Use the version from diffutils-2.8.2.

[gnulib.git] / lib / hash.h

diff --git a/lib/hash.h b/lib/hash.h
index b046bfe..a9fc187 100644 (file)
--- a/lib/hash.h
+++ b/lib/hash.h
@@ -1,5 +1,5 @@
 /* hash - hashing table processing.
-   Copyright (C) 1998, 1999 Free Software Foundation, Inc.
+   Copyright (C) 1998, 1999, 2001 Free Software Foundation, Inc.
    Written by Jim Meyering <meyering@ascend.com>, 1998.
 
    This program is free software; you can redistribute it and/or modify
@@ -21,15 +21,18 @@
 /* Make sure USE_OBSTACK is defined to 1 if you want the allocator to use
    obstacks instead of malloc, and recompile `hash.c' with same setting.  */
 
-#ifndef PARAMS
-# if PROTOTYPES || __STDC__
-#  define PARAMS(Args) Args
-# else
-#  define PARAMS(Args) ()
+#ifndef HASH_H_
+# define HASH_H_
+
+# ifndef PARAMS
+#  if PROTOTYPES || __STDC__
+#   define PARAMS(Args) Args
+#  else
+#   define PARAMS(Args) ()
+#  endif
 # 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 *));
@@ -40,44 +43,29 @@ struct hash_entry
     struct hash_entry *next;
   };
 
-struct hash_table
+struct hash_tuning
   {
-    /* The array of buckets starts at BUCKET and extends to BUCKET_LIMIT-1,
-       for a possibility of N_BUCKETS.  Among those, N_BUCKETS_USED buckets
-       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;
-
-    /* Three functions are given to `hash_initialize', see the documentation
-       block for this function.  In a word, HASHER randomizes a user entry
-       into a number up from 0 up to some maximum minus 1; COMPARATOR returns
-       true if two user entries compare equally; and DATA_FREER is the cleanup
-       function for a user entry.  */
-    Hash_hasher hasher;
-    Hash_comparator comparator;
-    Hash_data_freer data_freer;
-
-    /* A linked list of freed struct hash_entry structs.  */
-    struct hash_entry *free_entry_list;
-
-#if USE_OBSTACK
-    /* Whenever obstacks are used, it is possible to allocate all overflowed
-       entries into a single stack, so they all can be freed in a single
-       operation.  It is not clear if the speedup is worth the trouble.  */
-    struct obstack entry_stack;
-#endif
+    /* 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;
+
 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 +73,21 @@ 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 *));
+
+#endif