X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Fmath%2Fsort.c;h=a780d49c6b0a7d4f347ac3559885cddfb6c5bd41;hb=52d795d2fe3611efc1d51b2cdf6851bb7e67682e;hp=8719d877e096fcc9fc0d0f911d462d7bd0566725;hpb=b5c82cc9aabe7e641011130240ae1b2e84348e23;p=pspp

diff --git a/src/math/sort.c b/src/math/sort.c
index 8719d877e0..a780d49c6b 100644
--- a/src/math/sort.c
+++ b/src/math/sort.c
@@ -1,5 +1,5 @@
 /* PSPP - a program for statistical analysis.
-   Copyright (C) 1997-9, 2000, 2006, 2009 Free Software Foundation, Inc.
+   Copyright (C) 1997-9, 2000, 2006, 2009, 2011, 2012 Free Software Foundation, Inc.
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -16,21 +16,21 @@
 
 #include <config.h>
 
-#include "sort.h"
+#include "math/sort.h"
 
 #include <stdio.h>
 
-#include <data/case.h>
-#include <data/casereader.h>
-#include <data/casewriter.h>
-#include <data/casewriter-provider.h>
-#include <data/settings.h>
-#include <data/subcase.h>
-#include <libpspp/array.h>
-#include <libpspp/assertion.h>
-#include <math/merge.h>
+#include "data/case.h"
+#include "data/casereader.h"
+#include "data/casewriter-provider.h"
+#include "data/casewriter.h"
+#include "data/settings.h"
+#include "data/subcase.h"
+#include "libpspp/array.h"
+#include "libpspp/assertion.h"
+#include "math/merge.h"
 
-#include "xalloc.h"
+#include "gl/xalloc.h"
 
 #include "gettext.h"
 #define _(msgid) gettext (msgid)
@@ -169,7 +169,9 @@ static struct casewriter_class sort_casewriter_class =
   };
 
 /* Reads all the cases from INPUT.  Sorts the cases according to
-   ORDERING.  Returns the sorted cases in a new casereader. */
+   ORDERING.  Returns the sorted cases in a new casereader.
+   INPUT is destroyed by this function.
+ */
 struct casereader *
 sort_execute (struct casereader *input, const struct subcase *ordering)
 {
@@ -181,7 +183,7 @@ sort_execute (struct casereader *input, const struct subcase *ordering)
 
 /* Reads all the cases from INPUT.  Sorts the cases in ascending
    order according to VARIABLE.  Returns the sorted cases in a
-   new casereader. */
+   new casereader.  INPUT is destroyed by this function. */
 struct casereader *
 sort_execute_1var (struct casereader *input, const struct variable *var)
 {
@@ -198,8 +200,9 @@ struct pqueue
   {
     struct subcase ordering;
     struct pqueue_record *records;
-    size_t record_cnt;
-    size_t record_cap;
+    size_t record_cnt;          /* Current number of records. */
+    size_t record_cap;          /* Space currently allocated for records. */
+    size_t record_max;          /* Max space we are willing to allocate. */
     casenumber idx;
   };
 
@@ -220,13 +223,14 @@ pqueue_create (const struct subcase *ordering, const struct caseproto *proto)
 
   pq = xmalloc (sizeof *pq);
   subcase_clone (&pq->ordering, ordering);
-  pq->record_cap = settings_get_workspace_cases (proto);
-  if (pq->record_cap > max_buffers)
-    pq->record_cap = max_buffers;
-  else if (pq->record_cap < min_buffers)
-    pq->record_cap = min_buffers;
+  pq->record_max = settings_get_workspace_cases (proto);
+  if (pq->record_max > max_buffers)
+    pq->record_max = max_buffers;
+  else if (pq->record_max < min_buffers)
+    pq->record_max = min_buffers;
   pq->record_cnt = 0;
-  pq->records = xnmalloc (pq->record_cap, sizeof *pq->records);
+  pq->record_cap = 0;
+  pq->records = NULL;
   pq->idx = 0;
 
   return pq;
@@ -252,7 +256,7 @@ pqueue_destroy (struct pqueue *pq)
 static bool
 pqueue_is_full (const struct pqueue *pq)
 {
-  return pq->record_cnt >= pq->record_cap;
+  return pq->record_cnt >= pq->record_max;
 }
 
 static bool
@@ -268,6 +272,17 @@ pqueue_push (struct pqueue *pq, struct ccase *c, casenumber id)
 
   assert (!pqueue_is_full (pq));
 
+  if (pq->record_cnt >= pq->record_cap)
+    {
+      pq->record_cap = pq->record_cap * 2;
+      if (pq->record_cap < 16)
+        pq->record_cap = 16;
+      else if (pq->record_cap > pq->record_max)
+        pq->record_cap = pq->record_max;
+      pq->records = xrealloc (pq->records,
+                              pq->record_cap * sizeof *pq->records);
+    }
+
   r = &pq->records[pq->record_cnt++];
   r->id = id;
   r->c = c;