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| 6 | #include <cstdlib> |
6 | #include <cstdlib> |
| 7 | |
7 | |
| 8 | #include <tr1/unordered_set> |
8 | #include <tr1/unordered_set> |
| 9 | |
9 | |
| 10 | #include "shstr.h" |
10 | #include "shstr.h" |
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11 | #include "util.h" |
| 11 | |
12 | |
| 12 | struct hash |
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| 13 | { |
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| 14 | std::size_t operator ()(const char *s) const |
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| 15 | { |
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| 16 | unsigned long hash = 0; |
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| 17 | unsigned int i = 0; |
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| 18 | |
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| 19 | /* use the one-at-a-time hash function, which supposedly is |
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| 20 | * better than the djb2-like one used by perl5.005, but |
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| 21 | * certainly is better then the bug used here before. |
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| 22 | * see http://burtleburtle.net/bob/hash/doobs.html |
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| 23 | */ |
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| 24 | while (*s) |
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| 25 | { |
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| 26 | hash += *s++; |
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| 27 | hash += hash << 10; |
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| 28 | hash ^= hash >> 6; |
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| 29 | } |
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| 30 | |
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| 31 | hash += hash << 3; |
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| 32 | hash ^= hash >> 11; |
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| 33 | hash += hash << 15; |
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| 34 | |
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| 35 | return hash; |
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| 36 | } |
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| 37 | }; |
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| 38 | |
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| 39 | struct equal |
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| 40 | { |
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| 41 | bool operator ()(const char *a, const char *b) const |
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| 42 | { |
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| 43 | return !strcmp (a, b); |
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| 44 | } |
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| 45 | }; |
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| 46 | |
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| 47 | typedef std::tr1::unordered_set<const char *, hash, equal> HT; |
13 | typedef std::tr1::unordered_set<const char *, str_hash, str_equal> HT; |
| 48 | |
14 | |
| 49 | static HT ht; |
15 | static HT ht; |
| 50 | |
16 | |
| 51 | static const char *makevec (const char *s) |
17 | static const char *makevec (const char *s) |
| 52 | { |
18 | { |
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| 57 | shstr::length (v) = len; |
23 | shstr::length (v) = len; |
| 58 | shstr::refcnt (v) = 1; |
24 | shstr::refcnt (v) = 1; |
| 59 | |
25 | |
| 60 | memcpy ((char *)v, s, len + 1); |
26 | memcpy ((char *)v, s, len + 1); |
| 61 | |
27 | |
| 62 | return s; |
28 | return v; |
| 63 | } |
29 | } |
| 64 | |
30 | |
| 65 | const char *shstr::null = makevec ("<nil>"); |
31 | const char *shstr::null = makevec ("<nil>"); |
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32 | |
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33 | // what weird misoptimisation is this again? |
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34 | const shstr undead_name ("undead"); |
| 66 | |
35 | |
| 67 | const char * |
36 | const char * |
| 68 | shstr::find (const char *s) |
37 | shstr::find (const char *s) |
| 69 | { |
38 | { |
| 70 | if (!s) |
39 | if (!s) |
