Homework 7 - Computer Architecture I - ShanghaiTech University

Homework 7 - Ring Buffer in C++

Computer Architecture I ShanghaiTech University
HW6 HW7 HW8

Goals

In this assignment, you need to reimplement ring buffer in C++. You need to learn about following topics

• Template
• Iterator
• Function object

Setup

You can download the template here. We provided a header file for you.

Overview

Your task is to implement a ring buffer in C++ using templates. In ringbuffer.hpp, we’ve declared all classes you need. You need to finish the implementation of the class and methods in ringbuffer.hpp. All you implementation should be in a file named ringbuffer.ipp. If you don’t know what is ipp file, here is a brief explanation.

Before templates, you put the declarations of methods in the header file and the implementation went to a .cpp file. These files were compiled separately as their own compilation unit.

With templates, this is no longer possible almost all template methods need to be defined in the header. To separated them at least on a logical level, some people put the declarations in the header but move all implementations of template methods to .ipp files (i for “inline”) and include the .ipp file at the end of the header.

Implementation Details

Please obey the following rules:

• You may NOT use any STL containers like vector.
• We assume type _Tp has default constructor and destructor. And it is both copy constructible and assignable.
• The number of line of comments should be at least 25%. Otherwise you may be unable to pass any testcases. The script used to check this is provided here and you can precheck your code before submission.

Ring buffer

Requirements of implementing the ring buffer is the same as HW2.

• read_pos points to the slot that next read operation should read from and write_pos should point to the slot that next write operation should write to.
• If the buffer is full after one write operation, you should grow the capacity immediately.
• When allocate larger buffer, you should re-arrange the data in correct order. Oldest data in buffer should be put at the first slot, followed by rest elements. (This one is exactly the same as hw2, we just change a way to describe it.)

Other detailed requirements are in ringbuffer.hpp .

Iterator

Finish the implementation of __detail::__iterator<_Tp>. You have to implement the following methods:

• Constructor: __iterator ()

  Default constructor.

• Constructor: __iterator ( const __iterator & other )

  Copy constructor.

• Constructor: __iterator ( _Tp * ptr, RingBuffer<_Tp> * buffer )

  Initialize the iterator with a pointer.

• Destructor: __iterator ()

  Destructor.

You should also overload the following operators:

• =: copy assignment operator.
• *: dereference operator.
• ->: arrow operator.
• ==, !=: comparison operator.
• ++, --: self increment and decrement operator.
• +, -: arithmetic operator.
• +=, -=: compound assignment operator.

You can refer to std::vector<_Tp>::iterator for some detailed implementation.

Const Iterator

It is similar to the iterator except for the dereferenced value should be const type (they cannot be modified). All methods for iterator should also be implemented for const iterator. You should also implement one additional method:

• Constructor: __const_iterator ( const __iterator & other )

  this method convert an iterator into a const iterator. Please notice that the reverse conversion (const iterator to iterator) is not required and you should consider why.

Hints

• You can refer to the GNU C++ Library’s implementation. In GNU/Linux, the header file for std::vector is placed at /usr/include/c++/<GCC version>/.
• Because the compiler will not generate any code if the templates are not used, so it won’t complain about errors exist in methods you do not use. It is strongly suggested that you test all your methods before submission. One easy approach is to specialize your templates and compile it.

Submission

Archive ringbuffer.ipp and create hw7.tar. Submit hw7.tar to Autolab.

Last Modified: Fri May 6 01:06:34 CST 2022