#9 TI-1: Add TransactionFactory

- CmdUndo pops last transaction from array (and applies undo actions - tbd)
- TransactionFactory reads contents of undo.data into transaction array
- Transaction array is written back to undo.data

src/CMakeLists.txt

@@ -14,6 +14,7 @@ set (timew_SRCS CLI.cpp        CLI.h
                 Range.cpp      Range.h
                 Rules.cpp      Rules.h
                 Transaction.cpp Transaction.h
+                TransactionsFactory.cpp TransactionsFactory.h
                 UndoAction.cpp UndoAction.h
                 data.cpp
                 dom.cpp

src/Database.cpp

@@ -32,6 +32,7 @@
 #include <sstream>
 #include <iterator>
 #include <iomanip>
+#include <TransactionsFactory.h>
 #include <ctime>
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -236,6 +237,45 @@ void Database::recordIntervalAction (
   recordUndoAction ("interval", before, after);
 }
 
+////////////////////////////////////////////////////////////////////////////////
+Transaction Database::popLastTransaction ()
+{
+  File undo (_location + "/undo.data");
+
+  std::vector <std::string> read_lines;
+  undo.read (read_lines);
+  undo.close ();
+
+  TransactionsFactory transactionsFactory;
+
+  for (auto& line: read_lines)
+  {
+    transactionsFactory.parseLine (line);
+  }
+
+  std::vector <Transaction> transactions = transactionsFactory.get ();
+
+  if (transactions.empty ())
+  {
+    return Transaction {};
+  }
+
+  Transaction last = transactions.back ();
+  transactions.pop_back ();
+
+  File::remove (undo._data);
+  undo.open ();
+
+  for (auto& transaction : transactions)
+  {
+    undo.append (transaction.toString ());
+  }
+
+  undo.close ();
+
+  return last;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 std::string Database::dump () const
 {

src/Database.h

@@ -54,6 +54,8 @@ public:
   void recordConfigAction(const std::string&, const std::string&);
   void recordIntervalAction(const std::string&, const std::string&);
 
+  Transaction popLastTransaction ();
+
   std::string dump () const;
 
 private:

src/Transaction.cpp

@@ -35,6 +35,11 @@ void Transaction::addUndoAction (
    _actions.emplace_back (type, before, after);
 }
 
+std::vector<UndoAction> Transaction::getActions ()
+{
+  return _actions;
+}
+
 std::string Transaction::toString ()
 {
   std::string output = "txn:\n";

src/Transaction.h

@@ -37,6 +37,8 @@ public:
 
   std::string toString();
 
+  std::vector<UndoAction> getActions ();
+
 private:
   std::vector<UndoAction> _actions {};
 };

src/TransactionsFactory.cpp

@@ -0,0 +1,59 @@
+////////////////////////////////////////////////////////////////////////////////
+//
+// Copyright 2018, Thomas Lauf, Paul Beckingham, Federico Hernandez.
+//
+// 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.
+//
+// https://www.opensource.org/licenses/mit-license.php
+//
+////////////////////////////////////////////////////////////////////////////////
+
+#include <vector>
+#include "TransactionsFactory.h"
+#include "Transaction.h"
+
+void TransactionsFactory::parseLine (const std::string& line)
+{
+  if (!line.compare(0, 4, "txn:"))
+  {
+    _transactions.emplace_back ();
+  }
+  else if (!line.compare(0, 7, "  type:"))
+  {
+    _type = line.substr (8, line.size ());
+  }
+  else if (!line.compare(0, 9, "  before:"))
+  {
+    _before = line.substr (10, line.size ());
+  }
+  else if (!line.compare(0, 8, "  after:"))
+  {
+    _after = line.substr (9, line.size ());
+    _transactions.back ().addUndoAction (_type, _before, _after);
+  }
+  else
+  {
+    throw "Cannot handle line '" + line + "'";
+  }
+}
+
+std::vector<Transaction> TransactionsFactory::get ()
+{
+  return _transactions;
+}

src/TransactionsFactory.h

@@ -0,0 +1,49 @@
+////////////////////////////////////////////////////////////////////////////////
+//
+// Copyright 2018, Thomas Lauf, Paul Beckingham, Federico Hernandez.
+//
+// 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.
+//
+// https://www.opensource.org/licenses/mit-license.php
+//
+////////////////////////////////////////////////////////////////////////////////
+
+#ifndef INCLUDED_TRANSACTIONSFACTORY
+#define INCLUDED_TRANSACTIONSFACTORY
+
+#include <string>
+#include <Transaction.h>
+
+class TransactionsFactory
+{
+public:
+  void parseLine(const std::string& line);
+
+  std::vector< Transaction > get();
+
+private:
+  std::string _type;
+  std::string _before;
+  std::string _after;
+
+  std::vector< Transaction > _transactions {};
+};
+
+
+#endif //INCLUDED_TRANSACTIONSFACTORY

src/commands/CmdUndo.cpp

@@ -31,6 +31,23 @@
 ////////////////////////////////////////////////////////////////////////////////
 int CmdUndo (Database& database)
 {
+  Transaction transaction = database.popLastTransaction ();
+
+  std::vector <UndoAction> actions = transaction.getActions ();
+
+  if (actions.empty ())
+  {
+    // No (more) undoing...
+  }
+  else
+  {
+    for (auto& action : actions)
+    {
+      // Select database...
+      // Rollback action...
+    }
+  }
+
   return 0;
 }