1 /*********************************************************************** 2 * * 3 * This software is part of the ast package * 4 * Copyright (c) 1985-2008 AT&T Intellectual Property * 5 * and is licensed under the * 6 * Common Public License, Version 1.0 * 7 * by AT&T Intellectual Property * 8 * * 9 * A copy of the License is available at * 10 * http://www.opensource.org/licenses/cpl1.0.txt * 11 * (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) * 12 * * 13 * Information and Software Systems Research * 14 * AT&T Research * 15 * Florham Park NJ * 16 * * 17 * Glenn Fowler <gsf@research.att.com> * 18 * David Korn <dgk@research.att.com> * 19 * Phong Vo <kpv@research.att.com> * 20 * * 21 ***********************************************************************/ 22 #pragma prototyped 23 /* 24 * Glenn Fowler 25 * AT&T Bell Laboratories 26 * 27 * hash table library 28 */ 29 30 #include "hashlib.h" 31 32 /* 33 * push/pop/query hash table scope 34 * 35 * bot==0 pop top scope 36 * bot==top query 37 * bot!=0 push top on bot 38 * 39 * scope table pointer returned 40 */ 41 42 Hash_table_t* 43 hashview(Hash_table_t* top, Hash_table_t* bot) 44 { 45 register Hash_bucket_t* b; 46 register Hash_bucket_t* p; 47 register Hash_bucket_t** sp; 48 register Hash_bucket_t** sx; 49 50 if (!top || top->frozen) 51 bot = 0; 52 else if (top == bot) 53 bot = top->scope; 54 else if (bot) 55 { 56 if (top->scope) 57 bot = 0; 58 else 59 { 60 sx = &top->table[top->size]; 61 sp = &top->table[0]; 62 while (sp < sx) 63 for (b = *sp++; b; b = b->next) 64 if (p = (Hash_bucket_t*)hashlook(bot, b->name, HASH_LOOKUP, NiL)) 65 { 66 b->name = (p->hash & HASH_HIDES) ? p->name : (char*)b; 67 b->hash |= HASH_HIDES; 68 } 69 top->scope = bot; 70 bot->frozen++; 71 } 72 } 73 else if (bot = top->scope) 74 { 75 sx = &top->table[top->size]; 76 sp = &top->table[0]; 77 while (sp < sx) 78 for (b = *sp++; b; b = b->next) 79 if (b->hash & HASH_HIDES) 80 { 81 b->hash &= ~HASH_HIDES; 82 b->name = ((Hash_bucket_t*)b->name)->name; 83 } 84 top->scope = 0; 85 bot->frozen--; 86 } 87 return(bot); 88 } 89