diff options
Diffstat (limited to 'ewah')
| -rw-r--r-- | ewah/bitmap.c | 221 | ||||
| -rw-r--r-- | ewah/ewah_bitmap.c | 714 | ||||
| -rw-r--r-- | ewah/ewah_io.c | 204 | ||||
| -rw-r--r-- | ewah/ewah_rlw.c | 115 | ||||
| -rw-r--r-- | ewah/ewok.h | 233 | ||||
| -rw-r--r-- | ewah/ewok_rlw.h | 114 |
6 files changed, 1601 insertions, 0 deletions
diff --git a/ewah/bitmap.c b/ewah/bitmap.c new file mode 100644 index 0000000000..710e58c1bf --- /dev/null +++ b/ewah/bitmap.c @@ -0,0 +1,221 @@ +/** + * 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, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + */ +#include "git-compat-util.h" +#include "ewok.h" + +#define MASK(x) ((eword_t)1 << (x % BITS_IN_WORD)) +#define BLOCK(x) (x / BITS_IN_WORD) + +struct bitmap *bitmap_new(void) +{ + struct bitmap *bitmap = ewah_malloc(sizeof(struct bitmap)); + bitmap->words = ewah_calloc(32, sizeof(eword_t)); + bitmap->word_alloc = 32; + return bitmap; +} + +void bitmap_set(struct bitmap *self, size_t pos) +{ + size_t block = BLOCK(pos); + + if (block >= self->word_alloc) { + size_t old_size = self->word_alloc; + self->word_alloc = block * 2; + self->words = ewah_realloc(self->words, + self->word_alloc * sizeof(eword_t)); + + memset(self->words + old_size, 0x0, + (self->word_alloc - old_size) * sizeof(eword_t)); + } + + self->words[block] |= MASK(pos); +} + +void bitmap_clear(struct bitmap *self, size_t pos) +{ + size_t block = BLOCK(pos); + + if (block < self->word_alloc) + self->words[block] &= ~MASK(pos); +} + +int bitmap_get(struct bitmap *self, size_t pos) +{ + size_t block = BLOCK(pos); + return block < self->word_alloc && + (self->words[block] & MASK(pos)) != 0; +} + +struct ewah_bitmap *bitmap_to_ewah(struct bitmap *bitmap) +{ + struct ewah_bitmap *ewah = ewah_new(); + size_t i, running_empty_words = 0; + eword_t last_word = 0; + + for (i = 0; i < bitmap->word_alloc; ++i) { + if (bitmap->words[i] == 0) { + running_empty_words++; + continue; + } + + if (last_word != 0) + ewah_add(ewah, last_word); + + if (running_empty_words > 0) { + ewah_add_empty_words(ewah, 0, running_empty_words); + running_empty_words = 0; + } + + last_word = bitmap->words[i]; + } + + ewah_add(ewah, last_word); + return ewah; +} + +struct bitmap *ewah_to_bitmap(struct ewah_bitmap *ewah) +{ + struct bitmap *bitmap = bitmap_new(); + struct ewah_iterator it; + eword_t blowup; + size_t i = 0; + + ewah_iterator_init(&it, ewah); + + while (ewah_iterator_next(&blowup, &it)) { + if (i >= bitmap->word_alloc) { + bitmap->word_alloc *= 1.5; + bitmap->words = ewah_realloc( + bitmap->words, bitmap->word_alloc * sizeof(eword_t)); + } + + bitmap->words[i++] = blowup; + } + + bitmap->word_alloc = i; + return bitmap; +} + +void bitmap_and_not(struct bitmap *self, struct bitmap *other) +{ + const size_t count = (self->word_alloc < other->word_alloc) ? + self->word_alloc : other->word_alloc; + + size_t i; + + for (i = 0; i < count; ++i) + self->words[i] &= ~other->words[i]; +} + +void bitmap_or_ewah(struct bitmap *self, struct ewah_bitmap *other) +{ + size_t original_size = self->word_alloc; + size_t other_final = (other->bit_size / BITS_IN_WORD) + 1; + size_t i = 0; + struct ewah_iterator it; + eword_t word; + + if (self->word_alloc < other_final) { + self->word_alloc = other_final; + self->words = ewah_realloc(self->words, + self->word_alloc * sizeof(eword_t)); + memset(self->words + original_size, 0x0, + (self->word_alloc - original_size) * sizeof(eword_t)); + } + + ewah_iterator_init(&it, other); + + while (ewah_iterator_next(&word, &it)) + self->words[i++] |= word; +} + +void bitmap_each_bit(struct bitmap *self, ewah_callback callback, void *data) +{ + size_t pos = 0, i; + + for (i = 0; i < self->word_alloc; ++i) { + eword_t word = self->words[i]; + uint32_t offset; + + if (word == (eword_t)~0) { + for (offset = 0; offset < BITS_IN_WORD; ++offset) + callback(pos++, data); + } else { + for (offset = 0; offset < BITS_IN_WORD; ++offset) { + if ((word >> offset) == 0) + break; + + offset += ewah_bit_ctz64(word >> offset); + callback(pos + offset, data); + } + pos += BITS_IN_WORD; + } + } +} + +size_t bitmap_popcount(struct bitmap *self) +{ + size_t i, count = 0; + + for (i = 0; i < self->word_alloc; ++i) + count += ewah_bit_popcount64(self->words[i]); + + return count; +} + +int bitmap_equals(struct bitmap *self, struct bitmap *other) +{ + struct bitmap *big, *small; + size_t i; + + if (self->word_alloc < other->word_alloc) { + small = self; + big = other; + } else { + small = other; + big = self; + } + + for (i = 0; i < small->word_alloc; ++i) { + if (small->words[i] != big->words[i]) + return 0; + } + + for (; i < big->word_alloc; ++i) { + if (big->words[i] != 0) + return 0; + } + + return 1; +} + +void bitmap_reset(struct bitmap *bitmap) +{ + memset(bitmap->words, 0x0, bitmap->word_alloc * sizeof(eword_t)); +} + +void bitmap_free(struct bitmap *bitmap) +{ + if (bitmap == NULL) + return; + + free(bitmap->words); + free(bitmap); +} diff --git a/ewah/ewah_bitmap.c b/ewah/ewah_bitmap.c new file mode 100644 index 0000000000..fccb42b52c --- /dev/null +++ b/ewah/ewah_bitmap.c @@ -0,0 +1,714 @@ +/** + * 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, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + */ +#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; + self->buffer = ewah_realloc(self->buffer, + self->alloc_size * sizeof(eword_t)); + 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_WORD; + 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_WORD; + + 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_WORD; + + 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 = + (i + BITS_IN_WORD) / BITS_IN_WORD - + (self->bit_size + BITS_IN_WORD - 1) / BITS_IN_WORD; + + 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_WORD)); + 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_WORD)); + return; + } + + self->buffer[self->buffer_size - 1] |= + ((eword_t)1 << (i % BITS_IN_WORD)); + + /* 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_WORD; + for (k = 0; k < len; ++k, ++pos) + callback(pos, payload); + } else { + pos += rlw_get_running_len(word) * BITS_IN_WORD; + } + + ++pointer; + + for (k = 0; k < rlw_get_literal_words(word); ++k) { + int c; + + /* todo: zero count optimization */ + for (c = 0; c < BITS_IN_WORD; ++c, ++pos) { + if ((self->buffer[pointer] & ((eword_t)1 << c)) != 0) + callback(pos, payload); + } + + ++pointer; + } + } +} + +struct ewah_bitmap *ewah_new(void) +{ + struct ewah_bitmap *self; + + self = ewah_malloc(sizeof(struct ewah_bitmap)); + if (self == NULL) + return NULL; + + self->buffer = ewah_malloc(32 * sizeof(eword_t)); + self->alloc_size = 32; + + ewah_clear(self); + return self; +} + +void ewah_clear(struct ewah_bitmap *self) +{ + self->buffer_size = 1; + self->buffer[0] = 0; + self->bit_size = 0; + self->rlw = self->buffer; +} + +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_not(struct ewah_bitmap *self) +{ + size_t pointer = 0; + + while (pointer < self->buffer_size) { + eword_t *word = &self->buffer[pointer]; + size_t literals, k; + + rlw_xor_run_bit(word); + ++pointer; + + literals = rlw_get_literal_words(word); + for (k = 0; k < literals; ++k) { + self->buffer[pointer] = ~self->buffer[pointer]; + ++pointer; + } + } +} + +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); +} + +void ewah_and( + 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; + + if (rlw_i.rlw.running_len < rlw_j.rlw.running_len) { + prey = &rlw_i; + predator = &rlw_j; + } else { + prey = &rlw_j; + predator = &rlw_i; + } + + if (predator->rlw.running_bit == 0) { + ewah_add_empty_words(out, 0, + predator->rlw.running_len); + rlwit_discard_first_words(prey, + predator->rlw.running_len); + rlwit_discard_first_words(predator, + predator->rlw.running_len); + } else { + size_t index = rlwit_discharge(prey, out, + predator->rlw.running_len, 0); + ewah_add_empty_words(out, 0, + 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_empty(&rlw_i, out); + else + rlwit_discharge_empty(&rlw_j, out); + + out->bit_size = max_size(ewah_i->bit_size, ewah_j->bit_size); +} + +void ewah_and_not( + 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; + + if (rlw_i.rlw.running_len < rlw_j.rlw.running_len) { + prey = &rlw_i; + predator = &rlw_j; + } else { + prey = &rlw_j; + predator = &rlw_i; + } + + if ((predator->rlw.running_bit && prey == &rlw_i) || + (!predator->rlw.running_bit && prey != &rlw_i)) { + ewah_add_empty_words(out, 0, + predator->rlw.running_len); + rlwit_discard_first_words(prey, + predator->rlw.running_len); + rlwit_discard_first_words(predator, + predator->rlw.running_len); + } else { + size_t index; + int negate_words; + + negate_words = (&rlw_i != prey); + 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_empty(&rlw_j, out); + + out->bit_size = max_size(ewah_i->bit_size, ewah_j->bit_size); +} + +void ewah_or( + 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; + + if (rlw_i.rlw.running_len < rlw_j.rlw.running_len) { + prey = &rlw_i; + predator = &rlw_j; + } else { + prey = &rlw_j; + predator = &rlw_i; + } + + if (predator->rlw.running_bit) { + ewah_add_empty_words(out, 0, + predator->rlw.running_len); + rlwit_discard_first_words(prey, + predator->rlw.running_len); + rlwit_discard_first_words(predator, + predator->rlw.running_len); + } else { + size_t index = rlwit_discharge(prey, out, + predator->rlw.running_len, 0); + ewah_add_empty_words(out, 0, + 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; +} diff --git a/ewah/ewah_io.c b/ewah/ewah_io.c new file mode 100644 index 0000000000..1c2d7afd4c --- /dev/null +++ b/ewah/ewah_io.c @@ -0,0 +1,204 @@ +/** + * 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, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + */ +#include "git-compat-util.h" +#include "ewok.h" + +int ewah_serialize_native(struct ewah_bitmap *self, int fd) +{ + uint32_t write32; + size_t to_write = self->buffer_size * 8; + + /* 32 bit -- bit size for the map */ + write32 = (uint32_t)self->bit_size; + if (write(fd, &write32, 4) != 4) + return -1; + + /** 32 bit -- number of compressed 64-bit words */ + write32 = (uint32_t)self->buffer_size; + if (write(fd, &write32, 4) != 4) + return -1; + + if (write(fd, self->buffer, to_write) != to_write) + return -1; + + /** 32 bit -- position for the RLW */ + write32 = self->rlw - self->buffer; + if (write(fd, &write32, 4) != 4) + return -1; + + return (3 * 4) + to_write; +} + +int ewah_serialize_to(struct ewah_bitmap *self, + int (*write_fun)(void *, const void *, size_t), + void *data) +{ + size_t i; + eword_t dump[2048]; + const size_t words_per_dump = sizeof(dump) / sizeof(eword_t); + uint32_t bitsize, word_count, rlw_pos; + + const eword_t *buffer; + size_t words_left; + + /* 32 bit -- bit size for the map */ + bitsize = htonl((uint32_t)self->bit_size); + if (write_fun(data, &bitsize, 4) != 4) + return -1; + + /** 32 bit -- number of compressed 64-bit words */ + word_count = htonl((uint32_t)self->buffer_size); + if (write_fun(data, &word_count, 4) != 4) + return -1; + + /** 64 bit x N -- compressed words */ + buffer = self->buffer; + words_left = self->buffer_size; + + while (words_left >= words_per_dump) { + for (i = 0; i < words_per_dump; ++i, ++buffer) + dump[i] = htonll(*buffer); + + if (write_fun(data, dump, sizeof(dump)) != sizeof(dump)) + return -1; + + words_left -= words_per_dump; + } + + if (words_left) { + for (i = 0; i < words_left; ++i, ++buffer) + dump[i] = htonll(*buffer); + + if (write_fun(data, dump, words_left * 8) != words_left * 8) + return -1; + } + + /** 32 bit -- position for the RLW */ + rlw_pos = (uint8_t*)self->rlw - (uint8_t *)self->buffer; + rlw_pos = htonl(rlw_pos / sizeof(eword_t)); + + if (write_fun(data, &rlw_pos, 4) != 4) + return -1; + + return (3 * 4) + (self->buffer_size * 8); +} + +static int write_helper(void *fd, const void *buf, size_t len) +{ + return write((intptr_t)fd, buf, len); +} + +int ewah_serialize(struct ewah_bitmap *self, int fd) +{ + return ewah_serialize_to(self, write_helper, (void *)(intptr_t)fd); +} + +int ewah_read_mmap(struct ewah_bitmap *self, const void *map, size_t len) +{ + const uint8_t *ptr = map; + size_t i; + + self->bit_size = get_be32(ptr); + ptr += sizeof(uint32_t); + + self->buffer_size = self->alloc_size = get_be32(ptr); + ptr += sizeof(uint32_t); + + self->buffer = ewah_realloc(self->buffer, + self->alloc_size * sizeof(eword_t)); + + if (!self->buffer) + return -1; + + /* + * Copy the raw data for the bitmap as a whole chunk; + * if we're in a little-endian platform, we'll perform + * the endianness conversion in a separate pass to ensure + * we're loading 8-byte aligned words. + */ + memcpy(self->buffer, ptr, self->buffer_size * sizeof(uint64_t)); + ptr += self->buffer_size * sizeof(uint64_t); + + for (i = 0; i < self->buffer_size; ++i) + self->buffer[i] = ntohll(self->buffer[i]); + + self->rlw = self->buffer + get_be32(ptr); + + return (3 * 4) + (self->buffer_size * 8); +} + +int ewah_deserialize(struct ewah_bitmap *self, int fd) +{ + size_t i; + eword_t dump[2048]; + const size_t words_per_dump = sizeof(dump) / sizeof(eword_t); + uint32_t bitsize, word_count, rlw_pos; + + eword_t *buffer = NULL; + size_t words_left; + + ewah_clear(self); + + /* 32 bit -- bit size for the map */ + if (read(fd, &bitsize, 4) != 4) + return -1; + + self->bit_size = (size_t)ntohl(bitsize); + + /** 32 bit -- number of compressed 64-bit words */ + if (read(fd, &word_count, 4) != 4) + return -1; + + self->buffer_size = self->alloc_size = (size_t)ntohl(word_count); + self->buffer = ewah_realloc(self->buffer, + self->alloc_size * sizeof(eword_t)); + + if (!self->buffer) + return -1; + + /** 64 bit x N -- compressed words */ + buffer = self->buffer; + words_left = self->buffer_size; + + while (words_left >= words_per_dump) { + if (read(fd, dump, sizeof(dump)) != sizeof(dump)) + return -1; + + for (i = 0; i < words_per_dump; ++i, ++buffer) + *buffer = ntohll(dump[i]); + + words_left -= words_per_dump; + } + + if (words_left) { + if (read(fd, dump, words_left * 8) != words_left * 8) + return -1; + + for (i = 0; i < words_left; ++i, ++buffer) + *buffer = ntohll(dump[i]); + } + + /** 32 bit -- position for the RLW */ + if (read(fd, &rlw_pos, 4) != 4) + return -1; + + self->rlw = self->buffer + ntohl(rlw_pos); + return 0; +} diff --git a/ewah/ewah_rlw.c b/ewah/ewah_rlw.c new file mode 100644 index 0000000000..c723f1aefd --- /dev/null +++ b/ewah/ewah_rlw.c @@ -0,0 +1,115 @@ +/** + * 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, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + */ +#include "git-compat-util.h" +#include "ewok.h" +#include "ewok_rlw.h" + +static inline int next_word(struct rlw_iterator *it) +{ + if (it->pointer >= it->size) + return 0; + + it->rlw.word = &it->buffer[it->pointer]; + it->pointer += rlw_get_literal_words(it->rlw.word) + 1; + + it->rlw.literal_words = rlw_get_literal_words(it->rlw.word); + it->rlw.running_len = rlw_get_running_len(it->rlw.word); + it->rlw.running_bit = rlw_get_run_bit(it->rlw.word); + it->rlw.literal_word_offset = 0; + + return 1; +} + +void rlwit_init(struct rlw_iterator *it, struct ewah_bitmap *from_ewah) +{ + it->buffer = from_ewah->buffer; + it->size = from_ewah->buffer_size; + it->pointer = 0; + + next_word(it); + + it->literal_word_start = rlwit_literal_words(it) + + it->rlw.literal_word_offset; +} + +void rlwit_discard_first_words(struct rlw_iterator *it, size_t x) +{ + while (x > 0) { + size_t discard; + + if (it->rlw.running_len > x) { + it->rlw.running_len -= x; + return; + } + + x -= it->rlw.running_len; + it->rlw.running_len = 0; + + discard = (x > it->rlw.literal_words) ? it->rlw.literal_words : x; + + it->literal_word_start += discard; + it->rlw.literal_words -= discard; + x -= discard; + + if (x > 0 || rlwit_word_size(it) == 0) { + if (!next_word(it)) + break; + + it->literal_word_start = + rlwit_literal_words(it) + it->rlw.literal_word_offset; + } + } +} + +size_t rlwit_discharge( + struct rlw_iterator *it, struct ewah_bitmap *out, size_t max, int negate) +{ + size_t index = 0; + + while (index < max && rlwit_word_size(it) > 0) { + size_t pd, pl = it->rlw.running_len; + + if (index + pl > max) + pl = max - index; + + ewah_add_empty_words(out, it->rlw.running_bit ^ negate, pl); + index += pl; + + pd = it->rlw.literal_words; + if (pd + index > max) + pd = max - index; + + ewah_add_dirty_words(out, + it->buffer + it->literal_word_start, pd, negate); + + rlwit_discard_first_words(it, pd + pl); + index += pd; + } + + return index; +} + +void rlwit_discharge_empty(struct rlw_iterator *it, struct ewah_bitmap *out) +{ + while (rlwit_word_size(it) > 0) { + ewah_add_empty_words(out, 0, rlwit_word_size(it)); + rlwit_discard_first_words(it, rlwit_word_size(it)); + } +} diff --git a/ewah/ewok.h b/ewah/ewok.h new file mode 100644 index 0000000000..13c6e20412 --- /dev/null +++ b/ewah/ewok.h @@ -0,0 +1,233 @@ +/** + * 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, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + */ +#ifndef __EWOK_BITMAP_H__ +#define __EWOK_BITMAP_H__ + +#ifndef ewah_malloc +# define ewah_malloc xmalloc +#endif +#ifndef ewah_realloc +# define ewah_realloc xrealloc +#endif +#ifndef ewah_calloc +# define ewah_calloc xcalloc +#endif + +typedef uint64_t eword_t; +#define BITS_IN_WORD (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; +} + +/* __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); + +/** + * Clear all the bits in the bitmap. Does not free or resize + * memory. + */ +void ewah_clear(struct ewah_bitmap *self); + +/** + * 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(struct ewah_bitmap *self, int fd); +int ewah_serialize_native(struct ewah_bitmap *self, int fd); + +int ewah_deserialize(struct ewah_bitmap *self, int fd); +int ewah_read_mmap(struct ewah_bitmap *self, const void *map, size_t len); + +uint32_t ewah_checksum(struct ewah_bitmap *self); + +/** + * Logical not (bitwise negation) in-place on the bitmap + * + * This operation is linear time based on the size of the bitmap. + */ +void ewah_not(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); + +void ewah_or( + struct ewah_bitmap *ewah_i, + struct ewah_bitmap *ewah_j, + struct ewah_bitmap *out); + +void ewah_and_not( + struct ewah_bitmap *ewah_i, + struct ewah_bitmap *ewah_j, + struct ewah_bitmap *out); + +void ewah_xor( + struct ewah_bitmap *ewah_i, + struct ewah_bitmap *ewah_j, + struct ewah_bitmap *out); + +void ewah_and( + 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); +void bitmap_set(struct bitmap *self, size_t pos); +void bitmap_clear(struct bitmap *self, size_t pos); +int bitmap_get(struct bitmap *self, size_t pos); +void bitmap_reset(struct bitmap *self); +void bitmap_free(struct bitmap *self); +int bitmap_equals(struct bitmap *self, struct bitmap *other); +int bitmap_is_subset(struct bitmap *self, struct bitmap *super); + +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); + +void bitmap_each_bit(struct bitmap *self, ewah_callback callback, void *data); +size_t bitmap_popcount(struct bitmap *self); + +#endif diff --git a/ewah/ewok_rlw.h b/ewah/ewok_rlw.h new file mode 100644 index 0000000000..63efdf9698 --- /dev/null +++ b/ewah/ewok_rlw.h @@ -0,0 +1,114 @@ +/** + * 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, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + */ +#ifndef __EWOK_RLW_H__ +#define __EWOK_RLW_H__ + +#define RLW_RUNNING_BITS (sizeof(eword_t) * 4) +#define RLW_LITERAL_BITS (sizeof(eword_t) * 8 - 1 - RLW_RUNNING_BITS) + +#define RLW_LARGEST_RUNNING_COUNT (((eword_t)1 << RLW_RUNNING_BITS) - 1) +#define RLW_LARGEST_LITERAL_COUNT (((eword_t)1 << RLW_LITERAL_BITS) - 1) + +#define RLW_LARGEST_RUNNING_COUNT_SHIFT (RLW_LARGEST_RUNNING_COUNT << 1) + +#define RLW_RUNNING_LEN_PLUS_BIT (((eword_t)1 << (RLW_RUNNING_BITS + 1)) - 1) + +static int rlw_get_run_bit(const eword_t *word) +{ + return *word & (eword_t)1; +} + +static inline void rlw_set_run_bit(eword_t *word, int b) +{ + if (b) { + *word |= (eword_t)1; + } else { + *word &= (eword_t)(~1); + } +} + +static inline void rlw_xor_run_bit(eword_t *word) +{ + if (*word & 1) { + *word &= (eword_t)(~1); + } else { + *word |= (eword_t)1; + } +} + +static inline void rlw_set_running_len(eword_t *word, eword_t l) +{ + *word |= RLW_LARGEST_RUNNING_COUNT_SHIFT; + *word &= (l << 1) | (~RLW_LARGEST_RUNNING_COUNT_SHIFT); +} + +static inline eword_t rlw_get_running_len(const eword_t *word) +{ + return (*word >> 1) & RLW_LARGEST_RUNNING_COUNT; +} + +static inline eword_t rlw_get_literal_words(const eword_t *word) +{ + return *word >> (1 + RLW_RUNNING_BITS); +} + +static inline void rlw_set_literal_words(eword_t *word, eword_t l) +{ + *word |= ~RLW_RUNNING_LEN_PLUS_BIT; + *word &= (l << (RLW_RUNNING_BITS + 1)) | RLW_RUNNING_LEN_PLUS_BIT; +} + +static inline eword_t rlw_size(const eword_t *self) +{ + return rlw_get_running_len(self) + rlw_get_literal_words(self); +} + +struct rlw_iterator { + const eword_t *buffer; + size_t size; + size_t pointer; + size_t literal_word_start; + + struct { + const eword_t *word; + int literal_words; + int running_len; + int literal_word_offset; + int running_bit; + } rlw; +}; + +void rlwit_init(struct rlw_iterator *it, struct ewah_bitmap *bitmap); +void rlwit_discard_first_words(struct rlw_iterator *it, size_t x); +size_t rlwit_discharge( + struct rlw_iterator *it, struct ewah_bitmap *out, size_t max, int negate); +void rlwit_discharge_empty(struct rlw_iterator *it, struct ewah_bitmap *out); + +static inline size_t rlwit_word_size(struct rlw_iterator *it) +{ + return it->rlw.running_len + it->rlw.literal_words; +} + +static inline size_t rlwit_literal_words(struct rlw_iterator *it) +{ + return it->pointer - it->rlw.literal_words; +} + +#endif |