stream->data;
return data->orig;
}
static
int gzip_cmp_ino(IsoStream *s1, IsoStream *s2);
IsoStreamIface gzip_stream_compress_class = {
3,
"gzip",
gzip_stream_open,
gzip_stream_close,
gzip_stream_get_size,
gzip_stream_compress,
gzip_stream_is_repeatable,
gzip_stream_get_id,
gzip_stream_free,
gzip_update_size,
gzip_get_input_stream,
gzip_cmp_ino
};
IsoStreamIface gzip_stream_uncompress_class = {
3,
"pizg",
gzip_stream_open,
gzip_stream_close,
gzip_stream_get_size,
gzip_stream_uncompress,
gzip_stream_is_repeatable,
gzip_stream_get_id,
gzip_stream_free,
gzip_update_size,
gzip_get_input_stream,
gzip_cmp_ino
};
static
int gzip_cmp_ino(IsoStream *s1, IsoStream *s2)
{
if (s1->class != s2->class || (s1->class != &gzip_stream_compress_class &&
s2->class != &gzip_stream_compress_class))
return iso_stream_cmp_ino(s1, s2, 1);
return iso_stream_cmp_ino(iso_stream_get_input_stream(s1, 0),
iso_stream_get_input_stream(s2, 0), 0);
}
/* ------------------------------------------------------------------------- */
#ifdef Libisofs_with_zliB
static
void gzip_filter_free(FilterContext *filter)
{
/* no data are allocated */;
}
/*
* @param flag bit1= Install a decompression filter
*/
static
int gzip_filter_get_filter(FilterContext *filter, IsoStream *original,
IsoStream **filtered, int flag)
{
IsoStream *str;
GzipFilterStreamData *data;
if (filter == NULL || original == NULL || filtered == NULL) {
return ISO_NULL_POINTER;
}
str = calloc(sizeof(IsoStream), 1);
if (str == NULL) {
return ISO_OUT_OF_MEM;
}
data = calloc(sizeof(GzipFilterStreamData), 1);
if (data == NULL) {
free(str);
return ISO_OUT_OF_MEM;
}
/* These data items are not owned by this filter object */
data->id = ++gzip_ino_id;
data->orig = original;
data->size = -1;
data->running = NULL;
/* get reference to the source */
iso_stream_ref(data->orig);
str->refcount = 1;
str->data = data;
if (flag & 2) {
str->class = &gzip_stream_uncompress_class;
gunzip_ref_count++;
} else {
str->class = &gzip_stream_compress_class;
gzip_ref_count++;
}
*filtered = str;
return ISO_SUCCESS;
}
/* To be called by iso_file_add_filter().
* The FilterContext input parameter is not furtherly needed for the
* emerging IsoStream.
*/
static
int gzip_filter_get_compressor(FilterContext *filter, IsoStream *original,
IsoStream **filtered)
{
return gzip_filter_get_filter(filter, original, filtered, 0);
}
static
int gzip_filter_get_uncompressor(FilterContext *filter, IsoStream *original,
IsoStream **filtered)
{
return gzip_filter_get_filter(filter, original, filtered, 2);
}
/* Produce a parameter object suitable for iso_file_add_filter().
* It may be disposed by free() after all those calls are made.
*
* This is quite a dummy as it does not carry individual data.
* @param flag bit1= Install a decompression filter
*/
static
int gzip_create_context(FilterContext **filter, int flag)
{
FilterContext *f;
*filter = f = calloc(1, sizeof(FilterContext));
if (f == NULL) {
return ISO_OUT_OF_MEM;
}
f->refcount = 1;
f->version = 0;
f->data = NULL;
f->free = gzip_filter_free;
if (flag & 2)
f->get_filter = gzip_filter_get_uncompressor;
else
f->get_filter = gzip_filter_get_compressor;
return ISO_SUCCESS;
}
#endif /* Libisofs_with_zliB */
/*
* @param flag bit0= if_block_reduction rather than if_reduction
* bit1= Install a decompression filter
* bit2= only inquire availability of gzip filtering
* bit3= do not inquire size
*/
int gzip_add_filter(IsoFile *file, int flag)
{
#ifdef Libisofs_with_zliB
int ret;
FilterContext *f = NULL;
IsoStream *stream;
off_t original_size = 0, filtered_size = 0;
if (flag & 4)
return 2;
original_size = iso_file_get_size(file);
ret = gzip_create_context(&f, flag & 2);
if (ret < 0) {
return ret;
}
ret = iso_file_add_filter(file, f, 0);
free(f);
if (ret < 0) {
return ret;
}
if (flag & 8) /* size will be filled in by caller */
return ISO_SUCCESS;
/* Run a full filter process getsize so that the size is cached */
stream = iso_file_get_stream(file);
filtered_size = iso_stream_get_size(stream);
if (filtered_size < 0) {
iso_file_remove_filter(file, 0);
return filtered_size;
}
if ((filtered_size >= original_size ||
((flag & 1) && filtered_size / 2048 >= original_size / 2048))
&& !(flag & 2)){
ret = iso_file_remove_filter(file, 0);
if (ret < 0) {
return ret;
}
return 2;
}
return ISO_SUCCESS;
#else
return ISO_ZLIB_NOT_ENABLED;
#endif /* ! Libisofs_with_zliB */
}
/* API function */
int iso_file_add_gzip_filter(IsoFile *file, int flag)
{
return gzip_add_filter(file, flag & ~8);
}
/* API function */
int iso_gzip_get_refcounts(off_t *gzip_count, off_t *gunzip_count, int flag)
{
*gzip_count = gzip_ref_count;
*gunzip_count = gunzip_ref_count;
return ISO_SUCCESS;
}
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