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authorArne Schwabe <arne@rfc2549.org>2012-04-16 19:21:14 +0200
committerArne Schwabe <arne@rfc2549.org>2012-04-16 19:21:14 +0200
commit3e4d8f433239c40311037616b1b8833a06651ae0 (patch)
tree98ab7fce0d011d34677b0beb762d389cb5c39199 /lzo/src/lzo1f_d.ch
Initial import
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+/* lzo1f_d.ch -- implementation of the LZO1F decompression algorithm
+
+ This file is part of the LZO real-time data compression library.
+
+ Copyright (C) 2008 Markus Franz Xaver Johannes Oberhumer
+ Copyright (C) 2007 Markus Franz Xaver Johannes Oberhumer
+ Copyright (C) 2006 Markus Franz Xaver Johannes Oberhumer
+ Copyright (C) 2005 Markus Franz Xaver Johannes Oberhumer
+ Copyright (C) 2004 Markus Franz Xaver Johannes Oberhumer
+ Copyright (C) 2003 Markus Franz Xaver Johannes Oberhumer
+ Copyright (C) 2002 Markus Franz Xaver Johannes Oberhumer
+ Copyright (C) 2001 Markus Franz Xaver Johannes Oberhumer
+ Copyright (C) 2000 Markus Franz Xaver Johannes Oberhumer
+ Copyright (C) 1999 Markus Franz Xaver Johannes Oberhumer
+ Copyright (C) 1998 Markus Franz Xaver Johannes Oberhumer
+ Copyright (C) 1997 Markus Franz Xaver Johannes Oberhumer
+ Copyright (C) 1996 Markus Franz Xaver Johannes Oberhumer
+ All Rights Reserved.
+
+ The LZO library 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 of
+ the License, or (at your option) any later version.
+
+ The LZO library 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 the LZO library; see the file COPYING.
+ If not, write to the Free Software Foundation, Inc.,
+ 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+
+ Markus F.X.J. Oberhumer
+ <markus@oberhumer.com>
+ http://www.oberhumer.com/opensource/lzo/
+ */
+
+
+#include "lzo1_d.ch"
+
+
+/***********************************************************************
+// decompress a block of data.
+************************************************************************/
+
+LZO_PUBLIC(int)
+DO_DECOMPRESS ( const lzo_bytep in , lzo_uint in_len,
+ lzo_bytep out, lzo_uintp out_len,
+ lzo_voidp wrkmem )
+{
+ register lzo_bytep op;
+ register const lzo_bytep ip;
+ register lzo_uint t;
+ register const lzo_bytep m_pos;
+
+ const lzo_bytep const ip_end = in + in_len;
+#if defined(HAVE_ANY_OP)
+ lzo_bytep const op_end = out + *out_len;
+#endif
+
+ LZO_UNUSED(wrkmem);
+
+ *out_len = 0;
+
+ op = out;
+ ip = in;
+
+ while (TEST_IP && TEST_OP)
+ {
+ t = *ip++;
+ if (t > 31)
+ goto match;
+
+ /* a literal run */
+ if (t == 0)
+ {
+ NEED_IP(1);
+ while (*ip == 0)
+ {
+ t += 255;
+ ip++;
+ NEED_IP(1);
+ }
+ t += 31 + *ip++;
+ }
+ /* copy literals */
+ assert(t > 0); NEED_OP(t); NEED_IP(t+1);
+#if defined(LZO_UNALIGNED_OK_4)
+ if (t >= 4)
+ {
+ do {
+ * (lzo_uint32p) op = * (const lzo_uint32p) ip;
+ op += 4; ip += 4; t -= 4;
+ } while (t >= 4);
+ if (t > 0) do *op++ = *ip++; while (--t > 0);
+ }
+ else
+#endif
+ do *op++ = *ip++; while (--t > 0);
+
+ t = *ip++;
+
+ while (TEST_IP && TEST_OP)
+ {
+ /* handle matches */
+ if (t < 32)
+ {
+ m_pos = op - 1 - 0x800;
+ m_pos -= (t >> 2) & 7;
+ m_pos -= *ip++ << 3;
+ TEST_LB(m_pos); NEED_OP(3);
+ *op++ = *m_pos++; *op++ = *m_pos++; *op++ = *m_pos++;
+ }
+ else
+ {
+match:
+ if (t < M3_MARKER)
+ {
+ m_pos = op - 1;
+ m_pos -= (t >> 2) & 7;
+ m_pos -= *ip++ << 3;
+ t >>= 5;
+ TEST_LB(m_pos); assert(t > 0); NEED_OP(t+3-1);
+ goto copy_match;
+ }
+ else
+ {
+ t &= 31;
+ if (t == 0)
+ {
+ NEED_IP(1);
+ while (*ip == 0)
+ {
+ t += 255;
+ ip++;
+ NEED_IP(1);
+ }
+ t += 31 + *ip++;
+ }
+ NEED_IP(2);
+ m_pos = op;
+#if defined(LZO_UNALIGNED_OK_2) && defined(LZO_ABI_LITTLE_ENDIAN)
+ m_pos -= (* (const lzo_ushortp) ip) >> 2;
+ ip += 2;
+#else
+ m_pos -= *ip++ >> 2;
+ m_pos -= *ip++ << 6;
+#endif
+ if (m_pos == op)
+ goto eof_found;
+ }
+
+ /* copy match */
+ TEST_LB(m_pos); assert(t > 0); NEED_OP(t+3-1);
+#if defined(LZO_UNALIGNED_OK_4)
+ if (t >= 2 * 4 - (3 - 1) && (op - m_pos) >= 4)
+ {
+ * (lzo_uint32p) op = * (const lzo_uint32p) m_pos;
+ op += 4; m_pos += 4; t -= 4 - (3 - 1);
+ do {
+ * (lzo_uint32p) op = * (const lzo_uint32p) m_pos;
+ op += 4; m_pos += 4; t -= 4;
+ } while (t >= 4);
+ if (t > 0) do *op++ = *m_pos++; while (--t > 0);
+ }
+ else
+#endif
+ {
+copy_match:
+ *op++ = *m_pos++; *op++ = *m_pos++;
+ do *op++ = *m_pos++; while (--t > 0);
+ }
+ }
+ t = ip[-2] & 3;
+ if (t == 0)
+ break;
+
+ /* copy literals */
+ assert(t > 0); NEED_OP(t); NEED_IP(t+1);
+ do *op++ = *ip++; while (--t > 0);
+ t = *ip++;
+ }
+ }
+
+#if defined(HAVE_TEST_IP) || defined(HAVE_TEST_OP)
+ /* no EOF code was found */
+ *out_len = pd(op, out);
+ return LZO_E_EOF_NOT_FOUND;
+#endif
+
+eof_found:
+ assert(t == 1);
+ *out_len = pd(op, out);
+ return (ip == ip_end ? LZO_E_OK :
+ (ip < ip_end ? LZO_E_INPUT_NOT_CONSUMED : LZO_E_INPUT_OVERRUN));
+
+
+#if defined(HAVE_NEED_IP)
+input_overrun:
+ *out_len = pd(op, out);
+ return LZO_E_INPUT_OVERRUN;
+#endif
+
+#if defined(HAVE_NEED_OP)
+output_overrun:
+ *out_len = pd(op, out);
+ return LZO_E_OUTPUT_OVERRUN;
+#endif
+
+#if defined(LZO_TEST_OVERRUN_LOOKBEHIND)
+lookbehind_overrun:
+ *out_len = pd(op, out);
+ return LZO_E_LOOKBEHIND_OVERRUN;
+#endif
+}
+
+
+/*
+vi:ts=4:et
+*/
+