From: Ben Pfaff <blp@gnu.org>
Date: Mon, 4 Jun 2007 01:19:03 +0000 (+0000)
Subject: (move_range): New function.
X-Git-Tag: v0.6.0~457
X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d08af71f38b751323cc9506631bf9ce71070a4ae;p=pspp-builds.git

(move_range): New function.
---

diff --git a/src/libpspp/ChangeLog b/src/libpspp/ChangeLog
index fa02a8b9..acdad231 100644
--- a/src/libpspp/ChangeLog
+++ b/src/libpspp/ChangeLog
@@ -2,6 +2,7 @@
 
 	* array.c (insert_range): New function.
 	(insert_element): New function.
+	(move_range): New function.
 
 2007-04-25  Ben Pfaff  <blp@gnu.org>
 
diff --git a/src/libpspp/array.c b/src/libpspp/array.c
index 8af5d8fe..f375f83d 100644
--- a/src/libpspp/array.c
+++ b/src/libpspp/array.c
@@ -415,6 +415,36 @@ move_element (void *array_, size_t count, size_t size,
     }
 }
 
+/* Moves N elements in ARRAY starting at OLD_IDX, which consists
+   of COUNT elements of SIZE bytes each, so that they now start
+   at NEW_IDX, shifting around other elements as needed. */
+void
+move_range (void *array_, size_t count, size_t size,
+            size_t old_idx, size_t new_idx, size_t n)
+{
+  assert (array_ != NULL || count == 0);
+  assert (n <= count);
+  assert (old_idx + n <= count);
+  assert (new_idx + n <= count);
+  
+  if (old_idx != new_idx && n > 0) 
+    {
+      char *array = array_;
+      char *range = xmalloc (size * n);
+      char *new = array + new_idx * size;
+      char *old = array + old_idx * size;
+
+      memcpy (range, old, size * n);
+      if (new < old)
+        memmove (new + size * n, new, (old_idx - new_idx) * size);
+      else
+        memmove (old, old + size * n, (new_idx - old_idx) * size);
+      memcpy (new, range, size * n);
+
+      free (range);
+    }
+}
+
 /* A predicate and its auxiliary data. */
 struct pred_aux 
   {
diff --git a/src/libpspp/array.h b/src/libpspp/array.h
index 3cfb245a..a867adea 100644
--- a/src/libpspp/array.h
+++ b/src/libpspp/array.h
@@ -129,6 +129,12 @@ void insert_element (void *array, size_t count, size_t size,
 void move_element (void *array, size_t count, size_t size,
                    size_t old_idx, size_t new_idx);
 
+/* Moves N elements in ARRAY starting at OLD_IDX, which consists
+   of COUNT elements of SIZE bytes each, so that they now start
+   at NEW_IDX, shifting around other elements as needed. */
+void move_range (void *array, size_t count, size_t size,
+                 size_t old_idx, size_t new_idx, size_t n);
+
 /* Removes elements equal to ELEMENT from ARRAY, which consists
    of COUNT elements of SIZE bytes each.  Returns the number of
    remaining elements.  AUX is passed to COMPARE as auxiliary