Diff: Value.h

Revision:

0:099f76422485

Child:

11:e1bee9a77652

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Value.h	Thu Jul 03 20:38:04 2014 +0200
@@ -0,0 +1,107 @@
+/*
+ * Value.h
+ *
+ * Created on: Nov 1, 2013
+ * * Authors: Vincent Wochnik <v.wochnik@gmail.com>
+ *
+ * Copyright (c) 2013 Cumulocity GmbH
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+/**
+ * @file Value.h
+ * Represents a generic data value.
+ */
+
+#ifndef VALUE_H
+#define VALUE_H
+
+#include "config.h"
+#include <stddef.h>
+#include <stdint.h>
+#include "AbstractDataSink.h"
+
+/** Return value indicating a null value. */
+#define VALUE_NULL 0
+/** Return value indicating an integer value. */
+#define VALUE_INTEGER 1
+/** Return value indicating a floating-point number. */
+#define VALUE_FLOAT 2
+/** Return value indicating a character string. */
+#define VALUE_CHARACTER 3
+
+/**
+ * A generic value offering means to obtain the value type and contents
+ * as well as writing the value to a sink.
+ */
+class Value
+{
+public:
+    virtual ~Value() { };
+
+    /**
+     * Returns the value type which can be VALUE_NULL, VALUE_INTEGER,
+     * VALUE_FLOAT or VALUE_CHARACTER.
+     * @return the value type
+     */
+    virtual uint8_t valueType() const = 0;
+
+    /**
+     * Returns the integer value if an integer type, otherwise zero.
+     * @return integer value
+     */
+    virtual long integerValue() const = 0;
+
+    /**
+     * Returns the float value if a float type, otherwise zero.
+     * @return float value
+     */
+    virtual double floatValue() const = 0;
+
+    /**
+     * Returns the character value if a character type, otherwise zero.
+     * @return character value
+     */
+    virtual const char * characterValue() const = 0;
+
+    /**
+     * Writes the value to a sink.
+     * If necessary, quotes and escape characters may be added.
+     * @param sink the sink to write the value to
+     * @return the number of bytes written
+     */
+    virtual size_t write(AbstractDataSink&) const = 0;
+
+    /**
+     * Returns the number of bytes required to write this value to a sink.
+     * @return number of bytes required to write this value
+     */
+    virtual size_t length() const = 0;
+
+    /**
+     * Copies this value to the heap. Referenced contents must also be
+     * copied.
+     * @return a new value instance allocated on the heap
+     */
+    virtual Value* copy() const = 0;
+};
+
+#endif