1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 /* 23 * Copyright (c) 2001 by Sun Microsystems, Inc. 24 * All rights reserved. 25 */ 26 27 #pragma ident "%Z%%M% %I% %E% SMI" 28 29 /* 30 * Routines for manipulating stacks 31 */ 32 33 #include <stdio.h> 34 #include <assert.h> 35 #include <stdlib.h> 36 37 #include "stack.h" 38 #include "memory.h" 39 40 #define STACK_SEEDSIZE 5 41 42 struct stk { 43 int st_nument; 44 int st_top; 45 void **st_data; 46 47 void (*st_free)(void *); 48 }; 49 50 stk_t * 51 stack_new(void (*freep)(void *)) 52 { 53 stk_t *sp; 54 55 sp = xmalloc(sizeof (stk_t)); 56 sp->st_nument = STACK_SEEDSIZE; 57 sp->st_top = -1; 58 sp->st_data = xmalloc(sizeof (void *) * sp->st_nument); 59 sp->st_free = freep; 60 61 return (sp); 62 } 63 64 void 65 stack_free(stk_t *sp) 66 { 67 int i; 68 69 if (sp->st_free) { 70 for (i = 0; i <= sp->st_top; i++) 71 sp->st_free(sp->st_data[i]); 72 } 73 free(sp->st_data); 74 free(sp); 75 } 76 77 void * 78 stack_pop(stk_t *sp) 79 { 80 assert(sp->st_top >= 0); 81 82 return (sp->st_data[sp->st_top--]); 83 } 84 85 void * 86 stack_peek(stk_t *sp) 87 { 88 if (sp->st_top == -1) 89 return (NULL); 90 91 return (sp->st_data[sp->st_top]); 92 } 93 94 void 95 stack_push(stk_t *sp, void *data) 96 { 97 sp->st_top++; 98 99 if (sp->st_top == sp->st_nument) { 100 sp->st_nument += STACK_SEEDSIZE; 101 sp->st_data = xrealloc(sp->st_data, 102 sizeof (void *) * sp->st_nument); 103 } 104 105 sp->st_data[sp->st_top] = data; 106 } 107 108 int 109 stack_level(stk_t *sp) 110 { 111 return (sp->st_top + 1); 112 } 113