X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/mLib/blobdiff_plain/cd3001477e8cada39b9db728f65ff610d89a8895..17119f584e90f494da54aa9e2d1d10227213d96b:/sym.c

diff --git a/sym.c b/sym.c
index 3bf52f3..a5cec57 100644
--- a/sym.c
+++ b/sym.c
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: sym.c,v 1.9 1999/10/22 22:36:37 mdw Exp $
+ * $Id: sym.c,v 1.15 2004/04/08 01:36:13 mdw Exp $
  *
  * Symbol table management
  *
@@ -27,39 +27,6 @@
  * MA 02111-1307, USA.
  */
 
-/*----- Revision history --------------------------------------------------*
- *
- * $Log: sym.c,v $
- * Revision 1.9  1999/10/22 22:36:37  mdw
- * New test structure for symbol tables.
- *
- * Revision 1.8  1999/08/02 14:45:48  mdw
- * Break low-level hashtable code out from sym.
- *
- * Revision 1.7  1999/06/01 09:49:08  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
- * Twiddle the extension threshold.  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 19:27:33  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
- *
- */
-
 /*----- Header files ------------------------------------------------------*/
 
 /* --- ANSI headers --- */
@@ -71,34 +38,13 @@
 /* --- Local headers --- */
 
 #include "alloc.h"
+#include "arena.h"
 #include "bits.h"
-#include "crc32.h"
 #include "exc.h"
 #include "hash.h"
 #include "sub.h"
 #include "sym.h"
-#include "track.h"
-
-/*----- 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 64			/* 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 */
+#include "unihash.h"
 
 /*----- Main code ---------------------------------------------------------*/
 
@@ -114,11 +60,9 @@
 
 void sym_create(sym_table *t)
 {
-  TRACK_CTX("symbol table creation");
-  TRACK_PUSH;
   hash_create(&t->t, SYM_INITSZ);
+  t->s = &sub_global;
   t->load = SYM_LIMIT(SYM_INITSZ);
-  TRACK_POP;
 }
 
 /* --- @sym_destroy@ --- *
@@ -135,28 +79,21 @@ void sym_destroy(sym_table *t)
 {
   sym_iter i;
 
-  TRACK_CTX("symbol table destruction");
-  TRACK_PUSH;
-
   SYM_MKITER(&i, t);
   for (;;) {
     sym_base *p;
     SYM_NEXT(&i, p);
     if (!p)
       break;
-    if (p->len > SYM_BUFSZ)
-      sub_free(p->name.p, p->len);
-    free(p);
+    x_free(t->t.a, p);
   }
   hash_destroy(&t->t);
-
-  TRACK_POP;
 }
 
 /* --- @sym_find@ --- *
  *
  * Arguments:	@sym_table *t@ = pointer to symbol table in question
- *		@const char *n@ = pointer to symbol table to look up
+ *		@const char *n@ = pointer to symbol name to look up
  *		@long l@ = length of the name string or negative to measure
  *		@size_t sz@ = size of desired symbol object, or zero
  *		@unsigned *f@ = pointer to a flag, or null.
@@ -193,8 +130,8 @@ void *sym_find(sym_table *t, const char *n, long l, size_t sz, unsigned *f)
 
   /* --- Find the correct bin --- */
 
-  len = l < 0 ? strlen(n) + 1 : l;
-  CRC32(hash, 0, n, len);
+  len = l < 0 ? strlen(n) : l;
+  hash = UNIHASH(&unihash_global, n, len);
   bin = HASH_BIN(&t->t, hash);
 
   /* --- Search the bin list --- */
@@ -225,34 +162,18 @@ void *sym_find(sym_table *t, const char *n, long l, size_t sz, unsigned *f)
   if (f) *f = 0;
   if (!sz) return (0);
 
-  /* --- Create a new symbol block and initialize it --- */
-
-  {
-    TRACK_CTX("new symbol creation");
-    TRACK_PUSH;
-
-    q = xmalloc(sz);
-    q->b.next = *bin;
-    q->b.hash = hash;
-    q->len = len;
-    if (n) {
-      if (len <= SYM_BUFSZ)
-	memcpy(q->name.b, n, len);
-      else {
-	TRY {
-	  q->name.p = sub_alloc(len);
-	  memcpy(q->name.p, n, len);
-	} CATCH {
-	  free(q);
-	  TRACK_POP;
-	  RETHROW;
-	} END_TRY;
-      }
-    }
-
-    TRACK_POP;
-  }
-
+  /* --- Create a new symbol block and initialize it --- *
+   *
+   * The name is attached to the end of the symbol block.
+   */
+
+  q = x_alloc(t->t.a, sz + len + 1);
+  q->b.next = *bin;
+  q->b.hash = hash;
+  q->name = (char *)q + sz;
+  memcpy(q->name, n, len);
+  q->name[len] = 0;
+  q->len = len;
   *bin = &q->b;
 
   /* --- Consider growing the array --- */
@@ -260,7 +181,7 @@ void *sym_find(sym_table *t, const char *n, long l, size_t sz, unsigned *f)
   if (t->load)
     t->load--;
   if (!t->load && hash_extend(&t->t))
-    t->load = SYM_LIMIT(t->t.mask / 2 + 1);
+    t->load = SYM_LIMIT(t->t.mask + 1);
 
   /* --- Finished that, so return the new symbol block --- */
 
@@ -269,7 +190,7 @@ void *sym_find(sym_table *t, const char *n, long l, size_t sz, unsigned *f)
 
 /* --- @sym_remove@ --- *
  *
- * Arguments:	@sym_table *i@ = pointer to a symbol table object
+ * Arguments:	@sym_table *t@ = pointer to a symbol table object
  *		@void *p@ = pointer to symbol table entry
  *
  * Returns:	---
@@ -283,9 +204,7 @@ void sym_remove(sym_table *t, void *p)
 {
   sym_base *q = p;
   hash_remove(&t->t, &q->b);
-  if (q->len > SYM_BUFSZ)
-    sub_free(q->name.p, q->len);
-  free(q);
+  xfree(q);
   t->load++;
 }