From: Russell Belfer <rb@github.com>
Date: Fri, 31 Aug 2012 23:06:32 +0000 (-0700)
Subject: Add allocation wrappers and error checking
X-Git-Tag: spawn-final~43^2~3
X-Git-Url: http://www.kaiwu.me/postgresql/commit/static/gitweb.js?a=commitdiff_plain;h=6a7e6f952d55f07fa74098bb758515a909ae9590;p=klib.git

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.
---

diff --git a/khash.h b/khash.h
index 9a4049a..1bc327c 100644
--- a/khash.h
+++ b/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;		\