X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Fdata%2Fcasereader.c;h=ee7facb769dbf9a26dc96d717f1249a7fe44879b;hb=ee7be3e962a4faba54d7bc01364365b51167242c;hp=8b78645627e1243f4efb875612b97eac2666cc70;hpb=83ad8f5b760cb46bd1d86f60a40d6aace21118ef;p=pspp

diff --git a/src/data/casereader.c b/src/data/casereader.c
index 8b78645627..ee7facb769 100644
--- a/src/data/casereader.c
+++ b/src/data/casereader.c
@@ -183,6 +183,24 @@ casereader_peek (struct casereader *reader, casenumber idx, struct ccase *c)
   return false;
 }
 
+/* Returns true if no cases remain to be read from READER, or if
+   an error has occurred on READER.  (A return value of false
+   does *not* mean that the next call to casereader_peek or
+   casereader_read will return true, because an error can occur
+   in the meantime.) */
+bool
+casereader_is_empty (struct casereader *reader)
+{
+  struct ccase c;
+  if (reader->case_cnt == 0 || !casereader_peek (reader, 0, &c))
+    return true;
+  else
+    {
+      case_destroy (&c);
+      return false;
+    }
+}
+
 /* Returns true if an I/O error or another hard error has
    occurred on READER, a clone of READER, or on some object on
    which READER's data has a dependency, false otherwise. */
@@ -338,7 +356,7 @@ casereader_create_sequential (const struct taint *taint,
    casereader to be replaced by a shim caseader). */
 void *
 casereader_dynamic_cast (struct casereader *reader,
-                         struct casereader_class *class)
+                         const struct casereader_class *class)
 {
   return reader->class == class ? reader->aux : NULL;
 }
@@ -375,7 +393,7 @@ struct random_reader_shared
     void *aux;
   };
 
-static struct casereader_class random_reader_casereader_class;
+static const struct casereader_class random_reader_casereader_class;
 
 /* Creates and returns a new random_reader with the given SHARED
    data and OFFSET.  Inserts the new random reader into the
@@ -523,7 +541,7 @@ random_reader_peek (struct casereader *reader, void *br_,
 }
 
 /* Casereader class for random reader. */
-static struct casereader_class random_reader_casereader_class =
+static const struct casereader_class random_reader_casereader_class =
   {
     random_reader_read,
     random_reader_destroy,
@@ -562,7 +580,7 @@ struct shim
     struct casereader *subreader;       /* Subordinate casereader. */
   };
 
-static struct casereader_random_class shim_class;
+static const struct casereader_random_class shim_class;
 
 /* Interposes a buffering shim atop READER. */
 static void
@@ -571,7 +589,7 @@ insert_shim (struct casereader *reader)
   size_t value_cnt = casereader_get_value_cnt (reader);
   casenumber case_cnt = casereader_get_case_cnt (reader);
   struct shim *b = xmalloc (sizeof *b);
-  b->window = casewindow_create (value_cnt, get_workspace_cases (value_cnt));
+  b->window = casewindow_create (value_cnt, settings_get_workspace_cases (value_cnt));
   b->subreader = casereader_create_random (value_cnt, case_cnt,
                                            &shim_class, b);
   casereader_swap (reader, b->subreader);
@@ -628,7 +646,7 @@ shim_advance (struct casereader *reader UNUSED, void *b_, casenumber case_cnt)
 }
 
 /* Class for the buffered reader. */
-static struct casereader_random_class shim_class =
+static const struct casereader_random_class shim_class =
   {
     shim_read,
     shim_destroy,