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, see <http://www.gnu.org/licenses/>.
  18 */
  19#ifndef __EWOK_RLW_H__
  20#define __EWOK_RLW_H__
  21
  22#define RLW_RUNNING_BITS (sizeof(eword_t) * 4)
  23#define RLW_LITERAL_BITS (sizeof(eword_t) * 8 - 1 - RLW_RUNNING_BITS)
  24
  25#define RLW_LARGEST_RUNNING_COUNT (((eword_t)1 << RLW_RUNNING_BITS) - 1)
  26#define RLW_LARGEST_LITERAL_COUNT (((eword_t)1 << RLW_LITERAL_BITS) - 1)
  27
  28#define RLW_LARGEST_RUNNING_COUNT_SHIFT (RLW_LARGEST_RUNNING_COUNT << 1)
  29
  30#define RLW_RUNNING_LEN_PLUS_BIT (((eword_t)1 << (RLW_RUNNING_BITS + 1)) - 1)
  31
  32static int rlw_get_run_bit(const eword_t *word)
  33{
  34        return *word & (eword_t)1;
  35}
  36
  37static inline void rlw_set_run_bit(eword_t *word, int b)
  38{
  39        if (b) {
  40                *word |= (eword_t)1;
  41        } else {
  42                *word &= (eword_t)(~1);
  43        }
  44}
  45
  46static inline void rlw_xor_run_bit(eword_t *word)
  47{
  48        if (*word & 1) {
  49                *word &= (eword_t)(~1);
  50        } else {
  51                *word |= (eword_t)1;
  52        }
  53}
  54
  55static inline void rlw_set_running_len(eword_t *word, eword_t l)
  56{
  57        *word |= RLW_LARGEST_RUNNING_COUNT_SHIFT;
  58        *word &= (l << 1) | (~RLW_LARGEST_RUNNING_COUNT_SHIFT);
  59}
  60
  61static inline eword_t rlw_get_running_len(const eword_t *word)
  62{
  63        return (*word >> 1) & RLW_LARGEST_RUNNING_COUNT;
  64}
  65
  66static inline eword_t rlw_get_literal_words(const eword_t *word)
  67{
  68        return *word >> (1 + RLW_RUNNING_BITS);
  69}
  70
  71static inline void rlw_set_literal_words(eword_t *word, eword_t l)
  72{
  73        *word |= ~RLW_RUNNING_LEN_PLUS_BIT;
  74        *word &= (l << (RLW_RUNNING_BITS + 1)) | RLW_RUNNING_LEN_PLUS_BIT;
  75}
  76
  77static inline eword_t rlw_size(const eword_t *self)
  78{
  79        return rlw_get_running_len(self) + rlw_get_literal_words(self);
  80}
  81
  82struct rlw_iterator {
  83        const eword_t *buffer;
  84        size_t size;
  85        size_t pointer;
  86        size_t literal_word_start;
  87
  88        struct {
  89                const eword_t *word;
  90                int literal_words;
  91                int running_len;
  92                int literal_word_offset;
  93                int running_bit;
  94        } rlw;
  95};
  96
  97void rlwit_init(struct rlw_iterator *it, struct ewah_bitmap *bitmap);
  98void rlwit_discard_first_words(struct rlw_iterator *it, size_t x);
  99size_t rlwit_discharge(
 100        struct rlw_iterator *it, struct ewah_bitmap *out, size_t max, int negate);
 101
 102static inline size_t rlwit_word_size(struct rlw_iterator *it)
 103{
 104        return it->rlw.running_len + it->rlw.literal_words;
 105}
 106
 107static inline size_t rlwit_literal_words(struct rlw_iterator *it)
 108{
 109        return it->pointer - it->rlw.literal_words;
 110}
 111
 112#endif