X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Fmath%2Fsort.c;h=13642e00ea7b8c0f84e71c2c8c54adec9ed111ad;hb=47af71b93ed4673d23594ed2b84743f15638f7b7;hp=3491a20bfd684abae50fe88f2f232d0bbe04a3e4;hpb=81579d9e9f994fb2908f50af41c3eb033d216e58;p=pspp

diff --git a/src/math/sort.c b/src/math/sort.c
index 3491a20bfd..13642e00ea 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, 2011 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
@@ -32,9 +32,6 @@
 
 #include "gl/xalloc.h"
 
-#include "gettext.h"
-#define _(msgid) gettext (msgid)
-
 /* These should only be changed for testing purposes. */
 int min_buffers = 64;
 int max_buffers = INT_MAX;
@@ -63,6 +60,9 @@ static struct ccase *pqueue_pop (struct pqueue *, casenumber *);
 
 static void output_record (struct sort_writer *);
 
+/* Creates a casewriter that sorts the cases written to it.  Once all the cases
+   have been written, use casewriter_make_reader() to obtain the sorted
+   results. */
 struct casewriter *
 sort_create_writer (const struct subcase *ordering,
                     const struct caseproto *proto)
@@ -102,7 +102,7 @@ sort_casewriter_destroy (struct casewriter *writer UNUSED, void *sort_)
 {
   struct sort_writer *sort = sort_;
 
-  subcase_destroy (&sort->ordering);
+  subcase_uninit (&sort->ordering);
   merge_destroy (sort->merge);
   pqueue_destroy (sort->pqueue);
   casewriter_destroy (sort->run);
@@ -192,7 +192,7 @@ sort_execute_1var (struct casereader *input, const struct variable *var)
 
   subcase_init_var (&sc, var, SC_ASCEND);
   reader = sort_execute (input, &sc);
-  subcase_destroy (&sc);
+  subcase_uninit (&sc);
   return reader;
 }
 
@@ -200,8 +200,9 @@ struct pqueue
   {
     struct subcase ordering;
     struct pqueue_record *records;
-    size_t record_cnt;
-    size_t record_cap;
+    size_t n_records;           /* Current number of records. */
+    size_t allocated_records;   /* Space currently allocated for records. */
+    size_t max_records;         /* Max space we are willing to allocate. */
     casenumber idx;
   };
 
@@ -222,13 +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_cnt = 0;
-  pq->records = xnmalloc (pq->record_cap, sizeof *pq->records);
+  pq->max_records = settings_get_workspace_cases (proto);
+  if (pq->max_records > max_buffers)
+    pq->max_records = max_buffers;
+  else if (pq->max_records < min_buffers)
+    pq->max_records = min_buffers;
+  pq->n_records = 0;
+  pq->allocated_records = 0;
+  pq->records = NULL;
   pq->idx = 0;
 
   return pq;
@@ -245,7 +247,7 @@ pqueue_destroy (struct pqueue *pq)
           struct ccase *c = pqueue_pop (pq, &id);
           case_unref (c);
         }
-      subcase_destroy (&pq->ordering);
+      subcase_uninit (&pq->ordering);
       free (pq->records);
       free (pq);
     }
@@ -254,13 +256,13 @@ pqueue_destroy (struct pqueue *pq)
 static bool
 pqueue_is_full (const struct pqueue *pq)
 {
-  return pq->record_cnt >= pq->record_cap;
+  return pq->n_records >= pq->max_records;
 }
 
 static bool
 pqueue_is_empty (const struct pqueue *pq)
 {
-  return pq->record_cnt == 0;
+  return pq->n_records == 0;
 }
 
 static void
@@ -270,12 +272,23 @@ pqueue_push (struct pqueue *pq, struct ccase *c, casenumber id)
 
   assert (!pqueue_is_full (pq));
 
-  r = &pq->records[pq->record_cnt++];
+  if (pq->n_records >= pq->allocated_records)
+    {
+      pq->allocated_records = pq->allocated_records * 2;
+      if (pq->allocated_records < 16)
+        pq->allocated_records = 16;
+      else if (pq->allocated_records > pq->max_records)
+        pq->allocated_records = pq->max_records;
+      pq->records = xrealloc (pq->records,
+                              pq->allocated_records * sizeof *pq->records);
+    }
+
+  r = &pq->records[pq->n_records++];
   r->id = id;
   r->c = c;
   r->idx = pq->idx++;
 
-  push_heap (pq->records, pq->record_cnt, sizeof *pq->records,
+  push_heap (pq->records, pq->n_records, sizeof *pq->records,
              compare_pqueue_records_minheap, pq);
 }
 
@@ -286,10 +299,10 @@ pqueue_pop (struct pqueue *pq, casenumber *id)
 
   assert (!pqueue_is_empty (pq));
 
-  pop_heap (pq->records, pq->record_cnt--, sizeof *pq->records,
+  pop_heap (pq->records, pq->n_records--, sizeof *pq->records,
             compare_pqueue_records_minheap, pq);
 
-  r = &pq->records[pq->record_cnt];
+  r = &pq->records[pq->n_records];
   *id = r->id;
   return r->c;
 }