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Class Ecrion.Ultrascale.Stream |
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Class Ecrion.Ultrascale.Stream |
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The Stream class is a generic stream interface. The user must implement this interface in order to supply input to the engine or to get the output.
class Stream
{
public:
virtual size_t read(unsigned char* destination, size_t bytesCountToRead) = 0;
virtual size_t write(const unsigned char* source, size_t bytesCountToWrite) = 0;
virtual size_t length() = 0;
virtual int seek(int offset, int position) = 0;
};
Interface Methods
Name |
Description |
read |
Read from the stream. |
write |
Write to the stream. |
length |
Get the length of the stream. |
seek |
Set the position indicator associated with the stream to a new position. |
Reads from the stream.
virtual size_t read(unsigned char* destination, size_t bytesCountToRead) = 0;
Parameters
destination
Where to store the bytes read.
bytesCountToRead
The number of bytes that should be read.
Return Value
The number of bytes read.
Writes to the stream.
virtual size_t write(const unsigned char* source, size_t bytesCountToWrite) = 0;
Parameters
source
The source for writing
bytesCountToWrite
The number of bytes that should be written.
Return Value
The number of bytes written.
Get the length of the stream.
virtual size_t length() = 0;
Return Value
The length of the stream.
Set the position indicator associated with the stream to a new position defined by adding offset to a reference position specified by position.
virtual int seek(int offset, int position) = 0;
Parameters
offset
The number of bytes to offset from position
position
Origin from where the offset is added. It is specified by one of the following constants defined in <stdio.h>:
SEEK_SET |
Beginning of the stream |
SEEK_CUR |
Current position in the stream |
SEEK_END |
End of the stream |
Return Value
If successful, returns a zero value. Otherwise, returns a nonzero value.
The FileStream Class
A sample FileStream class is included that implements the Stream interface. Its constructor is detailed below:
FileStream(const String filePath, bool write = false, bool create = false, bool append = false);
Parameters
filePath
A string representing the path to the file on the disk
write
Specifies whether the application will read from or write into the file
create
If write is set to true, this specifies whether or not to create the file if it does not exist
append
If write is set to true, this specifies whether to append to the existing file or overwrite all its contents