/* -*-c-*-
*
- * $Id: sym.h,v 1.1 1998/06/17 23:44:42 mdw Exp $
+ * $Id: sym.h,v 1.12 2001/01/20 11:49:37 mdw Exp $
*
* Symbol table management
*
* (c) 1998 Straylight/Edgeware
*/
-/*----- Licensing notice --------------------------------------------------*
+/*----- Licensing notice --------------------------------------------------*
*
* This file is part of the mLib utilities library.
*
* mLib is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
+ * it under the terms of the GNU Library General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
* mLib is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with mLib; if not, write to the Free Software Foundation,
- * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ * GNU Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with mLib; if not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
*/
/*----- Revision history --------------------------------------------------*
*
* $Log: sym.h,v $
- * Revision 1.1 1998/06/17 23:44:42 mdw
- * Initial revision
+ * Revision 1.12 2001/01/20 11:49:37 mdw
+ * Export tuning parameters from header file, for the benefit of other
+ * hashtable implementations. Change the storage of symbol names: store
+ * the name after the allocated symbol block in all cases. This replaces
+ * the previous complicated and slightly wasteful arrangement.
+ *
+ * Revision 1.11 2000/06/17 10:37:39 mdw
+ * Add support for arena management.
+ *
+ * Revision 1.10 1999/12/10 23:42:04 mdw
+ * Change header file guard names.
+ *
+ * Revision 1.9 1999/08/02 16:53:48 mdw
+ * Improve type safety for sym_iter objects.
+ *
+ * Revision 1.8 1999/08/02 14:45:48 mdw
+ * Break low-level hashtable code out from sym.
+ *
+ * Revision 1.7 1999/06/01 09:49:33 mdw
+ * Allow things to be looked up by just their caller-supplied hashes. This
+ * actually needs to be thought through better.
+ *
+ * Revision 1.6 1999/05/26 21:08:31 mdw
+ * Rename symbols in line with newer conventions.
+ *
+ * Revision 1.5 1999/05/13 22:48:37 mdw
+ * Change `-ise' to `-ize' throughout.
+ *
+ * Revision 1.4 1999/05/06 19:51:35 mdw
+ * Reformatted the LGPL notice a little bit.
+ *
+ * Revision 1.3 1999/05/05 18:50:31 mdw
+ * Change licensing conditions to LGPL.
+ *
+ * Revision 1.2 1998/11/26 19:27:34 mdw
+ * Move SYM_NAME into the header file. Fix bugs.
+ *
+ * Revision 1.1.1.1 1998/06/17 23:44:42 mdw
+ * Initial version of mLib
*
*/
-#ifndef SYM_H
-#define SYM_H
+#ifndef MLIB_SYM_H
+#define MLIB_SYM_H
#ifdef __cplusplus
extern "C" {
#include <stddef.h>
+#ifndef MLIB_BITS_H
+# include "bits.h"
+#endif
+
+#ifndef MLIB_HASH_H
+# include "hash.h"
+#endif
+
+#ifndef MLIB_SUB_H
+# include "sub.h"
+#endif
+
+/*----- Tuning parameters -------------------------------------------------*/
+
+/* --- Initial hash table size --- *
+ *
+ * This is the initial @mask@ value. It must be of the form %$2^n - 1$%,
+ * so that it can be used to mask of the bottom bits of a hash value.
+ */
+
+#define SYM_INITSZ 32 /* Size of a new hash table */
+
+/* --- Maximum load factor --- *
+ *
+ * This parameter controls how much the table has to be loaded before the
+ * table is extended. The number of elements %$n$%, the number of bins %$b$%
+ * and the limit %$l$% satisfy the relation %$n < bl$%; if a new item is
+ * added to the table and this relation is found to be false, the table is
+ * doubled in size.
+ */
+
+#define SYM_LIMIT(n) ((n) * 2) /* Load factor for growing table */
+
/*----- Type definitions --------------------------------------------------*/
/* --- Symbol table --- *
*/
typedef struct sym_table {
- unsigned long mask; /* Bit mask for hashing purposes */
- size_t c; /* Down counter for growing table */
- struct sym_base **a; /* Array of hash bins */
+ hash_table t;
+ subarena *s;
+ size_t load;
} sym_table;
/* --- A symbol table entry --- *
* sufficient to allow me to manipulate such objects.
*/
-#define SYM_BUFSZ 16 /* Size of local string buffer */
-
typedef struct sym_base {
- struct sym_base *next; /* Next symbol in hash bin */
- unsigned long hash; /* Hash value for symbol's name */
- union {
- char *p; /* Pointer to name string */
- char b[SYM_BUFSZ]; /* Buffer containing a short name */
- } name; /* Name of this symbol */
+ hash_base b; /* Base structure */
+ char *name; /* Pointer to name string */
size_t len; /* Length of the symbol's name */
} sym_base;
+/* --- Macros for picking out useful information --- *
+ *
+ * Note that @SYM_LEN@ returns the size of the symbol key. For textual keys,
+ * this will include the terminating null.
+ */
+
+#define SYM_NAME(sy) ((const char *)(((sym_base *)(sy))->name))
+#define SYM_LEN(sy) (((sym_base *)(sy))->len + 0)
+#define SYM_HASH(sy) (((sym_base *)(sy))->b.hash + 0)
+
/* --- An iterator block --- */
-typedef struct sym_iter {
- sym_table *t; /* Symbol table being iterated */
- sym_base *n; /* Address of next item to return */
- size_t i; /* Index of next hash bin to use */
-} sym_iter;
+typedef struct { hash_iter i; } sym_iter;
/*----- External functions ------------------------------------------------*/
-/* --- @sym_createTable@ --- *
+/* --- @sym_create@ --- *
*
- * Arguments: @sym_table *t@ = symbol table to initialise
+ * Arguments: @sym_table *t@ = symbol table to initialize
*
* Returns: ---
*
- * Use: Initialises the given symbol table. Raises @EXC_NOMEM@ if
+ * Use: Initializes the given symbol table. Raises @EXC_NOMEM@ if
* there isn't enough memory.
*/
-extern void sym_createTable(sym_table */*t*/);
+extern void sym_create(sym_table */*t*/);
-/* --- @sym_destroyTable@ --- *
+/* --- @sym_destroy@ --- *
*
* Arguments: @sym_table *t@ = pointer to symbol table in question
*
* occupy.
*/
-extern void sym_destroyTable(sym_table */*t*/);
+extern void sym_destroy(sym_table */*t*/);
/* --- @sym_find@ --- *
*
* may be given, in which case the name may contain arbitrary
* binary data, or it may be given as a negative number, in
* which case the length of the name is calculated as
- * @strlen(n)@.
+ * @strlen(n) + 1@.
*
* The return value is the address of a pointer to a @sym_base@
* block (which may have other things on the end, as above). If
/* --- @sym_remove@ --- *
*
- * Arguments: @sym_table *i@ = pointer to a symbol table object
+ * Arguments: @sym_table *t@ = pointer to a symbol table object
* @void *b@ = pointer to symbol table entry
*
* Returns: ---
extern void sym_remove(sym_table */*t*/, void */*b*/);
-/* --- @sym_createIter@ --- *
+/* --- @sym_mkiter@ --- *
*
* Arguments: @sym_iter *i@ = pointer to an iterator object
* @sym_table *t@ = pointer to a symbol table object
* iterate through a symbol table.
*/
-extern void sym_createIter(sym_iter */*i*/, sym_table */*t*/);
+#define SYM_MKITER(i_, t_) HASH_MKITER(&(i_)->i, &(t_)->t)
+
+extern void sym_mkiter(sym_iter */*i*/, sym_table */*t*/);
/* --- @sym_next@ --- *
*
* returned in any particular order.
*/
+#define SYM_NEXT(i_, p) do { \
+ hash_base *_q; \
+ HASH_NEXT(&(i_)->i, _q); \
+ (p) = (void *)_q; \
+} while (0)
+
extern void *sym_next(sym_iter */*i*/);
/*----- That's all, folks -------------------------------------------------*/
~mdw / mLib / blobdiff