mosesdecoder/jam-files/engine/hash.h

80 lines
2.1 KiB
C

/*
* Copyright 1993, 1995 Christopher Seiwald.
*
* This file is part of Jam - see jam.c for Copyright information.
*/
/*
* hash.h - simple in-memory hashing routines
*/
#ifndef BOOST_JAM_HASH_H
#define BOOST_JAM_HASH_H
#include "object.h"
/*
* An opaque struct representing an item in the hash table. The first element of
* every struct stored in the table must be an OBJECT * which is treated as the
* key.
*/
typedef struct hashdata HASHDATA;
/*
* hashinit() - initialize a hash table, returning a handle.
*
* Parameters:
* datalen - item size
* name - used for debugging
*/
struct hash * hashinit( int datalen, char const * name );
/*
* hash_free() - free a hash table, given its handle
*/
void hash_free( struct hash * );
void hashdone( struct hash * );
/*
* hashenumerate() - call f(i, data) on each item, i in the hash table. The
* enumeration order is unspecified.
*/
void hashenumerate( struct hash *, void (* f)( void *, void * ), void * data );
/*
* hash_insert() - insert a new item in a hash table, or return an existing one.
*
* Preconditions:
* - hp must be a hash table created by hashinit()
* - key must be an object created by object_new()
*
* Postconditions:
* - if the key does not already exist in the hash table, *found == 0 and the
* result will be a pointer to an uninitialized item. The key of the new
* item must be set to a value equal to key before any further operations on
* the hash table except hashdone().
* - if the key is present then *found == 1 and the result is a pointer to the
* existing record.
*/
HASHDATA * hash_insert( struct hash *, OBJECT * key, int * found );
/*
* hash_find() - find a record in the table or NULL if none exists
*/
HASHDATA * hash_find( struct hash *, OBJECT * key );
struct hashstats {
int count;
int num_items;
int tab_size;
int item_size;
int sets;
int num_hashes;
};
void hashstats_init( struct hashstats * stats );
void hashstats_add( struct hashstats * stats, struct hash * );
void hashstats_print( struct hashstats * stats, char const * name );
#endif