Added a hash function for configurations.

include/ccs/base.h

@@ -13,6 +13,8 @@ extern "C" {
 typedef double   ccs_float_t;
 typedef int64_t  ccs_int_t;
 typedef int32_t  ccs_bool_t;
+typedef uint32_t ccs_hash_t;
+
 typedef struct {
 	uint16_t major;
 	uint16_t minor;

include/ccs/configuration.h

@@ -48,6 +48,10 @@ ccs_configuration_get_value_by_name(ccs_configuration_t  configuration,
 extern ccs_error_t
 ccs_configuration_check(ccs_configuration_t configuration);
 
+extern ccs_error_t
+ccs_configuration_hash(ccs_configuration_t  configuration,
+                       ccs_hash_t          *hash_ret);
+
 #ifdef __cplusplus
 }
 #endif

src/configuration.c

 #include "cconfigspace_internal.h"
 #include "configuration_internal.h"
+#include "datum_hash.h"
 #include <string.h>
 
 static inline _ccs_configuration_ops_t *
@@ -160,3 +161,23 @@ ccs_configuration_check(ccs_configuration_t  configuration) {
 	return ccs_configuration_space_check_configuration(
 		configuration->data->configuration_space, configuration);
 }
+
+ccs_error_t
+ccs_configuration_hash(ccs_configuration_t  configuration,
+                       ccs_hash_t          *hash_ret) {
+	if (!configuration || !configuration->data)
+		return -CCS_INVALID_OBJECT;
+	if (!hash_ret)
+		return -CCS_INVALID_VALUE;
+	_ccs_configuration_data_t *data = configuration->data;
+	ccs_hash_t h, ht;
+	HASH_JEN(&(data->configuration_space), sizeof(data->configuration_space), h);
+	HASH_JEN(&(data->num_values), sizeof(data->num_values), ht);
+	h = _hash_combine(h, ht);
+	for (size_t i = 0; i < data->num_values; i++) {
+		ht = _hash_datum(data->values + i);
+		h = _hash_combine(h, ht);
+	}
+	*hash_ret = h;
+	return CCS_SUCCESS;
+}

src/configuration_space.c

 #include "cconfigspace_internal.h"
 #include "configuration_space_internal.h"
 #include "configuration_internal.h"
+#include "utlist.h"
 
 static ccs_error_t
 _generate_constraints(ccs_configuration_space_t configuration_space);

src/configuration_space_internal.h

 #ifndef _CONFIGURATION_SPACE_INTERNAL_H
 #define _CONFIGURATION_SPACE_INTERNAL_H
 #include "utarray.h"
+#include "context_internal.h"
 #define HASH_NONFATAL_OOM 1
 #include "uthash.h"
-#include "utlist.h"
-#include "context_internal.h"
 
 struct _ccs_distribution_wrapper_s;
 typedef struct _ccs_distribution_wrapper_s _ccs_distribution_wrapper_t;

src/datum_hash.h

-#ifndef _DATUMHASH_H
-#define _DATUMHASH_H
+#ifndef _DATUM_HASH_H
+#define _DATUM_HASH_H
 
 #define HASH_NONFATAL_OOM 1
 #define HASH_FUNCTION(s,len,hashv) (hashv) = _hash_datum((ccs_datum_t *)(s))
@@ -51,6 +51,7 @@ static inline int _datum_cmp(ccs_datum_t *a, ccs_datum_t *b) {
 			else
 				return strcmp(a->value.s, b->value.s);
 		case CCS_NONE:
+		case CCS_INACTIVE:
 			return 0;
 			break;
 		default:
@@ -59,16 +60,27 @@ static inline int _datum_cmp(ccs_datum_t *a, ccs_datum_t *b) {
 	}
 }
 
+//from boost
+static inline ccs_hash_t _hash_combine(ccs_hash_t h1, ccs_hash_t h2) {
+	h1 ^= h2 + 0x9e3779b9 + (h1 << 6) + (h1 >> 2);
+	return h1;
+}
+
 static inline unsigned _hash_datum(ccs_datum_t *d) {
 	unsigned h;
 	switch(d->type) {
 	case CCS_STRING:
-		if (d->value.s)
-			HASH_JEN(d->value.s, strlen(d->value.s), h);
+		if (d->value.s) {
+			unsigned h1, h2;
+			HASH_JEN(&(d->type), sizeof(d->type), h1);
+			HASH_JEN(d->value.s, strlen(d->value.s), h2);
+			h = _hash_combine(h1, h2);
+		}
 		else
 			HASH_JEN(d, sizeof(ccs_datum_t), h);
 		break;
 	case CCS_NONE:
+	case CCS_INACTIVE:
 		HASH_JEN(&(d->type), sizeof(d->type), h);
 		break;
 	default:
@@ -84,4 +96,4 @@ struct _ccs_hash_datum_s {
 typedef struct _ccs_hash_datum_s _ccs_hash_datum_t;
 
 
-#endif //_DATUMHASH_H
+#endif //_DATUM_HASH_H