msysGit-based Git for Windows 1.x was superseded by Git for Windows 2.x
[git/mingw/4msysgit.git] / ewah / ewah_io.c
blob1c2d7afd4cb9b70a324d355c3d69b732b181012b
1 /**
2 * Copyright 2013, GitHub, Inc
3 * Copyright 2009-2013, Daniel Lemire, Cliff Moon,
4 * David McIntosh, Robert Becho, Google Inc. and Veronika Zenz
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.
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.
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.
20 #include "git-compat-util.h"
21 #include "ewok.h"
23 int ewah_serialize_native(struct ewah_bitmap *self, int fd)
25 uint32_t write32;
26 size_t to_write = self->buffer_size * 8;
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;
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;
38 if (write(fd, self->buffer, to_write) != to_write)
39 return -1;
41 /** 32 bit -- position for the RLW */
42 write32 = self->rlw - self->buffer;
43 if (write(fd, &write32, 4) != 4)
44 return -1;
46 return (3 * 4) + to_write;
49 int ewah_serialize_to(struct ewah_bitmap *self,
50 int (*write_fun)(void *, const void *, size_t),
51 void *data)
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;
58 const eword_t *buffer;
59 size_t words_left;
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;
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;
71 /** 64 bit x N -- compressed words */
72 buffer = self->buffer;
73 words_left = self->buffer_size;
75 while (words_left >= words_per_dump) {
76 for (i = 0; i < words_per_dump; ++i, ++buffer)
77 dump[i] = htonll(*buffer);
79 if (write_fun(data, dump, sizeof(dump)) != sizeof(dump))
80 return -1;
82 words_left -= words_per_dump;
85 if (words_left) {
86 for (i = 0; i < words_left; ++i, ++buffer)
87 dump[i] = htonll(*buffer);
89 if (write_fun(data, dump, words_left * 8) != words_left * 8)
90 return -1;
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));
97 if (write_fun(data, &rlw_pos, 4) != 4)
98 return -1;
100 return (3 * 4) + (self->buffer_size * 8);
103 static int write_helper(void *fd, const void *buf, size_t len)
105 return write((intptr_t)fd, buf, len);
108 int ewah_serialize(struct ewah_bitmap *self, int fd)
110 return ewah_serialize_to(self, write_helper, (void *)(intptr_t)fd);
113 int ewah_read_mmap(struct ewah_bitmap *self, const void *map, size_t len)
115 const uint8_t *ptr = map;
116 size_t i;
118 self->bit_size = get_be32(ptr);
119 ptr += sizeof(uint32_t);
121 self->buffer_size = self->alloc_size = get_be32(ptr);
122 ptr += sizeof(uint32_t);
124 self->buffer = ewah_realloc(self->buffer,
125 self->alloc_size * sizeof(eword_t));
127 if (!self->buffer)
128 return -1;
131 * Copy the raw data for the bitmap as a whole chunk;
132 * if we're in a little-endian platform, we'll perform
133 * the endianness conversion in a separate pass to ensure
134 * we're loading 8-byte aligned words.
136 memcpy(self->buffer, ptr, self->buffer_size * sizeof(uint64_t));
137 ptr += self->buffer_size * sizeof(uint64_t);
139 for (i = 0; i < self->buffer_size; ++i)
140 self->buffer[i] = ntohll(self->buffer[i]);
142 self->rlw = self->buffer + get_be32(ptr);
144 return (3 * 4) + (self->buffer_size * 8);
147 int ewah_deserialize(struct ewah_bitmap *self, int fd)
149 size_t i;
150 eword_t dump[2048];
151 const size_t words_per_dump = sizeof(dump) / sizeof(eword_t);
152 uint32_t bitsize, word_count, rlw_pos;
154 eword_t *buffer = NULL;
155 size_t words_left;
157 ewah_clear(self);
159 /* 32 bit -- bit size for the map */
160 if (read(fd, &bitsize, 4) != 4)
161 return -1;
163 self->bit_size = (size_t)ntohl(bitsize);
165 /** 32 bit -- number of compressed 64-bit words */
166 if (read(fd, &word_count, 4) != 4)
167 return -1;
169 self->buffer_size = self->alloc_size = (size_t)ntohl(word_count);
170 self->buffer = ewah_realloc(self->buffer,
171 self->alloc_size * sizeof(eword_t));
173 if (!self->buffer)
174 return -1;
176 /** 64 bit x N -- compressed words */
177 buffer = self->buffer;
178 words_left = self->buffer_size;
180 while (words_left >= words_per_dump) {
181 if (read(fd, dump, sizeof(dump)) != sizeof(dump))
182 return -1;
184 for (i = 0; i < words_per_dump; ++i, ++buffer)
185 *buffer = ntohll(dump[i]);
187 words_left -= words_per_dump;
190 if (words_left) {
191 if (read(fd, dump, words_left * 8) != words_left * 8)
192 return -1;
194 for (i = 0; i < words_left; ++i, ++buffer)
195 *buffer = ntohll(dump[i]);
198 /** 32 bit -- position for the RLW */
199 if (read(fd, &rlw_pos, 4) != 4)
200 return -1;
202 self->rlw = self->buffer + ntohl(rlw_pos);
203 return 0;