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Diffstat (limited to 'fs/jffs2/compr_lzo.c')
-rw-r--r-- | fs/jffs2/compr_lzo.c | 405 |
1 files changed, 405 insertions, 0 deletions
diff --git a/fs/jffs2/compr_lzo.c b/fs/jffs2/compr_lzo.c new file mode 100644 index 0000000..e97c18f --- /dev/null +++ b/fs/jffs2/compr_lzo.c @@ -0,0 +1,405 @@ +/* + * JFFS2 -- Journalling Flash File System, Version 2. + * + * Copyright (C) 2004 Patrik Kluba, + * University of Szeged, Hungary + * + * For licensing information, see the file 'LICENCE' in the + * jffs2 directory. + * + * $Id: compr_lzo.c,v 1.3 2004/06/23 16:34:39 havasi Exp $ + * + */ + +/* + LZO1X-1 (and -999) compression module for jffs2 + based on the original LZO sources +*/ + +/* -*- Mode: C; indent-tabs-mode: t; c-basic-offset: 4; tab-width: 4 -*- */ + +/* + Original copyright notice follows: + + lzo1x_9x.c -- implementation of the LZO1X-999 compression algorithm + lzo_ptr.h -- low-level pointer constructs + lzo_swd.ch -- sliding window dictionary + lzoconf.h -- configuration for the LZO real-time data compression library + lzo_mchw.ch -- matching functions using a window + minilzo.c -- mini subset of the LZO real-time data compression library + config1x.h -- configuration for the LZO1X algorithm + lzo1x.h -- public interface of the LZO1X compression algorithm + + These files are part of the LZO real-time data compression library. + + Copyright (C) 1996-2002 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., + 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + + Markus F.X.J. Oberhumer + <markus@oberhumer.com> +*/ + +/* + + 2004-02-16 pajko <pajko(AT)halom(DOT)u-szeged(DOT)hu> + Initial release + -removed all 16 bit code + -all sensitive data will be on 4 byte boundary + -removed check parts for library use + -removed all but LZO1X-* compression + +*/ + + +#include <config.h> +#if ((CONFIG_COMMANDS & CFG_CMD_JFFS2) && defined(CONFIG_JFFS2_LZO)) + +#include <linux/stddef.h> +#include <jffs2/jffs2.h> +#include <jffs2/compr_rubin.h> + +/* Integral types that have *exactly* the same number of bits as a lzo_voidp */ +typedef unsigned long lzo_ptr_t; +typedef long lzo_sptr_t; + +/* data type definitions */ +#define U32 unsigned long +#define S32 signed long +#define I32 long +#define U16 unsigned short +#define S16 signed short +#define I16 short +#define U8 unsigned char +#define S8 signed char +#define I8 char + +#define M1_MAX_OFFSET 0x0400 +#define M2_MAX_OFFSET 0x0800 +#define M3_MAX_OFFSET 0x4000 +#define M4_MAX_OFFSET 0xbfff + +#define __COPY4(dst,src) * (lzo_uint32p)(dst) = * (const lzo_uint32p)(src) +#define COPY4(dst,src) __COPY4((lzo_ptr_t)(dst),(lzo_ptr_t)(src)) + +#define TEST_IP (ip < ip_end) +#define TEST_OP (op <= op_end) + +#define NEED_IP(x) \ + if ((lzo_uint)(ip_end - ip) < (lzo_uint)(x)) goto input_overrun +#define NEED_OP(x) \ + if ((lzo_uint)(op_end - op) < (lzo_uint)(x)) goto output_overrun +#define TEST_LOOKBEHIND(m_pos,out) if (m_pos < out) goto lookbehind_overrun + +typedef U32 lzo_uint32; +typedef I32 lzo_int32; +typedef U32 lzo_uint; +typedef I32 lzo_int; +typedef int lzo_bool; + +#define lzo_byte U8 +#define lzo_bytep U8 * +#define lzo_charp char * +#define lzo_voidp void * +#define lzo_shortp short * +#define lzo_ushortp unsigned short * +#define lzo_uint32p lzo_uint32 * +#define lzo_int32p lzo_int32 * +#define lzo_uintp lzo_uint * +#define lzo_intp lzo_int * +#define lzo_voidpp lzo_voidp * +#define lzo_bytepp lzo_bytep * +#define lzo_sizeof_dict_t sizeof(lzo_bytep) + +#define LZO_E_OK 0 +#define LZO_E_ERROR (-1) +#define LZO_E_OUT_OF_MEMORY (-2) /* not used right now */ +#define LZO_E_NOT_COMPRESSIBLE (-3) /* not used right now */ +#define LZO_E_INPUT_OVERRUN (-4) +#define LZO_E_OUTPUT_OVERRUN (-5) +#define LZO_E_LOOKBEHIND_OVERRUN (-6) +#define LZO_E_EOF_NOT_FOUND (-7) +#define LZO_E_INPUT_NOT_CONSUMED (-8) + +#define PTR(a) ((lzo_ptr_t) (a)) +#define PTR_LINEAR(a) PTR(a) +#define PTR_ALIGNED_4(a) ((PTR_LINEAR(a) & 3) == 0) +#define PTR_ALIGNED_8(a) ((PTR_LINEAR(a) & 7) == 0) +#define PTR_ALIGNED2_4(a,b) (((PTR_LINEAR(a) | PTR_LINEAR(b)) & 3) == 0) +#define PTR_ALIGNED2_8(a,b) (((PTR_LINEAR(a) | PTR_LINEAR(b)) & 7) == 0) +#define PTR_LT(a,b) (PTR(a) < PTR(b)) +#define PTR_GE(a,b) (PTR(a) >= PTR(b)) +#define PTR_DIFF(a,b) ((lzo_ptrdiff_t) (PTR(a) - PTR(b))) +#define pd(a,b) ((lzo_uint) ((a)-(b))) + +typedef ptrdiff_t lzo_ptrdiff_t; + +static int +lzo1x_decompress (const lzo_byte * in, lzo_uint in_len, + lzo_byte * out, lzo_uintp out_len, lzo_voidp wrkmem) +{ + register lzo_byte *op; + register const lzo_byte *ip; + register lzo_uint t; + + register const lzo_byte *m_pos; + + const lzo_byte *const ip_end = in + in_len; + lzo_byte *const op_end = out + *out_len; + + *out_len = 0; + + op = out; + ip = in; + + if (*ip > 17) + { + t = *ip++ - 17; + if (t < 4) + goto match_next; + NEED_OP (t); + NEED_IP (t + 1); + do + *op++ = *ip++; + while (--t > 0); + goto first_literal_run; + } + + while (TEST_IP && TEST_OP) + { + t = *ip++; + if (t >= 16) + goto match; + if (t == 0) + { + NEED_IP (1); + while (*ip == 0) + { + t += 255; + ip++; + NEED_IP (1); + } + t += 15 + *ip++; + } + NEED_OP (t + 3); + NEED_IP (t + 4); + if (PTR_ALIGNED2_4 (op, ip)) + { + COPY4 (op, ip); + + op += 4; + ip += 4; + if (--t > 0) + { + if (t >= 4) + { + do + { + COPY4 (op, ip); + op += 4; + ip += 4; + t -= 4; + } + while (t >= 4); + if (t > 0) + do + *op++ = *ip++; + while (--t > 0); + } + else + do + *op++ = *ip++; + while (--t > 0); + } + } + else + { + *op++ = *ip++; + *op++ = *ip++; + *op++ = *ip++; + do + *op++ = *ip++; + while (--t > 0); + } + first_literal_run: + + t = *ip++; + if (t >= 16) + goto match; + + m_pos = op - (1 + M2_MAX_OFFSET); + m_pos -= t >> 2; + m_pos -= *ip++ << 2; + TEST_LOOKBEHIND (m_pos, out); + NEED_OP (3); + *op++ = *m_pos++; + *op++ = *m_pos++; + *op++ = *m_pos; + + goto match_done; + + while (TEST_IP && TEST_OP) + { + match: + if (t >= 64) + { + m_pos = op - 1; + m_pos -= (t >> 2) & 7; + m_pos -= *ip++ << 3; + t = (t >> 5) - 1; + TEST_LOOKBEHIND (m_pos, out); + NEED_OP (t + 3 - 1); + goto copy_match; + + } + else if (t >= 32) + { + t &= 31; + if (t == 0) + { + NEED_IP (1); + while (*ip == 0) + { + t += 255; + ip++; + NEED_IP (1); + } + t += 31 + *ip++; + } + + m_pos = op - 1; + m_pos -= (ip[0] >> 2) + (ip[1] << 6); + + ip += 2; + } + else if (t >= 16) + { + m_pos = op; + m_pos -= (t & 8) << 11; + + t &= 7; + if (t == 0) + { + NEED_IP (1); + while (*ip == 0) + { + t += 255; + ip++; + NEED_IP (1); + } + t += 7 + *ip++; + } + + m_pos -= (ip[0] >> 2) + (ip[1] << 6); + + ip += 2; + if (m_pos == op) + goto eof_found; + m_pos -= 0x4000; + } + else + { + + m_pos = op - 1; + m_pos -= t >> 2; + m_pos -= *ip++ << 2; + TEST_LOOKBEHIND (m_pos, out); + NEED_OP (2); + *op++ = *m_pos++; + *op++ = *m_pos; + + goto match_done; + } + + TEST_LOOKBEHIND (m_pos, out); + NEED_OP (t + 3 - 1); + if (t >= 2 * 4 - (3 - 1) + && PTR_ALIGNED2_4 (op, m_pos)) + { + COPY4 (op, m_pos); + op += 4; + m_pos += 4; + t -= 4 - (3 - 1); + do + { + COPY4 (op, m_pos); + op += 4; + m_pos += 4; + t -= 4; + } + while (t >= 4); + if (t > 0) + do + *op++ = *m_pos++; + while (--t > 0); + } + else + + { + copy_match: + *op++ = *m_pos++; + *op++ = *m_pos++; + do + *op++ = *m_pos++; + while (--t > 0); + } + + match_done: + t = ip[-2] & 3; + + if (t == 0) + break; + + match_next: + NEED_OP (t); + NEED_IP (t + 1); + do + *op++ = *ip++; + while (--t > 0); + t = *ip++; + } + } + *out_len = op - out; + return LZO_E_EOF_NOT_FOUND; + + eof_found: + *out_len = op - out; + return (ip == ip_end ? LZO_E_OK : + (ip < + ip_end ? LZO_E_INPUT_NOT_CONSUMED : LZO_E_INPUT_OVERRUN)); + + input_overrun: + *out_len = op - out; + return LZO_E_INPUT_OVERRUN; + + output_overrun: + *out_len = op - out; + return LZO_E_OUTPUT_OVERRUN; + + lookbehind_overrun: + *out_len = op - out; + return LZO_E_LOOKBEHIND_OVERRUN; +} + +int lzo_decompress(unsigned char *data_in, unsigned char *cpage_out, + u32 srclen, u32 destlen) +{ + lzo_uint outlen = destlen; + return lzo1x_decompress (data_in, srclen, cpage_out, &outlen, NULL); +} + +#endif /* ((CONFIG_COMMANDS & CFG_CMD_JFFS2) && defined(CONFIG_JFFS2_LZO)) */ |