source: dict.c @ db0ac7e

barnowl_perlaimdebianrelease-1.10release-1.4release-1.5release-1.6release-1.7release-1.8release-1.9
Last change on this file since db0ac7e was af1920fd, checked in by Alejandro R. Sedeño <asedeno@mit.edu>, 17 years ago
Portability - removing C++ style comments.
  • Property mode set to 100644
File size: 5.5 KB
Line 
1/* Dictionary data abstraction. 
2 * Maps from strings to pointers.
3 * Stores as a sorted list of key/value pairs.
4 * O(n) on inserts and deletes.
5 * O(n) on searches, although it should switch to a binary search for O(log n)
6 */
7
8#include <stdlib.h>
9#include <string.h>
10#include <unistd.h>
11#include "owl.h"
12
13static const char fileIdent[] = "$Id$";
14
15
16#define INITSIZE 30
17#define GROWAT 2
18#define GROWBY 1.5
19
20int owl_dict_create(owl_dict *d) {
21  d->size=0;
22  d->els=(owl_dict_el *)owl_malloc(INITSIZE*sizeof(owl_dict_el));
23  d->avail=INITSIZE;
24  if (d->els==NULL) return(-1);
25  return(0);
26}
27
28int owl_dict_get_size(owl_dict *d) {
29  return(d->size);
30}
31
32/* Finds the position of an element with key k, or of the element where
33 * this element would logically go, and stores the index in pos.
34 * TODO: optimize to do a binary search.
35 * Returns 1 if found, else 0. */
36int _owl_dict_find_pos(owl_dict *d, char *k, int *pos) {
37  int i;
38  for (i=0; (i<d->size) && strcmp(k,d->els[i].k)>0; i++);
39  *pos = i;
40  if (i>=d->size || strcmp(k,d->els[i].k)) {
41    return(0);
42  } else {
43    return(1);
44  }
45}
46
47/* returns the value corresponding to key k */
48void *owl_dict_find_element(owl_dict *d, char *k) {
49  int found, pos;
50  found = _owl_dict_find_pos(d, k, &pos);
51  if (!found) {
52    return(NULL);
53  }
54  return(d->els[pos].v);
55}
56
57/* creates a list and fills it in with keys.  duplicates the keys,
58 * so they will need to be freed by the caller. */
59int owl_dict_get_keys(owl_dict *d, owl_list *l) {
60  int i;
61  char *dupk;
62  if (owl_list_create(l)) return(-1);
63  for (i=0; i<d->size; i++) {
64    if ((dupk = owl_strdup(d->els[i].k)) == NULL) return(-1);
65    owl_list_append_element(l, (void*)dupk);
66  }
67  return(0);
68}
69
70void owl_dict_noop_free(void *x) {
71  return;
72}
73
74/* Returns 0 on success.  Will copy the key but make
75   a reference to the value.  Will clobber an existing
76   entry with the same key iff free_on_replace!=NULL,
77   and will run free_on_replace on the old element.
78   Will return -2 if replace=NULL and match was found.
79*/
80int owl_dict_insert_element(owl_dict *d, char *k, void *v, void (*free_on_replace)(void *old)) {
81  int pos, found;
82  char *dupk;
83  found = _owl_dict_find_pos(d, k, &pos);
84  if (found && free_on_replace) {
85    free_on_replace(d->els[pos].v);
86    d->els[pos].v = v;
87    return(0);
88  } else if (found && !free_on_replace) {
89    return(-2);
90  } else {
91    if ((d->size+1) > (d->avail/GROWAT)) {
92      d->els=owl_realloc(d->els, d->avail*GROWBY*sizeof(void *));
93      d->avail=d->avail*GROWBY;
94      if (d->els==NULL) return(-1);
95    }
96    if ((dupk = owl_strdup(k)) == NULL) return(-1);
97    if (pos!=d->size) {
98      /* shift forward to leave us a slot */
99      memmove((void*)(d->els+pos+1), (void*)(d->els+pos), 
100              sizeof(owl_dict_el)*(d->size-pos));
101    }
102    d->size++;
103    d->els[pos].k = dupk;
104    d->els[pos].v = v;   
105    return(0);
106  }
107}
108
109/* Doesn't free the value of the element, but does
110 * return it so the caller can free it. */
111void *owl_dict_remove_element(owl_dict *d, char *k) {
112  int i;
113  int pos, found;
114  void *v;
115  found = _owl_dict_find_pos(d, k, &pos);
116  if (!found) return(NULL);
117  owl_free(d->els[pos].k);
118  v = d->els[pos].v;
119  for (i=pos; i<d->size-1; i++) {
120    d->els[i]=d->els[i+1];
121  }
122  d->size--;
123  return(v);
124}
125
126/* elefree should free the value as well */
127void owl_dict_free_all(owl_dict *d, void (*elefree)(void *)) {
128  int i;
129
130  for (i=0; i<d->size; i++) {
131    owl_free(d->els[i].k);
132    if (elefree) (elefree)(d->els[i].v);
133  }
134  if (d->els) owl_free(d->els);
135}
136
137void owl_dict_free_simple(owl_dict *d) {
138  owl_dict_free_all(d, NULL);
139}
140
141
142
143/************* REGRESSION TESTS **************/
144#ifdef OWL_INCLUDE_REG_TESTS
145
146#include "test.h"
147
148int owl_dict_regtest(void) {
149  owl_dict d;
150  owl_list l;
151  int numfailed=0;
152  char *av="aval", *bv="bval", *cv="cval", *dv="dval";
153
154  printf("# BEGIN testing owl_dict\n");
155  FAIL_UNLESS("create", 0==owl_dict_create(&d));
156  FAIL_UNLESS("insert b", 0==owl_dict_insert_element(&d, "b", (void*)bv, owl_dict_noop_free));
157  FAIL_UNLESS("insert d", 0==owl_dict_insert_element(&d, "d", (void*)dv, owl_dict_noop_free));
158  FAIL_UNLESS("insert a", 0==owl_dict_insert_element(&d, "a", (void*)av, owl_dict_noop_free));
159  FAIL_UNLESS("insert c", 0==owl_dict_insert_element(&d, "c", (void*)cv, owl_dict_noop_free));
160  FAIL_UNLESS("reinsert d (no replace)", -2==owl_dict_insert_element(&d, "d", (void*)dv, 0));
161  FAIL_UNLESS("find a", (void*)av==owl_dict_find_element(&d, "a"));
162  FAIL_UNLESS("find b", (void*)bv==owl_dict_find_element(&d, "b"));
163  FAIL_UNLESS("find c", (void*)cv==owl_dict_find_element(&d, "c"));
164  FAIL_UNLESS("find d", (void*)dv==owl_dict_find_element(&d, "d"));
165  FAIL_UNLESS("find e (non-existent)", NULL==owl_dict_find_element(&d, "e"));
166  FAIL_UNLESS("remove d", (void*)dv==owl_dict_remove_element(&d, "d"));
167  FAIL_UNLESS("find d (post-removal)", NULL==owl_dict_find_element(&d, "d"));
168
169  FAIL_UNLESS("get_size", 3==owl_dict_get_size(&d));
170  FAIL_UNLESS("get_keys", 0==owl_dict_get_keys(&d, &l));
171  FAIL_UNLESS("get_keys result size", 3==owl_list_get_size(&l));
172 
173  /* these assume the returned keys are sorted */
174  FAIL_UNLESS("get_keys result val",0==strcmp("a",owl_list_get_element(&l,0)));
175  FAIL_UNLESS("get_keys result val",0==strcmp("b",owl_list_get_element(&l,1)));
176  FAIL_UNLESS("get_keys result val",0==strcmp("c",owl_list_get_element(&l,2)));
177
178  owl_list_free_all(&l, owl_free);
179  owl_dict_free_all(&d, NULL);
180
181  /*  if (numfailed) printf("*** WARNING: failures encountered with owl_dict\n"); */
182  printf("# END testing owl_dict (%d failures)\n", numfailed);
183  return(numfailed);
184}
185
186#endif /* OWL_INCLUDE_REG_TESTS */
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