quakeforge/tools/pak/pakfile.c

#include <limits.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>

#include <QF/qendian.h>

#include "pakfile.h"

static const char *
pack_get_key (void *p, void *unused)
{
	return ((dpackfile_t *) p)->name;
}

pack_t *
pack_new (const char *name)
{
	pack_t *pack = calloc (sizeof (*pack), 1);

	if (!pack)
		return 0;
	pack->filename = strdup (name);
	if (!pack->filename) {
		free (pack);
		return 0;
	}
	pack->file_hash = Hash_NewTable (1021, pack_get_key, 0, 0);
	if (!pack->file_hash) {
		free (pack->filename);
		free (pack);
		return 0;
	}
	return pack;
}

void
pack_del (pack_t *pack)
{
	if (pack->files)
		free (pack->files);
	if (pack->handle)
		fclose (pack->handle);
	if (pack->filename)
		free (pack->filename);
	if (pack->file_hash)
		free (pack->file_hash);
	free (pack);
}

pack_t *
pack_open (const char *name)
{
	pack_t     *pack = pack_new (name);
	int         i;

	if (!pack)
		return 0;
	pack->handle = fopen (name, "rb");
	if (!pack->handle) {
		goto error;
	}
	if (fread (&pack->header, 1, sizeof (pack->header), pack->handle)
		!= sizeof (pack->header)) {
		fprintf (stderr, "%s: not a pack file", name);
		goto error;
	}
	if (strncmp (pack->header.id, "PACK", 4)) {
		fprintf (stderr, "%s: not a pack file", name);
		goto error;
	}

	pack->header.dirofs = LittleLong (pack->header.dirofs);
	pack->header.dirlen = LittleLong (pack->header.dirlen);

	pack->numfiles = pack->header.dirlen / sizeof (dpackfile_t);
	pack->old_numfiles = pack->files_size = pack->numfiles;
	if (pack->numfiles > MAX_FILES_IN_PACK) {
		fprintf (stderr, "%s: too many files in pack: %d", name, pack->numfiles);
		goto error;
	}
	pack->files = malloc (pack->files_size * sizeof (dpackfile_t));
	if (!pack->files) {
		fprintf (stderr, "out of memory\n");
		goto error;
	}
	fseek (pack->handle, pack->header.dirofs, SEEK_SET);
	fread (pack->files, pack->numfiles, sizeof (pack->files[0]), pack->handle);

	for (i = 0; i < pack->numfiles; i++) {
		pack->files[i].filepos = LittleLong (pack->files[i].filepos);
		pack->files[i].filelen = LittleLong (pack->files[i].filelen);
		Hash_Add (pack->file_hash, &pack->files[i]);
	}
	return pack;
error:
	pack_del (pack);
	return 0;
}

pack_t *
pack_create (const char *name)
{
	pack_t     *pack = pack_new (name);

	if (!pack)
		return 0;

	pack->handle = fopen (name, "wb");
	if (!pack->handle) {
		pack_del (pack);
		return 0;
	}
	strncpy (pack->header.id, "PACK", sizeof (pack->header.id));

	fwrite (&pack->header, 1, sizeof (pack->header), pack->handle);

	return pack;
}

void
pack_close (pack_t *pack)
{
	int         i;

	if (pack->modified) {
		if (pack->numfiles > pack->old_numfiles) {
			fseek (pack->handle, 0, SEEK_END);
			pack->header.dirofs = ftell (pack->handle);
		}
		for (i = 0; i < pack->numfiles; i++) {
			pack->files[i].filepos = LittleLong (pack->files[i].filepos);
			pack->files[i].filelen = LittleLong (pack->files[i].filelen);
		}
		fseek (pack->handle, pack->header.dirofs, SEEK_SET);
		fwrite (pack->files, pack->numfiles,
				sizeof (pack->files[0]), pack->handle);
		pack->header.dirlen = pack->numfiles * sizeof (pack->files[0]);
		pack->header.dirofs = LittleLong (pack->header.dirofs);
		pack->header.dirlen = LittleLong (pack->numfiles
										  * sizeof (pack->files[0]));
		fseek (pack->handle, 0, SEEK_SET);
		fwrite (&pack->header, 1, sizeof (pack->header), pack->handle);

		fseek (pack->handle, 0, SEEK_END);
	}
	pack_del (pack);
}

int
pack_add (pack_t *pack, const char *filename)
{
	dpackfile_t *pf;
	FILE       *file;
	char        buffer[16384];
	int         bytes;

	pf = Hash_Find (pack->file_hash, filename);
	if (pf)
		return -1;
	if (pack->numfiles == pack->files_size) {
		dpackfile_t *f;
		
		if (pack->files_size == MAX_FILES_IN_PACK)
			return -1;
		pack->files_size += 64;
		if (pack->files_size > MAX_FILES_IN_PACK)
			pack->files_size = MAX_FILES_IN_PACK;

		f = realloc (pack->files, pack->files_size * sizeof (dpackfile_t));
		if (!f)
			return -1;
		pack->files = f;
	}

	file = fopen (filename, "rb");
	if (!file)
		return -1;

	pack->modified = 1;

	pf = &pack->files[pack->numfiles++];

	strncpy (pf->name, filename, sizeof (pf->name));
	pf->name[sizeof (pf->name) - 1] = 0;

	fseek (pack->handle, 0, SEEK_END);
	pf->filepos = ftell (pack->handle);
	pf->filelen = 0;
	while ((bytes = fread (buffer, 1, sizeof (buffer), file))) {
		fwrite (buffer, 1, bytes, pack->handle);
		pf->filelen += bytes;
	}
	if (pf->filelen & 3) {
		static char buf[4];
		fwrite (buf, 1, 4 - (pf->filelen & 3), pack->handle);
	}
	return 0;
}