Merge branch 'rs/show-branch-argv-array'
[git] / ewah / ewah_io.c
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 #include "strbuf.h"
23
24 int ewah_serialize_native(struct ewah_bitmap *self, int fd)
25 {
26         uint32_t write32;
27         size_t to_write = self->buffer_size * 8;
28
29         /* 32 bit -- bit size for the map */
30         write32 = (uint32_t)self->bit_size;
31         if (write(fd, &write32, 4) != 4)
32                 return -1;
33
34         /** 32 bit -- number of compressed 64-bit words */
35         write32 = (uint32_t)self->buffer_size;
36         if (write(fd, &write32, 4) != 4)
37                 return -1;
38
39         if (write(fd, self->buffer, to_write) != to_write)
40                 return -1;
41
42         /** 32 bit -- position for the RLW */
43         write32 = self->rlw - self->buffer;
44         if (write(fd, &write32, 4) != 4)
45                 return -1;
46
47         return (3 * 4) + to_write;
48 }
49
50 int ewah_serialize_to(struct ewah_bitmap *self,
51                       int (*write_fun)(void *, const void *, size_t),
52                       void *data)
53 {
54         size_t i;
55         eword_t dump[2048];
56         const size_t words_per_dump = sizeof(dump) / sizeof(eword_t);
57         uint32_t bitsize, word_count, rlw_pos;
58
59         const eword_t *buffer;
60         size_t words_left;
61
62         /* 32 bit -- bit size for the map */
63         bitsize =  htonl((uint32_t)self->bit_size);
64         if (write_fun(data, &bitsize, 4) != 4)
65                 return -1;
66
67         /** 32 bit -- number of compressed 64-bit words */
68         word_count =  htonl((uint32_t)self->buffer_size);
69         if (write_fun(data, &word_count, 4) != 4)
70                 return -1;
71
72         /** 64 bit x N -- compressed words */
73         buffer = self->buffer;
74         words_left = self->buffer_size;
75
76         while (words_left >= words_per_dump) {
77                 for (i = 0; i < words_per_dump; ++i, ++buffer)
78                         dump[i] = htonll(*buffer);
79
80                 if (write_fun(data, dump, sizeof(dump)) != sizeof(dump))
81                         return -1;
82
83                 words_left -= words_per_dump;
84         }
85
86         if (words_left) {
87                 for (i = 0; i < words_left; ++i, ++buffer)
88                         dump[i] = htonll(*buffer);
89
90                 if (write_fun(data, dump, words_left * 8) != words_left * 8)
91                         return -1;
92         }
93
94         /** 32 bit -- position for the RLW */
95         rlw_pos = (uint8_t*)self->rlw - (uint8_t *)self->buffer;
96         rlw_pos = htonl(rlw_pos / sizeof(eword_t));
97
98         if (write_fun(data, &rlw_pos, 4) != 4)
99                 return -1;
100
101         return (3 * 4) + (self->buffer_size * 8);
102 }
103
104 static int write_helper(void *fd, const void *buf, size_t len)
105 {
106         return write((intptr_t)fd, buf, len);
107 }
108
109 int ewah_serialize(struct ewah_bitmap *self, int fd)
110 {
111         return ewah_serialize_to(self, write_helper, (void *)(intptr_t)fd);
112 }
113
114 static int write_strbuf(void *user_data, const void *data, size_t len)
115 {
116         struct strbuf *sb = user_data;
117         strbuf_add(sb, data, len);
118         return len;
119 }
120
121 int ewah_serialize_strbuf(struct ewah_bitmap *self, struct strbuf *sb)
122 {
123         return ewah_serialize_to(self, write_strbuf, sb);
124 }
125
126 int ewah_read_mmap(struct ewah_bitmap *self, const void *map, size_t len)
127 {
128         const uint8_t *ptr = map;
129         size_t i;
130
131         self->bit_size = get_be32(ptr);
132         ptr += sizeof(uint32_t);
133
134         self->buffer_size = self->alloc_size = get_be32(ptr);
135         ptr += sizeof(uint32_t);
136
137         self->buffer = ewah_realloc(self->buffer,
138                 self->alloc_size * sizeof(eword_t));
139
140         if (!self->buffer)
141                 return -1;
142
143         /*
144          * Copy the raw data for the bitmap as a whole chunk;
145          * if we're in a little-endian platform, we'll perform
146          * the endianness conversion in a separate pass to ensure
147          * we're loading 8-byte aligned words.
148          */
149         memcpy(self->buffer, ptr, self->buffer_size * sizeof(uint64_t));
150         ptr += self->buffer_size * sizeof(uint64_t);
151
152         for (i = 0; i < self->buffer_size; ++i)
153                 self->buffer[i] = ntohll(self->buffer[i]);
154
155         self->rlw = self->buffer + get_be32(ptr);
156
157         return (3 * 4) + (self->buffer_size * 8);
158 }
159
160 int ewah_deserialize(struct ewah_bitmap *self, int fd)
161 {
162         size_t i;
163         eword_t dump[2048];
164         const size_t words_per_dump = sizeof(dump) / sizeof(eword_t);
165         uint32_t bitsize, word_count, rlw_pos;
166
167         eword_t *buffer = NULL;
168         size_t words_left;
169
170         ewah_clear(self);
171
172         /* 32 bit -- bit size for the map */
173         if (read(fd, &bitsize, 4) != 4)
174                 return -1;
175
176         self->bit_size = (size_t)ntohl(bitsize);
177
178         /** 32 bit -- number of compressed 64-bit words */
179         if (read(fd, &word_count, 4) != 4)
180                 return -1;
181
182         self->buffer_size = self->alloc_size = (size_t)ntohl(word_count);
183         self->buffer = ewah_realloc(self->buffer,
184                 self->alloc_size * sizeof(eword_t));
185
186         if (!self->buffer)
187                 return -1;
188
189         /** 64 bit x N -- compressed words */
190         buffer = self->buffer;
191         words_left = self->buffer_size;
192
193         while (words_left >= words_per_dump) {
194                 if (read(fd, dump, sizeof(dump)) != sizeof(dump))
195                         return -1;
196
197                 for (i = 0; i < words_per_dump; ++i, ++buffer)
198                         *buffer = ntohll(dump[i]);
199
200                 words_left -= words_per_dump;
201         }
202
203         if (words_left) {
204                 if (read(fd, dump, words_left * 8) != words_left * 8)
205                         return -1;
206
207                 for (i = 0; i < words_left; ++i, ++buffer)
208                         *buffer = ntohll(dump[i]);
209         }
210
211         /** 32 bit -- position for the RLW */
212         if (read(fd, &rlw_pos, 4) != 4)
213                 return -1;
214
215         self->rlw = self->buffer + ntohl(rlw_pos);
216         return 0;
217 }