From 7070857b47373dafc1ab93fadec79243da589a1a Mon Sep 17 00:00:00 2001
From: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
Date: Sat, 4 May 2019 20:47:39 +0200
Subject: Rename lzma compressor to xz, zlib compressor to gzip

Stick to the terminology that SquashFS uses. SquashFS uses "lzma" to
refere to lzma1, "xz" to refere to lzma2 and confusingly "gzip" to
refere to raw zlib deflate. We can avoid a lot of confusion by
_consistently_ using the same terminology.

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
---
 lib/comp/gzip.c | 107 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 107 insertions(+)
 create mode 100644 lib/comp/gzip.c

(limited to 'lib/comp/gzip.c')

diff --git a/lib/comp/gzip.c b/lib/comp/gzip.c
new file mode 100644
index 0000000..ea634b8
--- /dev/null
+++ b/lib/comp/gzip.c
@@ -0,0 +1,107 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <zlib.h>
+
+#include "internal.h"
+
+typedef struct {
+	compressor_t base;
+
+	z_stream strm;
+	bool compress;
+
+	size_t block_size;
+} gzip_compressor_t;
+
+static void gzip_destroy(compressor_t *base)
+{
+	gzip_compressor_t *gzip = (gzip_compressor_t *)base;
+
+	if (gzip->compress) {
+		deflateEnd(&gzip->strm);
+	} else {
+		inflateEnd(&gzip->strm);
+	}
+
+	free(gzip);
+}
+
+static ssize_t gzip_do_block(compressor_t *base, const uint8_t *in,
+			     size_t size, uint8_t *out, size_t outsize)
+{
+	gzip_compressor_t *gzip = (gzip_compressor_t *)base;
+	size_t written;
+	int ret;
+
+	if (gzip->compress) {
+		ret = deflateReset(&gzip->strm);
+	} else {
+		ret = inflateReset(&gzip->strm);
+	}
+
+	if (ret != Z_OK) {
+		fputs("resetting zlib stream failed\n", stderr);
+		return -1;
+	}
+
+	gzip->strm.next_in = (void *)in;
+	gzip->strm.avail_in = size;
+	gzip->strm.next_out = out;
+	gzip->strm.avail_out = outsize;
+
+	if (gzip->compress) {
+		ret = deflate(&gzip->strm, Z_FINISH);
+	} else {
+		ret = inflate(&gzip->strm, Z_FINISH);
+	}
+
+	if (ret == Z_STREAM_END) {
+		written = gzip->strm.total_out;
+
+		if (gzip->compress && written >= size)
+			return 0;
+
+		return (ssize_t)written;
+	}
+
+	if (ret != Z_OK) {
+		fputs("gzip block processing failed\n", stderr);
+		return -1;
+	}
+
+	return 0;
+}
+
+compressor_t *create_gzip_compressor(bool compress, size_t block_size)
+{
+	gzip_compressor_t *gzip = calloc(1, sizeof(*gzip));
+	compressor_t *base = (compressor_t *)gzip;
+	int ret;
+
+	if (gzip == NULL) {
+		perror("creating gzip compressor");
+		return NULL;
+	}
+
+	gzip->compress = compress;
+	gzip->block_size = block_size;
+	base->do_block = gzip_do_block;
+	base->destroy = gzip_destroy;
+
+	if (compress) {
+		ret = deflateInit(&gzip->strm, Z_BEST_COMPRESSION);
+	} else {
+		ret = inflateInit(&gzip->strm);
+	}
+
+	if (ret != Z_OK) {
+		fputs("internal error creating zlib stream\n", stderr);
+		free(gzip);
+		return NULL;
+	}
+
+	return base;
+}
-- 
cgit v1.2.3