Annotation of parser3/src/include/pa_hash.h, revision 1.64
1.28 paf 1: /** @file
1.29 paf 2: Parser: hash class decl.
3:
1.62 paf 4: Copyright (c) 2001-2004 ArtLebedev Group (http://www.artlebedev.com)
1.29 paf 5:
1.54 paf 6: Author: Alexandr Petrosian <paf@design.ru> (http://paf.design.ru)
1.1 paf 7: */
8:
1.59 paf 9: /*
10: The prime numbers used from zend_hash.c,
11: the part of Zend scripting engine library,
12: Copyrighted (C) 1999-2000 Zend Technologies Ltd.
13: http://www.zend.com/license/0_92.txt
14: For more information about Zend please visit http://www.zend.com/
15: */
16:
1.1 paf 17: #ifndef PA_HASH_H
18: #define PA_HASH_H
1.56 paf 19:
1.64 ! paf 20: static const char * const IDENT_HASH_H="$Date: 2005/07/26 12:43:05 $";
1.1 paf 21:
1.59 paf 22: #include "pa_memory.h"
1.1 paf 23: #include "pa_types.h"
1.59 paf 24:
25: const int HASH_ALLOCATES_COUNT=29;
1.1 paf 26:
1.61 paf 27: /** Zend comment: Generated on an Octa-ALPHA 300MHz CPU & 2.5GB RAM monster
28:
29: paf: HPUX ld could not handle static member: unsatisfied symbols
30: */
31: static uint Hash_allocates[HASH_ALLOCATES_COUNT]={
32: 5, 11, 19, 53, 107, 223, 463, 983, 1979, 3907, 7963,
33: 16229, 32531, 65407, 130987, 262237, 524521, 1048793,
34: 2097397, 4194103, 8388857, 16777447, 33554201, 67108961,
35: 134217487, 268435697, 536870683, 1073741621, 2147483399};
36:
1.29 paf 37: /**
1.59 paf 38: Simple hash.
1.29 paf 39:
1.59 paf 40: Automatically rehashed when almost is_full.
1.51 paf 41: Contains no 0 values.
42: get returning 0 means there were no such.
43: "put value 0" means "remove"
1.29 paf 44: */
1.59 paf 45: template<typename K, typename V> class Hash: public PA_Object {
1.1 paf 46: public:
47:
1.59 paf 48: typedef K key_type;
49: typedef V value_type;
1.3 paf 50:
1.59 paf 51: Hash() {
1.61 paf 52: allocated=Hash_allocates[allocates_index=0];
1.59 paf 53: threshold=allocated*THRESHOLD_PERCENT/100;
54: fpairs_count=fused_refs=0;
55: refs=new(UseGC) Pair*[allocated];
56: }
1.25 paf 57:
1.59 paf 58: Hash(const Hash& source) {
59: allocates_index=source.allocates_index;
60: allocated=source.allocated;
61: threshold=source.threshold;
62: fused_refs=source.fused_refs;
63: fpairs_count=source.fpairs_count;
64: refs=new(UseGC) Pair*[allocated];
65:
66: // clone & rehash
67: Pair **old_ref=source.refs;
68: for(int index=0; index<allocated; index++)
69: for(Pair *pair=*old_ref++; pair; ) {
70: Pair *next=pair->link;
1.45 paf 71:
1.59 paf 72: Pair **new_ref=&refs[index];
73: *new_ref=new Pair(pair->code, pair->key, pair->value, *new_ref);
1.38 paf 74:
1.59 paf 75: pair=next;
76: }
1.43 parser 77: }
78:
1.59 paf 79: /// put a [value] under the [key] @returns existed or not
80: bool put(K key, V value) {
81: if(!value) {
82: remove(key);
83: return false;
84: }
85: if(is_full())
86: expand();
87:
88: uint code=hash_code(key);
89: uint index=code%allocated;
90: Pair **ref=&refs[index];
91: for(Pair *pair=*ref; pair; pair=pair->link)
92: if(pair->code==code && pair->key==key) {
93: // found a pair with the same key
94: pair->value=value;
95: return true;
96: }
97:
98: // proper pair not found -- create&link_in new pair
99: if(!*ref) // root cell were fused_refs?
100: fused_refs++; // not, we'll use it and record the fact
101: *ref=new Pair(code, key, value, *ref);
102: fpairs_count++;
103: return false;
1.24 paf 104: }
1.10 paf 105:
1.63 paf 106: /// put a [value] under the [key] @returns existed or not
107: template<typename R, typename F> R maybe_put(K key, V value, F prevent) {
1.64 ! paf 108: assert(value);
! 109:
1.63 paf 110: if(is_full())
111: expand();
112:
113: uint code=hash_code(key);
114: uint index=code%allocated;
115: Pair **ref=&refs[index];
116: for(Pair *pair=*ref; pair; pair=pair->link)
117: if(pair->code==code && pair->key==key) {
118: // found a pair with the same key
119:
120: // prevent-function intercepted put?
121: if(R result=prevent(pair->value))
122: return result;
123:
124: pair->value=value;
125: return reinterpret_cast<R>(1);
126: }
127:
128: // proper pair not found -- create&link_in new pair
129: if(!*ref) // root cell were fused_refs?
130: fused_refs++; // not, we'll use it and record the fact
131: *ref=new Pair(code, key, value, *ref);
132: fpairs_count++;
133: return 0;
134: }
135:
1.59 paf 136: /// remove the [key] @returns existed or not
137: bool remove(K key) {
138: uint code=hash_code(key);
139: uint index=code%allocated;
140: for(Pair **ref=&refs[index]; *ref; ref=&(*ref)->link)
141: if((*ref)->code==code && (*ref)->key==key) {
142: // found a pair with the same key
143: Pair *next=(*ref)->link;
144: delete *ref;
145: *ref=next;
146: --fpairs_count;
147: return true;
148: }
1.8 paf 149:
1.59 paf 150: return false;
151: }
1.48 paf 152:
1.59 paf 153: /// get associated [value] by the [key]
154: V get(K key) const {
155: uint code=hash_code(key);
156: uint index=code%allocated;
157: for(Pair *pair=refs[index]; pair; pair=pair->link)
158: if(pair->code==code && pair->key==key)
159: return pair->value;
160:
161: return V(0);
1.33 paf 162: }
1.17 paf 163:
1.51 paf 164: /// put a [value] under the [key] if that [key] existed @returns existed or not
1.63 paf 165: bool put_replaced(K key, V value) {
1.59 paf 166: if(!value) {
167: remove(key);
168: return false;
169: }
170: uint code=hash_code(key);
171: uint index=code%allocated;
172: for(Pair *pair=refs[index]; pair; pair=pair->link)
173: if(pair->code==code && pair->key==key) {
174: // found a pair with the same key, replacing
175: pair->value=value;
176: return true;
177: }
178:
179: // proper pair not found
180: return false;
1.64 ! paf 181: }
! 182:
! 183: /// put a [value] under the [key] if that [key] existed @returns existed or not
! 184: template<typename R, typename F> R maybe_put_replaced(K key, V value, F prevent) {
! 185: assert(value);
! 186:
! 187: uint code=hash_code(key);
! 188: uint index=code%allocated;
! 189: for(Pair *pair=refs[index]; pair; pair=pair->link)
! 190: if(pair->code==code && pair->key==key) {
! 191: // found a pair with the same key, replacing
! 192:
! 193: // prevent-function intercepted put?
! 194: if(R result=prevent(pair->value))
! 195: return result;
! 196:
! 197: pair->value=value;
! 198: return reinterpret_cast<R>(1);
! 199: }
! 200:
! 201: // proper pair not found
! 202: return 0;
1.59 paf 203: }
1.18 paf 204:
1.51 paf 205: /// put a [value] under the [key] if that [key] NOT existed @returns existed or not
1.59 paf 206: bool put_dont_replace(K key, V value) {
207: if(!value) {
208: remove(key);
209: return false;
210: }
211: if(is_full())
212: expand();
213:
214: uint code=hash_code(key);
215: uint index=code%allocated;
216: Pair **ref=&refs[index];
217: for(Pair *pair=*ref; pair; pair=pair->link)
218: if(pair->code==code && pair->key==key) {
219: // found a pair with the same key, NOT replacing
220: return true;
221: }
222:
223: // proper pair not found -- create&link_in new pair
224: if(!*ref) // root cell were fused_refs?
225: fused_refs++; // not, we'll use it and record the fact
226: *ref=new Pair(code, key, value, *ref);
227: fpairs_count++;
228: return false;
229: }
1.18 paf 230:
1.59 paf 231: /** put all 'src' values if NO with same key existed
232: @todo optimize this.allocated==src.allocated case
233: */
234: void merge_dont_replace(const Hash& src) {
235: for(int i=0; i<src.allocated; i++)
236: for(Pair *pair=src.refs[i]; pair; pair=pair->link)
237: put_dont_replace(pair->key, pair->value);
1.36 paf 238: }
1.11 paf 239:
1.29 paf 240: /// number of elements in hash
1.59 paf 241: int count() const { return fpairs_count; }
1.25 paf 242:
1.59 paf 243: /// iterate over all pairs
244: template<typename I> void for_each(void callback(K, V, I), I info) const {
245: Pair **ref=refs;
246: for(int index=0; index<allocated; index++)
247: for(Pair *pair=*ref++; pair; pair=pair->link)
248: callback(pair->key, pair->value, info);
249: }
1.45 paf 250:
1.59 paf 251: /// iterate over all pairs
252: template<typename I> void for_each_ref(void callback(K, V&, I), I info) const {
253: Pair **ref=refs;
254: for(int index=0; index<allocated; index++)
255: for(Pair *pair=*ref++; pair; pair=pair->link)
256: callback(pair->key, pair->value, info);
257: }
1.38 paf 258:
1.59 paf 259: /// iterate over all pairs until condition becomes true, return that element
260: template<typename I> V first_that(bool callback(K, V, I), I info) const {
261: Pair **ref=refs;
262: for(int index=0; index<allocated; index++)
263: for(Pair *pair=*ref++; pair; pair=pair->link)
264: if(callback(pair->key, pair->value, info))
265: return pair->value;
266:
267: return V(0);
268: }
1.27 paf 269:
1.29 paf 270: /// remove all elements
1.59 paf 271: void clear() {
272: memset(refs, 0, sizeof(*refs)*allocated);
273: fpairs_count=fused_refs=0;
274: }
1.15 paf 275:
1.1 paf 276: private:
277:
1.39 paf 278: /// expand when these %% of allocated exausted
1.1 paf 279: enum {
280: THRESHOLD_PERCENT=75
281: };
1.9 paf 282:
1.61 paf 283: /// the index of [allocated] in [Hash_allocates]
1.19 paf 284: int allocates_index;
1.1 paf 285:
1.39 paf 286: /// number of allocated pairs
1.19 paf 287: int allocated;
1.1 paf 288:
1.59 paf 289: /// helper: expanding when fused_refs == threshold
1.1 paf 290: int threshold;
291:
1.39 paf 292: /// used pairs
1.59 paf 293: int fused_refs;
1.44 parser 294:
295: /// stored pairs total (including those by links)
1.59 paf 296: int fpairs_count;
1.1 paf 297:
1.39 paf 298: /// pair storage
1.59 paf 299: class Pair: public PA_Allocated {
300: public:
1.1 paf 301: uint code;
1.59 paf 302: K key;
303: V value;
1.1 paf 304: Pair *link;
1.2 paf 305:
1.59 paf 306: Pair(uint acode, K akey, V avalue, Pair *alink) :
1.1 paf 307: code(acode),
308: key(akey),
309: value(avalue),
1.2 paf 310: link(alink) {}
311: } **refs;
1.1 paf 312:
1.39 paf 313: /// filled to threshold: needs expanding
1.59 paf 314: bool is_full() { return fused_refs==threshold; }
1.5 paf 315:
1.39 paf 316: /// allocate larger buffer & rehash
1.59 paf 317: void expand() {
318: int old_allocated=allocated;
319: Pair **old_refs=refs;
320:
321: allocates_index=allocates_index+1<HASH_ALLOCATES_COUNT?allocates_index+1:HASH_ALLOCATES_COUNT-1;
322: // allocated bigger refs array
1.61 paf 323: allocated=Hash_allocates[allocates_index];
1.59 paf 324: threshold=allocated*THRESHOLD_PERCENT/100;
325: refs=new(UseGC) Pair*[allocated];
326:
327: // rehash
328: Pair **old_ref=old_refs;
329: for(int old_index=0; old_index<old_allocated; old_index++)
330: for(Pair *pair=*old_ref++; pair; ) {
331: Pair *next=pair->link;
332:
333: uint new_index=pair->code%allocated;
334: Pair **new_ref=&refs[new_index];
335: pair->link=*new_ref;
336: *new_ref=pair;
337:
338: pair=next;
339: }
340:
341: delete[] old_refs;
342: }
1.4 paf 343:
344: private: //disabled
345:
1.12 paf 346: Hash& operator = (const Hash&) { return *this; }
1.1 paf 347: };
1.59 paf 348:
349: /// useful generic hash function
350: inline void generic_hash_code(uint& result, char c) {
351: result=(result<<4)+c;
352: if(uint g=(result&0xF0000000)) {
353: result=result^(g>>24);
354: result=result^g;
355: }
356: }
357: /// useful generic hash function
358: inline void generic_hash_code(uint& result, const char* s) {
359: while(char c=*s++) {
360: result=(result<<4)+c;
361: if(uint g=(result&0xF0000000)) {
362: result=result^(g>>24);
363: result=result^g;
364: }
365: }
366: }
367:
368: /// useful generic hash function
369: inline void generic_hash_code(uint& result, const char* buf, size_t size) {
370: const char* end=buf+size;
371: while(buf<end) {
372: result=(result<<4)+*buf++;
373: if(uint g=(result&0xF0000000)) {
374: result=result^(g>>24);
375: result=result^g;
376: }
377: }
378: }
379:
380: /// simple hash code of int. used by EXIF mapping
381: inline uint hash_code(int self) {
382: uint result=0;
383: generic_hash_code(result, (const char*)&self, sizeof(self));
384: return result;
385: }
386:
387: /// Auto-object used to temporarily substituting/removing hash values
388: template <typename K, typename V>
1.55 paf 389: class Temp_hash_value {
1.59 paf 390: Hash<K, V>& fhash;
391: K fname;
392: V saved_value;
1.55 paf 393: public:
1.59 paf 394: Temp_hash_value(Hash<K, V>& ahash, K aname, V avalue) :
1.55 paf 395: fhash(ahash),
396: fname(aname),
397: saved_value(ahash.get(aname)) {
398: fhash.put(aname, avalue);
399: }
400: ~Temp_hash_value() {
401: fhash.put(fname, saved_value);
402: }
403: };
1.1 paf 404:
405: #endif
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