archivers/mix.c
author Ryan C. Gordon <icculus@icculus.org>
Sun, 26 Sep 2004 00:25:04 +0000
changeset 648 5c993684b8f2
parent 631 17fdeeaf7b51
child 650 298b8bb26775
permissions -rw-r--r--
Cleaned up archiver interface to not deal with DirHandles anymore, which simplifies things, removes some responsibility and code duplication from the archivers, and trims some malloc pressure. Also ripped up the allocation hook code a little. We'll try to screw with memory locking later, since it makes everything ugly and complex. Oh well.

/*
 * MIX support routines for PhysicsFS.
 *
 * This driver handles old archives used in the famous games
 * Command&Conquer Tiberium Dawn and Command&Conquer Red Alert.
 *
 * Newer MIX files as they are used in C&C Tiberium Sun and C&C Red Alert 2
 * aren't supported yet. Keep your eyes open for future updates.
 *
 * A MIX file has three parts:
 *   (1) Header
 *        16bit integer  -> number of files stored in this MIX
 *        32bit integer  -> filesize
 *   (2) "Directory"
 *        32bit integer  -> hash of the filename
 *        32bit integer  -> starting offset in the MIX
 *        32bit integer  -> end offset in the MIX
 *   (3) Data (BODY)
 *        All data comes here
 *
 * NOTES:
 *  The offsets are relative to the body. So offset 0 is directly after
 *  the directory.
 *
 *  Filenames only exist as hashes. So enumerate_files() will only report all
 *  hashes. Searching a filename in hashes is extremly quick so I decided not
 *  to include any sorting routines after then opening of the archive.
 *
 *
 * I found the structure of MIX files here: 
 * http://www.geocities.com/SiliconValley/8682/cncmap1f.txt
 *
 *
 * Please see the file LICENSE in the source's root directory.
 *
 *  This file written by Sebastian Steinhauer <steini@steini-welt.de>
 */
 
#if HAVE_CONFIG_H
#  include <config.h>
#endif

#if (defined PHYSFS_SUPPORTS_MIX)

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "physfs.h"

#define __PHYSICSFS_INTERNAL__
#include "physfs_internal.h"

typedef struct
{
    PHYSFS_uint16 num_files;
    PHYSFS_uint32 filesize;
} MIXheader;

typedef struct
{
    PHYSFS_uint32 hash;
    PHYSFS_uint32 start_offset;
    PHYSFS_uint32 end_offset;
} MIXentry;

typedef struct
{
    char *filename; /* filename of the archive */
    MIXentry *entry; /* list of entries */
    MIXheader header; /* the header of the MIX file */
    PHYSFS_uint32 delta; /* size of header + entries */
} MIXinfo;

typedef struct
{
    PHYSFS_uint64 size; /* filesize */
    PHYSFS_uint64 cur_pos; /* position in this file */
    MIXentry *entry; /* pointer to the MIX entry */
    MIXinfo *info; /* pointer to our MIXinfo */
    void *handle; /* filehandle */
} MIXfileinfo;

static void MIX_dirClose(void *opaque);
static PHYSFS_sint64 MIX_read(FileHandle *handle, void *buffer,
                              PHYSFS_uint32 objSize, PHYSFS_uint32 objCount);
static PHYSFS_sint64 MIX_write(FileHandle *handle, const void *buffer,
                               PHYSFS_uint32 objSize, PHYSFS_uint32 objCount);
static int MIX_eof(FileHandle *handle);
static PHYSFS_sint64 MIX_tell(FileHandle *handle);
static int MIX_seek(FileHandle *handle, PHYSFS_uint64 offset);
static PHYSFS_sint64 MIX_fileLength(FileHandle *handle);
static int MIX_fileClose(FileHandle *handle);
static int MIX_isArchive(const char *filename, int forWriting);
static void *MIX_openArchive(const char *name, int forWriting);
static LinkedStringList *MIX_enumerateFiles(void *opaque,
                                            const char *dirname,
                                            int omitSymLinks);
static int MIX_exists(void *opaque, const char *name);
static int MIX_isDirectory(void *opaque, const char *name, int *fileExists);
static int MIX_isSymLink(void *opaque, const char *name, int *fileExists);
static PHYSFS_sint64 MIX_getLastModTime(void *opaque, const char *n, int *e);
static FileHandle *MIX_openRead(void *opaque, const char *name, int *exist);
static FileHandle *MIX_openWrite(void *opaque, const char *name);
static FileHandle *MIX_openAppend(void *opaque, const char *name);
static int MIX_remove(void *opaque, const char *name);
static int MIX_mkdir(void *opaque, const char *name);

const PHYSFS_ArchiveInfo __PHYSFS_ArchiveInfo_MIX =
{
    "MIX",
    "Westwood archive (Tiberian Dawn / Red Alert)",
    "Sebastian Steinhauer <steini@steini-welt.de>",
    "http://icculus.org/physfs/",
};


static const FileFunctions __PHYSFS_FileFunctions_MIX =
{
    MIX_read,       /* read() method       */
    MIX_write,      /* write() method      */
    MIX_eof,        /* eof() method        */
    MIX_tell,       /* tell() method       */
    MIX_seek,       /* seek() method       */
    MIX_fileLength, /* fileLength() method */
    MIX_fileClose   /* fileClose() method  */
};


const DirFunctions __PHYSFS_DirFunctions_MIX =
{
    &__PHYSFS_ArchiveInfo_MIX,
    MIX_isArchive,          /* isArchive() method      */
    MIX_openArchive,        /* openArchive() method    */
    MIX_enumerateFiles,     /* enumerateFiles() method */
    MIX_exists,             /* exists() method         */
    MIX_isDirectory,        /* isDirectory() method    */
    MIX_isSymLink,          /* isSymLink() method      */
    MIX_getLastModTime,     /* getLastModTime() method */
    MIX_openRead,           /* openRead() method       */
    MIX_openWrite,          /* openWrite() method      */
    MIX_openAppend,         /* openAppend() method     */
    MIX_remove,             /* remove() method         */
    MIX_mkdir,              /* mkdir() method          */
    MIX_dirClose            /* dirClose() method       */
};

static PHYSFS_uint32 MIX_hash(const char *name)
{
    PHYSFS_uint32 id = 0;
    PHYSFS_uint32 a = 0;
    PHYSFS_uint32 i = 0;
    PHYSFS_uint32 l;
    PHYSFS_uint32 j;
    
    l = strlen(name);
    while (i < l)
    {
        a = 0;
        for(j = 0; j < 4; j++)
        {
            a >>= 8;
            if (i < l)
            {
                a += (unsigned int) (name[i]) << 24;
                i++;
            } /* if */
        } /* for */

        id = (id << 1 | id >> 31) + a;
    } /* while */

    /* a bit debuggin :)
    /printf("Filename %s -> %X\n",name,id); */

    return(id);
} /* MIX_hash */


static void MIX_dirClose(void *opaque)
{
    MIXinfo *info = ((MIXinfo *) opaque);
    free(info->entry);
    free(info->filename);
} /* MIX_dirClose */


static PHYSFS_sint64 MIX_read(FileHandle *handle, void *buffer,
                              PHYSFS_uint32 objSize, PHYSFS_uint32 objCount)
{
    MIXfileinfo *finfo = (MIXfileinfo*)handle->opaque;
    MIXentry *entry = finfo->entry;
    PHYSFS_uint32 read;
    
    /* set position in the archive */
    __PHYSFS_platformSeek(finfo->handle,
                             finfo->info->delta +
                             entry->start_offset +
                             finfo->cur_pos);
    
    /* read n bytes */
    read = __PHYSFS_platformRead(finfo->handle, buffer, objSize, objCount);
    
    /* keep filepointer up to date */
    if (read)
        finfo->cur_pos += read * objSize;
    
    return(read);
} /* MIX_read */


static PHYSFS_sint64 MIX_write(FileHandle *handle, const void *buffer,
                               PHYSFS_uint32 objSize, PHYSFS_uint32 objCount)
{
    BAIL_MACRO(ERR_NOT_SUPPORTED, -1);
} /* MIX_write */


static int MIX_eof(FileHandle *handle)
{
    MIXfileinfo *fifo = (MIXfileinfo *) handle->opaque;
    return(fifo->cur_pos >= fifo->size);
} /* MIX_eof */


static PHYSFS_sint64 MIX_tell(FileHandle *handle)
{
    return(((MIXfileinfo *) (handle->opaque))->cur_pos);
} /* MIX_tell */


static int MIX_seek(FileHandle *handle, PHYSFS_uint64 offset)
{
    MIXfileinfo *h = (MIXfileinfo *) (handle->opaque);
    
    BAIL_IF_MACRO(offset < 0, ERR_INVALID_ARGUMENT, 0);
    BAIL_IF_MACRO(offset >= h->size, ERR_PAST_EOF, 0);
    h->cur_pos = offset;
    return(1);
} /* MIX_seek */


static PHYSFS_sint64 MIX_fileLength(FileHandle *handle)
{
    return (((MIXfileinfo *) (handle->opaque))->size);
} /* MIX_fileLength */


static int MIX_fileClose(FileHandle *handle)
{
    MIXfileinfo *finfo = (MIXfileinfo *) handle->opaque;
    __PHYSFS_platformClose(finfo->handle);
    free(finfo);
    free(handle);
    return(1);
} /* MIX_fileClose */


static int MIX_isArchive(const char *filename, int forWriting)
{
    /* TODO:
            write a simple detection routine for MIX files.
            Unfortunaly MIX files have no ID in the header.
    */
    return(1);
} /* MIX_isArchive */


/*
 * Read an unsigned 32-bit int and swap to native byte order.
 */
static int readui32(void *in, PHYSFS_uint32 *val)
{
    PHYSFS_uint32 v;
    BAIL_IF_MACRO(__PHYSFS_platformRead(in, &v, sizeof (v), 1) != 1, NULL, 0);
    *val = PHYSFS_swapULE32(v);
    return(1);
} /* readui32 */


/*
 * Read an unsigned 16-bit int and swap to native byte order.
 */
static int readui16(void *in, PHYSFS_uint16 *val)
{
    PHYSFS_uint16 v;
    BAIL_IF_MACRO(__PHYSFS_platformRead(in, &v, sizeof (v), 1) != 1, NULL, 0);
    *val = PHYSFS_swapULE16(v);
    return(1);
} /* readui16 */


static void *MIX_openArchive(const char *name, int forWriting)
{
    PHYSFS_uint32 i = 0;
    MIXinfo *info = NULL;
    void *handle = NULL;

    info = (MIXinfo *) malloc(sizeof (MIXinfo));
    BAIL_IF_MACRO(info == NULL, ERR_OUT_OF_MEMORY, 0);
    memset(info, '\0', sizeof (MIXinfo));

    info->filename = (char *) malloc(strlen(name) + 1);
    if (info->filename == NULL)
    {
        __PHYSFS_setError(ERR_OUT_OF_MEMORY);
        goto MIX_openArchive_failed;
    } /* if */
    
    /* store filename */
    strcpy(info->filename, name);
    
    /* open the file */
    handle = __PHYSFS_platformOpenRead(name);
    if (!handle)
        goto MIX_openArchive_failed;

    /* read the MIX header */
    if ( (!readui16(handle, &info->header.num_files)) ||
         (!readui32(handle, &info->header.filesize)) )
        goto MIX_openArchive_failed;

    info->delta = 6 + (info->header.num_files * 12);

    /* allocate space for the entries and read the entries */
    info->entry = malloc(sizeof (MIXentry) * info->header.num_files);
    if (info->entry == NULL)
    {
        __PHYSFS_setError(ERR_OUT_OF_MEMORY);
        goto MIX_openArchive_failed;
    } /* if */
    
    /* read the directory list */
    for (i = 0; i < header.num_files; i++)
    {
        if ( (!readui32(handle, &info->entry[i].hash)) ||
             (!readui32(handle, &info->entry[i].start_offset)) ||
             (!readui32(handle, &info->entry[i].end_offset)) )
            goto MIX_openArchive_failed;
    } /* for */

    __PHYSFS_platformClose(handle);

    return(info);

MIX_openArchive_failed:
    if (info != NULL)
    {
        if (info->filename != NULL)
            free(info->filename);
        if (info->entry != NULL)
            free(info->entry);
        free(info);
    } /* if */

    if (handle != NULL)
        __PHYSFS_platformClose(handle);

    return(NULL);
} /* MIX_openArchive */


static LinkedStringList *MIX_enumerateFiles(void *opaque,
                                            const char *dirname,
                                            int omitSymLinks)
{
    LinkedStringList *retval = NULL, *p = NULL;
    MIXinfo *info = (MIXinfo*) opaque;
    MIXentry *entry = info->entry;
    int i;
    char buffer[32];
    
    for (i = 0; i < info->header.num_files; i++, entry++)
    {
        sprintf(buffer, "%X", entry->hash);
        retval = __PHYSFS_addToLinkedStringList(retval, &p, buffer, -1);
    } /* for */

    return(retval);
} /* MIX_enumerateFiles */


static MIXentry *MIX_find_entry(MIXinfo *info, const char *name)
{
    MIXentry *entry = info->entry;
    PHYSFS_uint32 i, id;
    
    /* create hash */
    id = MIX_hash(name);
    
    /* look for this hash */
    for (i = 0; i < info->header.num_files; i++, entry++)
    {
        if (entry->hash == id)
            return(entry);
    } /* for */

    /* nothing found... :( */
    return(NULL);
} /* MIX_find_entry */


static int MIX_exists(void *opaque, const char *name)
{
    return(MIX_find_entry(((MIXinfo *) opaque), name) != NULL);
} /* MIX_exists */


static int MIX_isDirectory(void *opaque, const char *name, int *fileExists)
{
    *fileExists = MIX_exists(opaque, name);
    return(0);  /* never directories in a MIX */
} /* MIX_isDirectory */


static int MIX_isSymLink(void *opaque, const char *name, int *fileExists)
{
    *fileExists = MIX_exists(opaque, name);
    return(0);  /* never symlinks in a MIX. */
} /* MIX_isSymLink */


static PHYSFS_sint64 MIX_getLastModTime(void *opaque,
                                        const char *name,
                                        int *fileExists)
{
    BAIL_MACRO(ERR_NOT_SUPPORTED, 0);  /* !!! FIXME: return .MIX's modtime. */
} /* MIX_getLastModTime */


static FileHandle *MIX_openRead(void *opaque, const char *fnm, int *fileExists)
{
    FileHandle *retval;
    MIXinfo *info = ((MIXinfo*) opaque);
    MIXfileinfo *finfo;
    MIXentry *entry;
    
    /* try to find this file */
    entry = MIX_find_entry(info,fnm);
    BAIL_IF_MACRO(entry == NULL, ERR_NO_SUCH_FILE, NULL);
    
    /* allocate a MIX handle */
    finfo = (MIXfileinfo *) malloc(sizeof (MIXfileinfo));
    BAIL_IF_MACRO(finfo == NULL, ERR_OUT_OF_MEMORY, NULL);
    
    /* allocate a filehandle */
    retval = (FileHandle*) malloc(sizeof (FileHandle));
    if (!retval)
    {
        free(finfo);
        BAIL_MACRO(ERR_OUT_OF_MEMORY, NULL);
    } /* if */

    /* open the archive */
    finfo->handle = __PHYSFS_platformOpenRead(info->filename);
    if(!finfo->handle)
    {
        free(finfo);
        free(retval);
        return(NULL);
    };
    
    /* setup structures */
    finfo->cur_pos = 0;
    finfo->info = info;
    finfo->entry = entry;
    finfo->size = entry->end_offset - entry->start_offset;
    
    retval->opaque = (void *) finfo;
    retval->funcs = &__PHYSFS_FileFunctions_MIX;

    return(retval);
} /* MIX_openRead */


static FileHandle *MIX_openWrite(void *opaque, const char *name)
{
    BAIL_MACRO(ERR_NOT_SUPPORTED, NULL);
} /* MIX_openWrite */


static FileHandle *MIX_openAppend(void *opaque, const char *name)
{
    BAIL_MACRO(ERR_NOT_SUPPORTED, NULL);
} /* MIX_openAppend */


static int MIX_remove(void *opaque, const char *name)
{
    BAIL_MACRO(ERR_NOT_SUPPORTED, 0);
} /* MIX_remove */


static int MIX_mkdir(void *opaque, const char *name)
{
    BAIL_MACRO(ERR_NOT_SUPPORTED, 0);
} /* MIX_mkdir */

#endif  /* defined PHYSFS_SUPPORTS_MIX */

/* end of mix.c ... */