Description

Move and Copy Semantics
In this workshop, you work with a large dynamically allocated array of C++ Standard Library strings and compare the performance of copy and move operations on that collection.
LEARNING OUTCOMES
Upon successful completion of this workshop, you will have demonstrated the abilities
• to retrieve records from a text file using an input file stream object
• to count the number of records in a text file
• to monitor the time spent on a particular task using the std::chrono library
• to implement copy semantics for a class with a resource
• to implement move semantics for a class with a resource
• to identify the processing-intensive operations in copy and move assignments

SUBMISSION POLICY
All your work (all the files you create or modify) must contain your name, Seneca email and student number.
You are responsible to back up your work regularly.
Late Submission Penalties:
• In-lab portion submitted late, with at-home portion: 0 for in-lab. Maximum of 7/10 for the entire workshop.
• If any of in-lab, at-home or reflection portions is missing, the mark for the workshop will be 0/10.
SPECIFICATIONS – IN LAB
This workshop consists of three modules:
• w2 (supplied)
• Timekeeper
• Text
Enclose all your source code within the sict namespace and include the necessary guards in each header file. The output from your executable running Visual Studio with the following command line argument should look like
Command Line : C:Users…Debugw2_in_lab.exe gutenberg_shakespeare 0-arg Constructor – a.size = 0
1-arg Constructor – b.size = 124456
Copy Constructor – c.size = 124456
Copy Assignment – a.size = 124456

Execution Times:
0-arg Constructor 0 seconds 1-arg Constructor 1400 seconds Copy Constructor 171 seconds Copy Assignment 176 seconds Destructor 387 seconds

Timekeeper Module
Design and code a class named Timekeeper that manages a statically allocated array of record objects. Your class predefines the maximum number of record objects at 10. The instance variables for your class include:
a. The number records currently stored
b. The start time for the current event (an std::chrono::steady_clock::time_point object)
c. The end time for the current event (an std::chrono::steady_clock::time_point object)
d. An array of records of anonymous structure (no Tag) type named record where each element contains:
a. The address of a C-style null-terminated string containing a message in a literal string.
b. The address of a C-style null-terminated string containing the predefined units of time
c. The duration of the recorded event (an std::chrono::steady_clock::duration object)
Your class includes the following member functions:
• a default no-argument constructor
• start() a modifier that starts the stopwatch for an event
• stop() a modifier that stops the stopwatch for an event
• recordEvent() a modifier that receives the address of a C-style null terminated string that holds the description of the event – this function copies the address of the description into the next time record, calculates the duration of the event and copies it into the next time record, copies the address of the literal string containing a description of the units of time into the next time records, and increments the instance variable that identifies the next empty time record.
• report() a query that receives a reference to an std::ostream object, inserts the title “Execution Times:” into the object and inserts each of the time records stored in the Timekeeper object. Text Module
Design and code a class named Text that manages a dynamically allocated array of std::strings. Your class keeps track of the number of strings currently stored and defines the following member functions:
• a no-argument default constructor
• a 1-argument constructor that receives the address of a C-style null terminated string containing the name of a file from which this member function populates the current object. This function counts the number of records present in the file, allocates memory for that number of pointers to std::string object and copies the records into the objects. Note that you can determine the number of records by counting the number of newline characters in a file.
• a copy constructor
• a copy assignment operator
• a destructor
• size_t size() const a query that returns the number of records stored in the current object.
To review the syntax for reading from a text file using an std::ifstream object see the chapter in your notes entitled Custom File Operators. See also cplusplus.com
Execution
A text file named gutenberg_shakespeare has been included in the directory containing the Visual Studio project file. Make sure to include this file name as a command line argument.
In-Lab Submission (30%)
To test and demonstrate execution of your program use the same data as shown in the output example above.
Upload your source code to your matrix account. Compile and run your code using the latest version of the gcc compiler and make sure that everything works properly.
Then, run the following command from your account: (replace profname.proflastname with your professor’s Seneca userid)

SPECIFICATIONS – AT HOME
For this part of the workshop, upgrade your w2 module to call the move constructor and the move assignment operator on your Text class. Place your code snippet after the one for copy assignment and before the final call to start Timekeeper t. Upgrade your Text class to include a move constructor and a move assignment operator. Do not modify your Timekeeper module.
The output from your executable running Visual Studio with the following command line argument should look like
Command Line : C:Users…Debugw2_at_home.exe gutenberg_shakespeare 0-arg Constructor – a.size = 0
1-arg Constructor – b.size = 124456
Copy Constructor – c.size = 124456
Copy Assignment – a.size = 124456
Move Constructor – d.size = 124456 Move Assignment – a.size = 124456

Execution Times:
0-arg Constructor 0 seconds 1-arg Constructor 1451 seconds Copy Constructor 170 seconds
Copy Assignment 168 seconds
Move Constructor 0 seconds
Move Assignment 0 seconds Destructor 362 seconds

Reflection
Study your final solution, reread the related parts of the course notes, and make sure that you have understood the concepts covered by this workshop. This should take no less than 30 minutes of your time. Explain in your own words what you have learned in completing this workshop. Include in your explanation but do not limit it to the following points (40%):
• the reason for the difference between the copy and move operations • the dynamic allocation of addresses to objects instead of objects themselves
• the changes you made in upgrading your w2 and Text modules.
To avoid deductions, cite the code in your solution as an example of your implementation of the concepts that you describe.
Include all corrections to the Quiz you have received (30%).

At-Home Submission (70%)
To test and demonstrate execution of your program use the same data as shown in the output example above.
Upload your source code to your matrix account. Compile and run your code using the latest version of the gcc compiler and make sure that everything works properly.
Then, run the following command from your account: (replace profname.proflastname with your professor’s Seneca userid)
~profname.proflastname/submit 345XXX_w2_home<ENTER>