git/ewah/ewah_bitmap.c
Todd Zullinger 484257925f Replace Free Software Foundation address in license notices
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>
2017-11-09 13:21:21 +09:00

710 lines
16 KiB
C

/**
* 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;
}
}
}
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_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;
}