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flycast/core/deps/chdr/chdr.cpp

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project import
2013-12-19 17:10:14 +00:00
/***************************************************************************
chd.c
MAME Compressed Hunks of Data file format
****************************************************************************
Copyright Aaron Giles
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in
the documentation and/or other materials provided with the
distribution.
* Neither the name 'MAME' nor the names of its contributors may be
used to endorse or promote products derived from this software
without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY AARON GILES ''AS IS'' AND ANY EXPRESS OR
IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL AARON GILES BE LIABLE FOR ANY DIRECT,
INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
***************************************************************************/
#include "chd.h"
#include "deps/crypto/md5.h"
#include "deps/crypto/sha1.h"
#include "deps/zlib/zlib.h"
#include <time.h>
#include <stddef.h>
#include <stdlib.h>
#include <stdio.h>
#define TRUE 1
#define FALSE 0
/***************************************************************************
DEBUGGING
***************************************************************************/
#define PRINTF_MAX_HUNK (0)
/***************************************************************************
CONSTANTS
***************************************************************************/
#define MAP_STACK_ENTRIES 512 /* max number of entries to use on the stack */
#define MAP_ENTRY_SIZE 16 /* V3 and later */
#define OLD_MAP_ENTRY_SIZE 8 /* V1-V2 */
#define METADATA_HEADER_SIZE 16 /* metadata header size */
#define CRCMAP_HASH_SIZE 4095 /* number of CRC hashtable entries */
#define MAP_ENTRY_FLAG_TYPE_MASK 0x0f /* what type of hunk */
#define MAP_ENTRY_FLAG_NO_CRC 0x10 /* no CRC is present */
#define MAP_ENTRY_TYPE_INVALID 0x00 /* invalid type */
#define MAP_ENTRY_TYPE_COMPRESSED 0x01 /* standard compression */
#define MAP_ENTRY_TYPE_UNCOMPRESSED 0x02 /* uncompressed data */
#define MAP_ENTRY_TYPE_MINI 0x03 /* mini: use offset as raw data */
#define MAP_ENTRY_TYPE_SELF_HUNK 0x04 /* same as another hunk in this file */
#define MAP_ENTRY_TYPE_PARENT_HUNK 0x05 /* same as a hunk in the parent file */
#define CHD_V1_SECTOR_SIZE 512 /* size of a "sector" in the V1 header */
#define COOKIE_VALUE 0xbaadf00d
#define MAX_ZLIB_ALLOCS 64
#define END_OF_LIST_COOKIE "EndOfListCookie"
#define NO_MATCH (~0)
/***************************************************************************
MACROS
***************************************************************************/
#define EARLY_EXIT(x) do { (void)(x); goto cleanup; } while (0)
/***************************************************************************
TYPE DEFINITIONS
***************************************************************************/
/* interface to a codec */
typedef struct _codec_interface codec_interface;
struct _codec_interface
{
UINT32 compression; /* type of compression */
const char *compname; /* name of the algorithm */
UINT8 lossy; /* is this a lossy algorithm? */
chd_error (*init)(chd_file *chd); /* codec initialize */
void (*free)(chd_file *chd); /* codec free */
chd_error (*compress)(chd_file *chd, const void *src, UINT32 *complen); /* compress data */
chd_error (*decompress)(chd_file *chd, UINT32 complen, void *dst); /* decompress data */
chd_error (*config)(chd_file *chd, int param, void *config); /* configure */
};
/* a single map entry */
typedef struct _map_entry map_entry;
struct _map_entry
{
UINT64 offset; /* offset within the file of the data */
UINT32 crc; /* 32-bit CRC of the data */
UINT32 length; /* length of the data */
UINT8 flags; /* misc flags */
};
/* simple linked-list of hunks used for our CRC map */
typedef struct _crcmap_entry crcmap_entry;
struct _crcmap_entry
{
UINT32 hunknum; /* hunk number */
crcmap_entry * next; /* next entry in list */
};
/* a single metadata entry */
typedef struct _metadata_entry metadata_entry;
struct _metadata_entry
{
UINT64 offset; /* offset within the file of the header */
UINT64 next; /* offset within the file of the next header */
UINT64 prev; /* offset within the file of the previous header */
UINT32 length; /* length of the metadata */
UINT32 metatag; /* metadata tag */
UINT8 flags; /* flag bits */
};
/* internal representation of an open CHD file */
struct _chd_file
{
UINT32 cookie; /* cookie, should equal COOKIE_VALUE */
core_file * file; /* handle to the open core file */
UINT8 owns_file; /* flag indicating if this file should be closed on chd_close() */
chd_header header; /* header, extracted from file */
chd_file * parent; /* pointer to parent file, or NULL */
map_entry * map; /* array of map entries */
UINT8 * cache; /* hunk cache pointer */
UINT32 cachehunk; /* index of currently cached hunk */
UINT8 * compare; /* hunk compare pointer */
UINT32 comparehunk; /* index of current compare data */
UINT8 * compressed; /* pointer to buffer for compressed data */
const codec_interface * codecintf; /* interface to the codec */
void * codecdata; /* opaque pointer to codec data */
crcmap_entry * crcmap; /* CRC map entries */
crcmap_entry * crcfree; /* free list CRC entries */
crcmap_entry ** crctable; /* table of CRC entries */
UINT32 maxhunk; /* maximum hunk accessed */
UINT8 compressing; /* are we compressing? */
struct MD5Context compmd5; /* running MD5 during compression */
struct sha1_ctx compsha1; /* running SHA1 during compression */
UINT32 comphunk; /* next hunk we will compress */
UINT8 verifying; /* are we verifying? */
struct MD5Context vermd5; /* running MD5 during verification */
struct sha1_ctx versha1; /* running SHA1 during verification */
UINT32 verhunk; /* next hunk we will verify */
UINT32 async_hunknum; /* hunk index for asynchronous operations */
void * async_buffer; /* buffer pointer for asynchronous operations */
};
/* codec-private data for the ZLIB codec */
typedef struct _zlib_codec_data zlib_codec_data;
struct _zlib_codec_data
{
z_stream inflater;
z_stream deflater;
UINT32 * allocptr[MAX_ZLIB_ALLOCS];
};
/* a single metadata hash entry */
typedef struct _metadata_hash metadata_hash;
struct _metadata_hash
{
UINT8 tag[4]; /* tag of the metadata in big-endian */
UINT8 sha1[CHD_SHA1_BYTES]; /* hash */
};
/***************************************************************************
GLOBAL VARIABLES
***************************************************************************/
static const UINT8 nullmd5[CHD_MD5_BYTES] = { 0 };
static const UINT8 nullsha1[CHD_SHA1_BYTES] = { 0 };
/***************************************************************************
PROTOTYPES
***************************************************************************/
/* internal header operations */
static chd_error header_validate(const chd_header *header);
static chd_error header_read(core_file *file, chd_header *header);
/* internal hunk read/write */
static chd_error hunk_read_into_cache(chd_file *chd, UINT32 hunknum);
static chd_error hunk_read_into_memory(chd_file *chd, UINT32 hunknum, UINT8 *dest);
/* internal map access */
static chd_error map_read(chd_file *chd);
/* internal CRC map access */
static void crcmap_init(chd_file *chd, int prepopulate);
static void crcmap_add_entry(chd_file *chd, UINT32 hunknum);
static UINT32 crcmap_find_hunk(chd_file *chd, UINT32 hunknum, UINT32 crc, const UINT8 *rawdata);
/* metadata management */
static chd_error metadata_find_entry(chd_file *chd, UINT32 metatag, UINT32 metaindex, metadata_entry *metaentry);
static chd_error metadata_compute_hash(chd_file *chd, const UINT8 *rawsha1, UINT8 *finalsha1);
static int metadata_hash_compare(const void *elem1, const void *elem2);
/* zlib compression codec */
static chd_error zlib_codec_init(chd_file *chd);
static void zlib_codec_free(chd_file *chd);
static chd_error zlib_codec_compress(chd_file *chd, const void *src, UINT32 *length);
static chd_error zlib_codec_decompress(chd_file *chd, UINT32 srclength, void *dest);
static voidpf zlib_fast_alloc(voidpf opaque, uInt items, uInt size);
static void zlib_fast_free(voidpf opaque, voidpf address);
/***************************************************************************
CODEC INTERFACES
***************************************************************************/
static const codec_interface codec_interfaces[] =
{
/* "none" or no compression */
{
CHDCOMPRESSION_NONE,
"none",
FALSE,
NULL,
NULL,
NULL,
NULL,
NULL
},
/* standard zlib compression */
{
CHDCOMPRESSION_ZLIB,
"zlib",
FALSE,
zlib_codec_init,
zlib_codec_free,
zlib_codec_compress,
zlib_codec_decompress,
NULL
},
/* zlib+ compression */
{
CHDCOMPRESSION_ZLIB_PLUS,
"zlib+",
FALSE,
zlib_codec_init,
zlib_codec_free,
zlib_codec_compress,
zlib_codec_decompress,
NULL
},
};
#define MIN min
#define MAX max
/***************************************************************************
INLINE FUNCTIONS
***************************************************************************/
/*-------------------------------------------------
get_bigendian_uint64 - fetch a UINT64 from
the data stream in bigendian order
-------------------------------------------------*/
INLINE UINT64 get_bigendian_uint64(const UINT8 *base)
{
return ((UINT64)base[0] << 56) | ((UINT64)base[1] << 48) | ((UINT64)base[2] << 40) | ((UINT64)base[3] << 32) |
((UINT64)base[4] << 24) | ((UINT64)base[5] << 16) | ((UINT64)base[6] << 8) | (UINT64)base[7];
}
/*-------------------------------------------------
put_bigendian_uint64 - write a UINT64 to
the data stream in bigendian order
-------------------------------------------------*/
INLINE void put_bigendian_uint64(UINT8 *base, UINT64 value)
{
base[0] = value >> 56;
base[1] = value >> 48;
base[2] = value >> 40;
base[3] = value >> 32;
base[4] = value >> 24;
base[5] = value >> 16;
base[6] = value >> 8;
base[7] = value;
}
/*-------------------------------------------------
get_bigendian_uint32 - fetch a UINT32 from
the data stream in bigendian order
-------------------------------------------------*/
INLINE UINT32 get_bigendian_uint32(const UINT8 *base)
{
return (base[0] << 24) | (base[1] << 16) | (base[2] << 8) | base[3];
}
/*-------------------------------------------------
put_bigendian_uint32 - write a UINT32 to
the data stream in bigendian order
-------------------------------------------------*/
INLINE void put_bigendian_uint32(UINT8 *base, UINT32 value)
{
base[0] = value >> 24;
base[1] = value >> 16;
base[2] = value >> 8;
base[3] = value;
}
/*-------------------------------------------------
get_bigendian_uint16 - fetch a UINT16 from
the data stream in bigendian order
-------------------------------------------------*/
INLINE UINT16 get_bigendian_uint16(const UINT8 *base)
{
return (base[0] << 8) | base[1];
}
/*-------------------------------------------------
put_bigendian_uint16 - write a UINT16 to
the data stream in bigendian order
-------------------------------------------------*/
INLINE void put_bigendian_uint16(UINT8 *base, UINT16 value)
{
base[0] = value >> 8;
base[1] = value;
}
/*-------------------------------------------------
map_extract - extract a single map
entry from the datastream
-------------------------------------------------*/
INLINE void map_extract(const UINT8 *base, map_entry *entry)
{
entry->offset = get_bigendian_uint64(&base[0]);
entry->crc = get_bigendian_uint32(&base[8]);
entry->length = get_bigendian_uint16(&base[12]) | (base[14] << 16);
entry->flags = base[15];
}
/*-------------------------------------------------
map_assemble - write a single map
entry to the datastream
-------------------------------------------------*/
INLINE void map_assemble(UINT8 *base, map_entry *entry)
{
put_bigendian_uint64(&base[0], entry->offset);
put_bigendian_uint32(&base[8], entry->crc);
put_bigendian_uint16(&base[12], entry->length);
base[14] = entry->length >> 16;
base[15] = entry->flags;
}
/*-------------------------------------------------
map_extract_old - extract a single map
entry in old format from the datastream
-------------------------------------------------*/
INLINE void map_extract_old(const UINT8 *base, map_entry *entry, UINT32 hunkbytes)
{
entry->offset = get_bigendian_uint64(&base[0]);
entry->crc = 0;
entry->length = entry->offset >> 44;
entry->flags = MAP_ENTRY_FLAG_NO_CRC | ((entry->length == hunkbytes) ? MAP_ENTRY_TYPE_UNCOMPRESSED : MAP_ENTRY_TYPE_COMPRESSED);
#ifdef __MWERKS__
entry->offset = entry->offset & 0x00000FFFFFFFFFFFLL;
#else
entry->offset = (entry->offset << 20) >> 20;
#endif
}
/*-------------------------------------------------
queue_async_operation - queue a new work
item
-------------------------------------------------*/
/***************************************************************************
CHD FILE MANAGEMENT
***************************************************************************/
/*-------------------------------------------------
chd_open_file - open a CHD file for access
-------------------------------------------------*/
chd_error chd_open_file(core_file *file, int mode, chd_file *parent, chd_file **chd)
{
chd_file *newchd = NULL;
chd_error err;
int intfnum;
/* verify parameters */
if (file == NULL)
EARLY_EXIT(err = CHDERR_INVALID_PARAMETER);
/* punt if invalid parent */
if (parent != NULL && parent->cookie != COOKIE_VALUE)
EARLY_EXIT(err = CHDERR_INVALID_PARAMETER);
/* allocate memory for the final result */
newchd = (chd_file *)malloc(sizeof(**chd));
if (newchd == NULL)
EARLY_EXIT(err = CHDERR_OUT_OF_MEMORY);
memset(newchd, 0, sizeof(*newchd));
newchd->cookie = COOKIE_VALUE;
newchd->parent = parent;
newchd->file = file;
/* now attempt to read the header */
err = header_read(newchd->file, &newchd->header);
if (err != CHDERR_NONE)
EARLY_EXIT(err);
/* validate the header */
err = header_validate(&newchd->header);
if (err != CHDERR_NONE)
EARLY_EXIT(err);
/* make sure we don't open a read-only file writeable */
if (mode == CHD_OPEN_READWRITE && !(newchd->header.flags & CHDFLAGS_IS_WRITEABLE))
EARLY_EXIT(err = CHDERR_FILE_NOT_WRITEABLE);
/* also, never open an older version writeable */
if (mode == CHD_OPEN_READWRITE && newchd->header.version < CHD_HEADER_VERSION)
EARLY_EXIT(err = CHDERR_UNSUPPORTED_VERSION);
/* if we need a parent, make sure we have one */
if (parent == NULL && (newchd->header.flags & CHDFLAGS_HAS_PARENT))
EARLY_EXIT(err = CHDERR_REQUIRES_PARENT);
/* make sure we have a valid parent */
if (parent != NULL)
{
/* check MD5 if it isn't empty */
if (memcmp(nullmd5, newchd->header.parentmd5, sizeof(newchd->header.parentmd5)) != 0 &&
memcmp(nullmd5, newchd->parent->header.md5, sizeof(newchd->parent->header.md5)) != 0 &&
memcmp(newchd->parent->header.md5, newchd->header.parentmd5, sizeof(newchd->header.parentmd5)) != 0)
EARLY_EXIT(err = CHDERR_INVALID_PARENT);
/* check SHA1 if it isn't empty */
if (memcmp(nullsha1, newchd->header.parentsha1, sizeof(newchd->header.parentsha1)) != 0 &&
memcmp(nullsha1, newchd->parent->header.sha1, sizeof(newchd->parent->header.sha1)) != 0 &&
memcmp(newchd->parent->header.sha1, newchd->header.parentsha1, sizeof(newchd->header.parentsha1)) != 0)
EARLY_EXIT(err = CHDERR_INVALID_PARENT);
}
/* now read the hunk map */
err = map_read(newchd);
if (err != CHDERR_NONE)
EARLY_EXIT(err);
/* allocate and init the hunk cache */
newchd->cache = (UINT8 *)malloc(newchd->header.hunkbytes);
newchd->compare = (UINT8 *)malloc(newchd->header.hunkbytes);
if (newchd->cache == NULL || newchd->compare == NULL)
EARLY_EXIT(err = CHDERR_OUT_OF_MEMORY);
newchd->cachehunk = ~0;
newchd->comparehunk = ~0;
/* allocate the temporary compressed buffer */
newchd->compressed = (UINT8 *)malloc(newchd->header.hunkbytes);
if (newchd->compressed == NULL)
EARLY_EXIT(err = CHDERR_OUT_OF_MEMORY);
/* find the codec interface */
for (intfnum = 0; intfnum < ARRAY_LENGTH(codec_interfaces); intfnum++)
if (codec_interfaces[intfnum].compression == newchd->header.compression)
{
newchd->codecintf = &codec_interfaces[intfnum];
break;
}
if (intfnum == ARRAY_LENGTH(codec_interfaces))
EARLY_EXIT(err = CHDERR_UNSUPPORTED_FORMAT);
/* initialize the codec */
if (newchd->codecintf->init != NULL)
err = (*newchd->codecintf->init)(newchd);
if (err != CHDERR_NONE)
EARLY_EXIT(err);
/* all done */
*chd = newchd;
return CHDERR_NONE;
cleanup:
if (newchd != NULL)
chd_close(newchd);
return err;
}
/*-------------------------------------------------
chd_open - open a CHD file by
filename
-------------------------------------------------*/
chd_error chd_open(const wchar *filename, int mode, chd_file *parent, chd_file **chd)
{
chd_error err;
core_file *file = NULL;
UINT32 openflags;
/* choose the proper mode */
switch(mode)
{
case CHD_OPEN_READ:
break;
default:
err = CHDERR_INVALID_PARAMETER;
goto cleanup;
}
/* open the file */
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file=core_fopen(filename);
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if (file == 0)
{
err = CHDERR_FILE_NOT_FOUND;
goto cleanup;
}
/* now open the CHD */
err = chd_open_file(file, mode, parent, chd);
if (err != CHDERR_NONE)
goto cleanup;
/* we now own this file */
(*chd)->owns_file = TRUE;
cleanup:
if ((err != CHDERR_NONE) && (file != NULL))
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core_fclose(file);
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return err;
}
/*-------------------------------------------------
chd_close - close a CHD file for access
-------------------------------------------------*/
void chd_close(chd_file *chd)
{
/* punt if NULL or invalid */
if (chd == NULL || chd->cookie != COOKIE_VALUE)
return;
/* deinit the codec */
if (chd->codecintf != NULL && chd->codecintf->free != NULL)
(*chd->codecintf->free)(chd);
/* free the compressed data buffer */
if (chd->compressed != NULL)
free(chd->compressed);
/* free the hunk cache and compare data */
if (chd->compare != NULL)
free(chd->compare);
if (chd->cache != NULL)
free(chd->cache);
/* free the hunk map */
if (chd->map != NULL)
free(chd->map);
/* free the CRC table */
if (chd->crctable != NULL)
free(chd->crctable);
/* free the CRC map */
if (chd->crcmap != NULL)
free(chd->crcmap);
/* close the file */
if (chd->owns_file && chd->file != NULL)
chd over http support (EXPERIMENTAL AND SLOW)
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core_fclose(chd->file);
project import
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if (PRINTF_MAX_HUNK) printf("Max hunk = %d/%d\n", chd->maxhunk, chd->header.totalhunks);
/* free our memory */
free(chd);
}
/*-------------------------------------------------
chd_core_file - return the associated
core_file
-------------------------------------------------*/
core_file *chd_core_file(chd_file *chd)
{
return chd->file;
}
/*-------------------------------------------------
chd_error_string - return an error string for
the given CHD error
-------------------------------------------------*/
const char *chd_error_string(chd_error err)
{
switch (err)
{
case CHDERR_NONE: return "no error";
case CHDERR_NO_INTERFACE: return "no drive interface";
case CHDERR_OUT_OF_MEMORY: return "out of memory";
case CHDERR_INVALID_FILE: return "invalid file";
case CHDERR_INVALID_PARAMETER: return "invalid parameter";
case CHDERR_INVALID_DATA: return "invalid data";
case CHDERR_FILE_NOT_FOUND: return "file not found";
case CHDERR_REQUIRES_PARENT: return "requires parent";
case CHDERR_FILE_NOT_WRITEABLE: return "file not writeable";
case CHDERR_READ_ERROR: return "read error";
case CHDERR_WRITE_ERROR: return "write error";
case CHDERR_CODEC_ERROR: return "codec error";
case CHDERR_INVALID_PARENT: return "invalid parent";
case CHDERR_HUNK_OUT_OF_RANGE: return "hunk out of range";
case CHDERR_DECOMPRESSION_ERROR: return "decompression error";
case CHDERR_COMPRESSION_ERROR: return "compression error";
case CHDERR_CANT_CREATE_FILE: return "can't create file";
case CHDERR_CANT_VERIFY: return "can't verify file";
case CHDERR_NOT_SUPPORTED: return "operation not supported";
case CHDERR_METADATA_NOT_FOUND: return "can't find metadata";
case CHDERR_INVALID_METADATA_SIZE: return "invalid metadata size";
case CHDERR_UNSUPPORTED_VERSION: return "unsupported CHD version";
case CHDERR_VERIFY_INCOMPLETE: return "incomplete verify";
case CHDERR_INVALID_METADATA: return "invalid metadata";
case CHDERR_INVALID_STATE: return "invalid state";
case CHDERR_OPERATION_PENDING: return "operation pending";
case CHDERR_NO_ASYNC_OPERATION: return "no async operation in progress";
case CHDERR_UNSUPPORTED_FORMAT: return "unsupported format";
default: return "undocumented error";
}
}
/***************************************************************************
CHD HEADER MANAGEMENT
***************************************************************************/
/*-------------------------------------------------
chd_get_header - return a pointer to the
extracted header data
-------------------------------------------------*/
const chd_header *chd_get_header(chd_file *chd)
{
/* punt if NULL or invalid */
if (chd == NULL || chd->cookie != COOKIE_VALUE)
return NULL;
return &chd->header;
}
/***************************************************************************
CORE DATA READ/WRITE
***************************************************************************/
/*-------------------------------------------------
chd_read - read a single hunk from the CHD
file
-------------------------------------------------*/
chd_error chd_read(chd_file *chd, UINT32 hunknum, void *buffer)
{
/* punt if NULL or invalid */
if (chd == NULL || chd->cookie != COOKIE_VALUE)
return CHDERR_INVALID_PARAMETER;
/* if we're past the end, fail */
if (hunknum >= chd->header.totalhunks)
return CHDERR_HUNK_OUT_OF_RANGE;
/* perform the read */
return hunk_read_into_memory(chd, hunknum, (UINT8 *)buffer);
}
/***************************************************************************
METADATA MANAGEMENT
***************************************************************************/
/*-------------------------------------------------
chd_get_metadata - get the indexed metadata
of the given type
-------------------------------------------------*/
chd_error chd_get_metadata(chd_file *chd, UINT32 searchtag, UINT32 searchindex, void *output, UINT32 outputlen, UINT32 *resultlen, UINT32 *resulttag, UINT8 *resultflags)
{
metadata_entry metaentry;
chd_error err;
UINT32 count;
/* if we didn't find it, just return */
err = metadata_find_entry(chd, searchtag, searchindex, &metaentry);
if (err != CHDERR_NONE)
{
/* unless we're an old version and they are requesting hard disk metadata */
if (chd->header.version < 3 && (searchtag == HARD_DISK_METADATA_TAG || searchtag == CHDMETATAG_WILDCARD) && searchindex == 0)
{
char faux_metadata[256];
UINT32 faux_length;
/* fill in the faux metadata */
sprintf(faux_metadata, HARD_DISK_METADATA_FORMAT, chd->header.obsolete_cylinders, chd->header.obsolete_heads, chd->header.obsolete_sectors, chd->header.hunkbytes / chd->header.obsolete_hunksize);
faux_length = (UINT32)strlen(faux_metadata) + 1;
/* copy the metadata itself */
memcpy(output, faux_metadata, MIN(outputlen, faux_length));
/* return the length of the data and the tag */
if (resultlen != NULL)
*resultlen = faux_length;
if (resulttag != NULL)
*resulttag = HARD_DISK_METADATA_TAG;
return CHDERR_NONE;
}
return err;
}
/* read the metadata */
outputlen = min(outputlen, metaentry.length);
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core_fseek(chd->file, metaentry.offset + METADATA_HEADER_SIZE, SEEK_SET);
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count = core_fread(chd->file, output, outputlen);
if (count != outputlen)
return CHDERR_READ_ERROR;
/* return the length of the data and the tag */
if (resultlen != NULL)
*resultlen = metaentry.length;
if (resulttag != NULL)
*resulttag = metaentry.metatag;
if (resultflags != NULL)
*resultflags = metaentry.flags;
return CHDERR_NONE;
}
/***************************************************************************
COMPRESSION MANAGEMENT
***************************************************************************/
/***************************************************************************
VERIFICATION
***************************************************************************/
/*-------------------------------------------------
chd_verify_begin - begin compressing data
into a CHD
-------------------------------------------------*/
chd_error chd_verify_begin(chd_file *chd)
{
/* verify parameters */
if (chd == NULL)
return CHDERR_INVALID_PARAMETER;
/* if this is a writeable file image, we can't verify */
if (chd->header.flags & CHDFLAGS_IS_WRITEABLE)
return CHDERR_CANT_VERIFY;
/* init the MD5/SHA1 computations */
MD5Init(&chd->vermd5);
sha1_init(&chd->versha1);
chd->verifying = TRUE;
chd->verhunk = 0;
return CHDERR_NONE;
}
/*-------------------------------------------------
chd_verify_hunk - verify the next hunk in
the CHD
-------------------------------------------------*/
chd_error chd_verify_hunk(chd_file *chd)
{
UINT32 thishunk = chd->verhunk++;
UINT64 hunkoffset = (UINT64)thishunk * (UINT64)chd->header.hunkbytes;
map_entry *entry;
chd_error err;
/* error if in the wrong state */
if (!chd->verifying)
return CHDERR_INVALID_STATE;
/* read the hunk into the cache */
err = hunk_read_into_cache(chd, thishunk);
if (err != CHDERR_NONE)
return err;
/* update the MD5/SHA1 */
if (hunkoffset < chd->header.logicalbytes)
{
UINT64 bytestochecksum = MIN((u64)chd->header.hunkbytes, (u64)(chd->header.logicalbytes - hunkoffset));
if (bytestochecksum > 0)
{
MD5Update(&chd->vermd5, chd->cache, bytestochecksum);
sha1_update(&chd->versha1, bytestochecksum, chd->cache);
}
}
/* validate the CRC if we have one */
entry = &chd->map[thishunk];
if (!(entry->flags & MAP_ENTRY_FLAG_NO_CRC) && entry->crc != crc32(0, chd->cache, chd->header.hunkbytes))
return CHDERR_DECOMPRESSION_ERROR;
return CHDERR_NONE;
}
/*-------------------------------------------------
chd_verify_finish - finish verification of
the CHD
-------------------------------------------------*/
chd_error chd_verify_finish(chd_file *chd, chd_verify_result *result)
{
/* error if in the wrong state */
if (!chd->verifying)
return CHDERR_INVALID_STATE;
/* compute the final MD5 */
MD5Final(result->md5, &chd->vermd5);
/* compute the final SHA1 */
sha1_final(&chd->versha1);
sha1_digest(&chd->versha1, SHA1_DIGEST_SIZE, result->rawsha1);
/* compute the overall hash including metadata */
metadata_compute_hash(chd, result->rawsha1, result->sha1);
/* return an error */
chd->verifying = FALSE;
return (chd->verhunk < chd->header.totalhunks) ? CHDERR_VERIFY_INCOMPLETE : CHDERR_NONE;
}
/***************************************************************************
CODEC INTERFACES
***************************************************************************/
/*-------------------------------------------------
chd_codec_config - set internal codec
parameters
-------------------------------------------------*/
chd_error chd_codec_config(chd_file *chd, int param, void *config)
{
return CHDERR_INVALID_PARAMETER;
}
/*-------------------------------------------------
chd_get_codec_name - get the name of a
particular codec
-------------------------------------------------*/
const char *chd_get_codec_name(UINT32 codec)
{
return "Unknown";
}
/***************************************************************************
INTERNAL HEADER OPERATIONS
***************************************************************************/
/*-------------------------------------------------
header_validate - check the validity of a
CHD header
-------------------------------------------------*/
static chd_error header_validate(const chd_header *header)
{
int intfnum;
/* require a valid version */
if (header->version == 0 || header->version > CHD_HEADER_VERSION)
return CHDERR_UNSUPPORTED_VERSION;
/* require a valid length */
if ((header->version == 1 && header->length != CHD_V1_HEADER_SIZE) ||
(header->version == 2 && header->length != CHD_V2_HEADER_SIZE) ||
(header->version == 3 && header->length != CHD_V3_HEADER_SIZE) ||
(header->version == 4 && header->length != CHD_V4_HEADER_SIZE))
return CHDERR_INVALID_PARAMETER;
/* require valid flags */
if (header->flags & CHDFLAGS_UNDEFINED)
return CHDERR_INVALID_PARAMETER;
/* require a supported compression mechanism */
for (intfnum = 0; intfnum < ARRAY_LENGTH(codec_interfaces); intfnum++)
if (codec_interfaces[intfnum].compression == header->compression)
break;
if (intfnum == ARRAY_LENGTH(codec_interfaces))
return CHDERR_INVALID_PARAMETER;
/* require a valid hunksize */
if (header->hunkbytes == 0 || header->hunkbytes >= 65536 * 256)
return CHDERR_INVALID_PARAMETER;
/* require a valid hunk count */
if (header->totalhunks == 0)
return CHDERR_INVALID_PARAMETER;
/* require a valid MD5 and/or SHA1 if we're using a parent */
if ((header->flags & CHDFLAGS_HAS_PARENT) && memcmp(header->parentmd5, nullmd5, sizeof(nullmd5)) == 0 && memcmp(header->parentsha1, nullsha1, sizeof(nullsha1)) == 0)
return CHDERR_INVALID_PARAMETER;
/* if we're V3 or later, the obsolete fields must be 0 */
if (header->version >= 3 &&
(header->obsolete_cylinders != 0 || header->obsolete_sectors != 0 ||
header->obsolete_heads != 0 || header->obsolete_hunksize != 0))
return CHDERR_INVALID_PARAMETER;
/* if we're pre-V3, the obsolete fields must NOT be 0 */
if (header->version < 3 &&
(header->obsolete_cylinders == 0 || header->obsolete_sectors == 0 ||
header->obsolete_heads == 0 || header->obsolete_hunksize == 0))
return CHDERR_INVALID_PARAMETER;
return CHDERR_NONE;
}
/*-------------------------------------------------
header_read - read a CHD header into the
internal data structure
-------------------------------------------------*/
static chd_error header_read(core_file *file, chd_header *header)
{
UINT8 rawheader[CHD_MAX_HEADER_SIZE];
UINT32 count;
/* punt if NULL */
if (header == NULL)
return CHDERR_INVALID_PARAMETER;
/* punt if invalid file */
if (file == NULL)
return CHDERR_INVALID_FILE;
/* seek and read */
core_fseek(file, 0, SEEK_SET);
count = core_fread(file, rawheader, sizeof(rawheader));
if (count != sizeof(rawheader))
return CHDERR_READ_ERROR;
/* verify the tag */
if (strncmp((char *)rawheader, "MComprHD", 8) != 0)
return CHDERR_INVALID_DATA;
/* extract the direct data */
memset(header, 0, sizeof(*header));
header->length = get_bigendian_uint32(&rawheader[8]);
header->version = get_bigendian_uint32(&rawheader[12]);
/* make sure it's a version we understand */
if (header->version == 0 || header->version > CHD_HEADER_VERSION)
return CHDERR_UNSUPPORTED_VERSION;
/* make sure the length is expected */
if ((header->version == 1 && header->length != CHD_V1_HEADER_SIZE) ||
(header->version == 2 && header->length != CHD_V2_HEADER_SIZE) ||
(header->version == 3 && header->length != CHD_V3_HEADER_SIZE) ||
(header->version == 4 && header->length != CHD_V4_HEADER_SIZE))
return CHDERR_INVALID_DATA;
/* extract the common data */
header->flags = get_bigendian_uint32(&rawheader[16]);
header->compression = get_bigendian_uint32(&rawheader[20]);
/* extract the V1/V2-specific data */
if (header->version < 3)
{
int seclen = (header->version == 1) ? CHD_V1_SECTOR_SIZE : get_bigendian_uint32(&rawheader[76]);
header->obsolete_hunksize = get_bigendian_uint32(&rawheader[24]);
header->totalhunks = get_bigendian_uint32(&rawheader[28]);
header->obsolete_cylinders = get_bigendian_uint32(&rawheader[32]);
header->obsolete_heads = get_bigendian_uint32(&rawheader[36]);
header->obsolete_sectors = get_bigendian_uint32(&rawheader[40]);
memcpy(header->md5, &rawheader[44], CHD_MD5_BYTES);
memcpy(header->parentmd5, &rawheader[60], CHD_MD5_BYTES);
header->logicalbytes = (UINT64)header->obsolete_cylinders * (UINT64)header->obsolete_heads * (UINT64)header->obsolete_sectors * (UINT64)seclen;
header->hunkbytes = seclen * header->obsolete_hunksize;
header->metaoffset = 0;
}
/* extract the V3-specific data */
else if (header->version == 3)
{
header->totalhunks = get_bigendian_uint32(&rawheader[24]);
header->logicalbytes = get_bigendian_uint64(&rawheader[28]);
header->metaoffset = get_bigendian_uint64(&rawheader[36]);
memcpy(header->md5, &rawheader[44], CHD_MD5_BYTES);
memcpy(header->parentmd5, &rawheader[60], CHD_MD5_BYTES);
header->hunkbytes = get_bigendian_uint32(&rawheader[76]);
memcpy(header->sha1, &rawheader[80], CHD_SHA1_BYTES);
memcpy(header->parentsha1, &rawheader[100], CHD_SHA1_BYTES);
}
/* extract the V4-specific data */
else
{
header->totalhunks = get_bigendian_uint32(&rawheader[24]);
header->logicalbytes = get_bigendian_uint64(&rawheader[28]);
header->metaoffset = get_bigendian_uint64(&rawheader[36]);
header->hunkbytes = get_bigendian_uint32(&rawheader[44]);
memcpy(header->sha1, &rawheader[48], CHD_SHA1_BYTES);
memcpy(header->parentsha1, &rawheader[68], CHD_SHA1_BYTES);
memcpy(header->rawsha1, &rawheader[88], CHD_SHA1_BYTES);
}
/* guess it worked */
return CHDERR_NONE;
}
/***************************************************************************
INTERNAL HUNK READ/WRITE
***************************************************************************/
/*-------------------------------------------------
hunk_read_into_cache - read a hunk into
the CHD's hunk cache
-------------------------------------------------*/
static chd_error hunk_read_into_cache(chd_file *chd, UINT32 hunknum)
{
chd_error err;
/* track the max */
if (hunknum > chd->maxhunk)
chd->maxhunk = hunknum;
/* if we're already in the cache, we're done */
if (chd->cachehunk == hunknum)
return CHDERR_NONE;
chd->cachehunk = ~0;
/* otherwise, read the data */
err = hunk_read_into_memory(chd, hunknum, chd->cache);
if (err != CHDERR_NONE)
return err;
/* mark the hunk successfully cached in */
chd->cachehunk = hunknum;
return CHDERR_NONE;
}
/*-------------------------------------------------
hunk_read_into_memory - read a hunk into
memory at the given location
-------------------------------------------------*/
static chd_error hunk_read_into_memory(chd_file *chd, UINT32 hunknum, UINT8 *dest)
{
map_entry *entry = &chd->map[hunknum];
chd_error err;
UINT32 bytes;
/* return an error if out of range */
if (hunknum >= chd->header.totalhunks)
return CHDERR_HUNK_OUT_OF_RANGE;
/* switch off the entry type */
switch (entry->flags & MAP_ENTRY_FLAG_TYPE_MASK)
{
/* compressed data */
case MAP_ENTRY_TYPE_COMPRESSED:
/* read it into the decompression buffer */
core_fseek(chd->file, entry->offset, SEEK_SET);
bytes = core_fread(chd->file, chd->compressed, entry->length);
if (bytes != entry->length)
return CHDERR_READ_ERROR;
/* now decompress using the codec */
err = CHDERR_NONE;
if (chd->codecintf->decompress != NULL)
err = (*chd->codecintf->decompress)(chd, entry->length, dest);
if (err != CHDERR_NONE)
return err;
break;
/* uncompressed data */
case MAP_ENTRY_TYPE_UNCOMPRESSED:
core_fseek(chd->file, entry->offset, SEEK_SET);
bytes = core_fread(chd->file, dest, chd->header.hunkbytes);
if (bytes != chd->header.hunkbytes)
return CHDERR_READ_ERROR;
break;
/* mini-compressed data */
case MAP_ENTRY_TYPE_MINI:
put_bigendian_uint64(&dest[0], entry->offset);
for (bytes = 8; bytes < chd->header.hunkbytes; bytes++)
dest[bytes] = dest[bytes - 8];
break;
/* self-referenced data */
case MAP_ENTRY_TYPE_SELF_HUNK:
if (chd->cachehunk == entry->offset && dest == chd->cache)
break;
return hunk_read_into_memory(chd, entry->offset, dest);
/* parent-referenced data */
case MAP_ENTRY_TYPE_PARENT_HUNK:
err = hunk_read_into_memory(chd->parent, entry->offset, dest);
if (err != CHDERR_NONE)
return err;
break;
}
return CHDERR_NONE;
}
/***************************************************************************
INTERNAL MAP ACCESS
***************************************************************************/
/*-------------------------------------------------
map_write_initial - write an initial map to
a new CHD file
-------------------------------------------------*/
/*-------------------------------------------------
map_read - read the initial sector map
-------------------------------------------------*/
static chd_error map_read(chd_file *chd)
{
UINT32 entrysize = (chd->header.version < 3) ? OLD_MAP_ENTRY_SIZE : MAP_ENTRY_SIZE;
UINT8 raw_map_entries[MAP_STACK_ENTRIES * MAP_ENTRY_SIZE];
UINT64 fileoffset, maxoffset = 0;
UINT8 cookie[MAP_ENTRY_SIZE];
UINT32 count;
chd_error err;
int i;
/* first allocate memory */
chd->map = (map_entry *)malloc(sizeof(chd->map[0]) * chd->header.totalhunks);
if (!chd->map)
return CHDERR_OUT_OF_MEMORY;
/* read the map entries in in chunks and extract to the map list */
fileoffset = chd->header.length;
for (i = 0; i < chd->header.totalhunks; i += MAP_STACK_ENTRIES)
{
/* compute how many entries this time */
int entries = chd->header.totalhunks - i, j;
if (entries > MAP_STACK_ENTRIES)
entries = MAP_STACK_ENTRIES;
/* read that many */
core_fseek(chd->file, fileoffset, SEEK_SET);
count = core_fread(chd->file, raw_map_entries, entries * entrysize);
if (count != entries * entrysize)
{
err = CHDERR_READ_ERROR;
goto cleanup;
}
fileoffset += entries * entrysize;
/* process that many */
if (entrysize == MAP_ENTRY_SIZE)
{
for (j = 0; j < entries; j++)
map_extract(&raw_map_entries[j * MAP_ENTRY_SIZE], &chd->map[i + j]);
}
else
{
for (j = 0; j < entries; j++)
map_extract_old(&raw_map_entries[j * OLD_MAP_ENTRY_SIZE], &chd->map[i + j], chd->header.hunkbytes);
}
/* track the maximum offset */
for (j = 0; j < entries; j++)
if ((chd->map[i + j].flags & MAP_ENTRY_FLAG_TYPE_MASK) == MAP_ENTRY_TYPE_COMPRESSED ||
(chd->map[i + j].flags & MAP_ENTRY_FLAG_TYPE_MASK) == MAP_ENTRY_TYPE_UNCOMPRESSED)
maxoffset = MAX(maxoffset, chd->map[i + j].offset + chd->map[i + j].length);
}
/* verify the cookie */
core_fseek(chd->file, fileoffset, SEEK_SET);
count = core_fread(chd->file, &cookie, entrysize);
if (count != entrysize || memcmp(&cookie, END_OF_LIST_COOKIE, entrysize))
{
err = CHDERR_INVALID_FILE;
goto cleanup;
}
/* verify the length */
if (maxoffset > core_fsize(chd->file))
{
err = CHDERR_INVALID_FILE;
goto cleanup;
}
return CHDERR_NONE;
cleanup:
if (chd->map)
free(chd->map);
chd->map = NULL;
return err;
}
/***************************************************************************
INTERNAL CRC MAP ACCESS
***************************************************************************/
/*-------------------------------------------------
crcmap_init - initialize the CRC map
-------------------------------------------------*/
static void crcmap_init(chd_file *chd, int prepopulate)
{
int i;
/* if we already have one, bail */
if (chd->crcmap != NULL)
return;
/* reset all pointers */
chd->crcmap = NULL;
chd->crcfree = NULL;
chd->crctable = NULL;
/* allocate a list; one for each hunk */
chd->crcmap = (crcmap_entry *)malloc(chd->header.totalhunks * sizeof(chd->crcmap[0]));
if (chd->crcmap == NULL)
return;
/* allocate a CRC map table */
chd->crctable = (crcmap_entry **)malloc(CRCMAP_HASH_SIZE * sizeof(chd->crctable[0]));
if (chd->crctable == NULL)
{
free(chd->crcmap);
chd->crcmap = NULL;
return;
}
/* initialize the free list */
for (i = 0; i < chd->header.totalhunks; i++)
{
chd->crcmap[i].next = chd->crcfree;
chd->crcfree = &chd->crcmap[i];
}
/* initialize the table */
memset(chd->crctable, 0, CRCMAP_HASH_SIZE * sizeof(chd->crctable[0]));
/* if we're to prepopulate, go for it */
if (prepopulate)
for (i = 0; i < chd->header.totalhunks; i++)
crcmap_add_entry(chd, i);
}
/*-------------------------------------------------
crcmap_add_entry - log a CRC entry
-------------------------------------------------*/
static void crcmap_add_entry(chd_file *chd, UINT32 hunknum)
{
UINT32 hash = chd->map[hunknum].crc % CRCMAP_HASH_SIZE;
crcmap_entry *crcmap;
/* pull a free entry off the list */
crcmap = chd->crcfree;
chd->crcfree = crcmap->next;
/* set up the entry and link it into the hash table */
crcmap->hunknum = hunknum;
crcmap->next = chd->crctable[hash];
chd->crctable[hash] = crcmap;
}
/*-------------------------------------------------
crcmap_verify_hunk_match - verify that a
hunk really matches by doing a byte-for-byte
compare
-------------------------------------------------*/
static int crcmap_verify_hunk_match(chd_file *chd, UINT32 hunknum, const UINT8 *rawdata)
{
/* we have a potential match -- better be sure */
/* read the hunk from disk and compare byte-for-byte */
if (hunknum != chd->comparehunk)
{
chd->comparehunk = ~0;
if (hunk_read_into_memory(chd, hunknum, chd->compare) == CHDERR_NONE)
chd->comparehunk = hunknum;
}
return (hunknum == chd->comparehunk && memcmp(rawdata, chd->compare, chd->header.hunkbytes) == 0);
}
/*-------------------------------------------------
crcmap_find_hunk - find a hunk with a matching
CRC in the map
-------------------------------------------------*/
static UINT32 crcmap_find_hunk(chd_file *chd, UINT32 hunknum, UINT32 crc, const UINT8 *rawdata)
{
UINT32 lasthunk = (hunknum < chd->header.totalhunks) ? hunknum : chd->header.totalhunks;
int curhunk;
/* if we have a CRC map, use that */
if (chd->crctable)
{
crcmap_entry *curentry;
for (curentry = chd->crctable[crc % CRCMAP_HASH_SIZE]; curentry; curentry = curentry->next)
{
curhunk = curentry->hunknum;
if (chd->map[curhunk].crc == crc && !(chd->map[curhunk].flags & MAP_ENTRY_FLAG_NO_CRC) && crcmap_verify_hunk_match(chd, curhunk, rawdata))
return curhunk;
}
return NO_MATCH;
}
/* first see if the last match is a valid one */
if (chd->comparehunk < chd->header.totalhunks && chd->map[chd->comparehunk].crc == crc && !(chd->map[chd->comparehunk].flags & MAP_ENTRY_FLAG_NO_CRC) &&
memcmp(rawdata, chd->compare, chd->header.hunkbytes) == 0)
return chd->comparehunk;
/* scan through the CHD's hunk map looking for a match */
for (curhunk = 0; curhunk < lasthunk; curhunk++)
if (chd->map[curhunk].crc == crc && !(chd->map[curhunk].flags & MAP_ENTRY_FLAG_NO_CRC) && crcmap_verify_hunk_match(chd, curhunk, rawdata))
return curhunk;
return NO_MATCH;
}
/***************************************************************************
INTERNAL METADATA ACCESS
***************************************************************************/
/*-------------------------------------------------
metadata_find_entry - find a metadata entry
-------------------------------------------------*/
static chd_error metadata_find_entry(chd_file *chd, UINT32 metatag, UINT32 metaindex, metadata_entry *metaentry)
{
/* start at the beginning */
metaentry->offset = chd->header.metaoffset;
metaentry->prev = 0;
/* loop until we run out of options */
while (metaentry->offset != 0)
{
UINT8 raw_meta_header[METADATA_HEADER_SIZE];
UINT32 count;
/* read the raw header */
core_fseek(chd->file, metaentry->offset, SEEK_SET);
count = core_fread(chd->file, raw_meta_header, sizeof(raw_meta_header));
if (count != sizeof(raw_meta_header))
break;
/* extract the data */
metaentry->metatag = get_bigendian_uint32(&raw_meta_header[0]);
metaentry->length = get_bigendian_uint32(&raw_meta_header[4]);
metaentry->next = get_bigendian_uint64(&raw_meta_header[8]);
/* flags are encoded in the high byte of length */
metaentry->flags = metaentry->length >> 24;
metaentry->length &= 0x00ffffff;
/* if we got a match, proceed */
if (metatag == CHDMETATAG_WILDCARD || metaentry->metatag == metatag)
if (metaindex-- == 0)
return CHDERR_NONE;
/* no match, fetch the next link */
metaentry->prev = metaentry->offset;
metaentry->offset = metaentry->next;
}
/* if we get here, we didn't find it */
return CHDERR_METADATA_NOT_FOUND;
}
/*-------------------------------------------------
metadata_set_previous_next - set the 'next'
offset of a piece of metadata
-------------------------------------------------*/
/*-------------------------------------------------
metadata_set_length - set the length field of
a piece of metadata
-------------------------------------------------*/
/*-------------------------------------------------
metadata_compute_hash - compute the SHA1
hash of all metadata that requests it
-------------------------------------------------*/
static chd_error metadata_compute_hash(chd_file *chd, const UINT8 *rawsha1, UINT8 *finalsha1)
{
metadata_hash *hasharray = NULL;
chd_error err = CHDERR_NONE;
struct sha1_ctx sha1;
UINT32 hashindex = 0;
UINT32 hashalloc = 0;
UINT64 offset, next;
/* only works for V4 and above */
if (chd->header.version < 4)
{
memcpy(finalsha1, rawsha1, SHA1_DIGEST_SIZE);
return CHDERR_NONE;
}
/* loop until we run out of data */
for (offset = chd->header.metaoffset; offset != 0; offset = next)
{
UINT8 raw_meta_header[METADATA_HEADER_SIZE];
UINT32 count, metalength, metatag;
UINT8 *tempbuffer;
UINT8 metaflags;
/* read the raw header */
core_fseek(chd->file, offset, SEEK_SET);
count = core_fread(chd->file, raw_meta_header, sizeof(raw_meta_header));
if (count != sizeof(raw_meta_header))
break;
/* extract the data */
metatag = get_bigendian_uint32(&raw_meta_header[0]);
metalength = get_bigendian_uint32(&raw_meta_header[4]);
next = get_bigendian_uint64(&raw_meta_header[8]);
/* flags are encoded in the high byte of length */
metaflags = metalength >> 24;
metalength &= 0x00ffffff;
/* if not checksumming, continue */
if (!(metaflags & CHD_MDFLAGS_CHECKSUM))
continue;
/* allocate memory */
tempbuffer = (UINT8 *)malloc(metalength);
if (tempbuffer == NULL)
{
err = CHDERR_OUT_OF_MEMORY;
goto cleanup;
}
/* seek and read the metadata */
core_fseek(chd->file, offset + METADATA_HEADER_SIZE, SEEK_SET);
count = core_fread(chd->file, tempbuffer, metalength);
if (count != metalength)
{
free(tempbuffer);
err = CHDERR_READ_ERROR;
goto cleanup;
}
/* compute this entry's hash */
sha1_init(&sha1);
sha1_update(&sha1, metalength, tempbuffer);
sha1_final(&sha1);
free(tempbuffer);
/* expand the hasharray if necessary */
if (hashindex >= hashalloc)
{
hashalloc += 256;
hasharray = (metadata_hash *)realloc(hasharray, hashalloc * sizeof(hasharray[0]));
if (hasharray == NULL)
{
err = CHDERR_OUT_OF_MEMORY;
goto cleanup;
}
}
/* fill in the entry */
put_bigendian_uint32(hasharray[hashindex].tag, metatag);
sha1_digest(&sha1, SHA1_DIGEST_SIZE, hasharray[hashindex].sha1);
hashindex++;
}
/* sort the array */
qsort(hasharray, hashindex, sizeof(hasharray[0]), metadata_hash_compare);
/* compute the SHA1 of the raw plus the various metadata */
sha1_init(&sha1);
sha1_update(&sha1, CHD_SHA1_BYTES, rawsha1);
sha1_update(&sha1, hashindex * sizeof(hasharray[0]), (const UINT8 *)hasharray);
sha1_final(&sha1);
sha1_digest(&sha1, SHA1_DIGEST_SIZE, finalsha1);
cleanup:
if (hasharray != NULL)
free(hasharray);
return err;
}
/*-------------------------------------------------
metadata_hash_compare - compare two hash
entries
-------------------------------------------------*/
static int metadata_hash_compare(const void *elem1, const void *elem2)
{
return memcmp(elem1, elem2, sizeof(metadata_hash));
}
/***************************************************************************
ZLIB COMPRESSION CODEC
***************************************************************************/
/*-------------------------------------------------
zlib_codec_init - initialize the ZLIB codec
-------------------------------------------------*/
static chd_error zlib_codec_init(chd_file *chd)
{
zlib_codec_data *data;
chd_error err;
int zerr;
/* allocate memory for the 2 stream buffers */
data = (zlib_codec_data *)malloc(sizeof(*data));
if (data == NULL)
return CHDERR_OUT_OF_MEMORY;
/* clear the buffers */
memset(data, 0, sizeof(*data));
/* init the inflater first */
data->inflater.next_in = (Bytef *)data; /* bogus, but that's ok */
data->inflater.avail_in = 0;
data->inflater.zalloc = zlib_fast_alloc;
data->inflater.zfree = zlib_fast_free;
data->inflater.opaque = data;
zerr = inflateInit2(&data->inflater, -MAX_WBITS);
/* if that worked, initialize the deflater */
if (zerr == Z_OK)
{
data->deflater.next_in = (Bytef *)data; /* bogus, but that's ok */
data->deflater.avail_in = 0;
data->deflater.zalloc = zlib_fast_alloc;
data->deflater.zfree = zlib_fast_free;
data->deflater.opaque = data;
zerr = deflateInit2(&data->deflater, Z_BEST_COMPRESSION, Z_DEFLATED, -MAX_WBITS, 8, Z_DEFAULT_STRATEGY);
}
/* convert errors */
if (zerr == Z_MEM_ERROR)
err = CHDERR_OUT_OF_MEMORY;
else if (zerr != Z_OK)
err = CHDERR_CODEC_ERROR;
else
err = CHDERR_NONE;
/* handle an error */
if (err == CHDERR_NONE)
chd->codecdata = data;
else
free(data);
return err;
}
/*-------------------------------------------------
zlib_codec_free - free data for the ZLIB
codec
-------------------------------------------------*/
static void zlib_codec_free(chd_file *chd)
{
zlib_codec_data *data = (zlib_codec_data *)chd->codecdata;
/* deinit the streams */
if (data != NULL)
{
int i;
inflateEnd(&data->inflater);
deflateEnd(&data->deflater);
/* free our fast memory */
for (i = 0; i < MAX_ZLIB_ALLOCS; i++)
if (data->allocptr[i])
free(data->allocptr[i]);
free(data);
}
}
/*-------------------------------------------------
zlib_codec_compress - compress data using the
ZLIB codec
-------------------------------------------------*/
static chd_error zlib_codec_compress(chd_file *chd, const void *src, UINT32 *length)
{
zlib_codec_data *data = (zlib_codec_data *)chd->codecdata;
int zerr;
/* reset the decompressor */
data->deflater.next_in = (Bytef *)src;
data->deflater.avail_in = chd->header.hunkbytes;
data->deflater.total_in = 0;
data->deflater.next_out = chd->compressed;
data->deflater.avail_out = chd->header.hunkbytes;
data->deflater.total_out = 0;
zerr = deflateReset(&data->deflater);
if (zerr != Z_OK)
return CHDERR_COMPRESSION_ERROR;
/* do it */
zerr = deflate(&data->deflater, Z_FINISH);
/* if we ended up with more data than we started with, return an error */
if (zerr != Z_STREAM_END || data->deflater.total_out >= chd->header.hunkbytes)
return CHDERR_COMPRESSION_ERROR;
/* otherwise, fill in the length and return success */
*length = data->deflater.total_out;
return CHDERR_NONE;
}
/*-------------------------------------------------
zlib_codec_decompress - decomrpess data using
the ZLIB codec
-------------------------------------------------*/
static chd_error zlib_codec_decompress(chd_file *chd, UINT32 srclength, void *dest)
{
zlib_codec_data *data = (zlib_codec_data *)chd->codecdata;
int zerr;
/* reset the decompressor */
data->inflater.next_in = chd->compressed;
data->inflater.avail_in = srclength;
data->inflater.total_in = 0;
data->inflater.next_out = (Bytef *)dest;
data->inflater.avail_out = chd->header.hunkbytes;
data->inflater.total_out = 0;
zerr = inflateReset(&data->inflater);
if (zerr != Z_OK)
return CHDERR_DECOMPRESSION_ERROR;
/* do it */
zerr = inflate(&data->inflater, Z_FINISH);
if (data->inflater.total_out != chd->header.hunkbytes)
return CHDERR_DECOMPRESSION_ERROR;
return CHDERR_NONE;
}
/*-------------------------------------------------
zlib_fast_alloc - fast malloc for ZLIB, which
allocates and frees memory frequently
-------------------------------------------------*/
static voidpf zlib_fast_alloc(voidpf opaque, uInt items, uInt size)
{
zlib_codec_data *data = (zlib_codec_data *)opaque;
UINT32 *ptr;
int i;
/* compute the size, rounding to the nearest 1k */
size = (size * items + 0x3ff) & ~0x3ff;
/* reuse a hunk if we can */
for (i = 0; i < MAX_ZLIB_ALLOCS; i++)
{
ptr = data->allocptr[i];
if (ptr && size == *ptr)
{
/* set the low bit of the size so we don't match next time */
*ptr |= 1;
return ptr + 1;
}
}
/* alloc a new one */
ptr = (UINT32 *)malloc(size + sizeof(UINT32));
if (!ptr)
return NULL;
/* put it into the list */
for (i = 0; i < MAX_ZLIB_ALLOCS; i++)
if (!data->allocptr[i])
{
data->allocptr[i] = ptr;
break;
}
/* set the low bit of the size so we don't match next time */
*ptr = size | 1;
return ptr + 1;
}
/*-------------------------------------------------
zlib_fast_free - fast free for ZLIB, which
allocates and frees memory frequently
-------------------------------------------------*/
static void zlib_fast_free(voidpf opaque, voidpf address)
{
zlib_codec_data *data = (zlib_codec_data *)opaque;
UINT32 *ptr = (UINT32 *)address - 1;
int i;
/* find the hunk */
for (i = 0; i < MAX_ZLIB_ALLOCS; i++)
if (ptr == data->allocptr[i])
{
/* clear the low bit of the size to allow matches */
*ptr &= ~1;
return;
}
}
/***************************************************************************
AV COMPRESSION CODEC
***************************************************************************/
/*-------------------------------------------------
av_raw_data_size - compute the raw data size
-------------------------------------------------*/
INLINE UINT32 av_raw_data_size(const UINT8 *data)
{
int size = 0;
/* make sure we have a correct header */
if (data[0] == 'c' && data[1] == 'h' && data[2] == 'a' && data[3] == 'v')
{
/* add in header size plus metadata length */
size = 12 + data[4];
/* add in channels * samples */
size += 2 * data[5] * ((data[6] << 8) + data[7]);
/* add in 2 * width * height */
size += 2 * ((data[8] << 8) + data[9]) * (((data[10] << 8) + data[11]) & 0x7fff);
}
return size;
}
/*-------------------------------------------------
av_codec_init - initialize the A/V codec
-------------------------------------------------*/
/*-------------------------------------------------
av_codec_free - free data for the A/V
codec
-------------------------------------------------*/