/**

 * Copyright 2013, GitHub, Inc

 * Copyright 2009-2013, Daniel Lemire, Cliff Moon,

 *  David McIntosh, Robert Becho, Google Inc. and Veronika Zenz

 *

 * This program 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.

 *

 * This program 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 this program; if not, see <http://www.gnu.org/licenses/>.

 */

#ifndef __EWOK_BITMAP_H__

#define __EWOK_BITMAP_H__

struct strbuf;

typedef uint64_t eword_t;

#define BITS_IN_EWORD (sizeof(eword_t) * 8)

/**

 * Do not use __builtin_popcountll. The GCC implementation

 * is notoriously slow on all platforms.

 *

 * See: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36041

 */

static inline uint32_t ewah_bit_popcount64(uint64_t x)

{

  x = (x & 0x5555555555555555ULL) + ((x >>  1) & 0x5555555555555555ULL);

  x = (x & 0x3333333333333333ULL) + ((x >>  2) & 0x3333333333333333ULL);

  x = (x & 0x0F0F0F0F0F0F0F0FULL) + ((x >>  4) & 0x0F0F0F0F0F0F0F0FULL);

  return (x * 0x0101010101010101ULL) >> 56;

}

Unexecuted instantiation: dir.c:ewah_bit_popcount64

Unexecuted instantiation: ewah_bitmap.c:ewah_bit_popcount64

Unexecuted instantiation: ewah_io.c:ewah_bit_popcount64

Unexecuted instantiation: ewah_rlw.c:ewah_bit_popcount64

Unexecuted instantiation: fsmonitor.c:ewah_bit_popcount64

Unexecuted instantiation: sparse-index.c:ewah_bit_popcount64

Unexecuted instantiation: split-index.c:ewah_bit_popcount64

Unexecuted instantiation: commit-reach.c:ewah_bit_popcount64

Unexecuted instantiation: bitmap.c:ewah_bit_popcount64

Unexecuted instantiation: midx.c:ewah_bit_popcount64

/* __builtin_ctzll was not available until 3.4.0 */

#if defined(__GNUC__) && (__GNUC__ > 3 || (__GNUC__ == 3  && __GNUC_MINOR > 3))

#define ewah_bit_ctz64(x) __builtin_ctzll(x)

#else

static inline int ewah_bit_ctz64(uint64_t x)

{

  int n = 0;

  if ((x & 0xffffffff) == 0) { x >>= 32; n += 32; }

  if ((x &     0xffff) == 0) { x >>= 16; n += 16; }

  if ((x &       0xff) == 0) { x >>=  8; n +=  8; }

  if ((x &        0xf) == 0) { x >>=  4; n +=  4; }

  if ((x &        0x3) == 0) { x >>=  2; n +=  2; }

  if ((x &        0x1) == 0) { x >>=  1; n +=  1; }

  return n + !x;

}

#endif

struct ewah_bitmap {

  eword_t *buffer;

  size_t buffer_size;

  size_t alloc_size;

  size_t bit_size;

  eword_t *rlw;

};

typedef void (*ewah_callback)(size_t pos, void *);

struct ewah_bitmap *ewah_pool_new(void);

void ewah_pool_free(struct ewah_bitmap *self);

/**

 * Allocate a new EWAH Compressed bitmap

 */

struct ewah_bitmap *ewah_new(void);

/**

 * Free all the memory of the bitmap

 */

void ewah_free(struct ewah_bitmap *self);

int ewah_serialize_to(struct ewah_bitmap *self,

          int (*write_fun)(void *out, const void *buf, size_t len),

          void *out);

int ewah_serialize_strbuf(struct ewah_bitmap *self, struct strbuf *);

ssize_t ewah_read_mmap(struct ewah_bitmap *self, const void *map, size_t len);

uint32_t ewah_checksum(struct ewah_bitmap *self);

/**

 * Call the given callback with the position of every single bit

 * that has been set on the bitmap.

 *

 * This is an efficient operation that does not fully decompress

 * the bitmap.

 */

void ewah_each_bit(struct ewah_bitmap *self, ewah_callback callback, void *payload);

/**

 * Set a given bit on the bitmap.

 *

 * The bit at position `pos` will be set to true. Because of the

 * way that the bitmap is compressed, a set bit cannot be unset

 * later on.

 *

 * Furthermore, since the bitmap uses streaming compression, bits

 * can only set incrementally.

 *

 * E.g.

 *    ewah_set(bitmap, 1); // ok

 *    ewah_set(bitmap, 76); // ok

 *    ewah_set(bitmap, 77); // ok

 *    ewah_set(bitmap, 8712800127); // ok

 *    ewah_set(bitmap, 25); // failed, assert raised

 */

void ewah_set(struct ewah_bitmap *self, size_t i);

struct ewah_iterator {

  const eword_t *buffer;

  size_t buffer_size;

  size_t pointer;

  eword_t compressed, literals;

  eword_t rl, lw;

  int b;

};

/**

 * Initialize a new iterator to run through the bitmap in uncompressed form.

 *

 * The iterator can be stack allocated. The underlying bitmap must not be freed

 * before the iteration is over.

 *

 * E.g.

 *

 *    struct ewah_bitmap *bitmap = ewah_new();

 *    struct ewah_iterator it;

 *

 *    ewah_iterator_init(&it, bitmap);

 */

void ewah_iterator_init(struct ewah_iterator *it, struct ewah_bitmap *parent);

/**

 * Yield every single word in the bitmap in uncompressed form. This is:

 * yield single words (32-64 bits) where each bit represents an actual

 * bit from the bitmap.

 *

 * Return: true if a word was yield, false if there are no words left

 */

int ewah_iterator_next(eword_t *next, struct ewah_iterator *it);

struct ewah_or_iterator {

  struct ewah_iterator *its;

  size_t nr;

};

void ewah_or_iterator_init(struct ewah_or_iterator *it,

         struct ewah_bitmap **parents, size_t nr);

int ewah_or_iterator_next(eword_t *next, struct ewah_or_iterator *it);

void ewah_or_iterator_release(struct ewah_or_iterator *it);

void ewah_xor(

  struct ewah_bitmap *ewah_i,

  struct ewah_bitmap *ewah_j,

  struct ewah_bitmap *out);

/**

 * Direct word access

 */

size_t ewah_add_empty_words(struct ewah_bitmap *self, int v, size_t number);

void ewah_add_dirty_words(

  struct ewah_bitmap *self, const eword_t *buffer, size_t number, int negate);

size_t ewah_add(struct ewah_bitmap *self, eword_t word);

/**

 * Uncompressed, old-school bitmap that can be efficiently compressed

 * into an `ewah_bitmap`.

 */

struct bitmap {

  eword_t *words;

  size_t word_alloc;

};

struct bitmap *bitmap_new(void);

struct bitmap *bitmap_word_alloc(size_t word_alloc);

struct bitmap *bitmap_dup(const struct bitmap *src);

void bitmap_set(struct bitmap *self, size_t pos);

void bitmap_unset(struct bitmap *self, size_t pos);

int bitmap_get(struct bitmap *self, size_t pos);

void bitmap_free(struct bitmap *self);

int bitmap_equals(struct bitmap *self, struct bitmap *other);

int bitmap_equals_ewah(struct bitmap *self, struct ewah_bitmap *other);

/*

 * Both `bitmap_is_subset()` and `ewah_bitmap_is_subset()` return 1 if the set

 * of bits in 'self' are a subset of the bits in 'other'. Returns 0 otherwise.

 */

int bitmap_is_subset(struct bitmap *self, struct bitmap *other);

int ewah_bitmap_is_subset(struct ewah_bitmap *self, struct bitmap *other);

struct ewah_bitmap * bitmap_to_ewah(struct bitmap *bitmap);

struct bitmap *ewah_to_bitmap(struct ewah_bitmap *ewah);

void bitmap_and_not(struct bitmap *self, struct bitmap *other);

void bitmap_or_ewah(struct bitmap *self, struct ewah_bitmap *other);

void bitmap_or(struct bitmap *self, const struct bitmap *other);

size_t bitmap_popcount(struct bitmap *self);

size_t ewah_bitmap_popcount(struct ewah_bitmap *self);

int bitmap_is_empty(struct bitmap *self);

#endif