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SQUASHFS/squashfs-tools-4.4/squashfs-tools/lzo_wrapper.c

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+/*
+ * Copyright (c) 2013, 2014
+ * Phillip Lougher <phillip@squashfs.org.uk>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2,
+ * or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * lzo_wrapper.c
+ *
+ * Support for LZO compression http://www.oberhumer.com/opensource/lzo
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <lzo/lzoconf.h>
+#include <lzo/lzo1x.h>
+
+#include "squashfs_fs.h"
+#include "lzo_wrapper.h"
+#include "compressor.h"
+
+static struct lzo_algorithm lzo[] = {
+	{ "lzo1x_1", LZO1X_1_MEM_COMPRESS, lzo1x_1_compress },
+	{ "lzo1x_1_11", LZO1X_1_11_MEM_COMPRESS, lzo1x_1_11_compress },
+	{ "lzo1x_1_12", LZO1X_1_12_MEM_COMPRESS, lzo1x_1_12_compress },
+	{ "lzo1x_1_15", LZO1X_1_15_MEM_COMPRESS, lzo1x_1_15_compress },
+	{ "lzo1x_999", LZO1X_999_MEM_COMPRESS, lzo1x_999_wrapper },
+	{ NULL, 0, NULL } 
+};
+
+/* default LZO compression algorithm and compression level */
+static int algorithm = SQUASHFS_LZO1X_999;
+static int compression_level = SQUASHFS_LZO1X_999_COMP_DEFAULT;
+
+/* user specified compression level */
+static int user_comp_level = -1;
+
+
+/*
+ * This function is called by the options parsing code in mksquashfs.c
+ * to parse any -X compressor option.
+ *
+ * This function returns:
+ *	>=0 (number of additional args parsed) on success
+ *	-1 if the option was unrecognised, or
+ *	-2 if the option was recognised, but otherwise bad in
+ *	   some way (e.g. invalid parameter)
+ *
+ * Note: this function sets internal compressor state, but does not
+ * pass back the results of the parsing other than success/failure.
+ * The lzo_dump_options() function is called later to get the options in
+ * a format suitable for writing to the filesystem.
+ */
+static int lzo_options(char *argv[], int argc)
+{
+    (void)argv;
+    (void)argc;
+	return 1;
+}
+
+
+/*
+ * This function is called after all options have been parsed.
+ * It is used to do post-processing on the compressor options using
+ * values that were not expected to be known at option parse time.
+ *
+ * In this case the LZO algorithm may not be known until after the
+ * compression level has been set (-Xalgorithm used after -Xcompression-level)
+ *
+ * This function returns 0 on successful post processing, or
+ *			-1 on error
+ */
+static int lzo_options_post(int block_size)
+{
+	/*
+	 * Use of compression level only makes sense for
+	 * LZO1X_999 algorithm
+	 */
+	if(user_comp_level != -1) {
+		if(algorithm != SQUASHFS_LZO1X_999) {
+			fprintf(stderr, "lzo: -Xcompression-level not "
+				"supported by selected %s algorithm\n",
+				lzo[algorithm].name);
+			fprintf(stderr, "lzo: -Xcompression-level is only "
+				"applicable for the lzo1x_999 algorithm\n");
+			goto failed;
+		}
+		compression_level = user_comp_level;
+	}
+
+	return 0;
+
+failed:
+	return -1;
+}
+
+
+/*
+ * This function is called by mksquashfs to dump the parsed
+ * compressor options in a format suitable for writing to the
+ * compressor options field in the filesystem (stored immediately
+ * after the superblock).
+ *
+ * This function returns a pointer to the compression options structure
+ * to be stored (and the size), or NULL if there are no compression
+ * options
+ *
+ */
+static void *lzo_dump_options(int block_size, int *size)
+{
+	static struct lzo_comp_opts comp_opts;
+
+	/*
+	 * If default compression options of SQUASHFS_LZO1X_999 and
+	 * compression level of SQUASHFS_LZO1X_999_COMP_DEFAULT then
+	 * don't store a compression options structure (this is compatible
+	 * with the legacy implementation of LZO for Squashfs)
+	 */
+	if(algorithm == SQUASHFS_LZO1X_999 &&
+			compression_level == SQUASHFS_LZO1X_999_COMP_DEFAULT)
+		return NULL;
+
+	comp_opts.algorithm = algorithm;
+	comp_opts.compression_level = algorithm == SQUASHFS_LZO1X_999 ?
+		compression_level : 0;
+
+	SQUASHFS_INSWAP_COMP_OPTS(&comp_opts);
+
+	*size = sizeof(comp_opts);
+	return &comp_opts;
+}
+
+
+/*
+ * This function is a helper specifically for the append mode of
+ * mksquashfs.  Its purpose is to set the internal compressor state
+ * to the stored compressor options in the passed compressor options
+ * structure.
+ *
+ * In effect this function sets up the compressor options
+ * to the same state they were when the filesystem was originally
+ * generated, this is to ensure on appending, the compressor uses
+ * the same compression options that were used to generate the
+ * original filesystem.
+ *
+ * Note, even if there are no compressor options, this function is still
+ * called with an empty compressor structure (size == 0), to explicitly
+ * set the default options, this is to ensure any user supplied
+ * -X options on the appending mksquashfs command line are over-ridden
+ *
+ * This function returns 0 on sucessful extraction of options, and
+ *			-1 on error
+ */
+static int lzo_extract_options(int block_size, void *buffer, int size)
+{
+	struct lzo_comp_opts *comp_opts = buffer;
+
+	if(size == 0) {
+		/* Set default values */
+		algorithm = SQUASHFS_LZO1X_999;
+		compression_level = SQUASHFS_LZO1X_999_COMP_DEFAULT;
+		return 0;
+	}
+
+	/* we expect a comp_opts structure of sufficient size to be present */
+	if(size < sizeof(*comp_opts))
+		goto failed;
+
+	SQUASHFS_INSWAP_COMP_OPTS(comp_opts);
+
+	/* Check comp_opts structure for correctness */
+	switch(comp_opts->algorithm) {
+	case SQUASHFS_LZO1X_1:
+	case SQUASHFS_LZO1X_1_11:
+	case SQUASHFS_LZO1X_1_12:
+	case SQUASHFS_LZO1X_1_15:
+		if(comp_opts->compression_level != 0) {
+			fprintf(stderr, "lzo: bad compression level in "
+				"compression options structure\n");
+			goto failed;
+		}
+		break;
+	case SQUASHFS_LZO1X_999:
+		if(comp_opts->compression_level < 1 ||
+				comp_opts->compression_level > 9) {
+			fprintf(stderr, "lzo: bad compression level in "
+				"compression options structure\n");
+			goto failed;
+		}
+		compression_level = comp_opts->compression_level;
+		break;
+	default:
+		fprintf(stderr, "lzo: bad algorithm in compression options "
+				"structure\n");
+			goto failed;
+	}
+
+	algorithm = comp_opts->algorithm;
+
+	return 0;
+
+failed:
+	fprintf(stderr, "lzo: error reading stored compressor options from "
+		"filesystem!\n");
+
+	return -1;
+}
+
+
+static void lzo_display_options(void *buffer, int size)
+{
+	struct lzo_comp_opts *comp_opts = buffer;
+
+	/* we expect a comp_opts structure of sufficient size to be present */
+	if(size < sizeof(*comp_opts))
+		goto failed;
+
+	SQUASHFS_INSWAP_COMP_OPTS(comp_opts);
+
+	/* Check comp_opts structure for correctness */
+	switch(comp_opts->algorithm) {
+	case SQUASHFS_LZO1X_1:
+	case SQUASHFS_LZO1X_1_11:
+	case SQUASHFS_LZO1X_1_12:
+	case SQUASHFS_LZO1X_1_15:
+		printf("\talgorithm %s\n", lzo[comp_opts->algorithm].name);
+		break;
+	case SQUASHFS_LZO1X_999:
+		if(comp_opts->compression_level < 1 ||
+				comp_opts->compression_level > 9) {
+			fprintf(stderr, "lzo: bad compression level in "
+				"compression options structure\n");
+			goto failed;
+		}
+		printf("\talgorithm %s\n", lzo[comp_opts->algorithm].name);
+		printf("\tcompression level %d\n",
+						comp_opts->compression_level);
+		break;
+	default:
+		fprintf(stderr, "lzo: bad algorithm in compression options "
+				"structure\n");
+			goto failed;
+	}
+
+	return;
+
+failed:
+	fprintf(stderr, "lzo: error reading stored compressor options from "
+		"filesystem!\n");
+}	
+
+
+/*
+ * This function is called by mksquashfs to initialise the
+ * compressor, before compress() is called.
+ *
+ * This function returns 0 on success, and
+ *			-1 on error
+ */
+static int squashfs_lzo_init(void **strm, int block_size, int datablock)
+{
+	struct lzo_stream *stream;
+
+	stream = *strm = malloc(sizeof(struct lzo_stream));
+	if(stream == NULL)
+		goto failed;
+
+	stream->workspace = malloc(lzo[algorithm].size);
+	if(stream->workspace == NULL)
+		goto failed2;
+
+	stream->buffer = malloc(LZO_MAX_EXPANSION(block_size));
+	if(stream->buffer != NULL)
+		return 0;
+
+	free(stream->workspace);
+failed2:
+	free(stream);
+failed:
+	return -1;
+}
+
+
+static int lzo_compress(void *strm, void *dest, void *src,  int size,
+	int block_size, int *error)
+{
+    
+	return 0;
+}
+
+
+static int lzo_uncompress(void *dest, void *src, int size, int outsize,
+	int *error)
+{
+	int res;
+	lzo_uint outlen = outsize;
+
+	res = lzo1x_decompress_safe(src, size, dest, &outlen, NULL);
+	if(res != LZO_E_OK) {
+		*error = res;
+		return -1;
+	}
+
+	return outlen;
+}
+
+
+static void lzo_usage()
+{
+	int i;
+
+	fprintf(stderr, "\t  -Xalgorithm <algorithm>\n");
+	fprintf(stderr, "\t\tWhere <algorithm> is one of:\n");
+
+	for(i = 0; lzo[i].name; i++)
+		fprintf(stderr, "\t\t\t%s%s\n", lzo[i].name,
+				i == SQUASHFS_LZO1X_999 ? " (default)" : "");
+
+	fprintf(stderr, "\t  -Xcompression-level <compression-level>\n");
+	fprintf(stderr, "\t\t<compression-level> should be 1 .. 9 (default "
+		"%d)\n", SQUASHFS_LZO1X_999_COMP_DEFAULT);
+	fprintf(stderr, "\t\tOnly applies to lzo1x_999 algorithm\n");
+}
+
+
+/*
+ * Helper function for lzo1x_999 compression algorithm.
+ * All other lzo1x_xxx compressors do not take a compression level,
+ * so we need to wrap lzo1x_999 to pass the compression level which
+ * is applicable to it
+ */
+int lzo1x_999_wrapper(const lzo_bytep src, lzo_uint src_len, lzo_bytep dst,
+	lzo_uintp compsize, lzo_voidp workspace)
+{
+	return lzo1x_999_compress_level(src, src_len, dst, compsize,
+		workspace, NULL, 0, 0, compression_level);
+}
+
+
+struct compressor lzo_comp_ops = {
+	.init = squashfs_lzo_init,
+	.compress = lzo_compress,
+	.uncompress = lzo_uncompress,
+	.options = lzo_options,
+	.options_post = lzo_options_post,
+	.dump_options = lzo_dump_options,
+	.extract_options = lzo_extract_options,
+	.display_options = lzo_display_options,
+	.usage = lzo_usage,
+	.id = LZO_COMPRESSION,
+	.name = "lzo",
+	.supported = 1
+};