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Release 4.16 lib/lzo/lzo1x_compress.c

Directory: lib/lzo
/*
 *  LZO1X Compressor from LZO
 *
 *  Copyright (C) 1996-2012 Markus F.X.J. Oberhumer <markus@oberhumer.com>
 *
 *  The full LZO package can be found at:
 *  http://www.oberhumer.com/opensource/lzo/
 *
 *  Changed for Linux kernel use by:
 *  Nitin Gupta <nitingupta910@gmail.com>
 *  Richard Purdie <rpurdie@openedhand.com>
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <asm/unaligned.h>
#include <linux/lzo.h>
#include "lzodefs.h"


static noinline size_t lzo1x_1_do_compress(const unsigned char *in, size_t in_len, unsigned char *out, size_t *out_len, size_t ti, void *wrkmem) { const unsigned char *ip; unsigned char *op; const unsigned char * const in_end = in + in_len; const unsigned char * const ip_end = in + in_len - 20; const unsigned char *ii; lzo_dict_t * const dict = (lzo_dict_t *) wrkmem; op = out; ip = in; ii = ip; ip += ti < 4 ? 4 - ti : 0; for (;;) { const unsigned char *m_pos; size_t t, m_len, m_off; u32 dv; literal: ip += 1 + ((ip - ii) >> 5); next: if (unlikely(ip >= ip_end)) break; dv = get_unaligned_le32(ip); t = ((dv * 0x1824429d) >> (32 - D_BITS)) & D_MASK; m_pos = in + dict[t]; dict[t] = (lzo_dict_t) (ip - in); if (unlikely(dv != get_unaligned_le32(m_pos))) goto literal; ii -= ti; ti = 0; t = ip - ii; if (t != 0) { if (t <= 3) { op[-2] |= t; COPY4(op, ii); op += t; } else if (t <= 16) { *op++ = (t - 3); COPY8(op, ii); COPY8(op + 8, ii + 8); op += t; } else { if (t <= 18) { *op++ = (t - 3); } else { size_t tt = t - 18; *op++ = 0; while (unlikely(tt > 255)) { tt -= 255; *op++ = 0; } *op++ = tt; } do { COPY8(op, ii); COPY8(op + 8, ii + 8); op += 16; ii += 16; t -= 16; } while (t >= 16); if (t > 0) do { *op++ = *ii++; } while (--t > 0); } } m_len = 4; { #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && defined(LZO_USE_CTZ64) u64 v; v = get_unaligned((const u64 *) (ip + m_len)) ^ get_unaligned((const u64 *) (m_pos + m_len)); if (unlikely(v == 0)) { do { m_len += 8; v = get_unaligned((const u64 *) (ip + m_len)) ^ get_unaligned((const u64 *) (m_pos + m_len)); if (unlikely(ip + m_len >= ip_end)) goto m_len_done; } while (v == 0); } # if defined(__LITTLE_ENDIAN) m_len += (unsigned) __builtin_ctzll(v) / 8; # elif defined(__BIG_ENDIAN) m_len += (unsigned) __builtin_clzll(v) / 8; # else # error "missing endian definition" # endif #elif defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && defined(LZO_USE_CTZ32) u32 v; v = get_unaligned((const u32 *) (ip + m_len)) ^ get_unaligned((const u32 *) (m_pos + m_len)); if (unlikely(v == 0)) { do { m_len += 4; v = get_unaligned((const u32 *) (ip + m_len)) ^ get_unaligned((const u32 *) (m_pos + m_len)); if (v != 0) break; m_len += 4; v = get_unaligned((const u32 *) (ip + m_len)) ^ get_unaligned((const u32 *) (m_pos + m_len)); if (unlikely(ip + m_len >= ip_end)) goto m_len_done; } while (v == 0); } # if defined(__LITTLE_ENDIAN) m_len += (unsigned) __builtin_ctz(v) / 8; # elif defined(__BIG_ENDIAN) m_len += (unsigned) __builtin_clz(v) / 8; # else # error "missing endian definition" # endif #else if (unlikely(ip[m_len] == m_pos[m_len])) { do { m_len += 1; if (ip[m_len] != m_pos[m_len]) break; m_len += 1; if (ip[m_len] != m_pos[m_len]) break; m_len += 1; if (ip[m_len] != m_pos[m_len]) break; m_len += 1; if (ip[m_len] != m_pos[m_len]) break; m_len += 1; if (ip[m_len] != m_pos[m_len]) break; m_len += 1; if (ip[m_len] != m_pos[m_len]) break; m_len += 1; if (ip[m_len] != m_pos[m_len]) break; m_len += 1; if (unlikely(ip + m_len >= ip_end)) goto m_len_done; } while (ip[m_len] == m_pos[m_len]); } #endif } m_len_done: m_off = ip - m_pos; ip += m_len; ii = ip; if (m_len <= M2_MAX_LEN && m_off <= M2_MAX_OFFSET) { m_off -= 1; *op++ = (((m_len - 1) << 5) | ((m_off & 7) << 2)); *op++ = (m_off >> 3); } else if (m_off <= M3_MAX_OFFSET) { m_off -= 1; if (m_len <= M3_MAX_LEN) *op++ = (M3_MARKER | (m_len - 2)); else { m_len -= M3_MAX_LEN; *op++ = M3_MARKER | 0; while (unlikely(m_len > 255)) { m_len -= 255; *op++ = 0; } *op++ = (m_len); } *op++ = (m_off << 2); *op++ = (m_off >> 6); } else { m_off -= 0x4000; if (m_len <= M4_MAX_LEN) *op++ = (M4_MARKER | ((m_off >> 11) & 8) | (m_len - 2)); else { m_len -= M4_MAX_LEN; *op++ = (M4_MARKER | ((m_off >> 11) & 8)); while (unlikely(m_len > 255)) { m_len -= 255; *op++ = 0; } *op++ = (m_len); } *op++ = (m_off << 2); *op++ = (m_off >> 6); } goto next; } *out_len = op - out; return in_end - (ii - ti); }

Contributors

PersonTokensPropCommitsCommitProp
Markus F.X.J. Oberhumer81964.54%133.33%
Richard Purdie45035.46%266.67%
Total1269100.00%3100.00%


int lzo1x_1_compress(const unsigned char *in, size_t in_len, unsigned char *out, size_t *out_len, void *wrkmem) { const unsigned char *ip = in; unsigned char *op = out; size_t l = in_len; size_t t = 0; while (l > 20) { size_t ll = l <= (M4_MAX_OFFSET + 1) ? l : (M4_MAX_OFFSET + 1); uintptr_t ll_end = (uintptr_t) ip + ll; if ((ll_end + ((t + ll) >> 5)) <= ll_end) break; BUILD_BUG_ON(D_SIZE * sizeof(lzo_dict_t) > LZO1X_1_MEM_COMPRESS); memset(wrkmem, 0, D_SIZE * sizeof(lzo_dict_t)); t = lzo1x_1_do_compress(ip, ll, op, out_len, t, wrkmem); ip += ll; op += *out_len; l -= ll; } t += l; if (t > 0) { const unsigned char *ii = in + in_len - t; if (op == out && t <= 238) { *op++ = (17 + t); } else if (t <= 3) { op[-2] |= t; } else if (t <= 18) { *op++ = (t - 3); } else { size_t tt = t - 18; *op++ = 0; while (tt > 255) { tt -= 255; *op++ = 0; } *op++ = tt; } if (t >= 16) do { COPY8(op, ii); COPY8(op + 8, ii + 8); op += 16; ii += 16; t -= 16; } while (t >= 16); if (t > 0) do { *op++ = *ii++; } while (--t > 0); } *op++ = M4_MARKER | 1; *op++ = 0; *op++ = 0; *out_len = op - out; return LZO_E_OK; }

Contributors

PersonTokensPropCommitsCommitProp
Richard Purdie22758.66%150.00%
Markus F.X.J. Oberhumer16041.34%150.00%
Total387100.00%2100.00%

EXPORT_SYMBOL_GPL(lzo1x_1_compress); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("LZO1X-1 Compressor");

Overall Contributors

PersonTokensPropCommitsCommitProp
Markus F.X.J. Oberhumer98258.21%133.33%
Richard Purdie70541.79%266.67%
Total1687100.00%3100.00%
Directory: lib/lzo
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