zip.c

嵌入式环境下的GUI

/*
 * ZIP support routines for PhysicsFS.
 *
 * Please see the file LICENSE in the source's root directory.
 *
 *  This file written by Ryan C. Gordon, with some peeking at "unzip.c"
 *   by Gilles Vollant.
 */

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

#if (defined PHYSFS_SUPPORTS_ZIP)

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifndef _WIN32_WCE
#include <errno.h>
#include <time.h>
#endif
#include "physfs.h"
#include "zlib.h"

#define __PHYSICSFS_INTERNAL__
#include "physfs_internal.h"

/*
 * A buffer of ZIP_READBUFSIZE is malloc() for each compressed file opened,
 *  and is free()'d when you close the file; compressed data is read into
 *  this buffer, and then is decompressed into the buffer passed to
 *  PHYSFS_read().
 *
 * Uncompressed entries in a zipfile do not allocate this buffer; they just
 *  read data directly into the buffer passed to PHYSFS_read().
 *
 * Depending on your speed and memory requirements, you should tweak this
 *  value.
 */
#define ZIP_READBUFSIZE   (16 * 1024)


/*
 * Entries are "unresolved" until they are first opened. At that time,
 *  local file headers parsed/validated, data offsets will be updated to look
 *  at the actual file data instead of the header, and symlinks will be
 *  followed and optimized. This means that we don't seek and read around the
 *  archive until forced to do so, and after the first time, we had to do
 *  less reading and parsing, which is very CD-ROM friendly.
 */
typedef enum
{
    ZIP_UNRESOLVED_FILE,
    ZIP_UNRESOLVED_SYMLINK,
    ZIP_RESOLVING,
    ZIP_RESOLVED,
    ZIP_BROKEN_FILE,
    ZIP_BROKEN_SYMLINK
} ZipResolveType;


/*
 * One ZIPentry is kept for each file in an open ZIP archive.
 */
typedef struct _ZIPentry
{
    char *name;                         /* Name of file in archive        */
    struct _ZIPentry *symlink;          /* NULL or file we symlink to     */
    ZipResolveType resolved;            /* Have we resolved file/symlink? */
    PHYSFS_uint32 offset;               /* offset of data in archive      */
    PHYSFS_uint16 version;              /* version made by                */
    PHYSFS_uint16 version_needed;       /* version needed to extract      */
    PHYSFS_uint16 compression_method;   /* compression method             */
    PHYSFS_uint32 crc;                  /* crc-32                         */
    PHYSFS_uint32 compressed_size;      /* compressed size                */
    PHYSFS_uint32 uncompressed_size;    /* uncompressed size              */
    PHYSFS_sint64 last_mod_time;        /* last file mod time             */
} ZIPentry;

/*
 * One ZIPinfo is kept for each open ZIP archive.
 */
typedef struct
{
    char *archiveName;        /* path to ZIP in platform-dependent notation. */
    PHYSFS_uint16 entryCount; /* Number of files in ZIP.                     */
    ZIPentry *entries;        /* info on all files in ZIP.                   */
} ZIPinfo;

/*
 * One ZIPfileinfo is kept for each open file in a ZIP archive.
 */
typedef struct
{
    ZIPentry *entry;                      /* Info on file.              */
    void *handle;                         /* physical file handle.      */
    PHYSFS_uint32 compressed_position;    /* offset in compressed data. */
    PHYSFS_uint32 uncompressed_position;  /* tell() position.           */
    PHYSFS_uint8 *buffer;                 /* decompression buffer.      */
    z_stream stream;                      /* zlib stream state.         */
} ZIPfileinfo;


/* Magic numbers... */
#define ZIP_LOCAL_FILE_SIG          0x04034b50
#define ZIP_CENTRAL_DIR_SIG         0x02014b50
#define ZIP_END_OF_CENTRAL_DIR_SIG  0x06054b50

/* compression methods... */
#define COMPMETH_NONE 0
/* ...and others... */


#define UNIX_FILETYPE_MASK    0170000
#define UNIX_FILETYPE_SYMLINK 0120000


static PHYSFS_sint64 ZIP_read(FileHandle *handle, void *buffer,
                              PHYSFS_uint32 objSize, PHYSFS_uint32 objCount);
static PHYSFS_sint64 ZIP_write(FileHandle *handle, const void *buffer,
                               PHYSFS_uint32 objSize, PHYSFS_uint32 objCount);
static int ZIP_eof(FileHandle *handle);
static PHYSFS_sint64 ZIP_tell(FileHandle *handle);
static int ZIP_seek(FileHandle *handle, PHYSFS_uint64 offset);
static PHYSFS_sint64 ZIP_fileLength(FileHandle *handle);
static int ZIP_fileClose(FileHandle *handle);
static int ZIP_isArchive(const char *filename, int forWriting);
static DirHandle *ZIP_openArchive(const char *name, int forWriting);
static LinkedStringList *ZIP_enumerateFiles(DirHandle *h,
                                            const char *dirname,
                                            int omitSymLinks);
static int ZIP_exists(DirHandle *h, const char *name);
static int ZIP_isDirectory(DirHandle *h, const char *name, int *fileExists);
static int ZIP_isSymLink(DirHandle *h, const char *name, int *fileExists);
static PHYSFS_sint64 ZIP_getLastModTime(DirHandle *h, const char *n, int *e);
static FileHandle *ZIP_openRead(DirHandle *h, const char *filename, int *e);
static FileHandle *ZIP_openWrite(DirHandle *h, const char *filename);
static FileHandle *ZIP_openAppend(DirHandle *h, const char *filename);
static void ZIP_dirClose(DirHandle *h);
static int zip_resolve(void *in, ZIPinfo *info, ZIPentry *entry);
static int ZIP_remove(DirHandle *h, const char *name);
static int ZIP_mkdir(DirHandle *h, const char *name);


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

static const FileFunctions __PHYSFS_FileFunctions_ZIP =
{
    ZIP_read,       /* read() method       */
    ZIP_write,      /* write() method      */
    ZIP_eof,        /* eof() method        */
    ZIP_tell,       /* tell() method       */
    ZIP_seek,       /* seek() method       */
    ZIP_fileLength, /* fileLength() method */
    ZIP_fileClose   /* fileClose() method  */
};


const DirFunctions __PHYSFS_DirFunctions_ZIP =
{
    &__PHYSFS_ArchiveInfo_ZIP,
    ZIP_isArchive,          /* isArchive() method      */
    ZIP_openArchive,        /* openArchive() method    */
    ZIP_enumerateFiles,     /* enumerateFiles() method */
    ZIP_exists,             /* exists() method         */
    ZIP_isDirectory,        /* isDirectory() method    */
    ZIP_isSymLink,          /* isSymLink() method      */
    ZIP_getLastModTime,     /* getLastModTime() method */
    ZIP_openRead,           /* openRead() method       */
    ZIP_openWrite,          /* openWrite() method      */
    ZIP_openAppend,         /* openAppend() method     */
    ZIP_remove,             /* remove() method         */
    ZIP_mkdir,              /* mkdir() method          */
    ZIP_dirClose            /* dirClose() method       */
};


static const char *zlib_error_string(int rc)
{
    switch (rc)
    {
        case Z_OK: return(NULL);  /* not an error. */
        case Z_STREAM_END: return(NULL); /* not an error. */
#ifndef _WIN32_WCE
        case Z_ERRNO: return(strerror(errno));
#endif
        case Z_NEED_DICT: return(ERR_ZLIB_NEED_DICT);
        case Z_DATA_ERROR: return(ERR_ZLIB_DATA_ERROR);
        case Z_MEM_ERROR: return(ERR_ZLIB_MEMORY_ERROR);
        case Z_BUF_ERROR: return(ERR_ZLIB_BUFFER_ERROR);
        case Z_VERSION_ERROR: return(ERR_ZLIB_VERSION_ERROR);
        default: return(ERR_ZLIB_UNKNOWN_ERROR);
    } /* switch */

    return(NULL);
} /* zlib_error_string */


/*
 * Wrap all zlib calls in this, so the physfs error state is set appropriately.
 */
static int zlib_err(int rc)
{
    const char *str = zlib_error_string(rc);
    if (str != NULL)
        __PHYSFS_setError(str);
    return(rc);
} /* zlib_err */


/*
 * 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 PHYSFS_sint64 ZIP_read(FileHandle *handle, void *buf,
                              PHYSFS_uint32 objSize, PHYSFS_uint32 objCount)
{
    ZIPfileinfo *finfo = (ZIPfileinfo *) (handle->opaque);
    ZIPentry *entry = finfo->entry;
    PHYSFS_sint64 retval = 0;
    PHYSFS_sint64 maxread = ((PHYSFS_sint64) objSize) * objCount;
    PHYSFS_sint64 avail = entry->uncompressed_size -
                          finfo->uncompressed_position;

    BAIL_IF_MACRO(maxread == 0, NULL, 0);    /* quick rejection. */

    if (avail < maxread)
    {
        maxread = avail - (avail % objSize);
        objCount = (PHYSFS_uint32) (maxread / objSize);
        BAIL_IF_MACRO(objCount == 0, ERR_PAST_EOF, 0);  /* quick rejection. */
        __PHYSFS_setError(ERR_PAST_EOF);   /* this is always true here. */
    } /* if */

    if (entry->compression_method == COMPMETH_NONE)
    {
        retval = __PHYSFS_platformRead(finfo->handle, buf, objSize, objCount);
    } /* if */

    else
    {
        finfo->stream.next_out = buf;
        finfo->stream.avail_out = objSize * objCount;

        while (retval < maxread)
        {
            PHYSFS_uint32 before = finfo->stream.total_out;
            int rc;

            if (finfo->stream.avail_in == 0)
            {
                PHYSFS_sint64 br;

                br = entry->compressed_size - finfo->compressed_position;
                if (br > 0)
                {
                    if (br > ZIP_READBUFSIZE)
                        br = ZIP_READBUFSIZE;

                    br = __PHYSFS_platformRead(finfo->handle,
                                               finfo->buffer,
                                               1, (PHYSFS_uint32) br);
                    if (br <= 0)
                        break;

                    finfo->compressed_position += (PHYSFS_uint32) br;
                    finfo->stream.next_in = finfo->buffer;
                    finfo->stream.avail_in = (PHYSFS_uint32) br;
                } /* if */
            } /* if */

            rc = zlib_err(inflate(&finfo->stream, Z_SYNC_FLUSH));
            retval += (finfo->stream.total_out - before);

            if (rc != Z_OK)
                break;
        } /* while */

        retval /= objSize;
    } /* else */

    if (retval > 0)
        finfo->uncompressed_position += (PHYSFS_uint32) (retval * objSize);

    return(retval);
} /* ZIP_read */


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


static int ZIP_eof(FileHandle *handle)
{
    ZIPfileinfo *finfo = ((ZIPfileinfo *) (handle->opaque));
    return(finfo->uncompressed_position >= finfo->entry->uncompressed_size);
} /* ZIP_eof */


static PHYSFS_sint64 ZIP_tell(FileHandle *handle)
{
    return(((ZIPfileinfo *) (handle->opaque))->uncompressed_position);
} /* ZIP_tell */


static int ZIP_seek(FileHandle *handle, PHYSFS_uint64 offset)
{
    ZIPfileinfo *finfo = (ZIPfileinfo *) (handle->opaque);
    ZIPentry *entry = finfo->entry;
    void *in = finfo->handle;

    BAIL_IF_MACRO(offset > entry->uncompressed_size, ERR_PAST_EOF, 0);

    if (entry->compression_method == COMPMETH_NONE)
    {
        PHYSFS_sint64 newpos = offset + entry->offset;
        BAIL_IF_MACRO(!__PHYSFS_platformSeek(in, newpos), NULL, 0);
        finfo->uncompressed_position = (PHYSFS_uint32) offset;
    } /* if */

    else
    {
        /*
         * If seeking backwards, we need to redecode the file
         *  from the start and throw away the compressed bits until we hit
         *  the offset we need. If seeking forward, we still need to
         *  decode, but we don't rewind first.
         */
        if (offset < finfo->uncompressed_position)
        {
            /* we do a copy so state is sane if inflateInit2() fails. */
            z_stream str;
            memset(&str, '\0', sizeof (z_stream));
            if (zlib_err(inflateInit2(&str, -MAX_WBITS)) != Z_OK)
                return(0);

            if (!__PHYSFS_platformSeek(in, entry->offset))
                return(0);

            inflateEnd(&finfo->stream);
            memcpy(&finfo->stream, &str, sizeof (z_stream));
            finfo->uncompressed_position = finfo->compressed_position = 0;
        } /* if */

        while (finfo->uncompressed_position != offset)
        {
            PHYSFS_uint8 buf[512];
            PHYSFS_uint32 maxread;

            maxread = (PHYSFS_uint32) (offset - finfo->uncompressed_position);
            if (maxread > sizeof (buf))
                maxread = sizeof (buf);

            if (ZIP_read(handle, buf, maxread, 1) != 1)
                return(0);
        } /* while */
    } /* else */

    return(1);
} /* ZIP_seek */


static PHYSFS_sint64 ZIP_fileLength(FileHandle *handle)
{
    ZIPfileinfo *finfo = (ZIPfileinfo *) (handle->opaque);
    return(finfo->entry->uncompressed_size);
} /* ZIP_fileLength */


static int ZIP_fileClose(FileHandle *handle)
{
    ZIPfileinfo *finfo = (ZIPfileinfo *) (handle->opaque);
    BAIL_IF_MACRO(!__PHYSFS_platformClose(finfo->handle), NULL, 0);

    if (finfo->entry->compression_method != COMPMETH_NONE)
        inflateEnd(&finfo->stream);

    if (finfo->buffer != NULL)
        free(finfo->buffer);

    free(finfo);
    free(handle);
    return(1);
} /* ZIP_fileClose */


static PHYSFS_sint64 zip_find_end_of_central_dir(void *in, PHYSFS_sint64 *len)
{
    PHYSFS_uint8 buf[256];
    PHYSFS_sint32 i = 0;
    PHYSFS_sint64 filelen;
    PHYSFS_sint64 filepos;
    PHYSFS_sint32 maxread;
    PHYSFS_sint32 totalread = 0;
    int found = 0;
    PHYSFS_uint32 extra = 0;

    filelen = __PHYSFS_platformFileLength(in);
    BAIL_IF_MACRO(filelen == -1, NULL, 0);
    BAIL_IF_MACRO(filelen > 0xFFFFFFFF, "ZIP bigger than 2 gigs?!", 0);

    /*
     * Jump to the end of the file and start reading backwards.
     *  The last thing in the file is the zipfile comment, which is variable
     *  length, and the field that specifies its size is before it in the
     *  file (argh!)...this means that we need to scan backwards until we
     *  hit the end-of-central-dir signature. We can then sanity check that
     *  the comment was as big as it should be to make sure we're in the
     *  right place. The comment length field is 16 bits, so we can stop
     *  searching for that signature after a little more than 64k at most,
     *  and call it a corrupted zipfile.
     */

    if (sizeof (buf) < filelen)
    {
        filepos = filelen - sizeof (buf);
        maxread = sizeof (buf);
    } /* if */
    else
    {
        filepos = 0;
        maxread = (PHYSFS_uint32) filelen;
    } /* else */

    while ((totalread < filelen) && (totalread < 65557))
    {
        BAIL_IF_MACRO(!__PHYSFS_platformSeek(in, filepos), NULL, -1);

        /* make sure we catch a signature between buffers. */
        if (totalread != 0)
        {
            if (__PHYSFS_platformRead(in, buf, maxread - 4, 1) != 1)
                return(-1);
            *((PHYSFS_uint32 *) (&buf[maxread - 4])) = extra;
            totalread += maxread - 4;
        } /* if */
        else
        {
            if (__PHYSFS_platformRead(in, buf, maxread, 1) != 1)
                return(-1);
            totalread += maxread;
        } /* else */

        extra = *((PHYSFS_uint32 *) (&buf[0]));

        for (i = maxread - 4; i > 0; i--)
        {
            if ((buf[i + 0] == 0x50) &&
                (buf[i + 1] == 0x4B) &&
                (buf[i + 2] == 0x05) &&
                (buf[i + 3] == 0x06) )
            {
                found = 1;  /* that's the signature! */
                break;  
            } /* if */
        } /* for */

        if (found)