199767f8919635c4928607450d9e0abb932109ceToomas Soome/*
199767f8919635c4928607450d9e0abb932109ceToomas Soome * CDDL HEADER START
199767f8919635c4928607450d9e0abb932109ceToomas Soome *
199767f8919635c4928607450d9e0abb932109ceToomas Soome * The contents of this file are subject to the terms of the
199767f8919635c4928607450d9e0abb932109ceToomas Soome * Common Development and Distribution License (the "License").
199767f8919635c4928607450d9e0abb932109ceToomas Soome * You may not use this file except in compliance with the License.
199767f8919635c4928607450d9e0abb932109ceToomas Soome *
199767f8919635c4928607450d9e0abb932109ceToomas Soome * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
199767f8919635c4928607450d9e0abb932109ceToomas Soome * or http://www.opensolaris.org/os/licensing.
199767f8919635c4928607450d9e0abb932109ceToomas Soome * See the License for the specific language governing permissions
199767f8919635c4928607450d9e0abb932109ceToomas Soome * and limitations under the License.
199767f8919635c4928607450d9e0abb932109ceToomas Soome *
199767f8919635c4928607450d9e0abb932109ceToomas Soome * When distributing Covered Code, include this CDDL HEADER in each
199767f8919635c4928607450d9e0abb932109ceToomas Soome * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
199767f8919635c4928607450d9e0abb932109ceToomas Soome * If applicable, add the following below this CDDL HEADER, with the
199767f8919635c4928607450d9e0abb932109ceToomas Soome * fields enclosed by brackets "[]" replaced with your own identifying
199767f8919635c4928607450d9e0abb932109ceToomas Soome * information: Portions Copyright [yyyy] [name of copyright owner]
199767f8919635c4928607450d9e0abb932109ceToomas Soome *
199767f8919635c4928607450d9e0abb932109ceToomas Soome * CDDL HEADER END
199767f8919635c4928607450d9e0abb932109ceToomas Soome */
199767f8919635c4928607450d9e0abb932109ceToomas Soome
199767f8919635c4928607450d9e0abb932109ceToomas Soome/*
199767f8919635c4928607450d9e0abb932109ceToomas Soome * Copyright 2009 Sun Microsystems, Inc. All rights reserved.
199767f8919635c4928607450d9e0abb932109ceToomas Soome * Use is subject to license terms.
199767f8919635c4928607450d9e0abb932109ceToomas Soome */
199767f8919635c4928607450d9e0abb932109ceToomas Soome
199767f8919635c4928607450d9e0abb932109ceToomas Soome/*
199767f8919635c4928607450d9e0abb932109ceToomas Soome * Zero-length encoding. This is a fast and simple algorithm to eliminate
199767f8919635c4928607450d9e0abb932109ceToomas Soome * runs of zeroes. Each chunk of compressed data begins with a length byte, b.
199767f8919635c4928607450d9e0abb932109ceToomas Soome * If b < n (where n is the compression parameter) then the next b + 1 bytes
199767f8919635c4928607450d9e0abb932109ceToomas Soome * are literal values. If b >= n then the next (256 - b + 1) bytes are zero.
199767f8919635c4928607450d9e0abb932109ceToomas Soome */
199767f8919635c4928607450d9e0abb932109ceToomas Soome
199767f8919635c4928607450d9e0abb932109ceToomas Soomestatic int
199767f8919635c4928607450d9e0abb932109ceToomas Soomezle_decompress(void *s_start, void *d_start, size_t s_len, size_t d_len, int n)
199767f8919635c4928607450d9e0abb932109ceToomas Soome{
199767f8919635c4928607450d9e0abb932109ceToomas Soome unsigned char *src = s_start;
199767f8919635c4928607450d9e0abb932109ceToomas Soome unsigned char *dst = d_start;
199767f8919635c4928607450d9e0abb932109ceToomas Soome unsigned char *s_end = src + s_len;
199767f8919635c4928607450d9e0abb932109ceToomas Soome unsigned char *d_end = dst + d_len;
199767f8919635c4928607450d9e0abb932109ceToomas Soome
199767f8919635c4928607450d9e0abb932109ceToomas Soome while (src < s_end && dst < d_end) {
199767f8919635c4928607450d9e0abb932109ceToomas Soome int len = 1 + *src++;
199767f8919635c4928607450d9e0abb932109ceToomas Soome if (len <= n) {
199767f8919635c4928607450d9e0abb932109ceToomas Soome while (len-- != 0)
199767f8919635c4928607450d9e0abb932109ceToomas Soome *dst++ = *src++;
199767f8919635c4928607450d9e0abb932109ceToomas Soome } else {
199767f8919635c4928607450d9e0abb932109ceToomas Soome len -= n;
199767f8919635c4928607450d9e0abb932109ceToomas Soome while (len-- != 0)
199767f8919635c4928607450d9e0abb932109ceToomas Soome *dst++ = 0;
199767f8919635c4928607450d9e0abb932109ceToomas Soome }
199767f8919635c4928607450d9e0abb932109ceToomas Soome }
199767f8919635c4928607450d9e0abb932109ceToomas Soome return (dst == d_end ? 0 : -1);
199767f8919635c4928607450d9e0abb932109ceToomas Soome}