lib/compression: Import of lzxpress decompression algorithm

[bbaumbach/samba-autobuild/.git] / source4 / lib / compression / lzxpress.c

diff --git a/source4/lib/compression/lzxpress.c b/source4/lib/compression/lzxpress.c
new file mode 100644 (file)
index 0000000..5063051
--- /dev/null
+++ b/source4/lib/compression/lzxpress.c
@@ -0,0 +1,144 @@
+/*
+ * 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);
+}