Merge branch 'es/utf8-stupid-compiler-workaround' into maint
[git/git.git] / ewah / ewok.h
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 #ifndef __EWOK_BITMAP_H__
21 #define __EWOK_BITMAP_H__
22
23 #ifndef ewah_malloc
24 # define ewah_malloc xmalloc
25 #endif
26 #ifndef ewah_realloc
27 # define ewah_realloc xrealloc
28 #endif
29 #ifndef ewah_calloc
30 # define ewah_calloc xcalloc
31 #endif
32
33 typedef uint64_t eword_t;
34 #define BITS_IN_WORD (sizeof(eword_t) * 8)
35
36 /**
37 * Do not use __builtin_popcountll. The GCC implementation
38 * is notoriously slow on all platforms.
39 *
40 * See: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36041
41 */
42 static inline uint32_t ewah_bit_popcount64(uint64_t x)
43 {
44 x = (x & 0x5555555555555555ULL) + ((x >> 1) & 0x5555555555555555ULL);
45 x = (x & 0x3333333333333333ULL) + ((x >> 2) & 0x3333333333333333ULL);
46 x = (x & 0x0F0F0F0F0F0F0F0FULL) + ((x >> 4) & 0x0F0F0F0F0F0F0F0FULL);
47 return (x * 0x0101010101010101ULL) >> 56;
48 }
49
50 /* __builtin_ctzll was not available until 3.4.0 */
51 #if defined(__GNUC__) && (__GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR > 3))
52 #define ewah_bit_ctz64(x) __builtin_ctzll(x)
53 #else
54 static inline int ewah_bit_ctz64(uint64_t x)
55 {
56 int n = 0;
57 if ((x & 0xffffffff) == 0) { x >>= 32; n += 32; }
58 if ((x & 0xffff) == 0) { x >>= 16; n += 16; }
59 if ((x & 0xff) == 0) { x >>= 8; n += 8; }
60 if ((x & 0xf) == 0) { x >>= 4; n += 4; }
61 if ((x & 0x3) == 0) { x >>= 2; n += 2; }
62 if ((x & 0x1) == 0) { x >>= 1; n += 1; }
63 return n + !x;
64 }
65 #endif
66
67 struct ewah_bitmap {
68 eword_t *buffer;
69 size_t buffer_size;
70 size_t alloc_size;
71 size_t bit_size;
72 eword_t *rlw;
73 };
74
75 typedef void (*ewah_callback)(size_t pos, void *);
76
77 struct ewah_bitmap *ewah_pool_new(void);
78 void ewah_pool_free(struct ewah_bitmap *self);
79
80 /**
81 * Allocate a new EWAH Compressed bitmap
82 */
83 struct ewah_bitmap *ewah_new(void);
84
85 /**
86 * Clear all the bits in the bitmap. Does not free or resize
87 * memory.
88 */
89 void ewah_clear(struct ewah_bitmap *self);
90
91 /**
92 * Free all the memory of the bitmap
93 */
94 void ewah_free(struct ewah_bitmap *self);
95
96 int ewah_serialize_to(struct ewah_bitmap *self,
97 int (*write_fun)(void *out, const void *buf, size_t len),
98 void *out);
99 int ewah_serialize(struct ewah_bitmap *self, int fd);
100 int ewah_serialize_native(struct ewah_bitmap *self, int fd);
101
102 int ewah_deserialize(struct ewah_bitmap *self, int fd);
103 int ewah_read_mmap(struct ewah_bitmap *self, const void *map, size_t len);
104
105 uint32_t ewah_checksum(struct ewah_bitmap *self);
106
107 /**
108 * Logical not (bitwise negation) in-place on the bitmap
109 *
110 * This operation is linear time based on the size of the bitmap.
111 */
112 void ewah_not(struct ewah_bitmap *self);
113
114 /**
115 * Call the given callback with the position of every single bit
116 * that has been set on the bitmap.
117 *
118 * This is an efficient operation that does not fully decompress
119 * the bitmap.
120 */
121 void ewah_each_bit(struct ewah_bitmap *self, ewah_callback callback, void *payload);
122
123 /**
124 * Set a given bit on the bitmap.
125 *
126 * The bit at position `pos` will be set to true. Because of the
127 * way that the bitmap is compressed, a set bit cannot be unset
128 * later on.
129 *
130 * Furthermore, since the bitmap uses streaming compression, bits
131 * can only set incrementally.
132 *
133 * E.g.
134 * ewah_set(bitmap, 1); // ok
135 * ewah_set(bitmap, 76); // ok
136 * ewah_set(bitmap, 77); // ok
137 * ewah_set(bitmap, 8712800127); // ok
138 * ewah_set(bitmap, 25); // failed, assert raised
139 */
140 void ewah_set(struct ewah_bitmap *self, size_t i);
141
142 struct ewah_iterator {
143 const eword_t *buffer;
144 size_t buffer_size;
145
146 size_t pointer;
147 eword_t compressed, literals;
148 eword_t rl, lw;
149 int b;
150 };
151
152 /**
153 * Initialize a new iterator to run through the bitmap in uncompressed form.
154 *
155 * The iterator can be stack allocated. The underlying bitmap must not be freed
156 * before the iteration is over.
157 *
158 * E.g.
159 *
160 * struct ewah_bitmap *bitmap = ewah_new();
161 * struct ewah_iterator it;
162 *
163 * ewah_iterator_init(&it, bitmap);
164 */
165 void ewah_iterator_init(struct ewah_iterator *it, struct ewah_bitmap *parent);
166
167 /**
168 * Yield every single word in the bitmap in uncompressed form. This is:
169 * yield single words (32-64 bits) where each bit represents an actual
170 * bit from the bitmap.
171 *
172 * Return: true if a word was yield, false if there are no words left
173 */
174 int ewah_iterator_next(eword_t *next, struct ewah_iterator *it);
175
176 void ewah_or(
177 struct ewah_bitmap *ewah_i,
178 struct ewah_bitmap *ewah_j,
179 struct ewah_bitmap *out);
180
181 void ewah_and_not(
182 struct ewah_bitmap *ewah_i,
183 struct ewah_bitmap *ewah_j,
184 struct ewah_bitmap *out);
185
186 void ewah_xor(
187 struct ewah_bitmap *ewah_i,
188 struct ewah_bitmap *ewah_j,
189 struct ewah_bitmap *out);
190
191 void ewah_and(
192 struct ewah_bitmap *ewah_i,
193 struct ewah_bitmap *ewah_j,
194 struct ewah_bitmap *out);
195
196 /**
197 * Direct word access
198 */
199 size_t ewah_add_empty_words(struct ewah_bitmap *self, int v, size_t number);
200 void ewah_add_dirty_words(
201 struct ewah_bitmap *self, const eword_t *buffer, size_t number, int negate);
202 size_t ewah_add(struct ewah_bitmap *self, eword_t word);
203
204
205 /**
206 * Uncompressed, old-school bitmap that can be efficiently compressed
207 * into an `ewah_bitmap`.
208 */
209 struct bitmap {
210 eword_t *words;
211 size_t word_alloc;
212 };
213
214 struct bitmap *bitmap_new(void);
215 void bitmap_set(struct bitmap *self, size_t pos);
216 void bitmap_clear(struct bitmap *self, size_t pos);
217 int bitmap_get(struct bitmap *self, size_t pos);
218 void bitmap_reset(struct bitmap *self);
219 void bitmap_free(struct bitmap *self);
220 int bitmap_equals(struct bitmap *self, struct bitmap *other);
221 int bitmap_is_subset(struct bitmap *self, struct bitmap *super);
222
223 struct ewah_bitmap * bitmap_to_ewah(struct bitmap *bitmap);
224 struct bitmap *ewah_to_bitmap(struct ewah_bitmap *ewah);
225
226 void bitmap_and_not(struct bitmap *self, struct bitmap *other);
227 void bitmap_or_ewah(struct bitmap *self, struct ewah_bitmap *other);
228 void bitmap_or(struct bitmap *self, const struct bitmap *other);
229
230 void bitmap_each_bit(struct bitmap *self, ewah_callback callback, void *data);
231 size_t bitmap_popcount(struct bitmap *self);
232
233 #endif