ref: 3542f5b20dd7342b642f8434ec3c5799df21e8bb
dir: /Engine/src/filesystem.c/
//
// filesystem.c
// Duke3D
//
// Created by fabien sanglard on 12-12-19.
// Copyright (c) 2012 fabien sanglard. All rights reserved.
//
#include "filesystem.h"
#include "platform.h"
#include "cache.h"
#include "fixedPoint_math.h"
#include "../../Game/src/global.h"
char game_dir[512];
//The multiplayer module in game.dll needs direct access to the crc32 (sic).
int32_t groupefil_crc32[MAXGROUPFILES];
// A typical GRP index entry:
// - 12 bytes for filename
// - 4 for filesize
typedef uint8_t grpIndexEntry_t[16];
typedef struct grpArchive_s{
int32_t numFiles ;//Number of files in the archive.
grpIndexEntry_t *gfilelist ;//Array containing the filenames.
int32_t *fileOffsets ;//Array containing the file offsets.
int32_t *filesizes ;//Array containing the file offsets.
int fileDescriptor ;//The fd used for open,read operations.
uint32_t crc32 ;//Hash to recognize GRP: Duke Shareware, Duke plutonimum etc...
} grpArchive_t;
//All GRP opened are in this structure
typedef struct grpSet_s{
grpArchive_t archives[MAXGROUPFILES];
int32_t num;
} grpSet_t;
// Marking it static gurantee not only invisility outside module
// but also that the content will be set to 0.
static grpSet_t grpSet;
uint8_t crcBuffer[ 1 << 20] ;
int32_t initgroupfile(const char *filename)
{
uint8_t buf[16] ;
int32_t i, j, k ;
grpArchive_t* archive ;
printf("Loading %s ...\n", filename);
if (grpSet.num == MAXGROUPFILES){
printf("Error: Unable to open an extra GRP archive <= No more slot available.\n");
return(-1);
}
archive = &grpSet.archives[grpSet.num];
//Init the slot
memset(archive, 0, sizeof(grpArchive_t));
//groupfil_memory[numgroupfiles] = NULL; // addresses of raw GRP files in memory
//groupefil_crc32[numgroupfiles] = 0;
archive->fileDescriptor = open(filename,O_BINARY|O_RDONLY,S_IREAD);
if (archive->fileDescriptor < 0){
printf("Error: Unable to open file %s.\n",filename);
getchar();
exit(0);
}
read(archive->fileDescriptor,buf,16);
//FCS : The ".grp" file format is just a collection of a lot of files stored into 1 big one.
//KS doc: 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. - ken
// Check the magic number (12 bytes header).
if ((buf[0] != 'K') || (buf[1] != 'e') || (buf[2] != 'n') ||
(buf[3] != 'S') || (buf[4] != 'i') || (buf[5] != 'l') ||
(buf[6] != 'v') || (buf[7] != 'e') || (buf[8] != 'r') ||
(buf[9] != 'm') || (buf[10] != 'a') || (buf[11] != 'n')){
printf("Error: File %s is not a GRP archive.\n",filename);
return(-1);
}
// The next 4 bytes of the header feature the number of files in the GRP archive.
archive->numFiles = BUILDSWAP_INTEL32(*((int32_t *)&buf[12]));
archive->gfilelist = malloc(archive->numFiles * sizeof(grpIndexEntry_t));
archive->fileOffsets = malloc(archive->numFiles * sizeof(int32_t));
archive->filesizes = malloc(archive->numFiles * sizeof(int32_t));
// Load the full index 16 bytes per file (12bytes for name + 4 bytes for the size).
read(archive->fileDescriptor,archive->gfilelist, archive->numFiles * 16);
//Initialize all file offset and pointers.
j = 12 + 4 + archive->numFiles * sizeof(grpIndexEntry_t);
for(i=0;i<archive->numFiles;i++){
k = BUILDSWAP_INTEL32(*((int32_t *)&archive->gfilelist[i][12])); // get size
// Now that the filesize has been read, we can replace it with '0' and hence have a
// valid, null terminated character string that will be usable.
archive->gfilelist[i][12] = '\0';
archive->filesizes[i] = k;
archive->fileOffsets[i] = j; // absolute offset list of all files.
j += k;
}
//archive->fileOffsets[archive->numFiles-1] = j;
// Compute CRC32 of the whole grp and implicitely caches the GRP in memory through windows caching service.
// Rewind the fileDescriptor
lseek(archive->fileDescriptor, 0, SEEK_SET);
//i = 1000000;
//groupfil_memory[numgroupfiles] = malloc(i);
//Load the full GRP in RAM.
while((j=read(archive->fileDescriptor, crcBuffer, sizeof(crcBuffer)))){
archive->crc32 = crc32_update(crcBuffer,j,archive->crc32);
}
// The game layer seems to absolutely need to access an array int[4] groupefil_crc32
// so we need to store the crc32 in there too.
groupefil_crc32[grpSet.num] = archive->crc32;
//free(groupfil_memory[numgroupfiles]);
//groupfil_memory[numgroupfiles] = 0;
grpSet.num++;
return(grpSet.num-1);
}
void uninitgroupfile(void)
{
int i;
for( i=0 ; i < grpSet.num ;i++){
free(grpSet.archives[i].gfilelist);
free(grpSet.archives[i].fileOffsets);
free(grpSet.archives[i].filesizes);
memset(&grpSet.archives[i], 0, sizeof(grpArchive_t));
}
}
void crc32_table_gen(unsigned int* crc32_table) /* build CRC32 table */
{
unsigned int crc, poly;
int i, j;
poly = 0xEDB88320L;
for (i = 0; i < 256; i++)
{
crc = i;
for (j = 8; j > 0; j--)
{
if (crc & 1)
crc = (crc >> 1) ^ poly;
else
crc >>= 1;
}
crc32_table[i] = crc;
}
}
unsigned int crc32(uint8_t *buf, unsigned int length)
{
unsigned int initial_crc;
initial_crc = 0;
return(crc32_update(buf, length, initial_crc));
}
unsigned int crc32_update(uint8_t *buf, unsigned int length, unsigned int crc_to_update)
{
unsigned int crc32_table[256];
crc32_table_gen(crc32_table);
crc_to_update ^= 0xFFFFFFFF;
while (length--)
crc_to_update = crc32_table[(crc_to_update ^ *buf++) & 0xFF] ^ (crc_to_update >> 8);
return crc_to_update ^ 0xFFFFFFFF;
}
/*
* 16 12 5
* this is the CCITT CRC 16 polynomial X + X + X + 1.
* This is 0x1021 when x is 2, but the way the algorithm works
* we use 0x8408 (the reverse of the bit pattern). The high
* bit is always assumed to be set, thus we only use 16 bits to
* represent the 17 bit value.
*/
#define POLY 0x8408 /* 1021H bit reversed */
uint16_t crc16(uint8_t *data_p, uint16_t length)
{
uint8_t i;
unsigned int data;
unsigned int crc = 0xffff;
if (length == 0)
return (~crc);
do
{
for (i=0, data=(unsigned int)0xff & *data_p++;
i < 8;
i++, data >>= 1)
{
if ((crc & 0x0001) ^ (data & 0x0001))
crc = (crc >> 1) ^ POLY;
else crc >>= 1;
}
} while (--length);
crc = ~crc;
data = crc;
crc = (crc << 8) | (data >> 8 & 0xff);
return (crc);
}
// The engine can open files transparently on the filesystem or on the GRPsystem
enum fileType_e{ SYSTEM_FILE, GRP_FILE} ;
//An entry in the array tracking open files
typedef struct openFile_s{
enum fileType_e type ;
int fd ; //Either the fileDescriptor or the fileIndex in a GRP depending on the type.
int cursor ; //lseek cursor
int grpID ; //GRP id
int used ; //Marker 1=used
} openFile_t;
#define MAXOPENFILES 64
static openFile_t openFiles[MAXOPENFILES];
int32_t kopen4load(const char *filename, int openOnlyFromGRP){
int32_t i, k;
int32_t newhandle;
grpArchive_t* archive;
//Search a free slot
newhandle = MAXOPENFILES-1;
while (openFiles[newhandle].used && newhandle >= 0)
newhandle--;
if (newhandle < 0)
Error(EXIT_FAILURE, "Too Many files open!\n");
//Try to look in the filesystem first. In this case fd = filedescriptor.
if(!openOnlyFromGRP){
openFiles[newhandle].fd = open(filename,O_BINARY|O_RDONLY);
if (openFiles[newhandle].fd != -1){
openFiles[newhandle].type = SYSTEM_FILE;
openFiles[newhandle].cursor = 0;
openFiles[newhandle].used = 1;
return(newhandle);
}
}
//Try to look in the GRP archives. In this case fd = index of the file in the GRP.
for(k=grpSet.num-1;k>=0;k--)
{
archive = &grpSet.archives[k];
for(i=archive->numFiles-1;i>=0;i--){
if (!strncasecmp((char*)archive->gfilelist[i],filename,12)){
openFiles[newhandle].type = GRP_FILE;
openFiles[newhandle].used = 1;
openFiles[newhandle].cursor = 0;
openFiles[newhandle].fd = i;
openFiles[newhandle].grpID = k;
return(newhandle);
}
}
}
return(-1);
}
int32_t kread(int32_t handle, void *buffer, int32_t leng){
openFile_t * openFile ;
grpArchive_t * archive ;
openFile = &openFiles[handle];
if (!openFile->used){
printf("Invalide handle. Unrecoverable error.\n");
getchar();
exit(0);
}
//FILESYSTEM ? OS takes care of it !
if (openFile->type == SYSTEM_FILE){
return(read(openFile->fd,buffer,leng));
}
//File is actually in the GRP
archive = & grpSet.archives[openFile->grpID];
lseek(archive->fileDescriptor,
archive->fileOffsets[openFile->fd] + openFile->cursor,
SEEK_SET);
//Adjust leng so we cannot read more than filesystem-cursor location.
leng = min(leng,archive->filesizes[openFile->fd]-openFile->cursor);
leng = read(archive->fileDescriptor,buffer,leng);
openFile->cursor += leng;
return leng;
}
int kread16(int32_t handle, short *buffer){
if (kread(handle, buffer, 2) != 2)
return(0);
*buffer = BUILDSWAP_INTEL16(*buffer);
return(1);
}
int kread32(int32_t handle, int32_t *buffer){
if (kread(handle, buffer, 4) != 4)
return(0);
*buffer = BUILDSWAP_INTEL32(*buffer);
return(1);
}
int kread8(int32_t handle, uint8_t *buffer){
if (kread(handle, buffer, 1) != 1)
return(0);
return(1);
}
int32_t klseek(int32_t handle, int32_t offset, int whence){
grpArchive_t* archive;
if (!openFiles[handle].used){
printf("Invalide handle. Unrecoverable error.\n");
getchar();
exit(0);
}
// FILESYSTEM ? OS will take care of it.
if (openFiles[handle].type == SYSTEM_FILE){
return lseek(openFiles[handle].fd,offset,whence);
}
archive = & grpSet.archives [ openFiles[handle].grpID ];
switch(whence){
case SEEK_SET: openFiles[handle].cursor = offset; break;
case SEEK_END: openFiles[handle].cursor = archive->filesizes[openFiles[handle].fd]; break;
case SEEK_CUR: openFiles[handle].cursor += offset; break;
}
return(openFiles[handle].cursor);
}
#if defined(__APPLE__) || defined(__linux__)
int32_t filelength(int32_t fd){
struct stat stats;
fstat(fd, &stats);
return (int32_t )stats.st_size;
}
#endif
int32_t kfilelength(int32_t handle)
{
openFile_t* openFile = &openFiles[handle];
if (!openFile->used){
printf("Invalide handle. Unrecoverable error.\n");
getchar();
exit(0);
}
if (openFile->type == SYSTEM_FILE){
return(filelength(openFile->fd));
}
else{
grpArchive_t* archive = &grpSet.archives[ openFile->grpID ];
return archive->filesizes[openFile->fd];
}
}
void kclose(int32_t handle)
{
openFile_t* openFile = &openFiles[handle];
//This is a typical handle for a non existing file.
if (handle == -1)
return;
if (!openFile->used){
printf("Invalide handle. Unrecoverable error.\n");
getchar();
exit(0);
}
if (openFile->type == SYSTEM_FILE){
close(openFile->fd);
}
memset(openFile, 0, sizeof(openFile_t));
}
/* Internal LZW variables */
#define LZWSIZE 16384 /* Watch out for shorts! */
static uint8_t *lzwbuf1, *lzwbuf4, *lzwbuf5;
static uint8_t lzwbuflock[5];
static short *lzwbuf2, *lzwbuf3;
int32_t compress(uint8_t *lzwinbuf, int32_t uncompleng, uint8_t *lzwoutbuf)
{
int32_t i, addr, newaddr, addrcnt, zx, *longptr;
int32_t bytecnt1, bitcnt, numbits, oneupnumbits;
short *shortptr;
for(i=255;i>=0;i--) { lzwbuf1[i] = (uint8_t ) i; lzwbuf3[i] = (short) ((i+1)&255); }
clearbuf((void *) (lzwbuf2),256>>1,0xffffffff);
clearbuf((void *) (lzwoutbuf),((uncompleng+15)+3)>>2,0L);
addrcnt = 256; bytecnt1 = 0; bitcnt = (4<<3);
numbits = 8; oneupnumbits = (1<<8);
do
{
addr = lzwinbuf[bytecnt1];
do
{
bytecnt1++;
if (bytecnt1 == uncompleng) break;
if (lzwbuf2[addr] < 0) {lzwbuf2[addr] = (short) addrcnt; break;}
newaddr = lzwbuf2[addr];
while (lzwbuf1[newaddr] != lzwinbuf[bytecnt1])
{
zx = lzwbuf3[newaddr];
if (zx < 0) {lzwbuf3[newaddr] = (short) addrcnt; break;}
newaddr = zx;
}
if (lzwbuf3[newaddr] == addrcnt) break;
addr = newaddr;
} while (addr >= 0);
lzwbuf1[addrcnt] = lzwinbuf[bytecnt1];
lzwbuf2[addrcnt] = -1;
lzwbuf3[addrcnt] = -1;
longptr = (int32_t *)&lzwoutbuf[bitcnt>>3];
longptr[0] |= (addr<<(bitcnt&7));
bitcnt += numbits;
if ((addr&((oneupnumbits>>1)-1)) > ((addrcnt-1)&((oneupnumbits>>1)-1)))
bitcnt--;
addrcnt++;
if (addrcnt > oneupnumbits) { numbits++; oneupnumbits <<= 1; }
} while ((bytecnt1 < uncompleng) && (bitcnt < (uncompleng<<3)));
longptr = (int32_t *)&lzwoutbuf[bitcnt>>3];
longptr[0] |= (addr<<(bitcnt&7));
bitcnt += numbits;
if ((addr&((oneupnumbits>>1)-1)) > ((addrcnt-1)&((oneupnumbits>>1)-1)))
bitcnt--;
shortptr = (short *)lzwoutbuf;
shortptr[0] = (short)uncompleng;
if (((bitcnt+7)>>3) < uncompleng)
{
shortptr[1] = (short)addrcnt;
return((bitcnt+7)>>3);
}
shortptr[1] = (short)0;
for(i=0;i<uncompleng;i++) lzwoutbuf[i+4] = lzwinbuf[i];
return(uncompleng+4);
}
int32_t uncompress(uint8_t *lzwinbuf, int32_t compleng, uint8_t *lzwoutbuf)
{
int32_t strtot, currstr, numbits, oneupnumbits;
int32_t i, dat, leng, bitcnt, outbytecnt, *longptr;
short *shortptr;
shortptr = (short *)lzwinbuf;
strtot = (int32_t )shortptr[1];
if (strtot == 0)
{
copybuf((void *)((lzwinbuf)+4),(void *)((lzwoutbuf)),((compleng-4)+3)>>2);
return((int32_t )shortptr[0]); /* uncompleng */
}
for(i=255;i>=0;i--) { lzwbuf2[i] = (short) i; lzwbuf3[i] = (short) i; }
currstr = 256; bitcnt = (4<<3); outbytecnt = 0;
numbits = 8; oneupnumbits = (1<<8);
do
{
longptr = (int32_t *)&lzwinbuf[bitcnt>>3];
dat = ((longptr[0]>>(bitcnt&7)) & (oneupnumbits-1));
bitcnt += numbits;
if ((dat&((oneupnumbits>>1)-1)) > ((currstr-1)&((oneupnumbits>>1)-1)))
{ dat &= ((oneupnumbits>>1)-1); bitcnt--; }
lzwbuf3[currstr] = (short) dat;
for(leng=0;dat>=256;leng++,dat=lzwbuf3[dat])
lzwbuf1[leng] = (uint8_t ) lzwbuf2[dat];
lzwoutbuf[outbytecnt++] = (uint8_t ) dat;
for(i=leng-1;i>=0;i--) lzwoutbuf[outbytecnt++] = lzwbuf1[i];
lzwbuf2[currstr-1] = (short) dat; lzwbuf2[currstr] = (short) dat;
currstr++;
if (currstr > oneupnumbits) { numbits++; oneupnumbits <<= 1; }
} while (currstr < strtot);
return((int32_t )shortptr[0]); /* uncompleng */
}
void kdfread(void *buffer, size_t dasizeof, size_t count, int32_t fil)
{
size_t i, j;
int32_t k, kgoal;
short leng;
uint8_t *ptr;
lzwbuflock[0] = lzwbuflock[1] = lzwbuflock[2] = lzwbuflock[3] = lzwbuflock[4] = 200;
if (lzwbuf1 == NULL) allocache(&lzwbuf1,LZWSIZE+(LZWSIZE>>4),&lzwbuflock[0]);
if (lzwbuf2 == NULL) allocache((uint8_t**)&lzwbuf2,(LZWSIZE+(LZWSIZE>>4))*2,&lzwbuflock[1]);
if (lzwbuf3 == NULL) allocache((uint8_t**)&lzwbuf3,(LZWSIZE+(LZWSIZE>>4))*2,&lzwbuflock[2]);
if (lzwbuf4 == NULL) allocache(&lzwbuf4,LZWSIZE,&lzwbuflock[3]);
if (lzwbuf5 == NULL) allocache(&lzwbuf5,LZWSIZE+(LZWSIZE>>4),&lzwbuflock[4]);
if (dasizeof > LZWSIZE) { count *= dasizeof; dasizeof = 1; }
ptr = (uint8_t *)buffer;
kread(fil,&leng,2); kread(fil,lzwbuf5,(int32_t )leng);
k = 0;
kgoal = uncompress(lzwbuf5,leng,lzwbuf4);
copybufbyte(lzwbuf4,ptr,(int32_t )dasizeof);
k += (int32_t )dasizeof;
for(i=1;i<count;i++)
{
if (k >= kgoal)
{
kread(fil,&leng,2); kread(fil,lzwbuf5,(int32_t )leng);
k = 0; kgoal = uncompress(lzwbuf5,(int32_t )leng,lzwbuf4);
}
for(j=0;j<dasizeof;j++) ptr[j+dasizeof] = (uint8_t ) ((ptr[j]+lzwbuf4[j+k])&255);
k += dasizeof;
ptr += dasizeof;
}
lzwbuflock[0] = lzwbuflock[1] = lzwbuflock[2] = lzwbuflock[3] = lzwbuflock[4] = 1;
}
void dfread(void *buffer, size_t dasizeof, size_t count, FILE *fil)
{
size_t i, j;
int32_t k, kgoal;
short leng;
uint8_t *ptr;
lzwbuflock[0] = lzwbuflock[1] = lzwbuflock[2] = lzwbuflock[3] = lzwbuflock[4] = 200;
if (lzwbuf1 == NULL) allocache(&lzwbuf1,LZWSIZE+(LZWSIZE>>4),&lzwbuflock[0]);
if (lzwbuf2 == NULL) allocache((uint8_t**)&lzwbuf2,(LZWSIZE+(LZWSIZE>>4))*2,&lzwbuflock[1]);
if (lzwbuf3 == NULL) allocache((uint8_t**)&lzwbuf3,(LZWSIZE+(LZWSIZE>>4))*2,&lzwbuflock[2]);
if (lzwbuf4 == NULL) allocache(&lzwbuf4,LZWSIZE,&lzwbuflock[3]);
if (lzwbuf5 == NULL) allocache(&lzwbuf5,LZWSIZE+(LZWSIZE>>4),&lzwbuflock[4]);
if (dasizeof > LZWSIZE) {
count *= dasizeof;
dasizeof = 1;
}
ptr = (uint8_t *)buffer;
fread(&leng,2,1,fil);
fread(lzwbuf5,(int32_t )leng,1,fil);
k = 0;
kgoal = uncompress(lzwbuf5,(int32_t )leng,lzwbuf4);
copybufbyte(lzwbuf4,ptr,(int32_t )dasizeof);
k += (int32_t )dasizeof;
for(i=1;i<count;i++)
{
if (k >= kgoal)
{
fread(&leng,2,1,fil); fread(lzwbuf5,(int32_t )leng,1,fil);
k = 0; kgoal = uncompress(lzwbuf5,(int32_t )leng,lzwbuf4);
}
for(j=0;j<dasizeof;j++) ptr[j+dasizeof] = (uint8_t ) ((ptr[j]+lzwbuf4[j+k])&255);
k += dasizeof;
ptr += dasizeof;
}
lzwbuflock[0] = lzwbuflock[1] = lzwbuflock[2] = lzwbuflock[3] = lzwbuflock[4] = 1;
}
void dfwrite(void *buffer, size_t dasizeof, size_t count, FILE *fil)
{
size_t i, j, k;
short leng;
uint8_t *ptr;
lzwbuflock[0] = lzwbuflock[1] = lzwbuflock[2] = lzwbuflock[3] = lzwbuflock[4] = 200;
if (lzwbuf1 == NULL) allocache(&lzwbuf1,LZWSIZE+(LZWSIZE>>4),&lzwbuflock[0]);
if (lzwbuf2 == NULL) allocache((uint8_t**)&lzwbuf2,(LZWSIZE+(LZWSIZE>>4))*2,&lzwbuflock[1]);
if (lzwbuf3 == NULL) allocache((uint8_t**)&lzwbuf3,(LZWSIZE+(LZWSIZE>>4))*2,&lzwbuflock[2]);
if (lzwbuf4 == NULL) allocache(&lzwbuf4,LZWSIZE,&lzwbuflock[3]);
if (lzwbuf5 == NULL) allocache(&lzwbuf5,LZWSIZE+(LZWSIZE>>4),&lzwbuflock[4]);
if (dasizeof > LZWSIZE) { count *= dasizeof; dasizeof = 1; }
ptr = (uint8_t *)buffer;
copybufbyte(ptr,lzwbuf4,(int32_t )dasizeof);
k = dasizeof;
if (k > LZWSIZE-dasizeof)
{
leng = (short)compress(lzwbuf4,k,lzwbuf5); k = 0;
fwrite(&leng,2,1,fil); fwrite(lzwbuf5,(int32_t )leng,1,fil);
}
for(i=1;i<count;i++)
{
for(j=0;j<dasizeof;j++) lzwbuf4[j+k] = (uint8_t ) ((ptr[j+dasizeof]-ptr[j])&255);
k += dasizeof;
if (k > LZWSIZE-dasizeof)
{
leng = (short)compress(lzwbuf4,k,lzwbuf5); k = 0;
fwrite(&leng,2,1,fil); fwrite(lzwbuf5,(int32_t )leng,1,fil);
}
ptr += dasizeof;
}
if (k > 0)
{
leng = (short)compress(lzwbuf4,k,lzwbuf5);
fwrite(&leng,2,1,fil); fwrite(lzwbuf5,(int32_t )leng,1,fil);
}
lzwbuflock[0] = lzwbuflock[1] = lzwbuflock[2] = lzwbuflock[3] = lzwbuflock[4] = 1;
}
int SafeFileExists ( const char * _filename );
int32_t TCkopen4load(const char *filename, int readfromGRP)
{
char fullfilename[512];
int32_t result = 0;
if(game_dir[0] != '\0' && !readfromGRP)
{
sprintf(fullfilename, "%s\\%s", game_dir, filename);
if (!SafeFileExists(fullfilename)) // try root
sprintf(fullfilename, "%s", filename);
}
else
{
sprintf(fullfilename, "%s", filename);
}
result = kopen4load(fullfilename, readfromGRP);
return result;
}
void setGameDir(char* gameDir){
if (gameDir == NULL)
return;
strncpy(game_dir,gameDir,sizeof(game_dir));
}
char* getGameDir(void){
return game_dir;
}
int getGRPcrc32(int grpID){
return grpSet.archives[grpID].crc32;
}