1 /*
2 * (c) Copyright 1992, 1993 by Panagiotis Tsirigotis
3 * All rights reserved. The file named COPYRIGHT specifies the terms
4 * and conditions for redistribution.
5 */
6
7
8 #include "config.h"
9 #include <stdlib.h>
10 #include "pset.h"
11
12
13 #define ALLOC_START 20
14 #define ALLOC_STEP 10
15
16
17 static __pset_pointer pset_insert( pset_h pset, const __pset_pointer p );
18
19
20 /*
21 * Create a pointer set and return a handle to it.
22 * Some space is initially allocated for the set.
23 */
pset_create(unsigned alloc_start,unsigned alloc_step)24 pset_h pset_create( unsigned alloc_start, unsigned alloc_step )
25 {
26 pset_h pset ;
27 unsigned start ;
28
29 pset = (pset_h) malloc( sizeof( struct __pset ) ) ;
30 if ( pset == NULL )
31 return( NULL ) ;
32
33 start = ( alloc_start == 0 ) ? ALLOC_START : alloc_start ;
34 pset->ptrs = (__pset_pointer *) malloc( start * sizeof( __pset_pointer ) ) ;
35 if ( pset->ptrs == NULL )
36 {
37 free( (char *) pset ) ;
38 return( NULL ) ;
39 }
40
41 pset->max = start ;
42 pset->count = 0 ;
43 pset->alloc_step = ( alloc_step == 0 ) ? ALLOC_STEP : alloc_step ;
44 return( pset ) ;
45 }
46
47
48 /*
49 * Destroy a pset
50 */
pset_destroy(pset_h pset)51 void pset_destroy( pset_h pset )
52 {
53 if ( pset == NULL )
54 return;
55 free( (char *) pset->ptrs ) ;
56 free( (char *) pset ) ;
57 }
58
pset_add(pset_h pset,const __pset_pointer ptr)59 __pset_pointer pset_add( pset_h pset, const __pset_pointer ptr )
60 {
61 return (pset->count < pset->max )
62 ? (pset->ptrs[ pset->count++ ] = ptr)
63 : pset_insert( pset, ptr) ;
64 }
65
66 /*
67 * Append a pointer to a pset
68 */
pset_insert(pset_h pset,const __pset_pointer p)69 static __pset_pointer pset_insert( pset_h pset, const __pset_pointer p )
70 {
71 if ( pset->count >= pset->max )
72 {
73 unsigned new_max = pset->max + pset->alloc_step ;
74 __pset_pointer *new_ptrs ;
75
76 new_ptrs = (__pset_pointer *) realloc(
77 (char *)pset->ptrs, new_max * sizeof( __pset_pointer ) ) ;
78 if ( new_ptrs == NULL )
79 return( NULL ) ;
80 pset->max = new_max ;
81 pset->ptrs = new_ptrs ;
82 }
83 return( pset->ptrs[ pset->count++ ] = p ) ;
84 }
85
86
87 /*
88 * Remove a pointer from a pset by moving every thing above it down 1 spot.
89 */
pset_delete(register pset_h pset,register const __pset_pointer ptr)90 void pset_delete( register pset_h pset, register const __pset_pointer ptr )
91 {
92 register unsigned u = 0;
93 register int found_it = 0;
94
95 if ( pset->count == 0 )
96 return ;
97
98 while ( u < pset->count )
99 {
100 if ( pset->ptrs[ u ] == ptr )
101 found_it = 1;
102 if ( found_it )
103 { /* If not the last one, copy it */
104 if ( (u+1) < pset->count )
105 pset->ptrs[ u ] = pset->ptrs[ u+1 ];
106 }
107 u++;
108 }
109 pset->count--;
110 }
111
112
113 /*
114 * Create a pset iterator
115 */
psi_create(pset_h pset)116 psi_h psi_create( pset_h pset )
117 {
118 psi_h iter = (psi_h) malloc( sizeof( struct __pset_iterator ) ) ;
119
120 if ( iter == NULL )
121 return( NULL ) ;
122 iter->pset = pset ;
123 return( iter ) ;
124 }
125
126 /*
127 * Remove an element from a pset
128 */
psi_remove(psi_h iter)129 void psi_remove( psi_h iter )
130 {
131 if ( iter->current < pset_count( iter->pset ) )
132 {
133 pset_remove_index( iter->pset, iter->current ) ;
134 iter->step = 0;
135 }
136 }
137
138