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Add allocation wrappers and error checking

When embedding khash in another project, it is convenient to be
able to replace the use of malloc/calloc/free with alternatives.
This wraps those calls with kmalloc/kcalloc/kfree, etc. macros
that can be easily redefined by the khash user to override the
allocators.

Additionally, the return value from allocations was not being
checked.  This adds a check whenever an allocation is performed
and a return code of -1 to indicate an allocation failure.
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arrbee committed Aug 31, 2012
1 parent cea612f commit 6a7e6f952d55f07fa74098bb758515a909ae9590
Showing with 39 additions and 13 deletions.
  1. +39 −13 khash.h
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52 khash.h
@@ -157,6 +157,19 @@ typedef khint_t khiter_t;
#define kroundup32(x) (--(x), (x)|=(x)>>1, (x)|=(x)>>2, (x)|=(x)>>4, (x)|=(x)>>8, (x)|=(x)>>16, ++(x))
#endif
+#ifndef kcalloc
+#define kcalloc(N,Z) calloc(N,Z)
+#endif
+#ifndef kmalloc
+#define kmalloc(Z) malloc(Z)
+#endif
+#ifndef krealloc
+#define krealloc(P,Z) realloc(P,Z)
+#endif
+#ifndef kfree
+#define kfree(P) free(P)
+#endif
+
static const double __ac_HASH_UPPER = 0.77;
#define __KHASH_TYPE(name, khkey_t, khval_t) \
@@ -172,7 +185,7 @@ static const double __ac_HASH_UPPER = 0.77;
extern void kh_destroy_##name(kh_##name##_t *h); \
extern void kh_clear_##name(kh_##name##_t *h); \
extern khint_t kh_get_##name(const kh_##name##_t *h, khkey_t key); \
- extern void kh_resize_##name(kh_##name##_t *h, khint_t new_n_buckets); \
+ extern int kh_resize_##name(kh_##name##_t *h, khint_t new_n_buckets); \
extern khint_t kh_put_##name(kh_##name##_t *h, khkey_t key, int *ret); \
extern void kh_del_##name(kh_##name##_t *h, khint_t x);
@@ -183,9 +196,9 @@ static const double __ac_HASH_UPPER = 0.77;
SCOPE void kh_destroy_##name(kh_##name##_t *h) \
{ \
if (h) { \
- free(h->keys); free(h->flags); \
- free(h->vals); \
- free(h); \
+ kfree((void *)h->keys); kfree(h->flags); \
+ kfree((void *)h->vals); \
+ kfree(h); \
} \
} \
SCOPE void kh_clear_##name(kh_##name##_t *h) \
@@ -209,7 +222,7 @@ static const double __ac_HASH_UPPER = 0.77;
return __ac_iseither(h->flags, i)? h->n_buckets : i; \
} else return 0; \
} \
- SCOPE void kh_resize_##name(kh_##name##_t *h, khint_t new_n_buckets) \
+ SCOPE int kh_resize_##name(kh_##name##_t *h, khint_t new_n_buckets) \
{ /* This function uses 0.25*n_bucktes bytes of working space instead of [sizeof(key_t+val_t)+.25]*n_buckets. */ \
khint32_t *new_flags = 0; \
khint_t j = 1; \
@@ -218,11 +231,18 @@ static const double __ac_HASH_UPPER = 0.77;
if (new_n_buckets < 4) new_n_buckets = 4; \
if (h->size >= (khint_t)(new_n_buckets * __ac_HASH_UPPER + 0.5)) j = 0; /* requested size is too small */ \
else { /* hash table size to be changed (shrink or expand); rehash */ \
- new_flags = (khint32_t*)malloc(__ac_fsize(new_n_buckets) * sizeof(khint32_t)); \
+ new_flags = (khint32_t*)kmalloc(__ac_fsize(new_n_buckets) * sizeof(khint32_t)); \
+ if (!new_flags) return -1; \
memset(new_flags, 0xaa, __ac_fsize(new_n_buckets) * sizeof(khint32_t)); \
if (h->n_buckets < new_n_buckets) { /* expand */ \
- h->keys = (khkey_t*)realloc(h->keys, new_n_buckets * sizeof(khkey_t)); \
- if (kh_is_map) h->vals = (khval_t*)realloc(h->vals, new_n_buckets * sizeof(khval_t)); \
+ khkey_t *new_keys = (khkey_t*)krealloc((void *)h->keys, new_n_buckets * sizeof(khkey_t)); \
+ if (!new_keys) return -1; \
+ h->keys = new_keys; \
+ if (kh_is_map) { \
+ khval_t *new_vals = (khval_t*)krealloc((void *)h->vals, new_n_buckets * sizeof(khval_t)); \
+ if (!new_vals) return -1; \
+ h->vals = new_vals; \
+ } \
} /* otherwise shrink */ \
} \
} \
@@ -255,22 +275,28 @@ static const double __ac_HASH_UPPER = 0.77;
} \
} \
if (h->n_buckets > new_n_buckets) { /* shrink the hash table */ \
- h->keys = (khkey_t*)realloc(h->keys, new_n_buckets * sizeof(khkey_t)); \
- if (kh_is_map) h->vals = (khval_t*)realloc(h->vals, new_n_buckets * sizeof(khval_t)); \
+ h->keys = (khkey_t*)krealloc((void *)h->keys, new_n_buckets * sizeof(khkey_t)); \
+ if (kh_is_map) h->vals = (khval_t*)krealloc((void *)h->vals, new_n_buckets * sizeof(khval_t)); \
} \
- free(h->flags); /* free the working space */ \
+ kfree(h->flags); /* free the working space */ \
h->flags = new_flags; \
h->n_buckets = new_n_buckets; \
h->n_occupied = h->size; \
h->upper_bound = (khint_t)(h->n_buckets * __ac_HASH_UPPER + 0.5); \
} \
+ return 0; \
} \
SCOPE khint_t kh_put_##name(kh_##name##_t *h, khkey_t key, int *ret) \
{ \
khint_t x; \
if (h->n_occupied >= h->upper_bound) { /* update the hash table */ \
- if (h->n_buckets > (h->size<<1)) kh_resize_##name(h, h->n_buckets - 1); /* clear "deleted" elements */ \
- else kh_resize_##name(h, h->n_buckets + 1); /* expand the hash table */ \
+ if (h->n_buckets > (h->size<<1)) { \
+ if (kh_resize_##name(h, h->n_buckets - 1) < 0) { /* clear "deleted" elements */ \
+ *ret = -1; return h->n_buckets; \
+ } \
+ } else if (kh_resize_##name(h, h->n_buckets + 1) < 0) { /* expand the hash table */ \
+ *ret = -1; return h->n_buckets; \
+ } \
} /* TODO: to implement automatically shrinking; resize() already support shrinking */ \
{ \
khint_t inc, k, i, site, last, mask = h->n_buckets - 1; \

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