Expunge revision histories in files.

[mLib] / darray.c

diff --git a/darray.c b/darray.c
index d7967c6219387859341085b15398ebf546f8c44d..f376ee57ef72eb1bf5f7401e096f7e84023ea99f 100644 (file)
--- a/darray.c
+++ b/darray.c
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
 /* -*-c-*-
  *

- * $Id: darray.c,v 1.3 1999/10/29 22:59:22 mdw Exp $
+ * $Id: darray.c,v 1.7 2004/04/08 01:36:11 mdw Exp $

  *
  * Dynamically growing dense arrays
  *
  *
  * Dynamically growing dense arrays
  *


@@ -27,20 +27,6 @@
  * MA 02111-1307, USA.
  */
 
  * MA 02111-1307, USA.
  */
 

-/*----- Revision history --------------------------------------------------* 
- *
- * $Log: darray.c,v $
- * Revision 1.3  1999/10/29 22:59:22  mdw
- * New array adjustment macros for unsigned arguments.
- *
- * Revision 1.2  1999/10/28 22:05:28  mdw
- * Modify and debug allocation routines.
- *
- * Revision 1.1  1999/10/22 22:37:26  mdw
- * New dynamic array implementation replaces `dynarray.h'.
- *
- */
-

 /*----- Header files ------------------------------------------------------*/
 
 #include <stdio.h>
 /*----- Header files ------------------------------------------------------*/
 
 #include <stdio.h>


@@ -48,6 +34,7 @@
 #include <stdlib.h>
 
 #include "alloc.h"
 #include <stdlib.h>
 
 #include "alloc.h"

+#include "arena.h"

 #include "darray.h"
 
 /*----- Magic numbers -----------------------------------------------------*/
 #include "darray.h"
 
 /*----- Magic numbers -----------------------------------------------------*/


@@ -106,10 +93,11 @@ void *da_ensure(da_base *b, void *v, size_t sz, size_t n)
   /* --- Maybe just shunt data around a bit --- *
    *
    * If the vector is large enough, then theoretically we could cope by
   /* --- Maybe just shunt data around a bit --- *
    *
    * If the vector is large enough, then theoretically we could cope by

-   * moving the objects about in their existing storage.
+   * moving the objects about in their existing storage.  It's not worth
+   * bothering if there's not actually double the amount of space I need.

    */
 
    */
 

-  if (rq < b->sz + b->off) {
+  if (rq * 2 < b->sz + b->off) {

     q = p - (b->off - slots) * sz;
     memmove(q, p, b->len * sz);
     b->sz += b->off - slots;
     q = p - (b->off - slots) * sz;
     memmove(q, p, b->len * sz);
     b->sz += b->off - slots;


@@ -118,26 +106,37 @@ void *da_ensure(da_base *b, void *v, size_t sz, size_t n)
     return (q);
   }
 
     return (q);
   }
 

-  /* --- Reallocate the array --- *
+  /* --- Decide on a new size --- *

    *
    *

-   * If the offset isn't changing, it's sensible to use @realloc@ if
-   * available.  Otherwise the overhead of copying all the data twice
-   * probably isn't worth it.
+   * There's a minimum possible size for the array which is used if it's
+   * currently completely empty.  Otherwise I choose the smallest power of
+   * two which is big enough, starting at double the current size.

    */
 
   nsz = v ? b->sz + b->off : (DA_INITSZ >> 1);
   do nsz <<= 1; while (nsz < rq);
    */
 
   nsz = v ? b->sz + b->off : (DA_INITSZ >> 1);
   do nsz <<= 1; while (nsz < rq);

+
+  /* --- Reallocate the block --- *
+   *
+   * If I'm not changing the base offset then it's worth using @realloc@;
+   * otherwise there'll probably be two calls to @memcpy@ to shunt the data
+   * around so it's not worth bothering.
+   */
+

   if (p && slots == b->off) {
   if (p && slots == b->off) {

-    q = xrealloc(p - b->off * sz, nsz * sz);
+    q = x_realloc(b->a, p - b->off * sz, nsz * sz, b->sz + b->off);

     q += slots * sz;
   } else {
     q += slots * sz;
   } else {

-    q = xmalloc(nsz * sz);
+    q = x_alloc(b->a, nsz * sz);

     q += slots * sz;
     if (p) {
       memcpy(q, p, b->len * sz);
     q += slots * sz;
     if (p) {
       memcpy(q, p, b->len * sz);

-      free(p - b->off * sz);
+      x_free(b->a, p - b->off * sz);

     }
   }
     }
   }

+
+  /* --- Fill in the other parts of the base structure --- */
+

   b->off = slots;
   b->sz = nsz - slots;
   b->unshift = b->push = 0;
   b->off = slots;
   b->sz = nsz - slots;
   b->unshift = b->push = 0;


@@ -196,10 +195,11 @@ void *da_shunt(da_base *b, void *v, size_t sz, size_t n)
   /* --- Maybe just shunt data around a bit --- *
    *
    * If the vector is large enough, then theoretically we could cope by
   /* --- Maybe just shunt data around a bit --- *
    *
    * If the vector is large enough, then theoretically we could cope by

-   * moving the objects about in their existing storage.
+   * moving the objects about in their existing storage.  Again, if there's
+   * not actually twice the space needed, reallocate the array.

    */
 
    */
 

-  if (rq < b->sz + b->off) {
+  if (rq * 2 < b->sz + b->off) {

     q = p + (b->sz - slots) * sz;
     memmove(q, p, b->len * sz);
     b->off += b->sz - slots;
     q = p + (b->sz - slots) * sz;
     memmove(q, p, b->len * sz);
     b->off += b->sz - slots;


@@ -214,14 +214,31 @@ void *da_shunt(da_base *b, void *v, size_t sz, size_t n)
    * almost all the time -- that's the whole point of this routine!
    */
 
    * almost all the time -- that's the whole point of this routine!
    */
 

+  /* --- Decide on a new size --- *
+   *
+   * There's a minimum possible size for the array which is used if it's
+   * currently completely empty.  Otherwise I choose the smallest power of
+   * two which is big enough, starting at double the current size.
+   */
+

   nsz = v ? b->sz + b->off : (DA_INITSZ >> 1);
   do nsz <<= 1; while (nsz < rq);
   nsz = v ? b->sz + b->off : (DA_INITSZ >> 1);
   do nsz <<= 1; while (nsz < rq);

-  q = xmalloc(nsz * sz);
+
+  /* --- Reallocate the block --- *
+   *
+   * The neat @realloc@ code doesn't need to be here: the offset changes
+   * almost all the time -- that's the whole point of this routine!
+   */
+
+  q = x_alloc(b->a, nsz * sz);

   q += (nsz - slots) * sz;
   if (p) {
     memcpy(q, p, b->len * sz);
   q += (nsz - slots) * sz;
   if (p) {
     memcpy(q, p, b->len * sz);

-    free(p - b->off * sz);
+    x_free(b->a, p - b->off * sz);

   }
   }

+
+  /* --- Fill in the other parts of the base structure --- */
+  

   b->off = nsz - slots;
   b->sz = slots;
   b->unshift = b->push = 0;
   b->off = nsz - slots;
   b->sz = slots;
   b->unshift = b->push = 0;


@@ -253,13 +270,13 @@ void *da_tidy(da_base *b, void *v, size_t sz)
     return (p);
 
   if (!b->len) {
     return (p);
 
   if (!b->len) {

-    free(p - b->off * sz);
+    xfree(p - b->off * sz);

     return (0);
   }
 
     return (0);
   }
 

-  q = xmalloc(b->len * sz);
+  q = x_alloc(b->a, b->len * sz);

   memcpy(q, p, b->len * sz);
   memcpy(q, p, b->len * sz);

-  free(p - b->off * sz);
+  x_free(b->a, p - b->off * sz);

   b->sz = b->len;
   b->off = 0;
   return (q);
   b->sz = b->len;
   b->off = 0;
   return (q);