zlib abstraction code, first part of support for compression

1 files changed, 191 insertions, 0 deletions

diff --git a/usr.bin/cvs/zlib.c b/usr.bin/cvs/zlib.c
new file mode 100644
index 00000000000..382a455d34e
--- /dev/null
+++ b/usr.bin/cvs/zlib.c
@@ -0,0 +1,191 @@
+/*	$OpenBSD: zlib.c,v 1.1 2005/01/13 18:59:03 jfb Exp $	*/
+/*
+ * Copyright (c) 2005 Jean-Francois Brousseau <jfb@openbsd.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+ * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL  DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+ * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/param.h>
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+
+#include "log.h"
+#include "cvs.h"
+#include "zlib.h"
+
+
+#define CVS_ZLIB_BUFSIZE  1024
+
+
+
+struct cvs_zlib_ctx {
+	int       z_level;
+	z_stream  z_instrm;
+	z_stream  z_destrm;
+};
+
+
+/*
+ * cvs_zlib_newctx()
+ *
+ * Allocate a new ZLIB context structure used for both inflation and deflation
+ * of data with compression level <level>, which must be between 0 and 9.  A
+ * value of 0 means no compression, and 9 is the highest level of compression.
+ */
+CVSZCTX*
+cvs_zlib_newctx(int level)
+{
+	CVSZCTX *ctx;
+
+	if ((level < 0) || (level > 9)) {
+		cvs_log(LP_ERR, "invalid compression level %d "
+		    "(must be between 0 and 9)", level);
+		return (NULL);
+	}
+
+	ctx = (CVSZCTX *)malloc(sizeof(*ctx));
+	if (ctx == NULL) {
+		cvs_log(LP_ERRNO, "failed to allocate zlib context");
+		return (NULL);
+	}
+	memset(ctx, 0, sizeof(*ctx));
+
+	ctx->z_level = level;
+
+	ctx->z_instrm.zalloc = Z_NULL;
+	ctx->z_instrm.zfree = Z_NULL;
+	ctx->z_instrm.opaque = Z_NULL;
+	ctx->z_destrm.zalloc = Z_NULL;
+	ctx->z_destrm.zfree = Z_NULL;
+	ctx->z_destrm.opaque = Z_NULL;
+
+	if ((inflateInit(&(ctx->z_instrm)) != Z_OK) ||
+	    (deflateInit(&(ctx->z_destrm), level) != Z_OK)) {
+		cvs_log(LP_ERR, "failed to initialize zlib streams");
+		free(ctx);
+		return (NULL);
+	}
+
+	return (ctx);
+}
+
+
+/*
+ * cvs_zlib_free()
+ *
+ * Free a ZLIB context previously allocated with cvs_zlib_newctx().
+ */
+void
+cvs_zlib_free(CVSZCTX *ctx)
+{
+	if (ctx != NULL) {
+		(void)inflateEnd(&(ctx->z_instrm));
+		(void)deflateEnd(&(ctx->z_destrm));
+		free(ctx);
+	}
+}
+
+/*
+ * cvs_zlib_inflate()
+ *
+ */
+int
+cvs_zlib_inflate(CVSZCTX *ctx, BUF *dst, u_char *src, size_t slen)
+{
+	int bytes, ret;
+	u_char buf[CVS_ZLIB_BUFSIZE];
+
+	bytes = 0;
+	cvs_buf_empty(dst);
+	inflateReset(&(ctx->z_instrm));
+
+	ctx->z_instrm.next_in = src;
+	ctx->z_instrm.avail_in = slen;
+
+	do {
+		ctx->z_instrm.next_out = buf;
+		ctx->z_instrm.avail_out = sizeof(buf);
+
+		ret = inflate(&(ctx->z_instrm), Z_FINISH);
+		if ((ret == Z_MEM_ERROR) || (ret == Z_BUF_ERROR) ||
+		    (ret == Z_STREAM_ERROR) || (ret == Z_DATA_ERROR)) {
+			cvs_log(LP_ERR, "inflate error: %s", ctx->z_instrm.msg);
+			return (-1);
+		}
+
+		cvs_buf_append(dst, buf, ctx->z_instrm.avail_out);
+		bytes += sizeof(buf) - ctx->z_instrm.avail_out;
+
+	} while (ret != Z_STREAM_END);
+
+	cvs_log(LP_WARN, "%u bytes decompressed to %d bytes", slen, bytes);
+
+	return (bytes);
+}
+
+
+/*
+ * cvs_zlib_deflate()
+ *
+ * Compress the first <slen> bytes of <src> using the zlib context <ctx> and
+ * store the resulting data in <dst>.
+ * Returns the number of bytes deflated on success, or -1 on failure.
+ */
+int
+cvs_zlib_deflate(CVSZCTX *ctx, BUF *dst, u_char *src, size_t slen)
+{
+	int bytes, ret;
+	u_char buf[CVS_ZLIB_BUFSIZE];
+
+	bytes = 0;
+	cvs_buf_empty(dst);
+	deflateReset(&(ctx->z_destrm));
+
+	ctx->z_destrm.next_in = src;
+	ctx->z_destrm.avail_in = slen;
+
+	do {
+		ctx->z_destrm.next_out = buf;
+		ctx->z_destrm.avail_out = sizeof(buf);
+		ret = deflate(&(ctx->z_destrm), Z_FINISH);
+		if ((ret == Z_STREAM_ERROR) || (ret == Z_BUF_ERROR)) {
+#if 0
+		if (ret != Z_OK) {
+#endif
+			cvs_log(LP_ERR, "deflate error: %s", ctx->z_destrm.msg);
+			return (-1);
+		}
+
+		if (cvs_buf_append(dst, buf,
+		    sizeof(buf) - ctx->z_destrm.avail_out) < 0)
+			return (-1);
+		bytes += sizeof(buf) - ctx->z_destrm.avail_out;
+	} while (ret != Z_STREAM_END);
+
+	cvs_log(LP_WARN, "%u bytes compressed to %d bytes", slen, bytes);
+
+	return (bytes);
+}