1 files changed, 51 insertions, 0 deletions
diff --git a/vbench/src/vbench/core/byte_input.h b/vbench/src/vbench/core/byte_input.h
new file mode 100644
index 00000000000..34468a2ffeb
--- /dev/null
+++ b/vbench/src/vbench/core/byte_input.h
@@ -0,0 +1,51 @@
+// Copyright 2016 Yahoo Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+
+#pragma once
+
+#include "input.h"
+
+namespace vbench {
+
+/**
+ * Concrete utility class used to read input data one byte at a time
+ * by wrapping a generic Input implementation.
+ **/
+class ByteInput
+{
+private:
+    Input  &_input;
+    Memory  _data;
+    size_t  _pos;
+    size_t  _chunkSize;
+
+public:
+    /**
+     * Wrap an Input to read one byte at a time.
+     *
+     * @param input the underlying Input
+     * @param chunkSize how much data to request from the input per transaction
+     **/
+    ByteInput(Input &input, size_t chunkSize)
+        : _input(input), _data(), _pos(0), _chunkSize(chunkSize) {}
+    ~ByteInput() { _input.evict(_pos); }
+
+    /**
+     * Read the next byte of input.
+     *
+     * @return next byte of input, or -1 if no more input is available
+     **/
+    int get() {
+        if (_pos < _data.size) {
+            return (_data.data[_pos++] & 0xff);
+        } else {
+            _data = _input.evict(_pos).obtain(_chunkSize, 1);
+            if ((_pos = 0) < _data.size) {
+                return (_data.data[_pos++] & 0xff);
+            }
+        }
+        return -1;
+    }
+};
+
+} // namespace vbench
+