initial check in

1 files changed, 46 insertions, 0 deletions

diff --git a/io.cc b/io.cc
new file mode 100644
index 00000000..b30acd22
--- /dev/null
+++ b/io.cc
@@ -0,0 +1,46 @@
+/* 
+Copyright (c) 2007 Yahoo! Inc.  All rights reserved.  The copyrights
+embodied in the content of this file are licensed under the BSD
+(revised) open source license
+ */
+
+#include "io.h"
+
+unsigned int buf_read(io_buf &i, char* &pointer, int n)
+{//return a pointer to the next n bytes.  n must be smaller than 2^24.
+  if (i.space.end + n <= i.space.end_array)
+    {
+      pointer = i.space.end;
+      i.space.end += n;
+      return n;
+    }
+  else if (n > (i.space.end_array - i.space.begin)) // the file is ending or ended.
+    {
+      pointer = i.space.end;
+      int ret = i.space.end_array - i.space.end;
+      i.space.end = i.space.end_array;
+      return ret;
+    }
+  else // Change locations and refill buffer.
+    {
+      int left = i.space.end_array - i.space.end;
+      memmove(i.space.begin, i.space.end, left);
+      i.fill(left);
+      i.space.end = i.space.begin;
+      return buf_read(i,pointer,n);
+    }
+}
+
+void buf_write(io_buf &o, char* &pointer, int n)
+{//return a pointer to the next n bytes to write into.
+  if (o.space.end + n <= o.space.end_array)
+    {
+      pointer = o.space.end;
+      o.space.end += n;
+    }
+  else // Time to dump the file
+    {
+      o.flush();
+      buf_write (o, pointer,n);
+    }
+}