source/gamelib/packfile.c

/*
 * OpenBOR - http://www.chronocrash.com
 * -----------------------------------------------------------------------
 * All rights reserved, see LICENSE in OpenBOR root for details.
 *
 * Copyright (c) 2004 - 2014 OpenBOR Team
 */

/*
	Code to read files from packfiles.

	============= Format description (a bit cryptical) ================

	dword	4B434150 ("PACK")
	dword	version
	?????	filedata
	{
		dword	structsize
		dword	filestart
		dword	filesize
		bytes	name
	} rep
	dword	headerstart
*/
#include <assert.h>
#ifndef SPK_SUPPORTED

#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include "utils.h"
#include "borendian.h"
#include "stristr.h"
#include "packfile.h"
#include "filecache.h"
#include "soundmix.h"
#include "savedata.h"
#include "List.h"

#if WIN || LINUX
#include <dirent.h>
#endif

#if _POSIX_SOURCE || SYMBIAN
#define	stricmp	strcasecmp
#endif

#ifndef DC
#pragma pack (1)
#endif


/////////////////////////////////////////////////////////////////////////////
//
// Requirements for Compressed Packfiles.
//
#define	MAXPACKHANDLES	8
#define	PACKMAGIC		0x4B434150
#define	PACKVERSION		0x00000000
static const size_t USED_FLAG = (((size_t) 1) << ((sizeof(size_t) * 8) - 1));

/////////////////////////////////////////////////////////////////////////////
//
// This defines are only used for Cached code
// CACHEBLOCKSIZE*CACHEBLOCKS is the size of the ever-present file cache
// cacheblocks must be 255 or less!
//
#define CACHEBLOCKSIZE (32768)
#ifndef OPENDINGUX
#define CACHEBLOCKS    (96)
#else
#define CACHEBLOCKS    (8)
#endif

static int pak_initialized;
int printFileUsageStatistics = 0;

/////////////////////////////////////////////////////////////////////////////
//
// This variables are only used for Non-Cached code
//
// Actual file handles.
static int packhandle[MAXPACKHANDLES] = { -1, -1, -1, -1, -1, -1, -1, -1 };

// Own file pointers and sizes
static unsigned int packfilepointer[MAXPACKHANDLES];
static unsigned int packfilesize[MAXPACKHANDLES];
//char packfile[128] <- defined in sdl/sdlport.c... hmmm
List *filenamelist = NULL;

/////////////////////////////////////////////////////////////////////////////
//
// This variables are only used for with Caching code
//
static int pakfd;
static int paksize;
static int pak_vfdexists[MAXPACKHANDLES];
static int pak_vfdstart[MAXPACKHANDLES];
static int pak_vfdsize[MAXPACKHANDLES];
static int pak_vfdpos[MAXPACKHANDLES];
static int pak_vfdreadahead[MAXPACKHANDLES];
static int pak_headerstart;
static int pak_headersize;
static unsigned char *pak_cdheader;
static unsigned char *pak_header;

/////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////
//
// Pointers to the Real Functions
//
typedef int (*OpenPackfile)(const char *, const char *);
typedef int (*ReadPackfile)(int, void *, int);
typedef int (*SeekPackfile)(int, int, int);
typedef int (*ClosePackfile)(int);

int openPackfile(const char *, const char *);
int readPackfile(int, void *, int);
int seekPackfile(int, int, int);
int closePackfile(int);
int openPackfileCached(const char *, const char *);
int readPackfileCached(int, void *, int);
int seekPackfileCached(int, int, int);
int closePackfileCached(int);

static OpenPackfile pOpenPackfile;
static ReadPackfile pReadPackfile;
static SeekPackfile pSeekPackfile;
static ClosePackfile pClosePackfile;

/////////////////////////////////////////////////////////////////////////////
//
// Generic but useful functions
//

char tolowerOneChar(const char *c)
{
    static const char diff = 'a' - 'A';
    switch(*c)
    {
    case 'A':
    case 'B':
    case 'C':
    case 'D':
    case 'E':
    case 'F':
    case 'G':
    case 'H':
    case 'I':
    case 'J':
    case 'K':
    case 'L':
    case 'M':
    case 'N':
    case 'O':
    case 'P':
    case 'Q':
    case 'R':
    case 'S':
    case 'T':
    case 'U':
    case 'V':
    case 'W':
    case 'X':
    case 'Y':
    case 'Z':
        return *c + diff;
    case '\\':
        return '/';
    default:
        return *c;
    }
    return '\0'; //should never be reached
}

// file name lowercase in-place.
void fnlc(char *buf)
{
    char *copy = buf;
    while(copy && *copy)
    {
        *copy = tolowerOneChar(copy);
        copy++;
    }
}

// we only return 0 on success, and non 0 on failure, to speed it up
int myfilenamecmp(const char *a, size_t asize, const char *b, size_t bsize)
{
    char *ca;
    char *cb;

    if (a == b)
    {
        return 0;
    }
    if(asize != bsize)
    {
        return 1;
    }

    ca = (char *) a;
    cb = (char *) b;

    for (;;)
    {
        if (!*ca)
        {
            if (*cb)
            {
                return -1;
            }
            else
            {
                return 0;    // default exit on match
            }
        }
        if (!*cb)
        {
            return 1;
        }
        if (*ca == *cb)
        {
            goto cont;
        }
        if (tolowerOneChar(ca) != tolowerOneChar(cb))
        {
            return 1;
        }
cont:
        ca++;
        cb++;
    }
    return -2; // should never be reached
}

// Convert slashes (UNIX) to backslashes (DOS).
// Return a pointer to buffer with filename converted to DOS format.
static char *slashback(const char *sz)
{
    int i = 0;
    static char new[PACKFILE_PATH_MAX];
    while(sz[i] && i < PACKFILE_PATH_MAX - 1)
    {
        new[i] = sz[i];
        if(new[i] == '/')
        {
            new[i] = '\\';
        }
        ++i;
    }
    new[i] = 0;
    return new;
}

#ifndef WIN
// Convert backslashes (DOS) to forward slashes (everything else).
// Return a pointer to buffer with filename using forward slash as separator.
static char *slashfwd(const char *sz)
{
    int i = 0;
    static char new[PACKFILE_PATH_MAX];
    while(sz[i] && i < PACKFILE_PATH_MAX - 1)
    {
        new[i] = sz[i];
        if(new[i] == '\\')
        {
            new[i] = '/';
        }
        ++i;
    }
    new[i] = 0;
    return new;
}
#endif

#ifdef LINUX
char *casesearch(const char *dir, const char *filepath)
{
    DIR *d;
    struct dirent *entry;;
    char filename[PACKFILE_PATH_MAX] = {""}, *rest_of_path;
    static char fullpath[PACKFILE_PATH_MAX];
    int i = 0;
#ifdef VERBOSE
    printf("casesearch: %s, %s\n", dir, filepath);
#endif

    if ((d = opendir(dir)) == NULL)
    {
        return NULL;
    }

    // are we searching for a file or a directory?
    rest_of_path = strchr(filepath, '/');
    if (rest_of_path != NULL) // directory
    {
        if(rest_of_path - filepath <= 0)
        {
            return NULL;
        }
        strncat(filename, filepath, rest_of_path - filepath);
        rest_of_path++;
    }
    else
    {
        strcpy(filename, filepath);    // file
    }

    while ((entry = readdir(d)) != NULL)
    {
        if (stricmp(entry->d_name, filename) == 0)
        {
            i = 1;
            break;
        }
    }

    //if (entry != NULL && entry->d_name != NULL)
    if (entry != NULL)
    {
        snprintf(fullpath, sizeof(fullpath), "%s/%s", dir, entry->d_name);
    }

    if (closedir(d))
    {
        return NULL;
    }
    if (i == 0)
    {
        return NULL;
    }

    return rest_of_path == NULL ? fullpath : casesearch(fullpath, rest_of_path);
}

#endif

/////////////////////////////////////////////////////////////////////////////

int getFreeHandle(void)
{
    int h;
    for(h = 0; h < MAXPACKHANDLES && packhandle[h] > -1; h++); // Find free handle
    if(h >= MAXPACKHANDLES)
    {
        printf ("no free handles\n"); // since this condition shuts down openbor, we can savely give more info.
        return -1;			// No free handles
    }
    return h;
}


void packfile_mode(int mode)
{
    if(!mode)
    {
#ifdef DC
        fs_chdir("/cd");
#endif
        pOpenPackfile = openPackfile;
        pReadPackfile = readPackfile;
        pSeekPackfile = seekPackfile;
        pClosePackfile = closePackfile;
        return;
    }
    pOpenPackfile = openPackfileCached;
    pReadPackfile = readPackfileCached;
    pSeekPackfile = seekPackfileCached;
    pClosePackfile = closePackfileCached;
}


/////////////////////////////////////////////////////////////////////////////

#if WIN || LINUX
int isRawData()
{
    DIR *d;
    if ((d = opendir("data")) == NULL)
    {
        return 0;
    }
    closedir(d);
    return 1;
}
#endif

/////////////////////////////////////////////////////////////////////////////

int openpackfile(const char *filename, const char *packfilename)
{
#ifdef VERBOSE
    char *pointsto;

    if (pOpenPackfile == openPackfileCached)
    {
        pointsto = "oPackCached";
    }
    else if (pOpenPackfile == openPackfile)
    {
        pointsto = "openPackFile";
    }
    else
    {
        pointsto = "unknown destination";
    }
    printf ("openpackfile called: f: %s, p: %s, dest: %s\n", filename, packfilename, pointsto);
#endif
    return pOpenPackfile(filename, packfilename);
}

int openPackfile(const char *filename, const char *packfilename)
{
    int h, handle;
    unsigned int magic, version, headerstart, p;
    pnamestruct pn;
#ifdef LINUX
    char *fspath;
#endif

    h = getFreeHandle();
    if (h == -1)
    {
        return -1;
    }

#ifdef WIN
    // Convert slashes to backslashes
    filename = slashback(filename);
#else
    // Convert backslashes to slashes
    filename = slashfwd(filename);
#endif

    packfilepointer[h] = 0;
	int per = 666;
    // Separate file present?
    if((handle = open(filename, O_RDONLY | O_BINARY, per)) != -1)
    {
        if((packfilesize[h] = lseek(handle, 0, SEEK_END)) == -1)
        {
#ifdef VERBOSE
            printf ("err handles 1\n");
#endif
            close(handle);
            return -1;
        }
        if(lseek(handle, 0, SEEK_SET) == -1)
        {
#ifdef VERBOSE
            printf ("err handles 2\n");
#endif
            close(handle);
            return -1;
        }
        packhandle[h] = handle;
        return h;
    }

#ifdef LINUX
    // Try a case-insensitive search for a separate file.
    fspath = casesearch(".", filename);
    if (fspath != NULL)
    {
        if((handle = open(fspath, O_RDONLY | O_BINARY, per)) != -1)
        {
            if((packfilesize[h] = lseek(handle, 0, SEEK_END)) == -1)
            {
#ifdef VERBOSE
                printf ("err handles 3\n");
#endif
                close(handle);
                return -1;
            }
            if(lseek(handle, 0, SEEK_SET) == -1)
            {
#ifdef VERBOSE
                printf ("err handles 4\n");
#endif
                close(handle);
                return -1;
            }
            packhandle[h] = handle;
            return h;
        }
    }
#endif

#ifndef WIN
    // Convert slashes to backslashes
    filename = slashback(filename);
#endif

    // Try to open packfile
    if((handle = open(packfilename, O_RDONLY | O_BINARY, per)) == -1)
    {
#ifdef VERBOSE
        printf ("perm err\n");
#endif
        return -1;
    }


    // Read magic dword ("PACK" identifier)
    if(read(handle, &magic, 4) != 4 || magic != SwapLSB32(PACKMAGIC))
    {
#ifdef VERBOSE
        printf ("err magic\n");
#endif
        close(handle);
        return -1;
    }
    // Read version from packfile
    if(read(handle, &version, 4) != 4 || version != SwapLSB32(PACKVERSION))
    {
#ifdef VERBOSE
        printf ("err version\n");
#endif

        close(handle);
        return -1;
    }

    // Seek to position of headerstart indicator
    if(lseek(handle, -4, SEEK_END) == -1)
    {
#ifdef VERBOSE
        printf ("seek failed\n");
#endif
        close(handle);
        return -1;
    }
    // Read headerstart
    if(read(handle, &headerstart, 4) != 4)
    {
#ifdef VERBOSE
        printf ("err header\n");
#endif
        close(handle);
        return -1;
    }

    headerstart = SwapLSB32(headerstart);

    // Seek to headerstart
    if(lseek(handle, headerstart, SEEK_SET) == -1)
    {
#ifdef VERBOSE
        printf ("err headerstart 1\n");
#endif
        close(handle);
        return -1;
    }

    p = headerstart;

    // Search for filename
    while(read(handle, &pn, sizeof(pn)) > 12)
    {
        pn.filesize = SwapLSB32(pn.filesize);
        pn.filestart = SwapLSB32(pn.filestart);
        pn.pns_len = SwapLSB32(pn.pns_len);

        if(stricmp(filename, pn.namebuf) == 0)
        {
            packhandle[h] = handle;
            packfilesize[h] = pn.filesize;
            lseek(handle, pn.filestart, SEEK_SET);
            return h;
        }
        p += pn.pns_len;
        if(lseek(handle, p, SEEK_SET) == -1)
        {
#ifdef VERBOSE
            printf ("err seek handles\n");
#endif
            close(handle);
            return -1;
        }
    }
    // Filename not found
#ifdef VERBOSE
    printf ("err filename not found\n");
#endif
    close(handle);
    return -1;
}

void update_filecache_vfd(int vfd)
{
    if(pak_vfdexists[vfd])
    {
        filecache_setvfd(vfd, pak_vfdstart[vfd], (pak_vfdstart[vfd] + pak_vfdpos[vfd]) / CACHEBLOCKSIZE, (pak_vfdreadahead[vfd] + (CACHEBLOCKSIZE - 1)) / CACHEBLOCKSIZE);
    }
    else
    {
        filecache_setvfd(vfd, -1, -1, 0);
    }
}

void makefilenamecache(void)
{
    ptrdiff_t hpos;
    char target[PACKFILE_PATH_MAX];

    if(!filenamelist)
    {
        filenamelist = malloc(sizeof(List));
    }
    List_Init(filenamelist);

    // look for filename in the header

    hpos = 0;
    for(;;)
    {
        if((hpos + 12) >= pak_headersize)
        {
            return;
        }
        strncpy(target, (char *)pak_header + hpos + 12, PACKFILE_PATH_MAX - 1);
        fnlc(target);
        List_InsertAfter(filenamelist, (void *) hpos, target);
        hpos += readlsb32(pak_header + hpos);
    }
}

void freefilenamecache(void)
{
    Node *n;
    size_t count = 0;
    size_t total = 0;
    if(filenamelist)
    {
        if(printFileUsageStatistics)
        {
            printf("unused files in the pack:\n");
            List_GotoFirst(filenamelist);
            n = List_GetCurrentNode(filenamelist);
            while(n)
            {
                if(((size_t) n->value & USED_FLAG) != USED_FLAG)
                {
                    count++;
                    printf("%s\n", n->name);
                }
                if(List_GotoNext(filenamelist))
                {
                    n = List_GetCurrentNode(filenamelist);
                }
                else
                {
                    break;
                }
                total++;
            }
            printf("Summary: %d of %d files have been unused\n", (int) count, (int) total);
            printf("WARNING\n");
            printf("to be completely sure if a file is unused, you have to play the entire mod\n");
            printf("in every possible branch, including every possible player, and so forth.\n");
            printf("so only remove stuff from a foreign mod if you're completely sure that it is unused.\n");
        }
        List_Clear(filenamelist);
        free(filenamelist);
        filenamelist = NULL;
    }
}

int openreadaheadpackfile(const char *filename, const char *packfilename, int readaheadsize, int prebuffersize)
{
    size_t hpos;
    int vfd;
    size_t fnl;
    size_t al;
    char target[PACKFILE_PATH_MAX];
    Node *n;

    if(packfilename != packfile)
    {
        fnl = strlen(packfile);
        al = strlen(packfilename);
        if(myfilenamecmp(packfilename, al, packfile, fnl))
        {
            printf("tried to open from unknown pack file (%s)\n", packfilename);
            return -1;
        }
    }

    if(!filenamelist)
    {
        makefilenamecache();
    }

    strncpy(target, filename, PACKFILE_PATH_MAX - 1);
    fnlc(target);

    n = List_GetNodeByName(filenamelist, target);
    if (!n)
    {
        return -1;
    }

    hpos = (size_t) n->value & ~USED_FLAG;
    n->value = (void *) (((size_t) n->value) | USED_FLAG);

    // find a free vfd
    for(vfd = 0; vfd < MAXPACKHANDLES; vfd++) if(!pak_vfdexists[vfd])
        {
            break;
        }
    if(vfd >= MAXPACKHANDLES)
    {
        return -1;
    }

    pak_vfdstart[vfd] = readlsb32(pak_header + hpos + 4);
    pak_vfdsize[vfd] = readlsb32(pak_header + hpos + 8);

    pak_vfdpos[vfd] = 0;
    pak_vfdexists[vfd] = 1;
    pak_vfdreadahead[vfd] = readaheadsize;

    // notify filecache that we have a new vfd
    update_filecache_vfd(vfd);

    // if we want prebuffering, wait for it
    if(prebuffersize > 0)
    {
        filecache_wait_for_prebuffer(vfd, (prebuffersize + ((CACHEBLOCKSIZE) - 1)) / CACHEBLOCKSIZE);
    }
    return vfd;
}

int openPackfileCached(const char *filename, const char *packfilename)
{
    return openreadaheadpackfile(filename, packfilename, 0, 0);
}

/////////////////////////////////////////////////////////////////////////////

int readpackfile(int handle, void *buf, int len)
{
    return pReadPackfile(handle, buf, len);
}

int readPackfile(int handle, void *buf, int len)
{
    int realhandle;
    if(handle < 0 || handle >= MAXPACKHANDLES)
    {
        return -1;
    }
    if(len < 0)
    {
        return -1;
    }
    if(len == 0)
    {
        return 0;
    }
    realhandle = packhandle[handle];
    if(realhandle == -1)
    {
        return -1;
    }
    if(len + packfilepointer[handle] > packfilesize[handle])
    {
        len = packfilesize[handle] - packfilepointer[handle];
    }
    if((len = read(realhandle, buf, len)) == -1)
    {
        return -1;
    }
    packfilepointer[handle] += len;
    return len;
}

int pak_isvalidhandle(int handle)
{
    if(handle < 0 || handle >= MAXPACKHANDLES)
    {
        return 0;
    }
    if(!pak_vfdexists[handle])
    {
        return 0;
    }
    return 1;
}

static int pak_rawread(int fd, unsigned char *dest, int len, int blocking)
{
    int end;
    int r;
    int total = 0;
    int pos = pak_vfdstart[fd] + pak_vfdpos[fd];

    if(pos < 0)
    {
        return 0;
    }
    if(pos >= paksize)
    {
        return 0;
    }
    if((pos + len) > paksize)
    {
        len = paksize - pos;
    }
    end = pos + len;

    update_filecache_vfd(fd);

    while(pos < end)
    {
        int b = pos / CACHEBLOCKSIZE;
        int startthisblock = pos % CACHEBLOCKSIZE;
        int sizethisblock = CACHEBLOCKSIZE - startthisblock;
        if(sizethisblock > (end - pos))
        {
            sizethisblock = (end - pos);
        }
        r = filecache_readpakblock(dest, b, startthisblock, sizethisblock, blocking);
        if(r >= 0)
        {
            total += r;
            pak_vfdpos[fd] += r;
            update_filecache_vfd(fd);
        }
        if(r < sizethisblock)
        {
            break;
        }

        dest += sizethisblock;
        pos += sizethisblock;
    }
    return total;
}

int readpackfileblocking(int fd, void *buf, int len, int blocking)
{
    int n;
    if(!pak_isvalidhandle(fd))
    {
        return -1;
    }
    if(pak_vfdpos[fd] < 0)
    {
        return 0;
    }
    if(pak_vfdpos[fd] > pak_vfdsize[fd])
    {
        pak_vfdpos[fd] = pak_vfdsize[fd];
    }
    if((len + pak_vfdpos[fd]) > pak_vfdsize[fd])
    {
        len = pak_vfdsize[fd] - pak_vfdpos[fd];
    }
    if(len < 1)
    {
        return 0;
    }
    update_filecache_vfd(fd);
    n = pak_rawread(fd, buf, len, blocking);
    if(n < 0)
    {
        n = 0;
    }
    if(pak_vfdpos[fd] > pak_vfdsize[fd])
    {
        pak_vfdpos[fd] = pak_vfdsize[fd];
    }
    update_filecache_vfd(fd);
    return n;
}

int readpackfile_noblock(int handle, void *buf, int len)
{
    return readpackfileblocking(handle, buf, len, 0);
}

int readPackfileCached(int handle, void *buf, int len)
{
    return readpackfileblocking(handle, buf, len, 1);
}

/////////////////////////////////////////////////////////////////////////////

int closepackfile(int handle)
{
#ifdef VERBOSE
    char *pointsto;

    if (pClosePackfile == closePackfileCached)
    {
        pointsto = "closePackCached";
    }
    else if (pClosePackfile == closePackfile)
    {
        pointsto = "closePackFile";
    }
    else
    {
        pointsto = "unknown destination";
    }
    printf ("closepackfile called: h: %d, dest: %s\n", handle, pointsto);
#endif
    return pClosePackfile(handle);
}

int closePackfile(int handle)
{
#ifdef VERBOSE
    printf ("closePackfile called: h: %d\n", handle);
#endif

    if(handle < 0 || handle >= MAXPACKHANDLES)
    {
#ifdef VERBOSE
        printf("handle too small/big\n");
#endif
        return -1;
    }
    if(packhandle[handle] == -1)
    {
#ifdef VERBOSE
        printf("packhandle -1\n");
#endif
        return -1;
    }
    close(packhandle[handle]);
    packhandle[handle] = -1;
    return 0;
}

int closePackfileCached(int handle)
{
    if(!pak_isvalidhandle(handle))
    {
        return -1;
    }
    pak_vfdexists[handle] = 0;
    update_filecache_vfd(handle);
    return 0;
}


/////////////////////////////////////////////////////////////////////////////

int seekpackfile(int handle, int offset, int whence)
{
    return pSeekPackfile(handle, offset, whence);
}

int seekPackfile(int handle, int offset, int whence)
{
    int realhandle;
    int desiredoffs;

    if(handle < 0 || handle >= MAXPACKHANDLES)
    {
        return -1;
    }
    realhandle = packhandle[handle];
    if(realhandle == -1)
    {
        return -1;
    }

    switch(whence)
    {
    case SEEK_SET:
        desiredoffs = offset;
        if(desiredoffs > packfilesize[handle])
        {
            desiredoffs = packfilesize[handle];
        }
        else if(desiredoffs < 0)
        {
            desiredoffs = 0;
        }
        break;

    case SEEK_CUR:
        desiredoffs = packfilepointer[handle] + offset;
        if(desiredoffs > packfilesize[handle])
        {
            desiredoffs = packfilesize[handle];
        }
        else if(desiredoffs < 0)
        {
            desiredoffs = 0;
        }
        break;

    case SEEK_END:
        desiredoffs = packfilesize[handle] + offset;
        if(desiredoffs > packfilesize[handle])
        {
            desiredoffs = packfilesize[handle];
        }
        else if(desiredoffs < 0)
        {
            desiredoffs = 0;
        }
        break;

    default:
        return -1;
    }
    desiredoffs -= packfilepointer[handle];
    if((lseek(realhandle, desiredoffs, SEEK_CUR)) == -1)
    {
        return -1;
    }
    packfilepointer[handle] += desiredoffs;
    return packfilepointer[handle];
}

int seekPackfileCached(int handle, int offset, int whence)
{
    if(!pak_isvalidhandle(handle))
    {
        return -1;
    }
    switch(whence)
    {
    case 0:
        pak_vfdpos[handle]  = offset;
        break; // set
    case 1:
        pak_vfdpos[handle] += offset;
        break; // cur
    case 2:
        pak_vfdpos[handle]  = pak_vfdsize[handle] + offset;
        break; // end
    default:
        return -1;
    }
    // original code had this check too, so do it here
    if(pak_vfdpos[handle] < 0)
    {
        pak_vfdpos[handle] = 0;
    }
    if(pak_vfdpos[handle] > pak_vfdsize[handle])
    {
        pak_vfdpos[handle] = pak_vfdsize[handle];
    }
    update_filecache_vfd(handle);
    return pak_vfdpos[handle];
}

/////////////////////////////////////////////////////////////////////////////
//
// returns number of sectors read successfully
//
static int pak_getsectors(void *dest, int lba, int n)
{
#ifdef DC
    if((lba + n) > ((paksize + 0x7FF) / 0x800))
    {
        n = ((paksize + 0x7FF) / 0x800) - lba;
    }
    if(pakfd >= 0)
    {
        lseek(pakfd, lba << 11, SEEK_SET);
        read(pakfd, dest, n << 11);
    }
    else
    {
        gdrom_readsectors(dest, (-pakfd) + lba, n);
        while(gdrom_poll());
    }
#else
    lseek(pakfd, lba << 11, SEEK_SET);
    read(pakfd, dest, n << 11);
#endif
    return n;
}

#ifdef DC
/////////////////////////////////////////////////////////////////////////////
//
// returns 0 if they match
//
static int fncmp(const char *filename, const char *isofilename, int isolen)
{
    for(; isolen > 0; isolen--)
    {
        char cf = *filename++;
        char ci = *isofilename++;
        if(!cf)
        {
            // allowed to omit the version on filename
            if(ci == ';' || ci == 0)
            {
                return 0;
            }
            return 1;
        }
        if(cf >= 'A' && cf <= 'Z')
        {
            cf += 'a' - 'A';
        }
        if(ci >= 'A' && ci <= 'Z')
        {
            ci += 'a' - 'A';
        }
        if(cf != ci)
        {
            return 1;
        }
    }
    // allowed to omit the version on isofilename too O_o
    if(*filename == ';' || *filename == 0)
    {
        return 0;
    }
    return 1;
}

/////////////////////////////////////////////////////////////////////////////
//
// input: starting lba of the track
// returns starting lba of the file, or 0 on failure
//
int find_iso_file(const char *filename, int lba, int *bytes)
{
    int dirlen;
    unsigned char sector[4096];
    int secofs;

    // read the root descriptor
    gdrom_readsectors(sector, lba + 16, 1);
    while(gdrom_poll());
    // get the root directory extent and size
    lba    = 150 + readmsb32(sector + 156 + 6);
    dirlen =       readmsb32(sector + 156 + 14);

    // at this point, lba is the lba of the root dir
    secofs = 4096;
    while(dirlen > 0)
    {
        if(secofs >= 4096 || ((secofs + sector[secofs]) > 4096))
        {
            memcpy(sector, sector + 2048, 2048);
            gdrom_readsectors(sector + 2048, lba, 1);
            while(gdrom_poll());
            lba++;
            secofs -= 2048;
        }
        if(!sector[secofs])
        {
            break;
        }
        if(!fncmp(filename, sector + secofs + 33, sector[secofs + 32]))
        {
            lba = 150 + readmsb32(sector + secofs + 6);
            if(bytes)
            {
                *bytes = readmsb32(sector + secofs + 14);
            }
            return lba;
        }
        secofs += sector[secofs];
        dirlen -= sector[secofs];
    }
    // didn't find the file
    return 0;
}
#endif

/////////////////////////////////////////////////////////////////////////////

void pak_term()
{
    int i;
    if(!pak_initialized)
    {
        return;
    }
    if(pak_cdheader != NULL)
    {
        free(pak_cdheader);
        pak_cdheader = NULL;
    }
    filecache_term();
    close(pakfd);
    pakfd           = -1;
    paksize         = -1;
    pak_headerstart = -1;
    pak_headersize  = -1;
    for(i = 0; i < MAXPACKHANDLES; i++)
    {
        pak_vfdexists[i]    = -1;
        pak_vfdstart[i]     = -1;
        pak_vfdsize[i]      = -1;
        pak_vfdpos[i]       = -1;
        pak_vfdreadahead[i] = -1;
    }
    pak_initialized = 0;
}

/////////////////////////////////////////////////////////////////////////////

int pak_init()
{
    int i;
    unsigned char *sectors;
    unsigned int magic, version;

    if(pak_initialized)
    {
        printf("pak_init already initialized!");
        return 0;
    }

#if WIN || LINUX
    if(isRawData())
    {
        pak_initialized = 1;
        return 0;
    }
#endif

    pOpenPackfile = openPackfileCached;
    pReadPackfile = readPackfileCached;
    pSeekPackfile = seekPackfileCached;
    pClosePackfile = closePackfileCached;

#if DC
    if(cd_lba)
    {
        paksize = 0;
        pakfd = find_iso_file(packfile, cd_lba, &paksize);
        if(pakfd <= 0)
        {
            printf("unable to find pak file on cd\n");
            return 0;
        }
        pakfd = -pakfd;
    }
    else
    {
#endif
	int per = 666;
        pakfd = open(packfile, O_RDONLY | O_BINARY, per);

        if(pakfd < 0)
        {
            printf("error opening %s (%d) - could not get a valid device descriptor.\n%s\n", packfile, pakfd, strerror(errno));
            return 0;
        }

        paksize = lseek(pakfd, 0, SEEK_END);

#ifdef DC
    }
#endif

    // Is it a valid Packfile
    close(pakfd);
    pakfd = open(packfile, O_RDONLY | O_BINARY, per);

    // Read magic dword ("PACK")
    if(read(pakfd, &magic, 4) != 4 || magic != SwapLSB32(PACKMAGIC))
    {
        close(pakfd);
        return -1;
    }
    // Read version from packfile
    if(read(pakfd, &version, 4) != 4 || version != SwapLSB32(PACKVERSION))
    {
        close(pakfd);
        return -1;
    }

    sectors = malloc(4096);
    if(!sectors)
    {
        printf("sector malloc failed\n");
        return 0;
    }
    {
        int getptrfrom = paksize - 4;
        if(pak_getsectors(sectors, getptrfrom >> 11, 2) < 1)
        {
            printf("unable to read pak header pointer\n");
            return 0;
        }
        pak_headerstart = readlsb32(sectors + (getptrfrom & 0x7FF));
    }
    free(sectors);
    if(pak_headerstart >= paksize || pak_headerstart < 0)
    {
        printf("invalid pak header pointer\n");
        return 0;
    }
    pak_headersize = paksize - pak_headerstart;
    {
        // let's cache it on CD sector boundaries
        int pak_cdheaderstart = pak_headerstart & (~0x7FF);
        int pak_cdheadersize = ((paksize - pak_cdheaderstart) + 0x7FF) & (~0x7FF);
        if(pak_cdheadersize > 524288)
        {
            // Original value was 262144, which has been doubled.
            // I can not find a reason why it was orginally set to
            // this size.  Hence, I have doubled it.  This could
            // pose a problem on optical media, but that is yet to be
            // determined.
            printf("Warning: pak header is too large: %d / 524288\n", pak_cdheadersize);
            //return 0;
        }
        pak_cdheader = malloc(pak_cdheadersize);
        if(!pak_cdheader)
        {
            printf("pak_cdheader malloc failed\n");
            return 0;
        }
        if(pak_getsectors(pak_cdheader, pak_cdheaderstart >> 11, pak_cdheadersize >> 11) != (pak_cdheadersize >> 11))
        {
            printf("unable to read pak header\n");
            return 0;
        }
        // ok, header is now cached
        pak_header = pak_cdheader + (pak_headerstart & 0x7FF);
    }
    // header does not include the last 4-byte stuff
    if(pak_headersize >= 4)
    {
        pak_headersize -= 4;
        // add a trailing null o/~
        pak_header[pak_headersize] = 0;
    }
    //printf("pak cached header (%d bytes)\n", pak_headersize);
    // initialize vfd table
    for(i = 0; i < MAXPACKHANDLES; i++)
    {
        pak_vfdexists[i] = 0;
    }
    // finally, initialize the filecache
    filecache_init(pakfd, (paksize + 0x7FF) / 0x800, CACHEBLOCKSIZE, CACHEBLOCKS, MAXPACKHANDLES);
    pak_initialized = 1;
    return (CACHEBLOCKSIZE * CACHEBLOCKS + 64);
}

/////////////////////////////////////////////////////////////////////////////

int packfileeof(int handle)
{
    if(!pak_isvalidhandle(handle))
    {
        return -1;
    }
    return (pak_vfdpos[handle] >= pak_vfdsize[handle]);
}

/////////////////////////////////////////////////////////////////////////////

int packfile_supported(const char *filename)
{
    if(stricmp(filename, "menu.pak") != 0)
    {
        if (stristr(filename, ".pak"))
        {
            return 1;
        }
    }
    return 0;
}

/////////////////////////////////////////////////////////////////////////////

void packfile_get_titlename(char In[MAX_FILENAME_LEN], char Out[MAX_FILENAME_LEN])
{
    int i, x = 0, y = 0;
    for(i = 0; i < (int)strlen(In); i++)
    {
        if((In[i] == '/') || (In[i] == '\\'))
        {
            x = i;
        }
    }
    for(i = 0; i < (int)strlen(In); i++)
    {
        if(i > x)
        {
            Out[y] = In[i];
            y++;
        }
    }
}

void packfile_music_read(fileliststruct *filelist, int dListTotal)
{
    pnamestruct pn;
    FILE *fd;
    int len, i;
    unsigned int off;
    char pack[4], *p = NULL;
    for(i = 0; i < dListTotal; i++)
    {
        getBasePath(packfile, filelist[i].filename, 1);
        if(stristr(packfile, ".pak"))
        {
            memset(filelist[i].bgmTracks, 0, MAX_TRACKS * sizeof(unsigned int));
            filelist[i].nTracks = 0;
            fd = fopen(packfile, "rb");
            if(fd == NULL)
            {
                continue;
            }
            if(!fread(pack, 4, 1, fd))
            {
                goto closepak;
            }
            if(fseek(fd, -4, SEEK_END) < 0)
            {
                goto closepak;
            }
            if(!fread(&off, 4, 1, fd))
            {
                goto closepak;
            }
            if(fseek(fd, off, SEEK_SET) < 0)
            {
                goto closepak;
            }
            while((len = fread(&pn, 1, sizeof(pn), fd)) > 12)
            {
                p = strrchr(pn.namebuf, '.');
                if((p && (!stricmp(p, ".bor") || !stricmp(p, ".ogg"))) || (stristr(pn.namebuf, "music")))
                {
                    if(!stristr(pn.namebuf, ".bor") && !stristr(pn.namebuf, ".ogg"))
                    {
                        goto nextpak;
                    }
                    if(filelist[i].nTracks < MAX_TRACKS)
                    {
                        packfile_get_titlename(pn.namebuf, filelist[i].bgmFileName[filelist[i].nTracks]);
                        filelist[i].bgmTracks[filelist[i].nTracks] = off;
                        filelist[i].nTracks++;
                    }
                }
nextpak:
                off += pn.pns_len;
                if(fseek(fd, off, SEEK_SET) < 0)
                {
                    goto closepak;
                }
            }
closepak:
            fclose(fd);
        }
    }
}

/////////////////////////////////////////////////////////////////////////////

int packfile_music_play(struct fileliststruct *filelist, FILE *bgmFile, int bgmLoop, int curPos, int scrPos)
{
    pnamestruct pn;
    int len;
    getBasePath(packfile, filelist[curPos + scrPos].filename, 1);
    if (bgmFile)
    {
        fclose(bgmFile);
        bgmFile = NULL;
    }
    bgmFile = fopen(packfile, "rb");
    if (!bgmFile)
    {
        return 0;
    }
    if (stristr(packfile, ".pak"))
    {
        if(fseek(bgmFile, filelist[curPos + scrPos].bgmTracks[filelist[curPos + scrPos].bgmTrack], SEEK_SET) < 0)
        {
            return 0;
        }
        if((len = fread(&pn, 1, sizeof(pn), bgmFile)) > 12)
        {
            sound_open_music(pn.namebuf, packfile, savedata.musicvol, bgmLoop, 0);
        }
    }
    return 1;
}

#endif