Collaboration diagram

Description

SFXAnsiString and SFXWideString

In the BREW environment, there are two kinds of character types: the char type that represents single byte character or multi-byte character, and the AECHAR type that represents 2 byte character.

SophiaFramewok defines these two kinds of types as AChar and WChar respectively.

And SophiaFramework provides two kinds of String classes: the SFXAnsiString class for the string of AChar characters and the SFXWideString class for the string of WChar characters.

How to Empty a String

There are two methods to empty a string:

In the former method, its heap is not released. By block allocation support, to allocate new memory is unnecessary when a string is newly created in this heap. Therefore its processing speed is very fast.

In the latter method, its heap is released. Though the released heap is free for other tasks, its processing speed slows down.

Which method to choose depends upon the trade-off between processing speed and memory usage.

SFXWideString str = "The best C++ Programming Environment for BREW";

str = ";
// OR:
str.SetLength(0);

// the heap is not released

SFXWideString str = "The best C++ Programming Environment for BREW";

str.Clear();

// the heap is released

When short strings are frequently processed, the method of calling the SFXWideString::SetLength function is more efficient.

SFXWideString str;

str = "BREW";
...
str.SetLength(0);
...
str = "C++";
...
str.SetLength(0);
...
str = "GUI";
...
str.SetLength(0);
...
str = "XML";
...

Attach Function and Detach Function

The SFXWideString::Attach function delegates the control privilege of the WChar string to the SFXWideString object. Therefore, it is unnecessary to release the memory of the WChar string. The SFXWideString::Detach function has the reverse functionality.

Though the data is copied by using the SFXWideString::Set function and the substitution operator(=), while using the SFXWideString::Attach function and the SFXWideString::Detach function, data will not be copied.

When there is not enough heap for copying a several hundreds KB string, or to avoid the performance deterioration, use these functions.

What is delegation?: In object oriented programming, delegation means that an object have another deputy object behave like itself.

SFXWideString str;
WCharPtr ptr;

// allocate the memory and cast to the WChar string(ptr)
ptr = static_cast<WCharPtr>(MemoryAllocate(10240)); 
...

// delegate the control privilege of WChar string(ptr) to the SFXWideString object(str)
str.Attach(ptr, 10240);
// hereafter, the WChar string(ptr) will be handled as the SFXWideString object(str)

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// after used, the allocated memory will be released automatically

SFXWideString str;
WCharPtr ptr;
SInt32 length;

str = "The best application for BREW.";

...

// delegate the control privilege of SFXWideString object(str) to the WChar string(ptr)
ptr = str.Detach(&length);
// hereafter, the SFXWideString object(str) can be handled as the WChar string(ptr)

...

// after used, it is necessary to release the memory of WChar string(ptr) explicitly 
MemoryFree(ptr);

AttachSFXBuffer Function and DetachSFXBuffer Function

These functions are used to delegate the control privilege between the SFXWideString and SFXBuffer objects.

Related information : Attach Function and Detach Function

Reference

SFXWideString | SFXBuffer

Member

Description

When the SFXWideString class or the SFXWideString class is specified for the constructor of the SFXWideString class, the string is copied.

If the pointer of WChar or WChar is specified, it is interpreted and copied as a null-terminated string.

If the length is specified, binary string contains null can be processed, too.

When WChar is specified, only one character is made.

Reference

SFXWideString::Set | SFXWideString::operator=

Description

The internal string buffer is released.

Return value

Description

The Add function influences the character string. If want to keep the source string, use the Concat() function.

Reference

SFXWideString::Concat | SFXWideString::Sub | SFXWideString::Mul | SFXWideString::operator<< | operator+ | SFXWideString::operator+=

Description

The source string will not be modified by calling the AsLower() function.

Reference

SFXWideString::AsUpper | SFXWideString::ToLower

Description

If unable to convert, a specified value is returned to substitute.

Reference

SFXWideString::AsUInt32

Description

If unable to convert, a specified value is returned to substitute.

Reference

SFXWideString::AsSInt32

Description

The source string will not be modified by calling the AsUpper() function.

Reference

SFXWideString::AsLower | SFXWideString::ToUpper

Return value

Description

The SFXWideString::Attach function is more efficient than the SFXWideString::Set function, since the WChar string is not copied and the problem on insufficient memory or performance deterioration can be avoided.

The memory allocated to the WChar string will be released automatically when the SFXWideString object is released. To release the memory allocated to the WChar string explicitly, it is necessary to call the SFXWideString::Detach function.

Example

SFXWideString str;
WCharPtr ptr;

// allocate the memory and cast to the WChar string(ptr)
ptr = static_cast<WCharPtr>(MemoryAllocate(10240));

...

// delegate the control privilege of WChar string(ptr) to the SFXWideString object(str)
str.Attach(ptr, 10240);
// hereafter, the WChar string(ptr) will be handled as the SFXWideString object(str)

･･･

// after used, the allocated memory will be released automatically

Reference

SFXWideString::Detach

Return value

Description

The SFXWideString::AttachSFXBuffer function is more efficient than the SFXWideString::Set function, since the SFXBuffer object is not copied and the problem on insufficient memory or performance deterioration can be avoided.

The SFXBuffer object instance will be released automatically when the SFXWideString object is released. To release the SFXBuffer object explicitly, it is necessary to call the SFXWideString::DetachSFXBuffer function.

Example

SFXWideString str;
SFXBuffer buffer;

// allocate the memory for the SFXBuffer object(buffer)
buffer.SetSize(10240);

...

// delegate the control privilege of SFXBuffer object(buffer) to the SFXWideString object(str)
str.AttachSFXBuffer(&buffer);
// hereafter, the SFXBuffer object(buffer) will be handled as the SFXWideString object(str)

･･･

// after used, the allocated memory will be released automatically

Reference

SFXWideString::Attach | SFXWideString::Detach | SFXWideString::DetachSFXBuffer

Description

It releases the heap.

Return value

Reference

SFXWideString::Equals | operator== | operator!=

Return value

It returns the concatenated string.

Description

The SFXWideString::Concat function concatenates the end of source string with a specified string. The source string will not be modified.

Reference

SFXWideString::Add | operator+ | SFXWideString::operator+=

Return value

Description

If the string after overwriting exceeds the end of source string, the source string is restored and return SFERR_INVALID_PARAM.

Return value

Return a WChar string which the SFXWideString object has.

Description

The SFXWideString::Detach function is more efficient than the SFXWideString::GetChar function, since the SFXWideString object is not copied and the problem on insufficient memory or performance deterioration can be avoided.

Example

SFXWideString str;
WCharPtr ptr;
SInt32 length;

str = "The best application for BREW.";

...

// delegate the control privilege of SFXWideString object(str) to the WChar string(ptr)
ptr = str.Detach(&length);
// hereafter, the SFXWideString object will be handled as the WChar string(ptr)

...

// after used, it is necessary to release the memory of WChar string(ptr)
MemoryFree(ptr);

Reference

SFXWideString::Attach

Return value

Description

The SFXWideString object is not copied and the problem on insufficient memory or performance deterioration can be avoided.

Example

SFXWideString str;
SFXBuffer buffer;

str = "The best application for BREW.";

...

// delegate the control privilege of SFXWideString object(str) to the SFXBuffer object(buffer)
str.DetachSFXBuffer(&buffer);  
// hereafter, the SFXWideString object will be handled as the SFXBuffer object(buffer)

･･･

// after used, the SFXBuffer object(buffer) will be released automatically

Reference

SFXWideString::Attach | SFXWideString::AttachSFXBuffer | SFXWideString::Detach

Description

Return the reference to the instance of enpty string as the return value of function.

Return value

Reference

SFXWideString::StartsWith

Return value

Reference

SFXWideString::Compare | operator== | operator!=

Return value

Description

To search from other than the beginning, specify the starting index to match with. (The origin index is 0.)

Reference

SFXWideString::LastIndexOf

Description

The SFXWideString::Format function is almost the same as the printf function in C language, the format on float is not available.

Example

SIntN year = 2003;
SIntN month = 8;
SFXWideString str = SFXWideString::Format("%d Year %d Month ", year, month);

Reference

BREW API VSNPRINTF

Description