diff options
Diffstat (limited to 'third_party/git/ewah/ewah_bitmap.c')
| -rw-r--r-- | third_party/git/ewah/ewah_bitmap.c | 484 |
1 files changed, 0 insertions, 484 deletions
diff --git a/third_party/git/ewah/ewah_bitmap.c b/third_party/git/ewah/ewah_bitmap.c deleted file mode 100644 index d59b1afe3d6a..000000000000 --- a/third_party/git/ewah/ewah_bitmap.c +++ /dev/null @@ -1,484 +0,0 @@ -/** - * 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/>. - */ -#include "git-compat-util.h" -#include "ewok.h" -#include "ewok_rlw.h" - -static inline size_t min_size(size_t a, size_t b) -{ - return a < b ? a : b; -} - -static inline size_t max_size(size_t a, size_t b) -{ - return a > b ? a : b; -} - -static inline void buffer_grow(struct ewah_bitmap *self, size_t new_size) -{ - size_t rlw_offset = (uint8_t *)self->rlw - (uint8_t *)self->buffer; - - if (self->alloc_size >= new_size) - return; - - self->alloc_size = new_size; - REALLOC_ARRAY(self->buffer, self->alloc_size); - self->rlw = self->buffer + (rlw_offset / sizeof(eword_t)); -} - -static inline void buffer_push(struct ewah_bitmap *self, eword_t value) -{ - if (self->buffer_size + 1 >= self->alloc_size) - buffer_grow(self, self->buffer_size * 3 / 2); - - self->buffer[self->buffer_size++] = value; -} - -static void buffer_push_rlw(struct ewah_bitmap *self, eword_t value) -{ - buffer_push(self, value); - self->rlw = self->buffer + self->buffer_size - 1; -} - -static size_t add_empty_words(struct ewah_bitmap *self, int v, size_t number) -{ - size_t added = 0; - eword_t runlen, can_add; - - if (rlw_get_run_bit(self->rlw) != v && rlw_size(self->rlw) == 0) { - rlw_set_run_bit(self->rlw, v); - } else if (rlw_get_literal_words(self->rlw) != 0 || - rlw_get_run_bit(self->rlw) != v) { - buffer_push_rlw(self, 0); - if (v) rlw_set_run_bit(self->rlw, v); - added++; - } - - runlen = rlw_get_running_len(self->rlw); - can_add = min_size(number, RLW_LARGEST_RUNNING_COUNT - runlen); - - rlw_set_running_len(self->rlw, runlen + can_add); - number -= can_add; - - while (number >= RLW_LARGEST_RUNNING_COUNT) { - buffer_push_rlw(self, 0); - added++; - if (v) rlw_set_run_bit(self->rlw, v); - rlw_set_running_len(self->rlw, RLW_LARGEST_RUNNING_COUNT); - number -= RLW_LARGEST_RUNNING_COUNT; - } - - if (number > 0) { - buffer_push_rlw(self, 0); - added++; - - if (v) rlw_set_run_bit(self->rlw, v); - rlw_set_running_len(self->rlw, number); - } - - return added; -} - -size_t ewah_add_empty_words(struct ewah_bitmap *self, int v, size_t number) -{ - if (number == 0) - return 0; - - self->bit_size += number * BITS_IN_EWORD; - return add_empty_words(self, v, number); -} - -static size_t add_literal(struct ewah_bitmap *self, eword_t new_data) -{ - eword_t current_num = rlw_get_literal_words(self->rlw); - - if (current_num >= RLW_LARGEST_LITERAL_COUNT) { - buffer_push_rlw(self, 0); - - rlw_set_literal_words(self->rlw, 1); - buffer_push(self, new_data); - return 2; - } - - rlw_set_literal_words(self->rlw, current_num + 1); - - /* sanity check */ - assert(rlw_get_literal_words(self->rlw) == current_num + 1); - - buffer_push(self, new_data); - return 1; -} - -void ewah_add_dirty_words( - struct ewah_bitmap *self, const eword_t *buffer, - size_t number, int negate) -{ - size_t literals, can_add; - - while (1) { - literals = rlw_get_literal_words(self->rlw); - can_add = min_size(number, RLW_LARGEST_LITERAL_COUNT - literals); - - rlw_set_literal_words(self->rlw, literals + can_add); - - if (self->buffer_size + can_add >= self->alloc_size) - buffer_grow(self, (self->buffer_size + can_add) * 3 / 2); - - if (negate) { - size_t i; - for (i = 0; i < can_add; ++i) - self->buffer[self->buffer_size++] = ~buffer[i]; - } else { - memcpy(self->buffer + self->buffer_size, - buffer, can_add * sizeof(eword_t)); - self->buffer_size += can_add; - } - - self->bit_size += can_add * BITS_IN_EWORD; - - if (number - can_add == 0) - break; - - buffer_push_rlw(self, 0); - buffer += can_add; - number -= can_add; - } -} - -static size_t add_empty_word(struct ewah_bitmap *self, int v) -{ - int no_literal = (rlw_get_literal_words(self->rlw) == 0); - eword_t run_len = rlw_get_running_len(self->rlw); - - if (no_literal && run_len == 0) { - rlw_set_run_bit(self->rlw, v); - assert(rlw_get_run_bit(self->rlw) == v); - } - - if (no_literal && rlw_get_run_bit(self->rlw) == v && - run_len < RLW_LARGEST_RUNNING_COUNT) { - rlw_set_running_len(self->rlw, run_len + 1); - assert(rlw_get_running_len(self->rlw) == run_len + 1); - return 0; - } else { - buffer_push_rlw(self, 0); - - assert(rlw_get_running_len(self->rlw) == 0); - assert(rlw_get_run_bit(self->rlw) == 0); - assert(rlw_get_literal_words(self->rlw) == 0); - - rlw_set_run_bit(self->rlw, v); - assert(rlw_get_run_bit(self->rlw) == v); - - rlw_set_running_len(self->rlw, 1); - assert(rlw_get_running_len(self->rlw) == 1); - assert(rlw_get_literal_words(self->rlw) == 0); - return 1; - } -} - -size_t ewah_add(struct ewah_bitmap *self, eword_t word) -{ - self->bit_size += BITS_IN_EWORD; - - if (word == 0) - return add_empty_word(self, 0); - - if (word == (eword_t)(~0)) - return add_empty_word(self, 1); - - return add_literal(self, word); -} - -void ewah_set(struct ewah_bitmap *self, size_t i) -{ - const size_t dist = - DIV_ROUND_UP(i + 1, BITS_IN_EWORD) - - DIV_ROUND_UP(self->bit_size, BITS_IN_EWORD); - - assert(i >= self->bit_size); - - self->bit_size = i + 1; - - if (dist > 0) { - if (dist > 1) - add_empty_words(self, 0, dist - 1); - - add_literal(self, (eword_t)1 << (i % BITS_IN_EWORD)); - return; - } - - if (rlw_get_literal_words(self->rlw) == 0) { - rlw_set_running_len(self->rlw, - rlw_get_running_len(self->rlw) - 1); - add_literal(self, (eword_t)1 << (i % BITS_IN_EWORD)); - return; - } - - self->buffer[self->buffer_size - 1] |= - ((eword_t)1 << (i % BITS_IN_EWORD)); - - /* check if we just completed a stream of 1s */ - if (self->buffer[self->buffer_size - 1] == (eword_t)(~0)) { - self->buffer[--self->buffer_size] = 0; - rlw_set_literal_words(self->rlw, - rlw_get_literal_words(self->rlw) - 1); - add_empty_word(self, 1); - } -} - -void ewah_each_bit(struct ewah_bitmap *self, void (*callback)(size_t, void*), void *payload) -{ - size_t pos = 0; - size_t pointer = 0; - size_t k; - - while (pointer < self->buffer_size) { - eword_t *word = &self->buffer[pointer]; - - if (rlw_get_run_bit(word)) { - size_t len = rlw_get_running_len(word) * BITS_IN_EWORD; - for (k = 0; k < len; ++k, ++pos) - callback(pos, payload); - } else { - pos += rlw_get_running_len(word) * BITS_IN_EWORD; - } - - ++pointer; - - for (k = 0; k < rlw_get_literal_words(word); ++k) { - int c; - - /* todo: zero count optimization */ - for (c = 0; c < BITS_IN_EWORD; ++c, ++pos) { - if ((self->buffer[pointer] & ((eword_t)1 << c)) != 0) - callback(pos, payload); - } - - ++pointer; - } - } -} - -/** - * Clear all the bits in the bitmap. Does not free or resize - * memory. - */ -static void ewah_clear(struct ewah_bitmap *self) -{ - self->buffer_size = 1; - self->buffer[0] = 0; - self->bit_size = 0; - self->rlw = self->buffer; -} - -struct ewah_bitmap *ewah_new(void) -{ - struct ewah_bitmap *self; - - self = xmalloc(sizeof(struct ewah_bitmap)); - self->alloc_size = 32; - ALLOC_ARRAY(self->buffer, self->alloc_size); - - ewah_clear(self); - return self; -} - -void ewah_free(struct ewah_bitmap *self) -{ - if (!self) - return; - - if (self->alloc_size) - free(self->buffer); - - free(self); -} - -static void read_new_rlw(struct ewah_iterator *it) -{ - const eword_t *word = NULL; - - it->literals = 0; - it->compressed = 0; - - while (1) { - word = &it->buffer[it->pointer]; - - it->rl = rlw_get_running_len(word); - it->lw = rlw_get_literal_words(word); - it->b = rlw_get_run_bit(word); - - if (it->rl || it->lw) - return; - - if (it->pointer < it->buffer_size - 1) { - it->pointer++; - } else { - it->pointer = it->buffer_size; - return; - } - } -} - -int ewah_iterator_next(eword_t *next, struct ewah_iterator *it) -{ - if (it->pointer >= it->buffer_size) - return 0; - - if (it->compressed < it->rl) { - it->compressed++; - *next = it->b ? (eword_t)(~0) : 0; - } else { - assert(it->literals < it->lw); - - it->literals++; - it->pointer++; - - assert(it->pointer < it->buffer_size); - - *next = it->buffer[it->pointer]; - } - - if (it->compressed == it->rl && it->literals == it->lw) { - if (++it->pointer < it->buffer_size) - read_new_rlw(it); - } - - return 1; -} - -void ewah_iterator_init(struct ewah_iterator *it, struct ewah_bitmap *parent) -{ - it->buffer = parent->buffer; - it->buffer_size = parent->buffer_size; - it->pointer = 0; - - it->lw = 0; - it->rl = 0; - it->compressed = 0; - it->literals = 0; - it->b = 0; - - if (it->pointer < it->buffer_size) - read_new_rlw(it); -} - -void ewah_xor( - struct ewah_bitmap *ewah_i, - struct ewah_bitmap *ewah_j, - struct ewah_bitmap *out) -{ - struct rlw_iterator rlw_i; - struct rlw_iterator rlw_j; - size_t literals; - - rlwit_init(&rlw_i, ewah_i); - rlwit_init(&rlw_j, ewah_j); - - while (rlwit_word_size(&rlw_i) > 0 && rlwit_word_size(&rlw_j) > 0) { - while (rlw_i.rlw.running_len > 0 || rlw_j.rlw.running_len > 0) { - struct rlw_iterator *prey, *predator; - size_t index; - int negate_words; - - if (rlw_i.rlw.running_len < rlw_j.rlw.running_len) { - prey = &rlw_i; - predator = &rlw_j; - } else { - prey = &rlw_j; - predator = &rlw_i; - } - - negate_words = !!predator->rlw.running_bit; - index = rlwit_discharge(prey, out, - predator->rlw.running_len, negate_words); - - ewah_add_empty_words(out, negate_words, - predator->rlw.running_len - index); - - rlwit_discard_first_words(predator, - predator->rlw.running_len); - } - - literals = min_size( - rlw_i.rlw.literal_words, - rlw_j.rlw.literal_words); - - if (literals) { - size_t k; - - for (k = 0; k < literals; ++k) { - ewah_add(out, - rlw_i.buffer[rlw_i.literal_word_start + k] ^ - rlw_j.buffer[rlw_j.literal_word_start + k] - ); - } - - rlwit_discard_first_words(&rlw_i, literals); - rlwit_discard_first_words(&rlw_j, literals); - } - } - - if (rlwit_word_size(&rlw_i) > 0) - rlwit_discharge(&rlw_i, out, ~0, 0); - else - rlwit_discharge(&rlw_j, out, ~0, 0); - - out->bit_size = max_size(ewah_i->bit_size, ewah_j->bit_size); -} - -#define BITMAP_POOL_MAX 16 -static struct ewah_bitmap *bitmap_pool[BITMAP_POOL_MAX]; -static size_t bitmap_pool_size; - -struct ewah_bitmap *ewah_pool_new(void) -{ - if (bitmap_pool_size) - return bitmap_pool[--bitmap_pool_size]; - - return ewah_new(); -} - -void ewah_pool_free(struct ewah_bitmap *self) -{ - if (self == NULL) - return; - - if (bitmap_pool_size == BITMAP_POOL_MAX || - self->alloc_size == 0) { - ewah_free(self); - return; - } - - ewah_clear(self); - bitmap_pool[bitmap_pool_size++] = self; -} - -uint32_t ewah_checksum(struct ewah_bitmap *self) -{ - const uint8_t *p = (uint8_t *)self->buffer; - uint32_t crc = (uint32_t)self->bit_size; - size_t size = self->buffer_size * sizeof(eword_t); - - while (size--) - crc = (crc << 5) - crc + (uint32_t)*p++; - - return crc; -} |