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libisofs/libisofs/filters/zisofs.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 zisofs
* compression resp. uncompression, read its output and forward it as IsoStream
* output to an IsoFile.
* The zisofs format was invented by H. Peter Anvin. See doc/zisofs_format.txt
* It is writeable and readable by zisofs-tools, readable by Linux kernels.
*
*/
#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 zisofs compressed files.
*/
/* --------------------------- ZisofsFilterRuntime ------------------------- */
/* Sizes to be used for compression. Decompression learns from input header. */
static uint8_t ziso_block_size_log2 = 15;
static int ziso_block_size = 32768;
/* Individual runtime properties exist only as long as the stream is opened.
*/
typedef struct
{
int state; /* processing: 0= header, 1= block pointers, 2= data blocks */
int block_size;
int block_pointer_fill;
int block_pointer_rpos;
uint32_t *block_pointers; /* These are in use only with uncompression.
Compression streams hold the pointer in
their persistent data.
*/
char *read_buffer;
char *block_buffer;
int buffer_size;
int buffer_fill;
int buffer_rpos;
off_t block_counter;
off_t in_counter;
off_t out_counter;
int error_ret;
} ZisofsFilterRuntime;
static
int ziso_running_destroy(ZisofsFilterRuntime **running, int flag)
{
ZisofsFilterRuntime *o= *running;
if (o == NULL)
return 0;
if (o->block_pointers != NULL)
free(o->block_pointers);
if (o->read_buffer != NULL)
free(o->read_buffer);
if (o->block_buffer != NULL)
free(o->block_buffer);
free((char *) o);
*running = NULL;
return 1;
}
/*
* @param flag bit0= do not set block_size, do not allocate buffers
*/
static
int ziso_running_new(ZisofsFilterRuntime **running, int flag)
{
ZisofsFilterRuntime *o;
*running = o = calloc(sizeof(ZisofsFilterRuntime), 1);
if (o == NULL) {
return ISO_OUT_OF_MEM;
}
o->state = 0;
o->block_size= 0;
o->block_pointer_fill = 0;
o->block_pointer_rpos = 0;
o->block_pointers = NULL;
o->read_buffer = NULL;
o->block_buffer = NULL;
o->buffer_size = 0;
o->buffer_fill = 0;
o->buffer_rpos = 0;
o->block_counter = 0;
o->in_counter = 0;
o->out_counter = 0;
o->error_ret = 0;
if (flag & 1)
return 1;
o->block_size = ziso_block_size;
#ifdef Libisofs_with_zliB
o->buffer_size= compressBound((uLong) ziso_block_size);
#else
o->buffer_size= 2 * ziso_block_size;
#endif
o->read_buffer = calloc(o->block_size, 1);
o->block_buffer = calloc(o->buffer_size, 1);
if (o->block_buffer == NULL || o->read_buffer == NULL)
goto failed;
return 1;
failed:
ziso_running_destroy(running, 0);
return -1;
}
/* ---------------------------- ZisofsFilterStreamData --------------------- */
/* The first 8 bytes of a zisofs compressed data file */
static unsigned char zisofs_magic[9] =
{0x37, 0xE4, 0x53, 0x96, 0xC9, 0xDB, 0xD6, 0x07};
/* Counts the number of active compression filters */
static off_t ziso_ref_count = 0;
/* Counts the number of active uncompression filters */
static off_t ziso_osiz_ref_count = 0;
#ifdef Libisofs_with_zliB
/* Parameter for compress2() , see <zlib.h> */
static int ziso_compression_level = 6;
#endif /* Libisofs_with_zliB */
/*
* The common data payload of an individual Zisofs Filter IsoStream
*/
typedef struct
{
IsoStream *orig;
off_t size; /* -1 means that the size is unknown yet */
ZisofsFilterRuntime *running; /* is non-NULL when open */
ino_t id;
} ZisofsFilterStreamData;
/*
* The data payload of an individual Zisofs Filter Compressor IsoStream
*/
typedef struct
{
ZisofsFilterStreamData std;
uint32_t orig_size;
uint32_t *block_pointers; /* Cache for output block addresses. They get
written before the data and so need 2 passes.
This cache avoids surplus passes.
*/
} ZisofsComprStreamData;
/*
* The data payload of an individual Zisofs Filter Uncompressor IsoStream
*/
typedef struct
{
ZisofsFilterStreamData std;
unsigned char header_size_div4;
unsigned char block_size_log2;
} ZisofsUncomprStreamData;
/* Each individual ZisofsFilterStreamData needs a unique id number. */
/* >>> This is very suboptimal:
The counter can rollover.
*/
static ino_t ziso_ino_id = 0;
/*
* Methods for the IsoStreamIface of an Zisofs Filter object.
*/
static
int ziso_stream_uncompress(IsoStream *stream, void *buf, size_t desired);
/*
* @param flag bit0= original stream is not open
*/
static
int ziso_stream_close_flag(IsoStream *stream, int flag)
{
ZisofsFilterStreamData *data;
if (stream == NULL) {
return ISO_NULL_POINTER;
}
data = stream->data;
if (data->running == NULL) {
return 1;
}
ziso_running_destroy(&(data->running), 0);
if (flag & 1)
return 1;
return iso_stream_close(data->orig);
}
static
int ziso_stream_close(IsoStream *stream)
{
return ziso_stream_close_flag(stream, 0);
}
/*
* @param flag bit0= do not run .get_size() if size is < 0
*/
static
int ziso_stream_open_flag(IsoStream *stream, int flag)
{
ZisofsFilterStreamData *data;
ZisofsFilterRuntime *running = NULL;
int ret;
if (stream == NULL) {
return ISO_NULL_POINTER;
}
data = (ZisofsFilterStreamData*) 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 = ziso_running_new(&running,
stream->class->read == &ziso_stream_uncompress);
if (ret < 0) {
return ret;
}
data->running = running;
ret = iso_stream_open(data->orig);
if (ret < 0) {
return ret;
}
return 1;
}
static
int ziso_stream_open(IsoStream *stream)
{
return ziso_stream_open_flag(stream, 0);
}
static
int ziso_stream_compress(IsoStream *stream, void *buf, size_t desired)
{
#ifdef Libisofs_with_zliB
int ret, todo, i;
ZisofsComprStreamData *data;
ZisofsFilterRuntime *rng;
size_t fill = 0;
off_t orig_size, next_pt;
char *cbuf = buf;
uLongf buf_len;
if (stream == NULL) {
return ISO_NULL_POINTER;
}
data = stream->data;
rng= data->std.running;
if (rng == NULL) {
return ISO_FILE_NOT_OPENED;
}
if (rng->error_ret < 0) {
return rng->error_ret;
}
while (1) {
if (rng->state == 0) {
/* Delivering file header */
if (rng->buffer_fill == 0) {
memcpy(rng->block_buffer, zisofs_magic, 8);
orig_size = iso_stream_get_size(data->std.orig);
if (orig_size > 4294967295.0) {
return (rng->error_ret = ISO_ZISOFS_TOO_LARGE);
}
data->orig_size = orig_size;
iso_lsb((unsigned char *) (rng->block_buffer + 8),
(uint32_t) orig_size, 4);
rng->block_buffer[12] = 4;
rng->block_buffer[13] = ziso_block_size_log2;
rng->block_buffer[14] = rng->block_buffer[15] = 0;
rng->buffer_fill = 16;
rng->buffer_rpos = 0;
} else if (rng->buffer_rpos >= rng->buffer_fill) {
rng->buffer_fill = rng->buffer_rpos = 0;
rng->state = 1; /* header is delivered */
}
}
if (rng->state == 1) {
/* Delivering block pointers */;
if (rng->block_pointer_fill == 0) {
/* Initialize block pointer writing */
rng->block_pointer_rpos = 0;
rng->block_pointer_fill = data->orig_size / rng->block_size
+ 1 + !!(data->orig_size % rng->block_size);
if (data->block_pointers == NULL) {
/* On the first pass, create pointer array with all 0s */
data->block_pointers = calloc(rng->block_pointer_fill, 4);
if (data->block_pointers == NULL) {
rng->block_pointer_fill = 0;
return (rng->error_ret = ISO_OUT_OF_MEM);
}
}
}
if (rng->buffer_rpos >= rng->buffer_fill) {
if (rng->block_pointer_rpos >= rng->block_pointer_fill) {
rng->buffer_fill = rng->buffer_rpos = 0;
rng->block_counter = 0;
data->block_pointers[0] = 16 + rng->block_pointer_fill * 4;
rng->state = 2; /* block pointers are delivered */
} else {
/* Provide a buffer full of block pointers */
todo = rng->block_pointer_fill - rng->block_pointer_rpos;
if (todo * 4 > rng->buffer_size)
todo = rng->buffer_size / 4;
memcpy(rng->block_buffer,
data->block_pointers + 4 * rng->block_pointer_rpos,
todo * 4);
rng->buffer_rpos = 0;
rng->buffer_fill = todo * 4;
rng->block_pointer_rpos += todo;
}
}
}
if (rng->state == 2 && rng->buffer_rpos >= rng->buffer_fill) {
/* Delivering data blocks */;
ret = iso_stream_read(data->std.orig, rng->read_buffer,
rng->block_size);
if (ret > 0) {
rng->in_counter += ret;
if (rng->in_counter > data->orig_size) {
/* Input size became larger */
return (rng->error_ret = ISO_FILTER_WRONG_INPUT);
}
/* Check whether all 0 : represent as 0-length block */;
for (i = 0; i < ret; i++)
if (rng->read_buffer[i])
break;
if (i >= ret) { /* All 0-bytes. Bypass compression. */
buf_len = 0;
} else {
buf_len = rng->buffer_size;
ret = compress2((Bytef *) rng->block_buffer, &buf_len,
(Bytef *) rng->read_buffer, (uLong) ret,
ziso_compression_level);
if (ret != Z_OK) {
return (rng->error_ret = ISO_ZLIB_COMPR_ERR);
}
}
rng->buffer_fill = buf_len;
rng->buffer_rpos = 0;
next_pt = data->block_pointers[rng->block_counter] + buf_len;
if (data->std.size >= 0 && next_pt > data->std.size) {
/* Compression yields more bytes than on first run */
return (rng->error_ret = ISO_FILTER_WRONG_INPUT);
}
/* Record resp. check block pointer */
rng->block_counter++;
if (data->block_pointers[rng->block_counter] > 0) {
if (next_pt != data->block_pointers[rng->block_counter] ) {
/* block pointers mismatch , content has changed */
return (rng->error_ret = ISO_FILTER_WRONG_INPUT);
}
} else {
data->block_pointers[rng->block_counter] = next_pt;
}
} else if (ret == 0) {
rng->state = 3;
if (rng->in_counter != data->orig_size) {
/* Input size shrunk */
return (rng->error_ret = ISO_FILTER_WRONG_INPUT);
}
return fill;
} else
return (rng->error_ret = ret);
if (rng->buffer_fill == 0) {
continue;
}
}
if (rng->state == 3 && rng->buffer_rpos >= rng->buffer_fill) {
return 0; /* EOF */
}
/* Transfer from rng->block_buffer to buf */
todo = desired - fill;
if (todo > rng->buffer_fill - rng->buffer_rpos)
todo = rng->buffer_fill - rng->buffer_rpos;
memcpy(cbuf + fill, rng->block_buffer + rng->buffer_rpos, todo);
fill += todo;
rng->buffer_rpos += todo;
rng->out_counter += todo;
if (fill >= desired) {
return fill;
}
}
return ISO_FILE_READ_ERROR; /* should never be hit */
#else
return ISO_ZLIB_NOT_ENABLED;
#endif
}
static
int ziso_parse_zisofs_head(IsoStream *stream, int *header_size_div4,
int *block_size_log2, uint32_t *uncompressed_size,
int flag)
{
int ret;
char zisofs_head[16];
ret = iso_stream_read(stream, zisofs_head, 16);
if (ret < 0)
return ret;
*header_size_div4 = ((unsigned char *) zisofs_head)[12];
*block_size_log2 = ((unsigned char *) zisofs_head)[13];
if (ret != 16 || memcmp(zisofs_head, zisofs_magic, 8) != 0 ||
*header_size_div4 < 4 ||
*block_size_log2 < 15 || *block_size_log2 > 17) {
return ISO_ZISOFS_WRONG_INPUT;
}
*uncompressed_size = iso_read_lsb(((uint8_t *) zisofs_head) + 8, 4);
return 1;
}
/* Note: A call with desired==0 directly after .open() only checks the file
head and loads the uncompressed size from that head.
*/
static
int ziso_stream_uncompress(IsoStream *stream, void *buf, size_t desired)
{
#ifdef Libisofs_with_zliB
int ret, todo, i, header_size, bs_log2, block_max = 1;
ZisofsFilterStreamData *data;
ZisofsFilterRuntime *rng;
ZisofsUncomprStreamData *nstd;
size_t fill = 0;
char *cbuf = buf;
uLongf buf_len;
uint32_t uncompressed_size;
char waste_word[4];
if (stream == NULL) {
return ISO_NULL_POINTER;
}
data = stream->data;
nstd = stream->data;
rng= data->running;
if (rng == NULL) {
return ISO_FILE_NOT_OPENED;
}
if (rng->error_ret < 0) {
return rng->error_ret;
}
while (1) {
if (rng->state == 0) {
/* Reading file header */
ret = ziso_parse_zisofs_head(data->orig, &header_size, &bs_log2,
&uncompressed_size, 0);
if (ret < 0)
return (rng->error_ret = ret);
nstd->header_size_div4 = header_size;
header_size *= 4;
data->size = uncompressed_size;
nstd->block_size_log2 = bs_log2;
rng->block_size = 1 << bs_log2;
for (i = 16; i < header_size; i += 4) {
/* Skip surplus header words */
ret = iso_stream_read(data->orig, waste_word, 4);
if (ret < 0)
return (rng->error_ret = ret);
if (ret != 4)
return (rng->error_ret = ISO_ZISOFS_WRONG_INPUT);
}
if (desired == 0) {
return 0;
}
/* Create and read pointer array */
rng->block_pointer_rpos = 0;
rng->block_pointer_fill = data->size / rng->block_size
+ 1 + !!(data->size % rng->block_size);
rng->block_pointers = calloc(rng->block_pointer_fill, 4);
if (rng->block_pointers == NULL) {
rng->block_pointer_fill = 0;
return (rng->error_ret = ISO_OUT_OF_MEM);
}
ret = iso_stream_read(data->orig, rng->block_pointers,
rng->block_pointer_fill * 4);
if (ret < 0)
return (rng->error_ret = ret);
if (ret != rng->block_pointer_fill * 4)
return (rng->error_ret = ISO_ZISOFS_WRONG_INPUT);
for (i = 0; i < rng->block_pointer_fill; i++) {
rng->block_pointers[i] =
iso_read_lsb((uint8_t *) (rng->block_pointers + i), 4);
if (i > 0)
if (rng->block_pointers[i] - rng->block_pointers[i - 1]
> block_max)
block_max = rng->block_pointers[i]
- rng->block_pointers[i - 1];
}
rng->read_buffer = calloc(block_max, 1);
rng->block_buffer = calloc(rng->block_size, 1);
if (rng->read_buffer == NULL || rng->block_buffer == NULL)
return (rng->error_ret = ISO_OUT_OF_MEM);
rng->state = 2; /* block pointers are read */
rng->buffer_fill = rng->buffer_rpos = 0;
}
if (rng->state == 2 && rng->buffer_rpos >= rng->buffer_fill) {
/* Delivering data blocks */;
i = ++(rng->block_pointer_rpos);
if (i >= rng->block_pointer_fill) {
if (rng->out_counter == data->size) {
rng->state = 3;
rng->block_pointer_rpos--;
return fill;
}
/* More data blocks needed than announced */
return (rng->error_ret = ISO_FILTER_WRONG_INPUT);
}
todo = rng->block_pointers[i] - rng->block_pointers[i- 1];
if (todo == 0) {
memset(rng->block_buffer, 0, rng->block_size);
rng->buffer_fill = rng->block_size;
if (rng->out_counter + rng->buffer_fill > data->size &&
i == rng->block_pointer_fill - 1)
rng->buffer_fill = data->size - rng->out_counter;
} else {
ret = iso_stream_read(data->orig, rng->read_buffer, todo);
if (ret > 0) {
rng->in_counter += ret;
buf_len = rng->block_size;
ret = uncompress((Bytef *) rng->block_buffer, &buf_len,
(Bytef *) rng->read_buffer, (uLong) ret);
if (ret != Z_OK)
return (rng->error_ret = ISO_ZLIB_COMPR_ERR);
rng->buffer_fill = buf_len;
if (buf_len < rng->block_size &&
i != rng->block_pointer_fill - 1)
return (rng->error_ret = ISO_ZISOFS_WRONG_INPUT);
} else if(ret == 0) {
rng->state = 3;
if (rng->out_counter != data->size) {
/* Input size shrunk */
return (rng->error_ret = ISO_FILTER_WRONG_INPUT);
}
return fill;
} else
return (rng->error_ret = ret);
}
rng->buffer_rpos = 0;
if (rng->out_counter + rng->buffer_fill > data->size) {
/* Uncompression yields more bytes than announced by header */
return (rng->error_ret = ISO_FILTER_WRONG_INPUT);
}
}
if (rng->state == 3 && rng->buffer_rpos >= rng->buffer_fill) {
return 0; /* EOF */
}
/* Transfer from rng->block_buffer to buf */
todo = desired - fill;
if (todo > rng->buffer_fill - rng->buffer_rpos)
todo = rng->buffer_fill - rng->buffer_rpos;
memcpy(cbuf + fill, rng->block_buffer + rng->buffer_rpos, todo);
fill += todo;
rng->buffer_rpos += todo;
rng->out_counter += todo;
if (fill >= desired) {
return fill;
}
}
return (rng->error_ret = ISO_FILE_READ_ERROR); /* should never be hit */
#else
return ISO_ZLIB_NOT_ENABLED;
#endif
}
static
off_t ziso_stream_get_size(IsoStream *stream)
{
int ret, ret_close;
off_t count = 0;
ZisofsFilterStreamData *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 = ziso_stream_open_flag(stream, 1);
if (ret < 0) {
return ret;
}
if (stream->class->read == &ziso_stream_uncompress) {
/* It is enough to read the header part of a compressed file */
ret = ziso_stream_uncompress(stream, buf, 0);
count = data->size;
} else {
/* The size of the compression result has to be counted */
while (1) {
ret = stream->class->read(stream, buf, bufsize);
if (ret <= 0)
break;
count += ret;
}
}
ret_close = ziso_stream_close(stream);
if (ret < 0)
return ret;
if (ret_close < 0)
return ret_close;
data->size = count;
return count;
}
static
int ziso_stream_is_repeatable(IsoStream *stream)
{
/* Only repeatable streams are accepted as orig */
return 1;
}
static
void ziso_stream_get_id(IsoStream *stream, unsigned int *fs_id,
dev_t *dev_id, ino_t *ino_id)
{
ZisofsFilterStreamData *data;
data = stream->data;
*fs_id = ISO_FILTER_FS_ID;
*dev_id = ISO_FILTER_ZISOFS_DEV_ID;
*ino_id = data->id;
}
static
void ziso_stream_free(IsoStream *stream)
{
ZisofsFilterStreamData *data;
ZisofsComprStreamData *nstd;
if (stream == NULL) {
return;
}
data = stream->data;
if (data->running != NULL) {
ziso_stream_close(stream);
}
if (stream->class->read == &ziso_stream_uncompress) {
if (--ziso_osiz_ref_count < 0)
ziso_osiz_ref_count = 0;
} else {
nstd = stream->data;
if (nstd->block_pointers != NULL)
free((char *) nstd->block_pointers);
if (--ziso_ref_count < 0)
ziso_ref_count = 0;
}
iso_stream_unref(data->orig);
free(data);
}
static
int ziso_update_size(IsoStream *stream)
{
/* By principle size is determined only once */
return 1;
}
static
IsoStream *ziso_get_input_stream(IsoStream *stream, int flag)
{
ZisofsFilterStreamData *data;
if (stream == NULL) {
return NULL;
}
data = stream->data;
return data->orig;
}
static
int ziso_cmp_ino(IsoStream *s1, IsoStream *s2);
IsoStreamIface ziso_stream_compress_class = {
3,
"ziso",
ziso_stream_open,
ziso_stream_close,
ziso_stream_get_size,
ziso_stream_compress,
ziso_stream_is_repeatable,
ziso_stream_get_id,
ziso_stream_free,
ziso_update_size,
ziso_get_input_stream,
ziso_cmp_ino
};
IsoStreamIface ziso_stream_uncompress_class = {
3,
"osiz",
ziso_stream_open,
ziso_stream_close,
ziso_stream_get_size,
ziso_stream_uncompress,
ziso_stream_is_repeatable,
ziso_stream_get_id,
ziso_stream_free,
ziso_update_size,
ziso_get_input_stream,
ziso_cmp_ino
};
static
int ziso_cmp_ino(IsoStream *s1, IsoStream *s2)
{
if (s1->class != s2->class || (s1->class != &ziso_stream_compress_class &&
s2->class != &ziso_stream_uncompress_class))
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);
}
/* ------------------------------------------------------------------------- */
static
void ziso_filter_free(FilterContext *filter)
{
/* no data are allocated */;
}
/*
* @param flag bit1= Install a decompression filter
*/
static
int ziso_filter_get_filter(FilterContext *filter, IsoStream *original,
IsoStream **filtered, int flag)
{
IsoStream *str;
ZisofsFilterStreamData *data;
ZisofsComprStreamData *cnstd = NULL;
ZisofsUncomprStreamData *unstd = NULL;
if (filter == NULL || original == NULL || filtered == NULL) {
return ISO_NULL_POINTER;
}
str = calloc(sizeof(IsoStream), 1);
if (str == NULL) {
return ISO_OUT_OF_MEM;
}
if (flag & 2) {
unstd = calloc(sizeof(ZisofsUncomprStreamData), 1);
data = (ZisofsFilterStreamData *) unstd;
} else {
cnstd = calloc(sizeof(ZisofsComprStreamData), 1);
data = (ZisofsFilterStreamData *) cnstd;
}
if (data == NULL) {
free(str);
return ISO_OUT_OF_MEM;
}
/* These data items are not owned by this filter object */
data->id = ++ziso_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) {
unstd->header_size_div4 = 0;
unstd->block_size_log2 = 0;
str->class = &ziso_stream_uncompress_class;
ziso_osiz_ref_count++;
} else {
cnstd->orig_size = 0;
cnstd->block_pointers = NULL;
str->class = &ziso_stream_compress_class;
ziso_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 ziso_filter_get_compressor(FilterContext *filter, IsoStream *original,
IsoStream **filtered)
{
return ziso_filter_get_filter(filter, original, filtered, 0);
}
static
int ziso_filter_get_uncompressor(FilterContext *filter, IsoStream *original,
IsoStream **filtered)
{
return ziso_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 ziso_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 = ziso_filter_free;
if (flag & 2)
f->get_filter = ziso_filter_get_uncompressor;
else
f->get_filter = ziso_filter_get_compressor;
return ISO_SUCCESS;
}
/*
* @param flag bit0= if_block_reduction rather than if_reduction
* bit1= Install a decompression filter
* bit2= only inquire availability of zisofs filtering
* bit3= do not inquire size
*/
int ziso_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);
if (!(flag & 2)) {
if (original_size <= 0 || ((flag & 1) && original_size <= 2048)) {
return 2;
}
if (original_size > 4294967295.0) {
return ISO_ZISOFS_TOO_LARGE;
}
}
ret = ziso_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_zisofs_filter(IsoFile *file, int flag)
{
return ziso_add_filter(file, flag & ~8);
}
/* API function */
int iso_zisofs_get_refcounts(off_t *ziso_count, off_t *osiz_count, int flag)
{
*ziso_count = ziso_ref_count;
*osiz_count = ziso_osiz_ref_count;
return ISO_SUCCESS;
}
int ziso_add_osiz_filter(IsoFile *file, uint8_t header_size_div4,
uint8_t block_size_log2, uint32_t uncompressed_size,
int flag)
{
#ifdef Libisofs_with_zliB
int ret;
ZisofsUncomprStreamData *unstd;
ret = ziso_add_filter(file, 2 | 8);
if (ret < 0)
return ret;
unstd = iso_file_get_stream(file)->data;
unstd->header_size_div4 = header_size_div4;
unstd->block_size_log2 = block_size_log2;
unstd->std.size = uncompressed_size;
return ISO_SUCCESS;
#else
return ISO_ZLIB_NOT_ENABLED;
#endif /* ! Libisofs_with_zliB */
}
/* Determine stream type : 1=ziso , -1=osiz , 0=other , 2=ziso_by_content
and eventual ZF field parameters
@param flag bit0= allow ziso_by_content which is based on content reading
bit1= do not inquire stream->class for filters
*/
int ziso_is_zisofs_stream(IsoStream *stream, int *stream_type,
int *header_size_div4, int *block_size_log2,
uint32_t *uncompressed_size, int flag)
{
int ret, close_ret;
ZisofsFilterStreamData *data;
ZisofsComprStreamData *cnstd;
ZisofsUncomprStreamData *unstd;
*stream_type = 0;
if (stream->class == &ziso_stream_compress_class && !(flag & 2)) {
*stream_type = 1;
cnstd = stream->data;
*header_size_div4 = 4;
*block_size_log2 = ziso_block_size_log2;
*uncompressed_size = cnstd->orig_size;
return 1;
} else if(stream->class == &ziso_stream_uncompress_class && !(flag & 2)) {
*stream_type = -1;
data = stream->data;
unstd = stream->data;
*header_size_div4 = unstd->header_size_div4;
*block_size_log2 = unstd->block_size_log2;
*uncompressed_size = data->size;
return 1;
}
if (!(flag & 1))
return 0;
ret = iso_stream_open(stream);
if (ret < 0)
return ret;
ret = ziso_parse_zisofs_head(stream, header_size_div4,
block_size_log2, uncompressed_size, 0);
if (ret == 1) {
*stream_type = 2;
} else {
ret = 0;
}
close_ret = iso_stream_close(stream);
if (close_ret < 0)
return close_ret;
return ret;
}
int iso_zisofs_set_params(struct iso_zisofs_ctrl *params, int flag)
{
#ifdef Libisofs_with_zliB
if (params->compression_level < 0 || params->compression_level > 9 ||
params->block_size_log2 < 15 || params->block_size_log2 > 17) {
return ISO_WRONG_ARG_VALUE;
}
if (ziso_ref_count > 0) {
return ISO_ZISOFS_PARAM_LOCK;
}
ziso_compression_level = params->compression_level;
ziso_block_size_log2 = params->block_size_log2;
ziso_block_size = 1 << ziso_block_size_log2;
return 1;
#else
return ISO_ZLIB_NOT_ENABLED;
#endif /* ! Libisofs_with_zliB */
}
int iso_zisofs_get_params(struct iso_zisofs_ctrl *params, int flag)
{
#ifdef Libisofs_with_zliB
params->compression_level = ziso_compression_level;
params->block_size_log2 = ziso_block_size_log2;
return 1;
#else
return ISO_ZLIB_NOT_ENABLED;
#endif /* ! Libisofs_with_zliB */
}
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