#ifndef HASH_TABLE_H
#define HASH_TABLE_H
-struct hash_table;
+#include <string.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <limits.h>
+#include <assert.h>
-typedef unsigned (*hash_func_t)(const void *key);
-typedef int (*hash_compare_func_t)(const void *key1, const void *key2);
+struct string_to_uint_map;
#ifdef __cplusplus
extern "C" {
#endif
+struct hash_table;
+
+typedef unsigned (*hash_func_t)(const void *key);
+typedef int (*hash_compare_func_t)(const void *key1, const void *key2);
+
/**
* Hash table constructor
*
/**
* Add an element to a hash table
+ *
+ * \warning
+ * If \c key is already in the hash table, it will be added again. Future
+ * calls to \c hash_table_find and \c hash_table_remove will return or remove,
+ * repsectively, the most recently added instance of \c key.
+ *
+ * \warning
+ * The value passed by \c key is kept in the hash table and is used by later
+ * calls to \c hash_table_find.
+ *
+ * \sa hash_table_replace
*/
extern void hash_table_insert(struct hash_table *ht, void *data,
const void *key);
+/**
+ * Add an element to a hash table with replacement
+ *
+ * \return
+ * 1 if it did replace the the value (in which case the old key is kept), 0 if
+ * it did not replace the value (in which case the new key is kept).
+ *
+ * \warning
+ * If \c key is already in the hash table, \c data will \b replace the most
+ * recently inserted \c data (see the warning in \c hash_table_insert) for
+ * that key.
+ *
+ * \sa hash_table_insert
+ */
+extern bool hash_table_replace(struct hash_table *ht, void *data,
+ const void *key);
+
/**
* Remove a specific element from a hash table.
*/
void *closure),
void *closure);
+struct string_to_uint_map *
+string_to_uint_map_ctor();
+
+void
+string_to_uint_map_dtor(struct string_to_uint_map *);
+
+
#ifdef __cplusplus
}
-#endif
+
+/**
+ * Map from a string (name) to an unsigned integer value
+ *
+ * \note
+ * Because of the way this class interacts with the \c hash_table
+ * implementation, values of \c UINT_MAX cannot be stored in the map.
+ */
+struct string_to_uint_map {
+public:
+ string_to_uint_map()
+ {
+ this->ht = hash_table_ctor(0, hash_table_string_hash,
+ hash_table_string_compare);
+ }
+
+ ~string_to_uint_map()
+ {
+ hash_table_call_foreach(this->ht, delete_key, NULL);
+ hash_table_dtor(this->ht);
+ }
+
+ /**
+ * Remove all mappings from this map.
+ */
+ void clear()
+ {
+ hash_table_call_foreach(this->ht, delete_key, NULL);
+ hash_table_clear(this->ht);
+ }
+
+ /**
+ * Get the value associated with a particular key
+ *
+ * \return
+ * If \c key is found in the map, \c true is returned. Otherwise \c false
+ * is returned.
+ *
+ * \note
+ * If \c key is not found in the table, \c value is not modified.
+ */
+ bool get(unsigned &value, const char *key)
+ {
+ const intptr_t v =
+ (intptr_t) hash_table_find(this->ht, (const void *) key);
+
+ if (v == 0)
+ return false;
+
+ value = (unsigned)(v - 1);
+ return true;
+ }
+
+ void put(unsigned value, const char *key)
+ {
+ /* The low-level hash table structure returns NULL if key is not in the
+ * hash table. However, users of this map might want to store zero as a
+ * valid value in the table. Bias the value by +1 so that a
+ * user-specified zero is stored as 1. This enables ::get to tell the
+ * difference between a user-specified zero (returned as 1 by
+ * hash_table_find) and the key not in the table (returned as 0 by
+ * hash_table_find).
+ *
+ * The net effect is that we can't store UINT_MAX in the table. This is
+ * because UINT_MAX+1 = 0.
+ */
+ assert(value != UINT_MAX);
+ char *dup_key = strdup(key);
+ bool result = hash_table_replace(this->ht,
+ (void *) (intptr_t) (value + 1),
+ dup_key);
+ if (result)
+ free(dup_key);
+ }
+
+private:
+ static void delete_key(const void *key, void *data, void *closure)
+ {
+ (void) data;
+ (void) closure;
+
+ free((char *)key);
+ }
+
+ struct hash_table *ht;
+};
+
+#endif /* __cplusplus */
#endif /* HASH_TABLE_H */
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