source: dict.c @ b711711

release-1.8release-1.9
Last change on this file since b711711 was ce68f23, checked in by David Benjamin <davidben@mit.edu>, 10 years ago
Make owl_dict_get_keys return a GPtrArray Almost all the remaining uses of owl_list are tightly coupled into this one giant blob.
  • Property mode set to 100644
File size: 3.4 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(log n) on searches
6 */
7
8#include <stdlib.h>
9#include <string.h>
10#include <unistd.h>
11#include "owl.h"
12
13
14#define INITSIZE 30
15#define GROWBY 3 / 2
16
17void owl_dict_create(owl_dict *d) {
18  d->size=0;
19  d->els=g_new(owl_dict_el, INITSIZE);
20  d->avail=INITSIZE;
21}
22
23int owl_dict_get_size(const owl_dict *d) {
24  return(d->size);
25}
26
27/* Finds the position of an element with key k, or of the element where
28 * this element would logically go, and stores the index in pos.
29 * Returns 1 if found, else 0. */
30int _owl_dict_find_pos(const owl_dict *d, const char *k, int *pos) {
31  int lo = 0, hi = d->size;
32  while (lo < hi) {
33    int mid = (lo + hi)/2; /* lo goes up and we can't hit hi, so no +1 */
34    int cmp = strcmp(k, d->els[mid].k);
35    if (cmp < 0) {
36      hi = mid;
37    } else if (cmp > 0) {
38      lo = mid+1;
39    } else {
40      *pos = mid;
41      return 1;
42    }
43  }
44  *pos = lo;
45  return 0;
46}
47
48/* returns the value corresponding to key k */
49void *owl_dict_find_element(const owl_dict *d, const char *k) {
50  int found, pos;
51  found = _owl_dict_find_pos(d, k, &pos);
52  if (!found) {
53    return(NULL);
54  }
55  return(d->els[pos].v);
56}
57
58/* Returns a GPtrArray of dictionary keys. Duplicates the keys, so
59 * they will need to be freed by the caller with g_free. */
60CALLER_OWN GPtrArray *owl_dict_get_keys(const owl_dict *d) {
61  GPtrArray *keys = g_ptr_array_sized_new(d->size);
62  int i;
63  for (i = 0; i < d->size; i++) {
64    g_ptr_array_add(keys, g_strdup(d->els[i].k));
65  }
66  return keys;
67}
68
69void owl_dict_noop_delete(void *x)
70{
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 delete_on_replace!=NULL,
77   and will run delete_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, const char *k, void *v, void (*delete_on_replace)(void *old))
81{
82  int pos, found;
83  found = _owl_dict_find_pos(d, k, &pos);
84  if (found && delete_on_replace) {
85    delete_on_replace(d->els[pos].v);
86    d->els[pos].v = v;
87    return(0);
88  } else if (found && !delete_on_replace) {
89    return(-2);
90  } else {
91    if (d->size + 1 > d->avail) {
92      int avail = MAX(d->avail * GROWBY, d->size + 1);
93      d->els = g_renew(owl_dict_el, d->els, avail);
94      d->avail = avail;
95      if (d->els==NULL) return(-1);
96    }
97    if (pos!=d->size) {
98      /* shift forward to leave us a slot */
99      memmove(d->els+pos+1, d->els+pos, 
100              sizeof(owl_dict_el)*(d->size-pos));
101    }
102    d->size++;
103    d->els[pos].k = g_strdup(k);
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. */
111CALLER_OWN void *owl_dict_remove_element(owl_dict *d, const char *k)
112{
113  int i;
114  int pos, found;
115  void *v;
116  found = _owl_dict_find_pos(d, k, &pos);
117  if (!found) return(NULL);
118  g_free(d->els[pos].k);
119  v = d->els[pos].v;
120  for (i=pos; i<d->size-1; i++) {
121    d->els[i]=d->els[i+1];
122  }
123  d->size--;
124  return(v);
125}
126
127/* elefree should free the value as well */
128void owl_dict_cleanup(owl_dict *d, void (*elefree)(void *))
129{
130  int i;
131
132  for (i=0; i<d->size; i++) {
133    g_free(d->els[i].k);
134    if (elefree) (elefree)(d->els[i].v);
135  }
136  if (d->els) g_free(d->els);
137}
138
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