Implemented support for very long strings a la spss v13/v14

[pspp-builds.git] / src / data / variable.c

diff --git a/src/data/variable.c b/src/data/variable.c
index 6c1414832b7c992fe5301940a80e33aca794b29d..56993e461c5d43998105123767037bba1a9be16d 100644 (file)
--- a/src/data/variable.c
+++ b/src/data/variable.c
@@ -350,3 +350,112 @@ dict_class_to_name (enum dict_class dict_class)
       abort ();
     }
 }
+
+
+/* Copies buffer SRC, of SRC_SIZE bytes, to DST, of DST_SIZE bytes.
+   Each 256th byte, which is expected to be a ' ', is deleted.
+   DST is then truncated to DST_SIZE bytes or padded on the right with
+   spaces as needed. */
+void
+copy_demangle (char *dst, size_t dst_size,
+           const char *src, size_t src_size)
+{
+  int src_bytes_left = src_size;
+  int dst_bytes_left = dst_size;
+  const char *s = src;
+  char *d = dst;
+
+
+  while( src_bytes_left > 0 ) 
+    {
+      const size_t s_chunk = min(MAX_LONG_STRING, src_bytes_left);
+      const size_t d_chunk = min(MAX_LONG_STRING, dst_bytes_left);
+
+      assert ( d < dst + dst_size);
+
+      buf_copy_rpad (d, d_chunk,
+                    s, s_chunk);
+
+      d += d_chunk;
+      s += s_chunk;
+      src_bytes_left -= s_chunk;
+      dst_bytes_left -= d_chunk;
+
+      if ( src_bytes_left > 0 && ! (++s - src) % (MAX_LONG_STRING+1) )
+       {
+         if ( *s != ' ') 
+           msg(MW, _("Expected a space in very long string"));
+         src_bytes_left--;
+       }
+    }
+}
+
+/* Copies buffer SRC, of SRC_SIZE bytes, to DST, of DST_SIZE bytes.
+   DST is rounded up to the nearest 8 byte boundary.
+   A space is inserted at each 256th byte.
+   DST is then truncated to DST_SIZE bytes or padded on the right with
+   spaces as needed. */
+void
+copy_mangle (char *dst, size_t dst_size,
+           const char *src, size_t src_size)
+{
+  int src_bytes_left = src_size;
+  int dst_bytes_left = dst_size;
+  const char *s = src;
+  char *d = dst;
+
+  memset(dst, ' ', dst_size);
+
+  while( src_bytes_left > 0 ) 
+    {
+      const size_t s_chunk = min(MAX_LONG_STRING, src_bytes_left);
+      const size_t d_chunk = min(MAX_LONG_STRING, dst_bytes_left);
+
+      buf_copy_rpad (d, d_chunk, s, s_chunk);
+
+      d += d_chunk;
+      s += s_chunk;
+      src_bytes_left -= s_chunk;
+      dst_bytes_left -= d_chunk;
+
+      if ( dst_bytes_left > 0 && 0 == ( d + 1 - dst ) % (MAX_LONG_STRING + 1) )
+       {
+         memset(d, ' ', 1);
+         d++;
+         dst_bytes_left--;
+       }
+    }
+}
+
+/* Return the number of bytes used when writing case_data for a variable 
+   of WIDTH */
+int
+width_to_bytes(int width)
+{
+  int bytes, mod8;
+
+  assert (width >= 0);
+
+  if ( width == 0 ) 
+    return MAX_SHORT_STRING ;
+
+  if ( width <= MAX_LONG_STRING) 
+    return MAX_SHORT_STRING * DIV_RND_UP(width, MAX_SHORT_STRING);
+
+  const int chunks = width / EFFECTIVE_LONG_STRING_LENGTH ;
+
+  const int remainder = width - (chunks * EFFECTIVE_LONG_STRING_LENGTH) ;
+
+  bytes =  remainder + (chunks * (MAX_LONG_STRING + 1) );
+
+  /* Round up to the nearest 8 */
+  mod8 = bytes % MAX_SHORT_STRING;
+
+  if ( mod8 ) 
+    bytes += MAX_SHORT_STRING - mod8;
+
+  assert( bytes % MAX_SHORT_STRING == 0 );
+
+  return bytes;
+}
+