grp.c

嵌入式环境下的GUI

/*
 * GRP support routines for PhysicsFS.
 *
 * This driver handles BUILD engine archives ("groupfiles"). This format
 *  (but not this driver) was put together by Ken Silverman.
 *
 * The format is simple enough. In Ken's words:
 *
 *    What's the .GRP file format?
 *
 *     The ".grp" file format is just a collection of a lot of files stored
 *     into 1 big one. I tried to make the format as simple as possible: The
 *     first 12 bytes contains my name, "KenSilverman". The next 4 bytes is
 *     the number of files that were compacted into the group file. Then for
 *     each file, there is a 16 byte structure, where the first 12 bytes are
 *     the filename, and the last 4 bytes are the file's size. The rest of
 *     the group file is just the raw data packed one after the other in the
 *     same order as the list of files.
 *
 * (That info is from http://www.advsys.net/ken/build.htm ...)
 *
 * Please see the file LICENSE in the source's root directory.
 *
 *  This file written by Ryan C. Gordon.
 */

#if HAVE_CONFIG_H
#  include <config.h>
#endif

#if (defined PHYSFS_SUPPORTS_GRP)

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

#define __PHYSICSFS_INTERNAL__
#include "physfs_internal.h"

typedef struct
{
    char name[13];
    PHYSFS_uint32 startPos;
    PHYSFS_uint32 size;
} GRPentry;

typedef struct
{
    char *filename;
    PHYSFS_sint64 last_mod_time;
    PHYSFS_uint32 entryCount;
    GRPentry *entries;
} GRPinfo;

typedef struct
{
    void *handle;
    GRPentry *entry;
    PHYSFS_uint32 curPos;
} GRPfileinfo;


static void GRP_dirClose(DirHandle *h);
static PHYSFS_sint64 GRP_read(FileHandle *handle, void *buffer,
                              PHYSFS_uint32 objSize, PHYSFS_uint32 objCount);
static PHYSFS_sint64 GRP_write(FileHandle *handle, const void *buffer,
                               PHYSFS_uint32 objSize, PHYSFS_uint32 objCount);
static int GRP_eof(FileHandle *handle);
static PHYSFS_sint64 GRP_tell(FileHandle *handle);
static int GRP_seek(FileHandle *handle, PHYSFS_uint64 offset);
static PHYSFS_sint64 GRP_fileLength(FileHandle *handle);
static int GRP_fileClose(FileHandle *handle);
static int GRP_isArchive(const char *filename, int forWriting);
static DirHandle *GRP_openArchive(const char *name, int forWriting);
static LinkedStringList *GRP_enumerateFiles(DirHandle *h,
                                            const char *dirname,
                                            int omitSymLinks);
static int GRP_exists(DirHandle *h, const char *name);
static int GRP_isDirectory(DirHandle *h, const char *name, int *fileExists);
static int GRP_isSymLink(DirHandle *h, const char *name, int *fileExists);
static PHYSFS_sint64 GRP_getLastModTime(DirHandle *h, const char *n, int *e);
static FileHandle *GRP_openRead(DirHandle *h, const char *name, int *exist);
static FileHandle *GRP_openWrite(DirHandle *h, const char *name);
static FileHandle *GRP_openAppend(DirHandle *h, const char *name);
static int GRP_remove(DirHandle *h, const char *name);
static int GRP_mkdir(DirHandle *h, const char *name);

const PHYSFS_ArchiveInfo __PHYSFS_ArchiveInfo_GRP =
{
    "GRP",
    GRP_ARCHIVE_DESCRIPTION,
    "Ryan C. Gordon <[e-mail]>",
    "http://icculus.org/physfs/",
};


static const FileFunctions __PHYSFS_FileFunctions_GRP =
{
    GRP_read,       /* read() method       */
    GRP_write,      /* write() method      */
    GRP_eof,        /* eof() method        */
    GRP_tell,       /* tell() method       */
    GRP_seek,       /* seek() method       */
    GRP_fileLength, /* fileLength() method */
    GRP_fileClose   /* fileClose() method  */
};


const DirFunctions __PHYSFS_DirFunctions_GRP =
{
    &__PHYSFS_ArchiveInfo_GRP,
    GRP_isArchive,          /* isArchive() method      */
    GRP_openArchive,        /* openArchive() method    */
    GRP_enumerateFiles,     /* enumerateFiles() method */
    GRP_exists,             /* exists() method         */
    GRP_isDirectory,        /* isDirectory() method    */
    GRP_isSymLink,          /* isSymLink() method      */
    GRP_getLastModTime,     /* getLastModTime() method */
    GRP_openRead,           /* openRead() method       */
    GRP_openWrite,          /* openWrite() method      */
    GRP_openAppend,         /* openAppend() method     */
    GRP_remove,             /* remove() method         */
    GRP_mkdir,              /* mkdir() method          */
    GRP_dirClose            /* dirClose() method       */
};



static void GRP_dirClose(DirHandle *h)
{
    GRPinfo *info = ((GRPinfo *) h->opaque);
    free(info->filename);
    free(info->entries);
    free(info);
    free(h);
} /* GRP_dirClose */


static PHYSFS_sint64 GRP_read(FileHandle *handle, void *buffer,
                              PHYSFS_uint32 objSize, PHYSFS_uint32 objCount)
{
    GRPfileinfo *finfo = (GRPfileinfo *) (handle->opaque);
    GRPentry *entry = finfo->entry;
    PHYSFS_uint32 bytesLeft = entry->size - finfo->curPos;
    PHYSFS_uint32 objsLeft = (bytesLeft / objSize);
    PHYSFS_sint64 rc;

    if (objsLeft < objCount)
        objCount = objsLeft;

    rc = __PHYSFS_platformRead(finfo->handle, buffer, objSize, objCount);
    if (rc > 0)
        finfo->curPos += (PHYSFS_uint32) (rc * objSize);

    return(rc);
} /* GRP_read */


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


static int GRP_eof(FileHandle *handle)
{
    GRPfileinfo *finfo = (GRPfileinfo *) (handle->opaque);
    GRPentry *entry = finfo->entry;
    return(finfo->curPos >= entry->size);
} /* GRP_eof */


static PHYSFS_sint64 GRP_tell(FileHandle *handle)
{
    return(((GRPfileinfo *) (handle->opaque))->curPos);
} /* GRP_tell */


static int GRP_seek(FileHandle *handle, PHYSFS_uint64 offset)
{
    GRPfileinfo *finfo = (GRPfileinfo *) (handle->opaque);
    GRPentry *entry = finfo->entry;
    int rc;

    BAIL_IF_MACRO(offset < 0, ERR_INVALID_ARGUMENT, 0);
    BAIL_IF_MACRO(offset >= entry->size, ERR_PAST_EOF, 0);
    rc = __PHYSFS_platformSeek(finfo->handle, entry->startPos + offset);
    if (rc)
        finfo->curPos = (PHYSFS_uint32) offset;

    return(rc);
} /* GRP_seek */


static PHYSFS_sint64 GRP_fileLength(FileHandle *handle)
{
    GRPfileinfo *finfo = ((GRPfileinfo *) handle->opaque);
    return((PHYSFS_sint64) finfo->entry->size);
} /* GRP_fileLength */


static int GRP_fileClose(FileHandle *handle)
{
    GRPfileinfo *finfo = ((GRPfileinfo *) handle->opaque);
    BAIL_IF_MACRO(!__PHYSFS_platformClose(finfo->handle), NULL, 0);
    free(finfo);
    free(handle);
    return(1);
} /* GRP_fileClose */


static int grp_open(const char *filename, int forWriting,
                    void **fh, PHYSFS_uint32 *count)
{
    PHYSFS_uint8 buf[12];

    *fh = NULL;
    BAIL_IF_MACRO(forWriting, ERR_ARC_IS_READ_ONLY, 0);

    *fh = __PHYSFS_platformOpenRead(filename);
    BAIL_IF_MACRO(*fh == NULL, NULL, 0);
    
    if (__PHYSFS_platformRead(*fh, buf, 12, 1) != 1)
        goto openGrp_failed;

    if (memcmp(buf, "KenSilverman", 12) != 0)
    {
        __PHYSFS_setError(ERR_UNSUPPORTED_ARCHIVE);
        goto openGrp_failed;
    } /* if */

    if (__PHYSFS_platformRead(*fh, count, sizeof (PHYSFS_uint32), 1) != 1)
        goto openGrp_failed;

    *count = PHYSFS_swapULE32(*count);

    return(1);

openGrp_failed:
    if (*fh != NULL)
        __PHYSFS_platformClose(*fh);

    *count = -1;
    *fh = NULL;
    return(0);
} /* grp_open */


static int GRP_isArchive(const char *filename, int forWriting)
{
    void *fh;
    PHYSFS_uint32 fileCount;
    int retval = grp_open(filename, forWriting, &fh, &fileCount);

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

    return(retval);
} /* GRP_isArchive */


static int grp_entry_cmp(void *_a, PHYSFS_uint32 one, PHYSFS_uint32 two)
{
    GRPentry *a = (GRPentry *) _a;
    return(strcmp(a[one].name, a[two].name));