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Implemented a zisofs uncompression filter.

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This commit is contained in:
Thomas Schmitt 2009-04-10 12:16:41 +02:00
parent a809a87eef
commit ce7a5c810f
5 changed files with 315 additions and 73 deletions
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7
doc/zisofs_format.txt
View File

@ -29,6 +29,10 @@ The file header has this layout (quoted from zisofs-tools-1.0.8/mkzftree.c):
So its size is 16.
7.3.1 means little endian 4-byte words. 7.1.1. means unsigned single bytes.
Readers shall be able to handle log2(block_size) values 15, 16 and 17
i.e. block sizes 32 kB, 64 kB, and 128 kB.
Block Pointers
There are ceil(input_size / block_size) input resp. output blocks.
@ -43,6 +47,7 @@ So there are ceil(input_size / block_size) + 1 block pointers.
They are stored as an array of 4-byte values which are in ISO 9660:7.3.1 format
directly after the file header, i.e. beginning at byte 16.
Data Part
The data part begins immediately after the pointer array. In principle it
@ -98,7 +103,7 @@ Its fields are:
ISO 9660:7.3.3 means 4-byte word in both byte orders, first little endian, then
big endian.
Example (uncompressed file size = 1,234,567 bytes):
Example (block size 32 kB, uncompressed file size = 1,234,567 bytes):
{ 'Z', "F', 16, 1, 'p', 'z', 16, 15,
0x87, 0xD6, 0x12, 0x00, 0x00, 0x12, 0xD6, 0x87 }

2
libisofs/filter.h
View File

@ -22,7 +22,7 @@
#define ISO_FILTER_EXTERNAL_DEV_ID 2
/* libisofs/filters/zisofs.c */
#define ISO_FILTER_ZISOFSL_DEV_ID 3
#define ISO_FILTER_ZISOFS_DEV_ID 3
typedef struct filter_context FilterContext;

337
libisofs/filters/zisofs.c
View File

@ -66,6 +66,8 @@ typedef struct
off_t in_counter;
off_t out_counter;
int error_ret;
} ZisofsFilterRuntime;
@ -108,6 +110,7 @@ int ziso_running_new(ZisofsFilterRuntime **running, int flag)
o->block_counter = 0;
o->in_counter = 0;
o->out_counter = 0;
o->error_ret = 0;
if (flag & 1)
return 1;
@ -169,6 +172,8 @@ static ino_t ziso_ino_id = 0;
* Methods for the IsoStreamIface of an External Filter object.
*/
static
int ziso_stream_uncompress(IsoStream *stream, void *buf, size_t desired);
/*
* @param flag bit0= original stream is not open
@ -189,6 +194,13 @@ int ziso_stream_close_flag(IsoStream *stream, int flag)
ziso_running_destroy(&(data->running), 0);
if (flag & 1)
return 1;
if (stream->class->read == ziso_stream_uncompress &&
data->block_pointers != NULL) {
/* No permanent block pointers needed for uncompression */
free(data->block_pointers);
data->block_pointers = NULL;
}
return iso_stream_close(data->orig);
}
@ -224,7 +236,8 @@ int ziso_stream_open_flag(IsoStream *stream, int flag)
stream->class->get_size(stream);
}
ret = ziso_running_new(&running, 0);
ret = ziso_running_new(&running,
stream->class->read == ziso_stream_uncompress);
if (ret < 0) {
return ret;
}
@ -246,20 +259,18 @@ int ziso_stream_open(IsoStream *stream)
static
int ziso_stream_read(IsoStream *stream, void *buf, size_t desired)
int ziso_stream_compress(IsoStream *stream, void *buf, size_t desired)
{
#ifdef Libisofs_with_zliB
int ret, todo, i;
ZisofsFilterStreamData *data;
ZisofsFilterRuntime *rng;
size_t fill = 0;
off_t orig_size, next_pt;
char *cbuf = buf;
#ifdef Libisofs_with_zliB
uLongf buf_len;
#else
unsigned long buf_len;
#endif
if (stream == NULL) {
return ISO_NULL_POINTER;
@ -269,6 +280,9 @@ int ziso_stream_read(IsoStream *stream, void *buf, size_t desired)
if (rng == NULL) {
return ISO_FILE_NOT_OPENED;
}
if (rng->error_ret < 0) {
return rng->error_ret;
}
while (1) {
if (rng->state == 0) {
@ -278,11 +292,7 @@ int ziso_stream_read(IsoStream *stream, void *buf, size_t desired)
memcpy(rng->block_buffer, zisofs_magic, 8);
orig_size = iso_stream_get_size(data->orig);
if (orig_size > 4294967295.0) {
/* >>> cannot compress file >= 4 GiB to zisofs */;
/* <<< need better error code (or fallback strategy ?) */
return ISO_FILE_READ_ERROR;
return (rng->error_ret = ISO_ZISOFS_TOO_LARGE);
}
data->orig_size = orig_size;
iso_lsb((unsigned char *) (rng->block_buffer + 8),
@ -304,13 +314,13 @@ int ziso_stream_read(IsoStream *stream, void *buf, size_t desired)
/* Initialize block pointer writing */
rng->block_pointer_rpos = 0;
rng->block_pointer_fill = data->orig_size / rng->block_size
+ 1 + !!(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 ISO_OUT_OF_MEM;
return (rng->error_ret = ISO_OUT_OF_MEM);
}
}
}
@ -335,21 +345,16 @@ int ziso_stream_read(IsoStream *stream, void *buf, size_t desired)
}
}
if (rng->state == 2 && rng->buffer_rpos >= rng->buffer_fill) {
/* >>> Delivering data blocks */;
/* Delivering data blocks */;
ret = iso_stream_read(data->orig, rng->read_buffer,
rng->block_size);
if (ret > 0) {
rng->in_counter += ret;
if (rng->in_counter > data->orig_size) {
/* >>> Input size overflow */
/* <<< need better error code */
return ISO_FILE_READ_ERROR;
/* 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])
@ -358,45 +363,28 @@ int ziso_stream_read(IsoStream *stream, void *buf, size_t desired)
buf_len = 0;
} else {
buf_len = rng->buffer_size;
#ifdef Libisofs_with_zliB
ret = compress2((Bytef *) rng->block_buffer, &buf_len,
(Bytef *) rng->read_buffer, (uLong) ret, 9);
if (ret != Z_OK) {
#else
{
#endif
/* >>> compression failed */
/* <<< need better error code */
return ISO_FILE_READ_ERROR;
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;
/* >>> check for data->size overflow */;
if (data->size >= 0 && next_pt > data->size) {
/* >>> Compression yields more bytes than on first run */
/* <<< need better error code */
return ISO_FILE_READ_ERROR;
/* Compression yields more bytes than on first run */
return (rng->error_ret = ISO_FILTER_WRONG_INPUT);
}
/* >>> record resp. check block pointer */;
/* Record resp. check block pointer */
rng->block_counter++;
if (data->block_pointers[rng->block_counter] > 0) {
/* >>> check */;
if (next_pt != data->block_pointers[rng->block_counter] ) {
/* >>> block pointers mismatch , content has changed */
/* <<< need better error code */
return ISO_FILE_READ_ERROR;
/* block pointers mismatch , content has changed */
return (rng->error_ret = ISO_FILTER_WRONG_INPUT);
}
} else {
data->block_pointers[rng->block_counter] = next_pt;
@ -404,9 +392,13 @@ int ziso_stream_read(IsoStream *stream, void *buf, size_t desired)
} 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 ret;
return (rng->error_ret = ret);
if (rng->buffer_fill == 0) {
continue;
}
@ -429,6 +421,175 @@ int ziso_stream_read(IsoStream *stream, void *buf, size_t desired)
}
}
return ISO_FILE_READ_ERROR; /* should never be hit */
#else
return ISO_ZLIB_NOT_ENABLED;
#endif
}
/* 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;
size_t fill = 0;
char *cbuf = buf;
uLongf buf_len;
char zisofs_head[16];
if (stream == NULL) {
return ISO_NULL_POINTER;
}
data = 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 = iso_stream_read(data->orig, zisofs_head, 16);
if (ret < 0)
return (rng->error_ret = ret);
header_size = ((unsigned char *) zisofs_head)[12] * 4;
bs_log2 = ((unsigned char *) zisofs_head)[13];
if (ret != 16 || memcmp(zisofs_head, zisofs_magic, 8) != 0 ||
header_size < 16 || bs_log2 < 15 || bs_log2 > 17) {
return (rng->error_ret = ISO_ZISOFS_WRONG_INPUT);
}
rng->block_size = 1 << bs_log2;
if (header_size > 16) {
/* Skip surplus header bytes */
ret = iso_stream_read(data->orig, zisofs_head, header_size-16);
if (ret < 0)
return (rng->error_ret = ret);
if (ret != header_size - 16)
return (rng->error_ret = ISO_ZISOFS_WRONG_INPUT);
}
data->size = iso_read_lsb(((uint8_t *) zisofs_head) + 8, 4);
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);
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);
}
ret = iso_stream_read(data->orig, data->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++) {
data->block_pointers[i] =
iso_read_lsb((uint8_t *) (data->block_pointers + i), 4);
if (i > 0)
if (data->block_pointers[i] - data->block_pointers[i - 1]
> block_max)
block_max = data->block_pointers[i]
- data->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) {
/* More data blocks than announced */
return (rng->error_ret = ISO_FILTER_WRONG_INPUT);
}
todo = data->block_pointers[i] - data->block_pointers[i- 1];
if (todo == 0) {
memset(rng->read_buffer, 0, rng->block_size);
rng->buffer_fill = rng->block_size;
if (rng->in_counter + rng->buffer_fill > data->size &&
i == rng->block_pointer_fill - 1)
rng->buffer_fill = data->size - rng->in_counter;
rng->in_counter += rng->buffer_fill;
} 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
}
@ -455,12 +616,19 @@ off_t ziso_stream_get_size(IsoStream *stream)
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 = ziso_stream_read(stream, buf, bufsize);
ret = stream->class->read(stream, buf, bufsize);
if (ret <= 0)
break;
count += ret;
}
}
ret_close = ziso_stream_close(stream);
if (ret < 0)
return ret;
@ -488,7 +656,7 @@ void ziso_stream_get_id(IsoStream *stream, unsigned int *fs_id,
data = stream->data;
*fs_id = ISO_FILTER_FS_ID;
*dev_id = ISO_FILTER_ZISOFSL_DEV_ID;
*dev_id = ISO_FILTER_ZISOFS_DEV_ID;
*ino_id = data->id;
}
@ -534,13 +702,28 @@ IsoStream *ziso_get_input_stream(IsoStream *stream, int flag)
}
IsoStreamIface ziso_stream_class = {
IsoStreamIface ziso_stream_compress_class = {
2,
"ziso",
ziso_stream_open,
ziso_stream_close,
ziso_stream_get_size,
ziso_stream_read,
ziso_stream_compress,
ziso_stream_is_repeatable,
ziso_stream_get_id,
ziso_stream_free,
ziso_update_size,
ziso_get_input_stream
};
IsoStreamIface ziso_stream_uncompress_class = {
2,
"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,
@ -556,13 +739,12 @@ void ziso_filter_free(FilterContext *filter)
}
/* To be called by iso_file_add_filter().
* The FilterContext input parameter is not furtherly needed for the
* emerging IsoStream.
/*
* @param flag bit1= Install a decompression filter
*/
static
int ziso_filter_get_filter(FilterContext *filter, IsoStream *original,
IsoStream **filtered)
IsoStream **filtered, int flag)
{
IsoStream *str;
ZisofsFilterStreamData *data;
@ -594,7 +776,11 @@ int ziso_filter_get_filter(FilterContext *filter, IsoStream *original,
str->refcount = 1;
str->data = data;
str->class = &ziso_stream_class;
if (flag & 2) {
str->class = &ziso_stream_uncompress_class;
} else {
str->class = &ziso_stream_compress_class;
}
*filtered = str;
@ -602,10 +788,30 @@ int ziso_filter_get_filter(FilterContext *filter, IsoStream *original,
}
/* 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 dows not carry individual data.
* 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)
@ -620,14 +826,18 @@ int ziso_create_context(FilterContext **filter, int flag)
f->version = 0;
f->data = NULL;
f->free = ziso_filter_free;
f->get_filter = ziso_filter_get_filter;
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
* bit1= Install a decompression filter
* bit2= only inquire availability of zisofs filtering
*/
int iso_file_add_zisofs_filter(IsoFile *file, int flag)
{
@ -639,15 +849,20 @@ int iso_file_add_zisofs_filter(IsoFile *file, int flag)
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) {
return 2;
}
if (original_size > 4294967295.0) {
return ISO_ZISOFS_TOO_LARGE;
}
}
ret = ziso_create_context(&f, 0);
ret = ziso_create_context(&f, flag & 2);
if (ret < 0) {
return ret;
}
@ -663,8 +878,8 @@ int iso_file_add_zisofs_filter(IsoFile *file, int flag)
iso_file_remove_filter(file, 0);
return filtered_size;
}
if ((filtered_size >= original_size && !(flag & 1)) ||
filtered_size / 2048 >= original_size / 2048){
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;

18
libisofs/libisofs.h
View File

@ -782,6 +782,8 @@ struct IsoStream_Iface
* "mem " -> Read from memory
* "boot" -> Boot catalog
* "extf" -> External filter program
* "ziso" -> zisofs compression
* "osiz" -> zisofs uncompression
* "user" -> User supplied stream
*/
char type[4];
@ -4704,6 +4706,18 @@ int iso_local_set_attrs(char *disk_path, size_t num_attrs, char **names,
/** Cannot apply zisofs filter to file >= 4 GiB (FAILURE, HIGH, -346) */
#define ISO_ZISOFS_TOO_LARGE 0xE830FEA6
/* ts A90409 */
/** Filter input differs from previous run (FAILURE, HIGH, -347) */
#define ISO_FILTER_WRONG_INPUT 0xE830FEA5
/* ts A90409 */
/** zlib compression/decompression error (FAILURE, HIGH, -348) */
#define ISO_ZLIB_COMPR_ERR 0xE830FEA4
/* ts A90409 */
/** Input stream is not in zisofs format (FAILURE, HIGH, -349) */
#define ISO_ZISOFS_WRONG_INPUT 0xE830FEA3
/* --------------------------- Filters in General -------------------------- */
@ -4897,8 +4911,10 @@ int iso_stream_get_external_filter(IsoStream *stream,
* bit0= Do not install filter if the number of output blocks is
* not smaller than the number of input blocks. Block size is 2048.
* bit1= Install a decompression filter rather than one for compression.
* bit2= Only inquire availability of zisofs filtering. file may be NULL.
* If available return 2, else return error.
* @return
* 1 on success, 2 if filter installation revoked
* 1 on success, 2 if filter available but installation revoked
* <0 on error, e.g. ISO_ZLIB_NOT_ENABLED
*
* @since 0.6.18

6
libisofs/messages.c
View File

@ -253,6 +253,12 @@ const char *iso_error_to_msg(int errcode)
return "Use of zlib was not enabled at compile time";
case ISO_ZISOFS_TOO_LARGE:
return "Cannot apply zisofs filter to file >= 4 GiB";
case ISO_FILTER_WRONG_INPUT:
return "Filter input differs from previous run";
case ISO_ZLIB_COMPR_ERR:
return "zlib compression/decompression error";
case ISO_ZISOFS_WRONG_INPUT:
return "Input stream is not in zisofs format";
default:
return "Unknown error";
}