unzip.c

手机嵌入式Linux下可用的busybox源码

			for (j = 1 << (k - 1); i & j; j >>= 1)
				i ^= j;
			i ^= j;

			/* backup over finished tables */
			while ((i & ((1 << w) - 1)) != x[h]) {
				h--;			/* don't need to update q */
				w -= l;
			}
		}
	}
	/* Return true (1) if we were given an incomplete table */
	return y != 0 && g != 1;
}

/*
 * inflate (decompress) the codes in a deflated (compressed) block.
 * Return an error code or zero if it all goes ok.
 *
 * tl, td: literal/length and distance decoder tables
 * bl, bd: number of bits decoded by tl[] and td[]
 */
static int inflate_codes(huft_t *tl, huft_t *td, int bl, int bd)
{
	register unsigned long e;		/* table entry flag/number of extra bits */
	unsigned long n, d;				/* length and index for copy */
	unsigned long w;				/* current window position */
	huft_t *t;				/* pointer to table entry */
	unsigned ml, md;			/* masks for bl and bd bits */
	register unsigned long b;				/* bit buffer */
	register unsigned k;		/* number of bits in bit buffer */
	register int input_char;

	/* make local copies of globals */
	b = bb;					/* initialize bit buffer */
	k = bk;
	w = outcnt;				/* initialize window position */

	/* inflate the coded data */
	ml = mask_bits[bl];			/* precompute masks for speed */
	md = mask_bits[bd];
	for (;;) {				/* do until end of block */
		while (k < (unsigned) bl) {
			input_char = fgetc(in_file);
			if (input_char == EOF) return 1;
			b |= ((unsigned long)input_char) << k;
			k += 8;
		}
		if ((e = (t = tl + ((unsigned) b & ml))->e) > 16)
		do {
			if (e == 99) {
				return 1;
			}
			b >>= t->b;
			k -= t->b;
			e -= 16;
			while (k < e) {
				input_char = fgetc(in_file);
				if (input_char == EOF) return 1;
				b |= ((unsigned long)input_char) << k;
				k += 8;
			}
		} while ((e = (t = t->v.t + ((unsigned) b & mask_bits[e]))->e) > 16);
		b >>= t->b;
		k -= t->b;
		if (e == 16) {		/* then it's a literal */
			window[w++] = (unsigned char) t->v.n;
			if (w == WSIZE) {
				outcnt=(w),
				flush_window();
				w = 0;
			}
		} else {				/* it's an EOB or a length */

			/* exit if end of block */
			if (e == 15) {
				break;
			}

			/* get length of block to copy */
			while (k < e) {
				input_char = fgetc(in_file);
				if (input_char == EOF) return 1;
				b |= ((unsigned long)input_char) << k;
				k += 8;
			}
			n = t->v.n + ((unsigned) b & mask_bits[e]);
			b >>= e;
			k -= e;

			/* decode distance of block to copy */
			while (k < (unsigned) bd) {
				input_char = fgetc(in_file);
				if (input_char == EOF) return 1;
				b |= ((unsigned long)input_char) << k;
				k += 8;
			}

			if ((e = (t = td + ((unsigned) b & md))->e) > 16)
				do {
					if (e == 99)
						return 1;
					b >>= t->b;
					k -= t->b;
					e -= 16;
					while (k < e) {
						input_char = fgetc(in_file);
						if (input_char == EOF) return 1;
						b |= ((unsigned long)input_char) << k;
						k += 8;
					}
				} while ((e = (t = t->v.t + ((unsigned) b & mask_bits[e]))->e) > 16);
			b >>= t->b;
			k -= t->b;
			while (k < e) {
				input_char = fgetc(in_file);
				if (input_char == EOF) return 1;
				b |= ((unsigned long)input_char) << k;
				k += 8;
			}
			d = w - t->v.n - ((unsigned) b & mask_bits[e]);
			b >>= e;
			k -= e;

			/* do the copy */
			do {
				n -= (e = (e = WSIZE - ((d &= WSIZE - 1) > w ? d : w)) > n ? n : e);
#if !defined(NOMEMCPY) && !defined(DEBUG)
				if (w - d >= e) {	/* (this test assumes unsigned comparison) */
					memcpy(window + w, window + d, e);
					w += e;
					d += e;
				} else			/* do it slow to avoid memcpy() overlap */
#endif							/* !NOMEMCPY */
					do {
						window[w++] = window[d++];
					} while (--e);
				if (w == WSIZE) {
					outcnt=(w),
					flush_window();
					w = 0;
				}
			} while (n);
		}
	}

	/* restore the globals from the locals */
	outcnt = w;			/* restore global window pointer */
	bb = b;				/* restore global bit buffer */
	bk = k;

	/* done */
	return 0;
}

/*
 * decompress an inflated block
 * e: last block flag
 *
 * GLOBAL VARIABLES: bb, kk,
 */
static int inflate_block(int *e)
{
	unsigned t;			/* block type */
	register unsigned long b;			/* bit buffer */
	register unsigned k;		/* number of bits in bit buffer */
	static unsigned short cplens[] = {		/* Copy lengths for literal codes 257..285 */
		3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
		35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0
	};
	/* note: see note #13 above about the 258 in this list. */
	static unsigned short cplext[] = {		/* Extra bits for literal codes 257..285 */
		0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
		3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 99, 99
	};				/* 99==invalid */
	static unsigned short cpdist[] = {		/* Copy offsets for distance codes 0..29 */
		1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
		257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
		8193, 12289, 16385, 24577
	};
	static unsigned short cpdext[] = {		/* Extra bits for distance codes */
		0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
		7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
		12, 12, 13, 13
	};
	int input_char;

	/* make local bit buffer */
	b = bb;
	k = bk;

	/* read in last block bit */
	while (k < 1) {
		input_char = fgetc(in_file);
		if (input_char == EOF) return 1;
		b |= ((unsigned long)input_char) << k;
		k += 8;
	}
	*e = (int) b & 1;
	b >>= 1;
	k -= 1;

	/* read in block type */
	while (k < 2) {
		input_char = fgetc(in_file);
		if (input_char == EOF) return 1;
		b |= ((unsigned long)input_char) << k;
		k += 8;
	}
	t = (unsigned) b & 3;
	b >>= 2;
	k -= 2;

	/* restore the global bit buffer */
	bb = b;
	bk = k;

	/* inflate that block type */
	switch (t) {
	case 0:	/* Inflate stored */
		{
			unsigned long n;			/* number of bytes in block */
			unsigned long w;			/* current window position */
			register unsigned long b_stored;			/* bit buffer */
			register unsigned long k_stored;		/* number of bits in bit buffer */

			/* make local copies of globals */
			b_stored = bb;				/* initialize bit buffer */
			k_stored = bk;
			w = outcnt;			/* initialize window position */

			/* go to byte boundary */
			n = k_stored & 7;
			b_stored >>= n;
			k_stored -= n;

			/* get the length and its complement */
			while (k_stored < 16) {
				input_char = fgetc(in_file);
				if (input_char == EOF) return 1;
				b_stored |= ((unsigned long)input_char) << k_stored;
				k_stored += 8;
			}
			n = ((unsigned) b_stored & 0xffff);
			b_stored >>= 16;
			k_stored -= 16;
			while (k_stored < 16) {
				input_char = fgetc(in_file);
				if (input_char == EOF) return 1;
				b_stored |= ((unsigned long)input_char) << k_stored;
				k_stored += 8;
			}
			if (n != (unsigned) ((~b_stored) & 0xffff)) {
				return 1;		/* error in compressed data */
			}
			b_stored >>= 16;
			k_stored -= 16;

			/* read and output the compressed data */
			while (n--) {
				while (k_stored < 8) {
					input_char = fgetc(in_file);
					if (input_char == EOF) return 1;
					b_stored |= ((unsigned long)input_char) << k_stored;
					k_stored += 8;
				}
				window[w++] = (unsigned char) b_stored;
				if (w == (unsigned long)WSIZE) {
					outcnt=(w),
					flush_window();
					w = 0;
				}
				b_stored >>= 8;
				k_stored -= 8;
			}

			/* restore the globals from the locals */
			outcnt = w;			/* restore global window pointer */
			bb = b_stored;				/* restore global bit buffer */
			bk = k_stored;
			return 0;
		}
	case 1:	/* Inflate fixed 
			 * decompress an inflated type 1 (fixed Huffman codes) block.  We should
			 * either replace this with a custom decoder, or at least precompute the
			 * Huffman tables.
			 */
		{
			int i;					/* temporary variable */
			huft_t *tl;				/* literal/length code table */
			huft_t *td;				/* distance code table */
			int bl;					/* lookup bits for tl */
			int bd;					/* lookup bits for td */
			unsigned int l[288];	/* length list for huft_build */

			/* set up literal table */
			for (i = 0; i < 144; i++) {
				l[i] = 8;
			}
			for (; i < 256; i++) {
				l[i] = 9;
			}
			for (; i < 280; i++) {
				l[i] = 7;
			}
			for (; i < 288; i++) {	/* make a complete, but wrong code set */
				l[i] = 8;
			}
			bl = 7;
			if ((i = huft_build(l, 288, 257, cplens, cplext, &tl, &bl)) != 0) {
				return i;
			}

			/* set up distance table */
			for (i = 0; i < 30; i++) {	/* make an incomplete code set */
				l[i] = 5;
			}
			bd = 5;
			if ((i = huft_build(l, 30, 0, cpdist, cpdext, &td, &bd)) > 1) {
				huft_free(tl);
				return i;
			}

			/* decompress until an end-of-block code */
			if (inflate_codes(tl, td, bl, bd))
				return 1;

			/* free the decoding tables, return */
			huft_free(tl);
			huft_free(td);
			return 0;
		}
	case 2:	/* Inflate dynamic */
		{
			/* Tables for deflate from PKZIP's appnote.txt. */
			static unsigned border[] = {	/* Order of the bit length code lengths */
				16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15
			};
			int dbits = 6;					/* bits in base distance lookup table */
			int lbits = 9;					/* bits in base literal/length lookup table */

			int i;						/* temporary variables */
			unsigned j;
			unsigned l;					/* last length */
			unsigned m;					/* mask for bit lengths table */
			unsigned n;					/* number of lengths to get */
			huft_t *tl;			/* literal/length code table */
			huft_t *td;			/* distance code table */
			int bl;						/* lookup bits for tl */
			int bd;						/* lookup bits for td */
			unsigned nb;				/* number of bit length codes */
			unsigned nl;				/* number of literal/length codes */
			unsigned nd;				/* number of distance codes */

			unsigned ll[286 + 30];		/* literal/length and distance code lengths */
			register unsigned long b_dynamic;	/* bit buffer */
			register unsigned k_dynamic;		/* number of bits in bit buffer */

			/* make local bit buffer */
			b_dynamic = bb;
			k_dynamic = bk;