Diff: AbstractClient.h

Revision:

0:099f76422485

Child:

1:9a11a331e340

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/AbstractClient.h	Thu Jul 03 20:38:04 2014 +0200
@@ -0,0 +1,122 @@
+/*
+ * AbstractClient.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 AbstractClient.h
+ * An abstraction layer for the SmartREST http client.
+ */
+
+#ifndef ABSTRACTCLIENT_H
+#define ABSTRACTCLIENT_H
+
+#include "config.h"
+#include "DataGenerator.h"
+#include "AbstractDataSource.h"
+#include "AbstractDataSink.h"
+
+/** Return value indicating that the operation has been successful. */
+#define CLIENT_OK 0
+/** Return value indicating that there has been a connection error. */
+#define CLIENT_CONNECTION_ERROR 1
+/** Return value indicating that an internal error occurred. */
+#define CLIENT_INTERNAL_ERROR 2
+
+/*
+ * An abstraction layer for the SmartREST http client.
+ * Constructor arguments such as username and password strings must
+ * not be cpoied but instead stored as pointer as they are subject to
+ * change.
+ * 
+ * All methods have to be called in the following order:
+ * - beginRequest()
+ * - sendIdentifier() (optional)
+ * - sendData() (optional)
+ * - endRequest()
+ * - awaitResponse()
+ * - receiveData() (optional)
+ * - stop()
+ * 
+ * Additionally, stop() can be called at any time to reset the state of
+ * this instance.
+ */
+class AbstractClient
+{
+public:
+    virtual ~AbstractClient() { };
+
+    /**
+     * Begins a new request. This method has to be the first call for
+     * any request. A connection to the server will be established
+     * and the start of a HTTP post request will be sent over the
+     * connection including Host and Authorization headers.
+     */
+    virtual uint8_t beginRequest() = 0;
+
+    /**
+     * Sends the X-Id device identifier header.
+     * @param identifier the identifier to be sent. The value has to remain
+     *                   valid for the entire request.
+     */
+    virtual uint8_t sendIdentifier(const char*) = 0;
+
+    /**
+     * Sends POST data over the connection. Before the data is sent,
+     * a Content-Length header is also sent over the connection. if the
+     * estimated length does not match the actual conten length,
+     * unexpected behavior will occur.
+     * @param generator the data generator for the data to be sent
+     */
+    virtual uint8_t sendData(DataGenerator& generator) = 0;
+
+    /**
+     * Finishes the request. In case no data has been sent over the
+     * connection, this method will send twice carriage-return new-line.
+     */
+    virtual uint8_t endRequest() = 0;
+
+    /**
+     * Blocks until the start of a response has been received.
+     */
+    virtual uint8_t awaitResponse() = 0;
+
+    /**
+     * Returns a data source for reading data.
+     * When no data can be read for whatever reason,
+     * a data source with an error state may be returned.
+     * @return the data source to read from
+     */
+    virtual AbstractDataSource& receiveData() = 0;
+
+    /**
+     * Resets the connection. This method can be called at any time
+     * and resets the state of this instance.
+     */
+    virtual void stop() = 0;
+};
+
+#endif