X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Flibpspp%2Fstr.c;h=afe32de9f2049bfcc5a80ac7a95b36b348be4cb7;hb=8830c95bb9e8d72621787866141a27fc22e8c786;hp=44d325e072df297eb80977d1f03abd45af6bd543;hpb=5c3291dc396b795696e94f47780308fd7ace6fc4;p=pspp-builds.git

diff --git a/src/libpspp/str.c b/src/libpspp/str.c
index 44d325e0..afe32de9 100644
--- a/src/libpspp/str.c
+++ b/src/libpspp/str.c
@@ -1071,6 +1071,34 @@ ds_set_length (struct string *st, size_t new_length, char pad)
     st->ss.length = new_length;
 }
 
+/* Removes N characters from ST starting at offset START. */
+void
+ds_remove (struct string *st, size_t start, size_t n)
+{
+  if (n > 0 && start < st->ss.length)
+    {
+      if (st->ss.length - start <= n)
+        {
+          /* All characters at or beyond START are deleted. */
+          st->ss.length = start;
+        }
+      else
+        {
+          /* Some characters remain and must be shifted into
+             position. */
+          memmove (st->ss.string + st->ss.length,
+                   st->ss.string + st->ss.length + n,
+                   st->ss.length - start - n);
+          st->ss.length -= n;
+        }
+    }
+  else
+    {
+      /* There are no characters to delete or no characters at or
+         beyond START, hence deletion is a no-op. */
+    }
+}
+
 /* Returns true if ST is empty, false otherwise. */
 bool
 ds_is_empty (const struct string *st)
@@ -1413,3 +1441,25 @@ ds_relocate (struct string *st)
       free ((char *) rel);
     }
 }
+
+
+
+
+/* Operations on uint8_t "strings" */
+
+/* Copies buffer SRC, of SRC_SIZE bytes, to DST, of DST_SIZE bytes.
+   DST is truncated to DST_SIZE bytes or padded on the right with
+   copies of PAD as needed. */
+void
+u8_buf_copy_rpad (uint8_t *dst, size_t dst_size,
+		  const uint8_t *src, size_t src_size,
+		  char pad)
+{
+  if (src_size >= dst_size)
+    memmove (dst, src, dst_size);
+  else
+    {
+      memmove (dst, src, src_size);
+      memset (&dst[src_size], pad, dst_size - src_size);
+    }
+}