git-commit-vandalism/ewah/ewah_io.c
Jeff King fb7dbf3e7a convert ewah/bitmap code to use xmalloc
This code was originally written with the idea that it could
be spun off into its own ewah library, and uses the
overrideable ewah_malloc to do allocations.

We plug in xmalloc as our ewah_malloc, of course. But over
the years the ewah code itself has become more entangled
with git, and the return value of many ewah_malloc sites is
not checked.

Let's just drop the level of indirection and use xmalloc and
friends directly. This saves a few lines, and will let us
adapt these sites to our more advanced malloc helpers.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-02-22 14:51:09 -08:00

212 lines
5.4 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, 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 "strbuf.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);
}
static int write_strbuf(void *user_data, const void *data, size_t len)
{
struct strbuf *sb = user_data;
strbuf_add(sb, data, len);
return len;
}
int ewah_serialize_strbuf(struct ewah_bitmap *self, struct strbuf *sb)
{
return ewah_serialize_to(self, write_strbuf, sb);
}
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 = xrealloc(self->buffer,
self->alloc_size * sizeof(eword_t));
/*
* 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 = xrealloc(self->buffer,
self->alloc_size * sizeof(eword_t));
/** 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;
}