Annotation of parser3/src/include/pa_hash.h, revision 1.39
1.28 paf 1: /** @file
1.29 paf 2: Parser: hash class decl.
3:
1.21 paf 4: Copyright (c) 2001 ArtLebedev Group (http://www.artlebedev.com)
1.29 paf 5:
1.22 paf 6: Author: Alexander Petrosyan <paf@design.ru> (http://design.ru/paf)
1.1 paf 7:
1.39 ! paf 8: $Id: pa_hash.h,v 1.38 2001/04/23 08:52:19 paf Exp $
1.1 paf 9: */
10:
11: #ifndef PA_HASH_H
12: #define PA_HASH_H
13:
14: #include <stddef.h>
15:
1.14 paf 16: #include "pa_pool.h"
1.1 paf 17: #include "pa_types.h"
18: #include "pa_string.h"
19:
1.29 paf 20:
21: /**
22: Pooled hash.
23:
24: Automatically rehashed when almost full.
25: */
1.23 paf 26: class Hash : public Pooled {
1.1 paf 27: public:
28:
1.29 paf 29: typedef String Key; ///< hash Key type. longing for templates
1.30 paf 30: typedef void Val; ///< hash Val type. longing for templates
1.3 paf 31:
1.31 paf 32: /// for_each iterator function type
33: typedef void (*For_each_func)(const Key& key, Val *value, void *info);
1.25 paf 34:
1.38 paf 35: /// first_that iterator function type
36: typedef bool (*First_that_func)(const Key& key, Val *value, void *info);
37:
1.8 paf 38: public:
39:
1.35 paf 40: Hash(Pool& apool) : Pooled(apool) {
41: construct(apool);
1.24 paf 42: }
1.10 paf 43:
1.29 paf 44: /// useful generic hash function
1.19 paf 45: static uint generic_code(uint aresult, const char *start, uint allocated);
1.8 paf 46:
1.29 paf 47: /// put a [value] under the [key], return existed or not
1.30 paf 48: /*SYNCHRONIZED*/ bool put(const Key& key, Val *value);
1.33 paf 49: /*
50: /// dirty hack to allow constant items storage. I long for Hash<const Val*>
51: /*SYNCHRONIZED* / bool put(const Key& key, const Val *value) {
52: return put(key, const_cast<Val *>(value));
53: }
54: */
1.29 paf 55: /// get associated [value] by the [key]
1.30 paf 56: /*SYNCHRONIZED*/ Val *get(const Key& key) const;
1.17 paf 57:
1.29 paf 58: /// put a [value] under the [key] if that [key] existed, return existed or not
1.30 paf 59: /*SYNCHRONIZED*/ bool put_replace(const Key& key, Val *value);
1.18 paf 60:
1.29 paf 61: /// put a [value] under the [key] if that [key] NOT existed, return existed or not
1.30 paf 62: /*SYNCHRONIZED*/ bool put_dont_replace(const Key& key, Val *value);
1.18 paf 63:
1.29 paf 64: /// put all 'src' values if NO with same key existed
1.18 paf 65: /*SYNCHRONIZED*/ void merge_dont_replace(const Hash& src);
1.11 paf 66:
1.30 paf 67: void put(const Key& key, int value) { put(key, reinterpret_cast<Val *>(value)); }
1.36 paf 68: void put(const Key& key, const String *value) {
69: put(key, static_cast<Val *>(const_cast<String *>(value)));
70: }
1.11 paf 71:
1.29 paf 72: //@{
73: /// handy get, longing for Hash<int>, Hash<String *>
1.32 paf 74: int get_int(const Key& key) const { return reinterpret_cast<int>(get(key)); }
75: const String *get_string(const Key& key) const { return static_cast<String *>(get(key)); }
1.29 paf 76: //@}
1.10 paf 77:
1.29 paf 78: /// number of elements in hash
1.37 paf 79: int size() const { return used; }
1.25 paf 80:
1.29 paf 81: /// iterate over all not zero elements
1.36 paf 82: void for_each(For_each_func func, void *info=0) const;
1.38 paf 83:
84: /// iterate over all elements until condition
85: Val* first_that(First_that_func func, void *info=0) const;
1.27 paf 86:
1.29 paf 87: /// remove all elements
1.27 paf 88: void clear();
1.19 paf 89:
1.15 paf 90: protected:
91:
1.35 paf 92: void construct(Pool& apool);
1.15 paf 93:
1.1 paf 94: private:
95:
1.39 ! paf 96: /// expand when these %% of allocated exausted
1.1 paf 97: enum {
98: THRESHOLD_PERCENT=75
99: };
1.9 paf 100:
1.39 ! paf 101: /// the index of [allocated] in [allocates]
1.19 paf 102: int allocates_index;
1.1 paf 103:
1.39 ! paf 104: /// possible [allocates]. prime numbers
1.19 paf 105: static uint allocates[];
106: static int allocates_count;
1.1 paf 107:
1.39 ! paf 108: /// number of allocated pairs
1.19 paf 109: int allocated;
1.1 paf 110:
1.39 ! paf 111: /// helper: expanding when used == threshold
1.1 paf 112: int threshold;
113:
1.39 ! paf 114: /// used pairs
1.1 paf 115: int used;
116:
1.39 ! paf 117: /// pair storage
1.1 paf 118: class Pair {
1.2 paf 119: friend Hash;
120:
1.1 paf 121: uint code;
1.15 paf 122: const Key key;
1.30 paf 123: Val *value;
1.1 paf 124: Pair *link;
1.2 paf 125:
1.19 paf 126: void *operator new(size_t allocated, Pool& apool);
1.2 paf 127:
1.30 paf 128: Pair(uint acode, const Key& akey, Val *avalue, Pair *alink) :
1.1 paf 129: code(acode),
130: key(akey),
131: value(avalue),
1.2 paf 132: link(alink) {}
133: } **refs;
1.1 paf 134:
1.39 ! paf 135: /// filled to threshold: needs expanding
1.5 paf 136: bool full() { return used==threshold; }
137:
1.39 ! paf 138: /// allocate larger buffer & rehash
1.1 paf 139: void expand();
1.4 paf 140:
141: private: //disabled
142:
1.11 paf 143: //Hash(Hash&) {}
1.12 paf 144: Hash& operator = (const Hash&) { return *this; }
1.1 paf 145: };
146:
147: #endif
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