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ewah: compressed bitmap implementation 

EWAH is a word-aligned compressed variant of a bitset (i.e. a data
structure that acts as a 0-indexed boolean array for many entries).

It uses a 64-bit run-length encoding (RLE) compression scheme,
trading some compression for better processing speed.

The goal of this word-aligned implementation is not to achieve
the best compression, but rather to improve query processing time.
As it stands right now, this EWAH implementation will always be more
efficient storage-wise than its uncompressed alternative.

EWAH arrays will be used as the on-disk format to store reachability
bitmaps for all objects in a repository while keeping reasonable sizes,
in the same way that JGit does.

This EWAH implementation is a mostly straightforward port of the
original `javaewah` library that JGit currently uses. The library is
self-contained and has been embedded whole (4 files) inside the `ewah`
folder to ease redistribution.

The library is re-licensed under the GPLv2 with the permission of Daniel
Lemire, the original author. The source code for the C version can
be found on GitHub:

	https://github.com/vmg/libewok

The original Java implementation can also be found on GitHub:

	https://github.com/lemire/javaewah

[jc: stripped debug-only code per Peff's $gmane/239768]

Signed-off-by: Vicent Marti <tanoku@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
Helped-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Vicent Marti 2013-11-14 07:43:51 -05:00 committed by Junio C Hamano
parent 7e3dae4943
commit e1273106f6
7 changed files with 1599 additions and 2 deletions
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11
Makefile
View File

@ -667,6 +667,8 @@ LIB_H += diff.h
LIB_H += diffcore.h
LIB_H += dir.h
LIB_H += exec_cmd.h
LIB_H += ewah/ewok.h
LIB_H += ewah/ewok_rlw.h
LIB_H += fetch-pack.h
LIB_H += fmt-merge-msg.h
LIB_H += fsck.h
@ -800,6 +802,10 @@ LIB_OBJS += dir.o
LIB_OBJS += editor.o
LIB_OBJS += entry.o
LIB_OBJS += environment.o
LIB_OBJS += ewah/bitmap.o
LIB_OBJS += ewah/ewah_bitmap.o
LIB_OBJS += ewah/ewah_io.o
LIB_OBJS += ewah/ewah_rlw.o
LIB_OBJS += exec_cmd.o
LIB_OBJS += fetch-pack.o
LIB_OBJS += fsck.o
@ -2474,8 +2480,9 @@ profile-clean:
$(RM) $(addsuffix *.gcno,$(addprefix $(PROFILE_DIR)/, $(object_dirs)))
clean: profile-clean coverage-clean
$(RM) *.o *.res block-sha1/*.o ppc/*.o compat/*.o compat/*/*.o xdiff/*.o vcs-svn/*.o \
builtin/*.o $(LIB_FILE) $(XDIFF_LIB) $(VCSSVN_LIB)
$(RM) *.o *.res block-sha1/*.o ppc/*.o compat/*.o compat/*/*.o
$(RM) xdiff/*.o vcs-svn/*.o ewah/*.o builtin/*.o
$(RM) $(LIB_FILE) $(XDIFF_LIB) $(VCSSVN_LIB)
$(RM) $(ALL_PROGRAMS) $(SCRIPT_LIB) $(BUILT_INS) git$X
$(RM) $(TEST_PROGRAMS) $(NO_INSTALL)
$(RM) -r bin-wrappers $(dep_dirs)

221
ewah/bitmap.c Normal file
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@ -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);
}

714
ewah/ewah_bitmap.c Normal file
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@ -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(size_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;
}

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/**
* 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, void *map, size_t len)
{
uint32_t *read32 = map;
eword_t *read64;
size_t i;
self->bit_size = ntohl(*read32++);
self->buffer_size = self->alloc_size = ntohl(*read32++);
self->buffer = ewah_realloc(self->buffer,
self->alloc_size * sizeof(eword_t));
if (!self->buffer)
return -1;
for (i = 0, read64 = (void *)read32; i < self->buffer_size; ++i)
self->buffer[i] = ntohll(*read64++);
read32 = (void *)read64;
self->rlw = self->buffer + ntohl(*read32++);
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;
}

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/**
* 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));
}
}

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/**
* 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;
}
#ifdef __GNUC__
#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, void *map, size_t len);
int ewah_read_mmap_native(struct ewah_bitmap *self, 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

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/**
* 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