| … | |
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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 | |
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12 | // NOTE: even with lots of stuff loaded, we do not usually have >>20000 strings. |
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13 | // maybe refcounting is just overhead? |
| 11 | |
14 | |
| 12 | struct hash |
15 | struct hash |
| 13 | { |
16 | { |
| 14 | std::size_t operator ()(const char *s) const |
17 | std::size_t operator ()(const char *s) const |
| 15 | { |
18 | { |
| … | |
… | |
| 49 | static HT ht; |
52 | static HT ht; |
| 50 | |
53 | |
| 51 | const char * |
54 | const char * |
| 52 | shstr::find (const char *s) |
55 | shstr::find (const char *s) |
| 53 | { |
56 | { |
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57 | if (!s) |
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58 | return s; |
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59 | |
| 54 | HT::iterator i = ht.find (s); |
60 | HT::iterator i = ht.find (s); |
| 55 | |
61 | |
| 56 | return i != ht.end () |
62 | return i != ht.end () |
| 57 | ? (char *)*i |
63 | ? *i |
| 58 | : 0; |
64 | : 0; |
| 59 | } |
65 | } |
| 60 | |
66 | |
| 61 | const char * |
67 | const char * |
| 62 | shstr::intern (const char *s) |
68 | shstr::intern (const char *s) |
| 63 | { |
69 | { |
| 64 | HT::iterator i = ht.find (s); |
70 | if (!s) |
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71 | return s; |
| 65 | |
72 | |
| 66 | if (i != ht.end ()) |
73 | if (const char *found = find (s)) |
| 67 | return (char *)*i; |
74 | { |
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75 | ++refcnt (found); |
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76 | return found; |
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77 | } |
| 68 | |
78 | |
| 69 | int len = strlen (s); |
79 | int len = strlen (s); |
| 70 | |
80 | |
| 71 | int *v = (int *)malloc (sizeof (int) * 2 + len + 1); |
81 | const char *v = (const char *)(2 + (int *)malloc (sizeof (int) * 2 + len + 1)); |
| 72 | |
82 | |
| 73 | v [0] = len; |
83 | length (v) = len; |
| 74 | v [1] = 0; |
84 | refcnt (v) = 1; |
| 75 | |
85 | |
| 76 | v += 2; |
86 | memcpy ((char *)v, s, len + 1); |
| 77 | |
87 | |
| 78 | memcpy (v, s, len + 1); |
88 | ht.insert (v); |
| 79 | |
89 | |
| 80 | ht.insert ((char *)v); |
90 | return v; |
| 81 | |
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| 82 | return (char *)v; |
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| 83 | } |
91 | } |
| 84 | |
92 | |
| 85 | // TODO: periodically test refcounts == 0 for a few strings (e.g. one hash bucket, |
93 | // periodically test refcounts == 0 for a few strings |
| 86 | // exploiting the fatc that iterators stay valid for unordered_set). |
94 | // this is the ONLY thing that erases stuff from ht. keep it that way. |
| 87 | void |
95 | void |
| 88 | shstr::gc () |
96 | shstr::gc () |
| 89 | { |
97 | { |
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98 | static const char *curpos; |
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99 | |
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100 | HT::iterator i = curpos ? ht.find (curpos) : ht.begin (); |
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101 | |
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102 | if (i == ht.end ()) |
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103 | i = ht.begin (); |
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104 | |
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105 | // go through all strings roughly once every 4 minutes |
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106 | for (int n = ht.size () / 256 + 16; --n; ) |
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107 | { |
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108 | if (i == ht.end ()) |
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109 | { |
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110 | curpos = 0; |
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111 | return; |
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112 | } |
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113 | |
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114 | if (!refcnt (*i)) |
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115 | { |
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116 | HT::iterator o = i++; |
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117 | const char *s = *o; |
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118 | ht.erase (o); |
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119 | |
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120 | //printf ("GC %4d %3d %d >%s<%d\n", (int)ht.size (), n, shstr::refcnt (s), s, shstr::length (s)); |
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121 | free (-2 + (int *)s); |
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122 | } |
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123 | else |
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124 | ++i; |
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125 | } |
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126 | |
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127 | curpos = *i; |
| 90 | } |
128 | } |
| 91 | |
129 | |
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130 | //TODO: this should of course not be here |
| 92 | /* buf_overflow() - we don't want to exceed the buffer size of |
131 | /* buf_overflow() - we don't want to exceed the buffer size of |
| 93 | * buf1 by adding on buf2! Returns true if overflow will occur. |
132 | * buf1 by adding on buf2! Returns true if overflow will occur. |
| 94 | */ |
133 | */ |
| 95 | |
134 | |
| 96 | int |
135 | int |
