112 lines
2.8 KiB
C
112 lines
2.8 KiB
C
/*
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* stringmap.c: sucky implementation of binary trees
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*
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* This makes no attempt to balance the tree, so has bad worst-case behaviour.
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* Also, I haven't implemented removal of items from the tree. So sue me.
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*
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* Copyright (c) 2001 Chris Lightfoot. All rights reserved.
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*
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*/
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static const char rcsid[] = "$Id$";
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#include <stdlib.h>
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#include <string.h>
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#include "stringmap.h"
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#include "vector.h"
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/*include "util.h"*/
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/* stringmap_new:
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* Allocate memory for a new stringmap. */
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stringmap stringmap_new() {
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stringmap S;
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S = xcalloc(sizeof *S, 1);
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return S;
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}
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/* stringmap_delete:
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* Free memory for a stringmap. */
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void stringmap_delete(stringmap S) {
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if (!S) return;
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if (S->l) stringmap_delete(S->l);
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if (S->g) stringmap_delete(S->g);
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xfree(S->key);
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xfree(S);
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}
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/* stringmap_delete_free:
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* Free memory for a stringmap, and the objects contained in it, assuming that
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* they are pointers to memory allocated by xmalloc(3). */
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void stringmap_delete_free(stringmap S) {
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if (!S) return;
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if (S->l) stringmap_delete_free(S->l);
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if (S->g) stringmap_delete_free(S->g);
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xfree(S->key);
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xfree(S->d.v);
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xfree(S);
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}
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/* stringmap_insert:
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* Insert into S an item having key k and value d. Returns an existing key
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* or NULL if it was inserted.
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*/
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item *stringmap_insert(stringmap S, const char *k, const item d) {
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if (!S) return 0;
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if (S->key == NULL) {
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S->key = xstrdup(k);
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S->d = d;
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return NULL;
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} else {
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stringmap S2;
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for (S2 = S;;) {
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int i = strcmp(k, S2->key);
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if (i == 0) {
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return &(S2->d);
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}
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else if (i < 0) {
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if (S2->l) S2 = S2->l;
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else {
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if (!(S2->l = stringmap_new())) return NULL;
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S2->l->key = xstrdup(k);
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S2->l->d = d;
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return NULL;
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}
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} else if (i > 0) {
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if (S2->g) S2 = S2->g;
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else {
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if (!(S2->g = stringmap_new())) return NULL;
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S2->g->key = xstrdup(k);
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S2->g->d = d;
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return NULL;
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}
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}
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}
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}
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}
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/* stringmap_find:
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* Find in d an item having key k in the stringmap S, returning the item found
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* on success NULL if no key was found. */
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stringmap stringmap_find(const stringmap S, const char *k) {
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stringmap S2;
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int i;
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if (!S || S->key == NULL) return 0;
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for (S2 = S;;) {
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i = strcmp(k, S2->key);
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if (i == 0) return S2;
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else if (i < 0) {
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if (S2->l) S2 = S2->l;
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else return NULL;
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} else if (i > 0) {
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if (S2->g) S2 = S2->g;
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else return NULL;
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}
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}
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}
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