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-rw-r--r--source4/lib/compression/lzxpress.c144
1 files changed, 144 insertions, 0 deletions
diff --git a/source4/lib/compression/lzxpress.c b/source4/lib/compression/lzxpress.c
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+++ b/source4/lib/compression/lzxpress.c
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+/*
+ * Copyright (C) Matthieu Suiche 2008
+ *
+ * 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. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * 3. Neither the name of the author nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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 "includes.h"
+#include "replace.h"
+#include "lzxpress.h"
+
+
+#define __BUF_POS_CONST(buf,ofs)(((const uint8_t *)buf)+(ofs))
+#define __PULL_BYTE(buf,ofs) \
+ ((uint8_t)((*__BUF_POS_CONST(buf,ofs)) & 0xFF))
+
+#ifndef PULL_LE_UINT16
+#define PULL_LE_UINT16(buf,ofs) ((uint16_t)( \
+ ((uint16_t)(((uint16_t)(__PULL_BYTE(buf,(ofs)+0))) << 0)) | \
+ ((uint16_t)(((uint16_t)(__PULL_BYTE(buf,(ofs)+1))) << 8)) \
+))
+#endif
+
+#ifndef PULL_LE_UINT32
+#define PULL_LE_UINT32(buf,ofs) ((uint32_t)( \
+ ((uint32_t)(((uint32_t)(__PULL_BYTE(buf,(ofs)+0))) << 0)) | \
+ ((uint32_t)(((uint32_t)(__PULL_BYTE(buf,(ofs)+1))) << 8)) | \
+ ((uint32_t)(((uint32_t)(__PULL_BYTE(buf,(ofs)+2))) << 16)) | \
+ ((uint32_t)(((uint32_t)(__PULL_BYTE(buf,(ofs)+3))) << 24)) \
+))
+#endif
+
+static uint32_t xpress_decompress(uint8_t *input,
+ uint32_t input_size,
+ uint8_t *output,
+ uint32_t output_size)
+{
+ uint32_t output_index, input_index;
+ uint32_t indicator, indicator_bit;
+ uint32_t length;
+ uint32_t offset;
+ uint32_t nibble_index;
+
+ output_index = 0;
+ input_index = 0;
+ indicator = 0;
+ indicator_bit = 0;
+ length = 0;
+ offset = 0;
+ nibble_index = 0;
+
+ do {
+ if (indicator_bit == 0) {
+ indicator = PULL_LE_UINT32(input, input_index);
+ input_index += sizeof(uint32_t);
+ indicator_bit = 32;
+ }
+ indicator_bit--;
+
+ /*
+ * check whether the bit specified by indicator_bit is set or not
+ * set in indicator. For example, if indicator_bit has value 4
+ * check whether the 4th bit of the value in indicator is set
+ */
+ if (((indicator >> indicator_bit) & 1) == 0) {
+ output[output_index] = input[input_index];
+ input_index += sizeof(uint8_t);
+ output_index += sizeof(uint8_t);
+ } else {
+ length = PULL_LE_UINT16(input, input_index);
+ input_index += sizeof(uint16_t);
+ offset = length / 8;
+ length = length % 8;
+
+ if (length == 7) {
+ if (nibble_index == 0) {
+ nibble_index = input_index;
+ length = input[input_index] % 16;
+ input_index += sizeof(uint8_t);
+ } else {
+ length = input[nibble_index] / 16;
+ nibble_index = 0;
+ }
+
+ if (length == 15) {
+ length = input[input_index];
+ input_index += sizeof(uint8_t);
+ if (length == 255) {
+ length = PULL_LE_UINT16(input, input_index);
+ input_index += sizeof(uint16_t);
+ length -= (15 + 7);
+ }
+ length += 15;
+ }
+ length += 7;
+ }
+
+ length += 3;
+
+ do {
+ if (output_index >= output_size) break;
+ output[output_index] = output[output_index - offset - 1];
+ output_index += sizeof(uint8_t);
+ length -= sizeof(uint8_t);
+ } while (length != 0);
+ }
+
+ } while ((output_index < output_size) && (input_index < input_size));
+
+ return output_index;
+}
+
+uint32_t lzxpress_decompress(DATA_BLOB *inbuf,
+ DATA_BLOB *outbuf)
+{
+ return xpress_decompress(inbuf->data, inbuf->length, outbuf->data, outbuf->length);
+}