Buffer Class Reference

Very simple buffer with control on overflow. More...

#include <Buffer.hpp>

Public Member Functions
	Buffer (unsigned long int size)
	Constructor. It checks size and allocates memory.
virtual	~Buffer ()
char &	operator[] (unsigned long int p)
	Method to access a specific byte of the buffer.
unsigned long int	fill (const char *src, unsigned long int size)
	Method to fill the buffer.
unsigned long int	fill (Buffer *b, unsigned long int size)
	Method to fill the buffer with the content of another buffer.
bool	compare (Buffer *b, unsigned long int size)
	Method to compare two buffers' content.
bool	compare (const char *s, unsigned long int size)
	Method to compare the content of the buffer against a buffer in memory.
char *	getBuffer ()
	Method to get a pointer to the buffer.
unsigned long int	getSize () const
	Method to get the size of the buffer.
unsigned long int	fill (char *src, unsigned long int size)

Private Member Functions
	Buffer (const Buffer &)

Private Attributes
unsigned long int	size_
	Current size of the buffer.
char *	data_
	Pointer to the allocated memory.

Detailed Description

Very simple buffer with control on overflow.

This is a simple buffer, internally allocated as a char buffer with new and delete. With respect to hand-made buffers, it adds the check on boundaries.

Definition at line 35 of file Buffer.hpp.

Constructor & Destructor Documentation

Buffer ( const Buffer &  )

private

Buffer ( unsigned long int  size )

explicit

Constructor. It checks size and allocates memory.

Parameters

size	size of the buffer

Exceptions

invalid_argument

in case of wrong size

Definition at line 34 of file Buffer.cpp.

                                    : size_(size)
{
        if (size == 0)
                throw std::invalid_argument("Buffer with size 0");
        else
                data_ = new char[size_];
}

~Buffer ( )

virtual

Destructor. It deallocates memory.

Definition at line 46 of file Buffer.cpp.

{
        if (size_ != 0)
                delete[] data_;
}

Member Function Documentation

bool compare	(	Buffer *	b,
		unsigned long int	size
	)

Method to compare two buffers' content.

It compares the content of this buffer with the content of another buffer

Parameters

b	the buffer against whose content it must be compared
size	size of bytes to be compared

Returns

true if the contents match, false otherwise

Exceptions

out_of_range

in case the given size is greater than the size of one of the two buffers

Definition at line 123 of file Buffer.cpp.

{
        if (size > size_ || size > b->getSize())
                throw std::out_of_range("Operation on buffer out of boundary");
        return !std::memcmp(data_, b->getBuffer(), size);
}

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bool compare	(	const char *	s,
		unsigned long int	size
	)

Method to compare the content of the buffer against a buffer in memory.

It compares the content of this buffer with the content at a specified memory address

Parameters

s	pointer to the memory address against whose content it must be compared
size	size of bytes to be compared

Returns

true if the contents match, false otherwise

Exceptions

out_of_range

in case the given size is greater than the buffer buffers

Definition at line 142 of file Buffer.cpp.

{
        if (size > size_)
                throw std::out_of_range("Operation on buffer out of boundary");
        return !memcmp(data_, s, size);
}

unsigned long int fill	(	const char *	src,
		unsigned long int	size
	)

Method to fill the buffer.

It takes the content from a specified address.

Parameters

src	source of the content used to fill the buffer
size	number of bytes to be copied

Returns

number of bytes copied

Exceptions

out_of_range	in case the size is greater than the size of the buffer
invalid_argument	in case the source points to NULL

Definition at line 79 of file Buffer.cpp.

{
        if (size > size_)
                throw std::out_of_range("Operation on buffer out of boundary");
        else if (src == 0)
                throw std::invalid_argument("Attempt to copy from NULL pointer");
        else if (size == 0)
                return 0;
        std::memcpy (data_, src, size);
        return size;
}

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unsigned long int fill	(	Buffer *	b,
		unsigned long int	size
	)

Method to fill the buffer with the content of another buffer.

The number of bytes copied is the minimum between the size of the buffer and the size provided as argument.

Parameters

b	pointer to the buffer whose data must be used to fill this buffer
size	size of bytes to be copied

Returns

number of bytes copied

See Also

Buffer::fill(const char* src, unsigned long int size)

Definition at line 101 of file Buffer.cpp.

{
        unsigned long int min;
        if (size < b->getSize())
                min = size;
        else
                min = b->getSize();
        return fill (b->getBuffer(), min);
}

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unsigned long int fill ( char *  src, unsigned long int  size  )

inline

Definition at line 76 of file Buffer.hpp.

                                                                         {
                return fill (reinterpret_cast<const char*> (src), size);
        }

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char* getBuffer ( )

inline

Method to get a pointer to the buffer.

Returns

position of the first byte

Definition at line 63 of file Buffer.hpp.

                         {
                return reinterpret_cast<char*> (data_);
        }

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unsigned long int getSize ( ) const

inline

Method to get the size of the buffer.

Returns

Size of the buffer

Definition at line 72 of file Buffer.hpp.

                                                 {
                return size_;
        }

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char & operator[]

(

unsigned long int

p

)

Method to access a specific byte of the buffer.

It checks the argument and throws an exception in case of out of range.

Parameters

p	position in the buffer

Returns

the byte at the specified position

Exceptions

out_of_range

in case the position is out of boundary

Definition at line 60 of file Buffer.cpp.

{
        if (p > (size_ - 1))
                throw std::out_of_range("Operation on buffer out of boundary");
        else
                return data_[p];
}

Member Data Documentation

char* data_

private

Pointer to the allocated memory.

Definition at line 44 of file Buffer.hpp.

unsigned long int size_

private

Current size of the buffer.

Definition at line 39 of file Buffer.hpp.

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The documentation for this class was generated from the following files:

• /home/cloud/work/onposix-code/include/Buffer.hpp
• /home/cloud/work/onposix-code/src/Buffer.cpp