From 4d16beef1a586211504d4d510ea791bc65682ad3 Mon Sep 17 00:00:00 2001
From: Nicolay Korslund <korslund@gmail.com>
Date: Mon, 4 Jan 2010 12:13:47 +0100
Subject: [PATCH] Added Stream::PureFilter

---
 stream/filters/pure_filter.h | 39 ++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)
 create mode 100644 stream/filters/pure_filter.h

diff --git a/stream/filters/pure_filter.h b/stream/filters/pure_filter.h
new file mode 100644
index 000000000..4ce679d48
--- /dev/null
+++ b/stream/filters/pure_filter.h
@@ -0,0 +1,39 @@
+#ifndef MANGLE_STREAM_FILTER_H
+#define MANGLE_STREAM_FILTER_H
+
+#include "../stream.h"
+
+namespace Mangle {
+namespace Stream {
+
+/** A stream that filters another stream with no changes. Intended as
+    a base class for other filters.
+ */
+class PureFilter : public Stream
+{
+ protected:
+  StreamPtr src;
+
+ public:
+  PureFilter(StreamPtr _src)
+    : src(_src)
+    {
+      isSeekable = src->isSeekable;
+      hasPosition = src->hasPosition;
+      hasSize = src->hasSize;
+      hasPtr = src->hasPtr;
+    }
+
+  size_t read(void *buf, size_t count) { return src->read(buf, count); }
+  void seek(size_t pos) { src->seek(pos); }
+  size_t tell() const { return src->tell(); }
+  size_t size() const { return src->size(); }
+  bool eof() const { return src->eof(); }
+  const void *getPtr() { return src->getPtr(); }
+  const void *getPtr(size_t size) { return src->getPtr(size); }
+  const void *getPtr(size_t pos, size_t size)
+    { return src->getPtr(pos, size); }
+};
+
+}} // namespaces
+#endif