4a7fae6b8ceabcb5202c615724b73606795aa543
   1/**
   2 * Copyright 2013, GitHub, Inc
   3 * Copyright 2009-2013, Daniel Lemire, Cliff Moon,
   4 *      David McIntosh, Robert Becho, Google Inc. and Veronika Zenz
   5 *
   6 * This program is free software; you can redistribute it and/or
   7 * modify it under the terms of the GNU General Public License
   8 * as published by the Free Software Foundation; either version 2
   9 * of the License, or (at your option) any later version.
  10 *
  11 * This program is distributed in the hope that it will be useful,
  12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 * GNU General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * along with this program; if not, write to the Free Software
  18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  19 */
  20#include "git-compat-util.h"
  21#include "ewok.h"
  22
  23int ewah_serialize_native(struct ewah_bitmap *self, int fd)
  24{
  25        uint32_t write32;
  26        size_t to_write = self->buffer_size * 8;
  27
  28        /* 32 bit -- bit size for the map */
  29        write32 = (uint32_t)self->bit_size;
  30        if (write(fd, &write32, 4) != 4)
  31                return -1;
  32
  33        /** 32 bit -- number of compressed 64-bit words */
  34        write32 = (uint32_t)self->buffer_size;
  35        if (write(fd, &write32, 4) != 4)
  36                return -1;
  37
  38        if (write(fd, self->buffer, to_write) != to_write)
  39                return -1;
  40
  41        /** 32 bit -- position for the RLW */
  42        write32 = self->rlw - self->buffer;
  43        if (write(fd, &write32, 4) != 4)
  44                return -1;
  45
  46        return (3 * 4) + to_write;
  47}
  48
  49int ewah_serialize_to(struct ewah_bitmap *self,
  50                      int (*write_fun)(void *, const void *, size_t),
  51                      void *data)
  52{
  53        size_t i;
  54        eword_t dump[2048];
  55        const size_t words_per_dump = sizeof(dump) / sizeof(eword_t);
  56        uint32_t bitsize, word_count, rlw_pos;
  57
  58        const eword_t *buffer;
  59        size_t words_left;
  60
  61        /* 32 bit -- bit size for the map */
  62        bitsize =  htonl((uint32_t)self->bit_size);
  63        if (write_fun(data, &bitsize, 4) != 4)
  64                return -1;
  65
  66        /** 32 bit -- number of compressed 64-bit words */
  67        word_count =  htonl((uint32_t)self->buffer_size);
  68        if (write_fun(data, &word_count, 4) != 4)
  69                return -1;
  70
  71        /** 64 bit x N -- compressed words */
  72        buffer = self->buffer;
  73        words_left = self->buffer_size;
  74
  75        while (words_left >= words_per_dump) {
  76                for (i = 0; i < words_per_dump; ++i, ++buffer)
  77                        dump[i] = htonll(*buffer);
  78
  79                if (write_fun(data, dump, sizeof(dump)) != sizeof(dump))
  80                        return -1;
  81
  82                words_left -= words_per_dump;
  83        }
  84
  85        if (words_left) {
  86                for (i = 0; i < words_left; ++i, ++buffer)
  87                        dump[i] = htonll(*buffer);
  88
  89                if (write_fun(data, dump, words_left * 8) != words_left * 8)
  90                        return -1;
  91        }
  92
  93        /** 32 bit -- position for the RLW */
  94        rlw_pos = (uint8_t*)self->rlw - (uint8_t *)self->buffer;
  95        rlw_pos = htonl(rlw_pos / sizeof(eword_t));
  96
  97        if (write_fun(data, &rlw_pos, 4) != 4)
  98                return -1;
  99
 100        return (3 * 4) + (self->buffer_size * 8);
 101}
 102
 103static int write_helper(void *fd, const void *buf, size_t len)
 104{
 105        return write((intptr_t)fd, buf, len);
 106}
 107
 108int ewah_serialize(struct ewah_bitmap *self, int fd)
 109{
 110        return ewah_serialize_to(self, write_helper, (void *)(intptr_t)fd);
 111}
 112
 113int ewah_read_mmap(struct ewah_bitmap *self, void *map, size_t len)
 114{
 115        uint8_t *ptr = map;
 116
 117        self->bit_size = get_be32(ptr);
 118        ptr += sizeof(uint32_t);
 119
 120        self->buffer_size = self->alloc_size = get_be32(ptr);
 121        ptr += sizeof(uint32_t);
 122
 123        self->buffer = ewah_realloc(self->buffer,
 124                self->alloc_size * sizeof(eword_t));
 125
 126        if (!self->buffer)
 127                return -1;
 128
 129        /*
 130         * Copy the raw data for the bitmap as a whole chunk;
 131         * if we're in a little-endian platform, we'll perform
 132         * the endianness conversion in a separate pass to ensure
 133         * we're loading 8-byte aligned words.
 134         */
 135        memcpy(self->buffer, ptr, self->buffer_size * sizeof(uint64_t));
 136        ptr += self->buffer_size * sizeof(uint64_t);
 137
 138#if __BYTE_ORDER != __BIG_ENDIAN
 139        {
 140                size_t i;
 141                for (i = 0; i < self->buffer_size; ++i)
 142                        self->buffer[i] = ntohll(self->buffer[i]);
 143        }
 144#endif
 145
 146        self->rlw = self->buffer + get_be32(ptr);
 147
 148        return (3 * 4) + (self->buffer_size * 8);
 149}
 150
 151int ewah_deserialize(struct ewah_bitmap *self, int fd)
 152{
 153        size_t i;
 154        eword_t dump[2048];
 155        const size_t words_per_dump = sizeof(dump) / sizeof(eword_t);
 156        uint32_t bitsize, word_count, rlw_pos;
 157
 158        eword_t *buffer = NULL;
 159        size_t words_left;
 160
 161        ewah_clear(self);
 162
 163        /* 32 bit -- bit size for the map */
 164        if (read(fd, &bitsize, 4) != 4)
 165                return -1;
 166
 167        self->bit_size = (size_t)ntohl(bitsize);
 168
 169        /** 32 bit -- number of compressed 64-bit words */
 170        if (read(fd, &word_count, 4) != 4)
 171                return -1;
 172
 173        self->buffer_size = self->alloc_size = (size_t)ntohl(word_count);
 174        self->buffer = ewah_realloc(self->buffer,
 175                self->alloc_size * sizeof(eword_t));
 176
 177        if (!self->buffer)
 178                return -1;
 179
 180        /** 64 bit x N -- compressed words */
 181        buffer = self->buffer;
 182        words_left = self->buffer_size;
 183
 184        while (words_left >= words_per_dump) {
 185                if (read(fd, dump, sizeof(dump)) != sizeof(dump))
 186                        return -1;
 187
 188                for (i = 0; i < words_per_dump; ++i, ++buffer)
 189                        *buffer = ntohll(dump[i]);
 190
 191                words_left -= words_per_dump;
 192        }
 193
 194        if (words_left) {
 195                if (read(fd, dump, words_left * 8) != words_left * 8)
 196                        return -1;
 197
 198                for (i = 0; i < words_left; ++i, ++buffer)
 199                        *buffer = ntohll(dump[i]);
 200        }
 201
 202        /** 32 bit -- position for the RLW */
 203        if (read(fd, &rlw_pos, 4) != 4)
 204                return -1;
 205
 206        self->rlw = self->buffer + ntohl(rlw_pos);
 207        return 0;
 208}