btllib: include/btllib/rolling_hash.hpp Source File

btllib

rolling_hash.hpp
1 #ifndef BTLLIB_ROLLING_HASH_HPP
2 #define BTLLIB_ROLLING_HASH_HPP
3
4 #include "nthash.hpp"
5
6 #include <limits>
7 #include <string>
8 #include <vector>
9
10 namespace btllib {
11
12 class RollingHash;
13 class SeedRollingHash;
14 using SpacedSeed = std::vector<unsigned>;
15 static std::vector<SpacedSeed>
16 parse_seeds(const std::vector<std::string>& seed_strings);
17
26 class RollingHash
27 {
28
29 public:
37 RollingHash(const char* seq, size_t seq_len, unsigned k, unsigned hash_num);
38
45 RollingHash(const std::string& seq, unsigned k, unsigned hash_num);
46
47 bool roll();
48
49 const uint64_t* hashes() const;
50
51 size_t get_pos() const { return pos; }
52 unsigned get_k() const { return k; }
53 unsigned get_hash_num() const { return hash_num; }
54
55 protected:
57 bool init();
58
59 const char* seq;
60 const size_t seq_len;
61 const unsigned k;
62 const unsigned hash_num;
63 size_t pos = 0;
64 std::vector<uint64_t> hashes_vector;
65 uint64_t forward_hash = 0;
66 uint64_t reverse_hash = 0;
67 };
68
69 class SeedRollingHash : public RollingHash
70 {
71
72 public:
73 SeedRollingHash(const char* seq,
74 size_t seq_len,
75 unsigned k,
76 const std::vector<SpacedSeed>& seeds,
77 unsigned hash_num_per_seed);
78 SeedRollingHash(const std::string& seq,
79 unsigned k,
80 const std::vector<SpacedSeed>& seeds,
81 unsigned hash_num_per_seed);
82 SeedRollingHash(const char* seq,
83 size_t seq_len,
84 unsigned k,
85 const std::vector<std::string>& seeds,
86 unsigned hash_num_per_seed);
87 SeedRollingHash(const std::string& seq,
88 unsigned k,
89 const std::vector<std::string>& seeds,
90 unsigned hash_num_per_seed);
91
92 unsigned get_hash_num_per_seed() const { return hash_num_per_seed; }
93
94 bool roll();
95
96 private:
97 bool init();
98
99 const unsigned hash_num_per_seed;
100 std::vector<SpacedSeed> seeds;
101 };
102
103 inline RollingHash::RollingHash(const char* seq,
104 size_t seq_len,
105 unsigned k,
106 unsigned hash_num)
107 : seq(seq)
108 , seq_len(seq_len)
109 , k(k)
110 , hash_num(hash_num)
111 {
112 hashes_vector.resize(hash_num);
113 }
114
115 inline RollingHash::RollingHash(const std::string& seq,
116 unsigned k,
117 unsigned hash_num)
118 : RollingHash(seq.c_str(), seq.size(), k, hash_num)
119 {}
120
121 inline SeedRollingHash::SeedRollingHash(const char* seq,
122 size_t seq_len,
123 unsigned k,
124 const std::vector<SpacedSeed>& seeds,
125 unsigned hash_num_per_seed)
126 : RollingHash(seq, seq_len, k, seeds.size() * hash_num_per_seed)
127 , hash_num_per_seed(hash_num_per_seed)
128 , seeds(seeds)
129 {}
130
131 inline SeedRollingHash::SeedRollingHash(const std::string& seq,
132 unsigned k,
133 const std::vector<SpacedSeed>& seeds,
134 unsigned hash_num_per_seed)
135 : RollingHash(seq, k, seeds.size() * hash_num_per_seed)
136 , hash_num_per_seed(hash_num_per_seed)
137 , seeds(seeds)
138 {}
139
140 inline SeedRollingHash::SeedRollingHash(const char* seq,
141 size_t seq_len,
142 unsigned k,
143 const std::vector<std::string>& seeds,
144 unsigned hash_num_per_seed)
145 : RollingHash(seq, seq_len, k, seeds.size() * hash_num_per_seed)
146 , hash_num_per_seed(hash_num_per_seed)
147 , seeds(parse_seeds(seeds))
148 {}
149
150 inline SeedRollingHash::SeedRollingHash(const std::string& seq,
151 unsigned k,
152 const std::vector<std::string>& seeds,
153 unsigned hash_num_per_seed)
154 : RollingHash(seq, k, seeds.size() * hash_num_per_seed)
155 , hash_num_per_seed(hash_num_per_seed)
156 , seeds(parse_seeds(seeds))
157 {}
158
159 static std::vector<SpacedSeed>
160 parse_seeds(const std::vector<std::string>& seed_strings)
161 {
162 std::vector<SpacedSeed> seed_set;
163 for (const auto& seed_string : seed_strings) {
164 SpacedSeed seed;
165 size_t pos = 0;
166 for (const auto& c : seed_string) {
167 if (c != '1') {
168 seed.push_back(pos);
169 }
170 ++pos;
171 }
172 seed_set.push_back(seed);
173 }
174 return seed_set;
175 }
176
177 // NOLINTNEXTLINE
178 #define ROLLING_HASH_INIT(CLASS, NTHASH_CALL) \
179 inline bool CLASS::init() \
180 { \
181 if (k > seq_len) { \
182 pos = std::numeric_limits<std::size_t>::max(); \
183 return false; \
184 } \
185 unsigned posN = 0; \
186 while ((pos < seq_len - k + 1) && !(NTHASH_CALL)) { \
187 pos += posN + 1; \
188 } \
189 if (pos > seq_len - k) { \
190 pos = std::numeric_limits<std::size_t>::max(); \
191 return false; \
192 } \
193 ++pos; \
194 return true; \
195 }
196
197 // NOLINTNEXTLINE
198 #define ROLLING_HASH_ROLL(CLASS, NTHASH_CALL) \
199 inline bool CLASS::roll() \
200 { \
201 if (pos == 0) { \
202 return init(); \
203 } \
204 if (pos > seq_len - k) { \
205 return false; \
206 } \
207 if (seed_tab[(unsigned char)(seq[pos + k - 1])] == seedN) { \
208 pos += k; \
209 return init(); \
210 } \
211 (NTHASH_CALL); \
212 ++pos; \
213 return true; \
214 }
215
216 ROLLING_HASH_INIT(RollingHash,
217 NTMC64(seq + pos,
218 k,
219 hash_num,
220 forward_hash,
221 reverse_hash,
222 posN,
223 hashes_vector.data()))
224 ROLLING_HASH_ROLL(RollingHash,
225 NTMC64(seq[pos - 1],
226 seq[pos - 1 + k],
227 k,
228 hash_num,
229 forward_hash,
230 reverse_hash,
231 hashes_vector.data()))
232
233 ROLLING_HASH_INIT(SeedRollingHash,
234 NTMSM64(seq + pos,
235 seeds,
236 k,
237 seeds.size(),
238 hash_num_per_seed,
239 forward_hash,
240 reverse_hash,
241 posN,
242 hashes_vector.data()))
243 ROLLING_HASH_ROLL(SeedRollingHash,
244 NTMSM64(seq + pos,
245 seeds,
246 seq[pos - 1],
247 seq[pos - 1 + k],
248 k,
249 seeds.size(),
250 hash_num_per_seed,
251 forward_hash,
252 reverse_hash,
253 hashes_vector.data()))
254
255 #undef ROLLING_HASH_INIT
256 #undef ROLLING_HASH_ROLL
257
258 inline const uint64_t*
259 RollingHash::hashes() const
260 {
261 return hashes_vector.data();
262 }
263
264 } // namespace btllib
265
266 #endif
btllib::RollingHash::RollingHash
RollingHash(const char *seq, size_t seq_len, unsigned k, unsigned hash_num)
Definition: rolling_hash.hpp:103
btllib::SeedRollingHash
Definition: rolling_hash.hpp:69
btllib::RollingHash::init
bool init()
btllib::RollingHash
Definition: rolling_hash.hpp:26