List command is now fully working

Also changes for Ack timeouts and unit testing

src/uas/QGCUASFileManager.h

+/*=====================================================================
+ 
+ QGroundControl Open Source Ground Control Station
+ 
+ (c) 2009 - 2014 QGROUNDCONTROL PROJECT <http://www.qgroundcontrol.org>
+ 
+ This file is part of the QGROUNDCONTROL project
+ 
+ QGROUNDCONTROL is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+ 
+ QGROUNDCONTROL is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ GNU General Public License for more details.
+ 
+ You should have received a copy of the GNU General Public License
+ along with QGROUNDCONTROL. If not, see <http://www.gnu.org/licenses/>.
+ 
+ ======================================================================*/
+
 #ifndef QGCUASFILEMANAGER_H
 #define QGCUASFILEMANAGER_H
 
 #include <QObject>
+
 #include "UASInterface.h"
 
 class QGCUASFileManager : public QObject
@@ -9,17 +33,22 @@ class QGCUASFileManager : public QObject
     Q_OBJECT
 public:
     QGCUASFileManager(QObject* parent, UASInterface* uas);
+    
+    /// These methods are only used for testing purposes.
+    bool _sendCmdTestAck(void) { return _sendOpcodeOnlyCmd(kCmdNone, kCOAck); };
+    bool _sendCmdTestNoAck(void) { return _sendOpcodeOnlyCmd(kCmdTestNoAck, kCOAck); };
+    bool _sendCmdReset(void) { return _sendOpcodeOnlyCmd(kCmdReset, kCOAck); };
 
 signals:
     void statusMessage(const QString& msg);
     void resetStatusMessages();
+    void errorMessage(const QString& ms);
 
 public slots:
     void receiveMessage(LinkInterface* link, mavlink_message_t message);
     void nothingMessage();
     void listRecursively(const QString &from);
     void downloadPath(const QString& from, const QString& to);
-//    void timedOut();
 
 protected:
     struct RequestHeader
@@ -30,23 +59,32 @@ protected:
             uint8_t		size;
             uint32_t	crc32;
             uint32_t	offset;
-            uint8_t		data[];
         };
 
+    struct Request
+    {
+        struct RequestHeader hdr;
+        // The entire Request must fit into the data member of the mavlink_encapsulated_data_t structure. We use as many leftover bytes
+        // after we use up space for the RequestHeader for the data portion of the Request.
+        uint8_t data[sizeof(((mavlink_encapsulated_data_t*)0)->data) - sizeof(RequestHeader)];
+    };
+
     enum Opcode
         {
-            kCmdNone,	// ignored, always acked
+            kCmdNone,       // ignored, always acked
             kCmdTerminate,	// releases sessionID, closes file
-            kCmdReset,	// terminates all sessions
-            kCmdList,	// list files in <path> from <offset>
-            kCmdOpen,	// opens <path> for reading, returns <session>
-            kCmdRead,	// reads <size> bytes from <offset> in <session>
-            kCmdCreate,	// creates <path> for writing, returns <session>
-            kCmdWrite,	// appends <size> bytes at <offset> in <session>
-            kCmdRemove,	// remove file (only if created by server?)
+            kCmdReset,      // terminates all sessions
+            kCmdList,       // list files in <path> from <offset>
+            kCmdOpen,       // opens <path> for reading, returns <session>
+            kCmdRead,       // reads <size> bytes from <offset> in <session>
+            kCmdCreate,     // creates <path> for writing, returns <session>
+            kCmdWrite,      // appends <size> bytes at <offset> in <session>
+            kCmdRemove,     // remove file (only if created by server?)
 
             kRspAck,
-            kRspNak
+            kRspNak,
+            
+            kCmdTestNoAck,  // ignored, ack not sent back, for testing only, should timeout waiting for ack
         };
 
     enum ErrorCode
@@ -61,36 +99,49 @@ protected:
             kErrNotAppend,
             kErrTooBig,
             kErrIO,
-            kErrPerm
+            kErrPerm,
+            kErrUnknownCommand,
+            kErrCrc
         };
 
 
     enum OperationState
         {
             kCOIdle,    // not doing anything
-
+            kCOAck,     // waiting for an Ack
             kCOList,    // waiting for a List response
         };
-
-    OperationState _current_operation;
-    unsigned _retry_counter;
-
-    UASInterface* _mav;
-    quint16 _encdata_seq;
-
-    unsigned _session_id;       // session ID for current session
-    unsigned _list_offset;      // offset for the current List operation
-    QString _list_path;     // path for the current List operation
-
-    void sendTerminate();
-    void sendReset();
+    
+    
+protected slots:
+    void _ackTimeout(void);
+    
+protected:
+    bool _sendOpcodeOnlyCmd(uint8_t opcode, OperationState newOpState);
+    void _setupAckTimeout(void);
+    void _clearAckTimeout(void);
+    void _emitErrorMessage(const QString& msg);
+    void _sendRequest(Request* request);
 
     void sendList();
     void listDecode(const uint8_t *data, unsigned len);
 
-    static quint32 crc32(const uint8_t *src, unsigned len, unsigned state);
+    static quint32 crc32(Request* request, unsigned state = 0);
     static QString errorString(uint8_t errorCode);
 
+    OperationState      _currentOperation;              ///> Current operation of state machine
+    QTimer              _ackTimer;                      ///> Used to signal a timeout waiting for an ack
+    static const int    _ackTimerTimeoutMsecs = 1000;   ///> Timeout in msecs for ack timer
+    
+    UASInterface* _mav;
+    quint16 _encdata_seq;
+
+    unsigned    _listOffset;    // offset for the current List operation
+    QString     _listPath;      // path for the current List operation
+    
+    // We give MockMavlinkFileServer friend access so that it can use the data structures and opcodes
+    // to build a mock mavlink file server for testing.
+    friend class MockMavlinkFileServer;
 };
 
 #endif // QGCUASFILEMANAGER_H