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![Todd Zullinger](/assets/img/avatar_default.png)
The mailing address for the FSF has changed over the years. Rather than updating the address across all files, refer readers to gnu.org, as the GNU GPL documentation now suggests for license notices. The mailing address is retained in the full license files (COPYING and LGPL-2.1). The old address is still present in t/diff-lib/COPYING. This is intentional, as the file is used in tests and the contents are not expected to change. Signed-off-by: Todd Zullinger <tmz@pobox.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
213 lines
4.8 KiB
C
213 lines
4.8 KiB
C
/**
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* Copyright 2013, GitHub, Inc
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* Copyright 2009-2013, Daniel Lemire, Cliff Moon,
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* David McIntosh, Robert Becho, Google Inc. and Veronika Zenz
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, see <http://www.gnu.org/licenses/>.
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*/
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#include "cache.h"
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#include "ewok.h"
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#define EWAH_MASK(x) ((eword_t)1 << (x % BITS_IN_EWORD))
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#define EWAH_BLOCK(x) (x / BITS_IN_EWORD)
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struct bitmap *bitmap_new(void)
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{
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struct bitmap *bitmap = xmalloc(sizeof(struct bitmap));
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bitmap->words = xcalloc(32, sizeof(eword_t));
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bitmap->word_alloc = 32;
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return bitmap;
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}
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void bitmap_set(struct bitmap *self, size_t pos)
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{
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size_t block = EWAH_BLOCK(pos);
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if (block >= self->word_alloc) {
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size_t old_size = self->word_alloc;
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self->word_alloc = block * 2;
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REALLOC_ARRAY(self->words, self->word_alloc);
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memset(self->words + old_size, 0x0,
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(self->word_alloc - old_size) * sizeof(eword_t));
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}
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self->words[block] |= EWAH_MASK(pos);
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}
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void bitmap_clear(struct bitmap *self, size_t pos)
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{
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size_t block = EWAH_BLOCK(pos);
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if (block < self->word_alloc)
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self->words[block] &= ~EWAH_MASK(pos);
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}
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int bitmap_get(struct bitmap *self, size_t pos)
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{
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size_t block = EWAH_BLOCK(pos);
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return block < self->word_alloc &&
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(self->words[block] & EWAH_MASK(pos)) != 0;
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}
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struct ewah_bitmap *bitmap_to_ewah(struct bitmap *bitmap)
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{
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struct ewah_bitmap *ewah = ewah_new();
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size_t i, running_empty_words = 0;
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eword_t last_word = 0;
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for (i = 0; i < bitmap->word_alloc; ++i) {
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if (bitmap->words[i] == 0) {
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running_empty_words++;
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continue;
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}
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if (last_word != 0)
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ewah_add(ewah, last_word);
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if (running_empty_words > 0) {
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ewah_add_empty_words(ewah, 0, running_empty_words);
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running_empty_words = 0;
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}
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last_word = bitmap->words[i];
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}
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ewah_add(ewah, last_word);
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return ewah;
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}
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struct bitmap *ewah_to_bitmap(struct ewah_bitmap *ewah)
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{
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struct bitmap *bitmap = bitmap_new();
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struct ewah_iterator it;
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eword_t blowup;
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size_t i = 0;
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ewah_iterator_init(&it, ewah);
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while (ewah_iterator_next(&blowup, &it)) {
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ALLOC_GROW(bitmap->words, i + 1, bitmap->word_alloc);
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bitmap->words[i++] = blowup;
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}
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bitmap->word_alloc = i;
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return bitmap;
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}
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void bitmap_and_not(struct bitmap *self, struct bitmap *other)
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{
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const size_t count = (self->word_alloc < other->word_alloc) ?
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self->word_alloc : other->word_alloc;
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size_t i;
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for (i = 0; i < count; ++i)
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self->words[i] &= ~other->words[i];
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}
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void bitmap_or_ewah(struct bitmap *self, struct ewah_bitmap *other)
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{
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size_t original_size = self->word_alloc;
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size_t other_final = (other->bit_size / BITS_IN_EWORD) + 1;
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size_t i = 0;
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struct ewah_iterator it;
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eword_t word;
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if (self->word_alloc < other_final) {
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self->word_alloc = other_final;
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REALLOC_ARRAY(self->words, self->word_alloc);
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memset(self->words + original_size, 0x0,
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(self->word_alloc - original_size) * sizeof(eword_t));
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}
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ewah_iterator_init(&it, other);
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while (ewah_iterator_next(&word, &it))
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self->words[i++] |= word;
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}
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void bitmap_each_bit(struct bitmap *self, ewah_callback callback, void *data)
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{
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size_t pos = 0, i;
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for (i = 0; i < self->word_alloc; ++i) {
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eword_t word = self->words[i];
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uint32_t offset;
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if (word == (eword_t)~0) {
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for (offset = 0; offset < BITS_IN_EWORD; ++offset)
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callback(pos++, data);
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} else {
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for (offset = 0; offset < BITS_IN_EWORD; ++offset) {
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if ((word >> offset) == 0)
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break;
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offset += ewah_bit_ctz64(word >> offset);
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callback(pos + offset, data);
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}
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pos += BITS_IN_EWORD;
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}
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}
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}
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size_t bitmap_popcount(struct bitmap *self)
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{
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size_t i, count = 0;
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for (i = 0; i < self->word_alloc; ++i)
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count += ewah_bit_popcount64(self->words[i]);
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return count;
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}
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int bitmap_equals(struct bitmap *self, struct bitmap *other)
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{
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struct bitmap *big, *small;
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size_t i;
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if (self->word_alloc < other->word_alloc) {
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small = self;
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big = other;
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} else {
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small = other;
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big = self;
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}
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for (i = 0; i < small->word_alloc; ++i) {
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if (small->words[i] != big->words[i])
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return 0;
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}
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for (; i < big->word_alloc; ++i) {
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if (big->words[i] != 0)
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return 0;
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}
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return 1;
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}
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void bitmap_reset(struct bitmap *bitmap)
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{
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memset(bitmap->words, 0x0, bitmap->word_alloc * sizeof(eword_t));
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}
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void bitmap_free(struct bitmap *bitmap)
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{
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if (bitmap == NULL)
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return;
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free(bitmap->words);
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free(bitmap);
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}
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