diff options
Diffstat (limited to 'ewah/ewah_io.c')
| -rw-r--r-- | ewah/ewah_io.c | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/ewah/ewah_io.c b/ewah/ewah_io.c new file mode 100644 index 0000000..1c2d7af --- /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; +} |