(struct hash_tuning): Define.

(struct hash_table) [tuning]: Add member.
(hash_initialize): Add `tuning' parameter.

1 files changed, 33 insertions, 16 deletions

diff --git a/lib/hash.h b/lib/hash.h
index b046bfe9a..27b6fa45a 100644
--- a/lib/hash.h
+++ b/lib/hash.h
@@ -29,7 +29,7 @@
 # endif
 #endif
 
-typedef unsigned int (*Hash_hasher) PARAMS ((const void *, unsigned int));
+typedef unsigned (*Hash_hasher) PARAMS ((const void *, unsigned));
 typedef bool (*Hash_comparator) PARAMS ((const void *, const void *));
 typedef void (*Hash_data_freer) PARAMS ((void *));
 typedef bool (*Hash_processor) PARAMS ((void *, void *));
@@ -40,6 +40,20 @@ struct hash_entry
     struct hash_entry *next;
   };
 
+struct hash_tuning
+  {
+    /* This structure is mainly used for `hash_initialize', see the block
+       documentation of `hash_reset_tuning' for more complete comments.  */
+
+    float shrink_threshold;	/* ratio of used buckets to trigger a shrink */
+    float shrink_factor;	/* ratio of new smaller size to original size */
+    float growth_threshold;	/* ratio of used buckets to trigger a growth */
+    float growth_factor;	/* ratio of new bigger size to original size */
+    bool is_n_buckets;		/* if CANDIDATE really means table size */
+  };
+
+typedef struct hash_tuning Hash_tuning;
+
 struct hash_table
   {
     /* The array of buckets starts at BUCKET and extends to BUCKET_LIMIT-1,
@@ -47,9 +61,12 @@ struct hash_table
        are not empty, there are N_ENTRIES active entries in the table.  */
     struct hash_entry *bucket;
     struct hash_entry *bucket_limit;
-    unsigned int n_buckets;
-    unsigned int n_buckets_used;
-    unsigned int n_entries;
+    unsigned n_buckets;
+    unsigned n_buckets_used;
+    unsigned n_entries;
+
+    /* Tuning arguments, kept in a physicaly separate structure.  */
+    const Hash_tuning *tuning;
 
     /* Three functions are given to `hash_initialize', see the documentation
        block for this function.  In a word, HASHER randomizes a user entry
@@ -74,10 +91,10 @@ struct hash_table
 typedef struct hash_table Hash_table;
 
 /* Information and lookup.  */
-unsigned int hash_get_n_buckets PARAMS ((const Hash_table *));
-unsigned int hash_get_n_buckets_used PARAMS ((const Hash_table *));
-unsigned int hash_get_n_entries PARAMS ((const Hash_table *));
-unsigned int hash_get_max_bucket_length PARAMS ((const Hash_table *));
+unsigned hash_get_n_buckets PARAMS ((const Hash_table *));
+unsigned hash_get_n_buckets_used PARAMS ((const Hash_table *));
+unsigned hash_get_n_entries PARAMS ((const Hash_table *));
+unsigned hash_get_max_bucket_length PARAMS ((const Hash_table *));
 bool hash_table_ok PARAMS ((const Hash_table *));
 void hash_print_statistics PARAMS ((const Hash_table *, FILE *));
 void *hash_lookup PARAMS ((const Hash_table *, const void *));
@@ -85,19 +102,19 @@ void *hash_lookup PARAMS ((const Hash_table *, const void *));
 /* Walking.  */
 void *hash_get_first PARAMS ((const Hash_table *));
 void *hash_get_next PARAMS ((const Hash_table *, const void *));
-unsigned int hash_get_entries PARAMS ((const Hash_table *, void **,
-				       unsigned int));
-unsigned int hash_do_for_each PARAMS ((const Hash_table *, Hash_processor,
-				       void *));
+unsigned hash_get_entries PARAMS ((const Hash_table *, void **, unsigned));
+unsigned hash_do_for_each PARAMS ((const Hash_table *, Hash_processor, void *));
 
 /* Allocation and clean-up.  */
-unsigned int hash_string PARAMS ((const char *, unsigned int));
-Hash_table *hash_initialize PARAMS ((unsigned int, Hash_hasher,
-				     Hash_comparator, Hash_data_freer));
+unsigned hash_string PARAMS ((const char *, unsigned));
+void hash_reset_tuning PARAMS ((Hash_tuning *));
+Hash_table *hash_initialize PARAMS ((unsigned, const Hash_tuning *,
+				     Hash_hasher, Hash_comparator,
+				     Hash_data_freer));
 void hash_clear PARAMS ((Hash_table *));
 void hash_free PARAMS ((Hash_table *));
 
 /* Insertion and deletion.  */
-bool hash_rehash PARAMS ((Hash_table *, unsigned int));
+bool hash_rehash PARAMS ((Hash_table *, unsigned));
 void *hash_insert PARAMS ((Hash_table *, const void *));
 void *hash_delete PARAMS ((Hash_table *, const void *));