Andrew's git - gitweb.git/blob

   1/**
   2 * Copyright 2013, GitHub, Inc
   3 * Copyright 2009-2013, Daniel Lemire, Cliff Moon,
   4 *      David McIntosh, Robert Becho, Google Inc. and Veronika Zenz
   5 *
   6 * This program is free software; you can redistribute it and/or
   7 * modify it under the terms of the GNU General Public License
   8 * as published by the Free Software Foundation; either version 2
   9 * of the License, or (at your option) any later version.
  10 *
  11 * This program is distributed in the hope that it will be useful,
  12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 * GNU General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * along with this program; if not, write to the Free Software
  18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  19 */
  20#ifndef __EWOK_RLW_H__
  21#define __EWOK_RLW_H__
  22
  23#define RLW_RUNNING_BITS (sizeof(eword_t) * 4)
  24#define RLW_LITERAL_BITS (sizeof(eword_t) * 8 - 1 - RLW_RUNNING_BITS)
  25
  26#define RLW_LARGEST_RUNNING_COUNT (((eword_t)1 << RLW_RUNNING_BITS) - 1)
  27#define RLW_LARGEST_LITERAL_COUNT (((eword_t)1 << RLW_LITERAL_BITS) - 1)
  28
  29#define RLW_LARGEST_RUNNING_COUNT_SHIFT (RLW_LARGEST_RUNNING_COUNT << 1)
  30
  31#define RLW_RUNNING_LEN_PLUS_BIT (((eword_t)1 << (RLW_RUNNING_BITS + 1)) - 1)
  32
  33static int rlw_get_run_bit(const eword_t *word)
  34{
  35        return *word & (eword_t)1;
  36}
  37
  38static inline void rlw_set_run_bit(eword_t *word, int b)
  39{
  40        if (b) {
  41                *word |= (eword_t)1;
  42        } else {
  43                *word &= (eword_t)(~1);
  44        }
  45}
  46
  47static inline void rlw_xor_run_bit(eword_t *word)
  48{
  49        if (*word & 1) {
  50                *word &= (eword_t)(~1);
  51        } else {
  52                *word |= (eword_t)1;
  53        }
  54}
  55
  56static inline void rlw_set_running_len(eword_t *word, eword_t l)
  57{
  58        *word |= RLW_LARGEST_RUNNING_COUNT_SHIFT;
  59        *word &= (l << 1) | (~RLW_LARGEST_RUNNING_COUNT_SHIFT);
  60}
  61
  62static inline eword_t rlw_get_running_len(const eword_t *word)
  63{
  64        return (*word >> 1) & RLW_LARGEST_RUNNING_COUNT;
  65}
  66
  67static inline eword_t rlw_get_literal_words(const eword_t *word)
  68{
  69        return *word >> (1 + RLW_RUNNING_BITS);
  70}
  71
  72static inline void rlw_set_literal_words(eword_t *word, eword_t l)
  73{
  74        *word |= ~RLW_RUNNING_LEN_PLUS_BIT;
  75        *word &= (l << (RLW_RUNNING_BITS + 1)) | RLW_RUNNING_LEN_PLUS_BIT;
  76}
  77
  78static inline eword_t rlw_size(const eword_t *self)
  79{
  80        return rlw_get_running_len(self) + rlw_get_literal_words(self);
  81}
  82
  83struct rlw_iterator {
  84        const eword_t *buffer;
  85        size_t size;
  86        size_t pointer;
  87        size_t literal_word_start;
  88
  89        struct {
  90                const eword_t *word;
  91                int literal_words;
  92                int running_len;
  93                int literal_word_offset;
  94                int running_bit;
  95        } rlw;
  96};
  97
  98void rlwit_init(struct rlw_iterator *it, struct ewah_bitmap *bitmap);
  99void rlwit_discard_first_words(struct rlw_iterator *it, size_t x);
 100size_t rlwit_discharge(
 101        struct rlw_iterator *it, struct ewah_bitmap *out, size_t max, int negate);
 102void rlwit_discharge_empty(struct rlw_iterator *it, struct ewah_bitmap *out);
 103
 104static inline size_t rlwit_word_size(struct rlw_iterator *it)
 105{
 106        return it->rlw.running_len + it->rlw.literal_words;
 107}
 108
 109static inline size_t rlwit_literal_words(struct rlw_iterator *it)
 110{
 111        return it->pointer - it->rlw.literal_words;
 112}
 113
 114#endif