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