- Andrew Lloyd Webber and Tim Rice
FileStream
FileStream Methods
| FileStream() | Constructor for the FileStream class using a file name |
| FileStream() | Constructor for the FileStream class using a File object |
| File() | Returns reference to the File object it used in constructor |
| FileName() | Returns the file name associated with this file stream |
| Open() | Opens the file for I/O based on the parameters sent to constructor |
| Flush() | Flush the contents of internal buffers to the file |
| Close() | Close the file and flush all internal buffers to the file |
| Size() | Returns the current size of the binary file |
| BytesAvailable() | Virtual method to return the number of bytes available to read before end of file |
| Pos() | Virtual method to return the current position within the file |
| SetPos() | Virtual method to set the current position within the file |
| DirectAccess() | Virtual method to return true since Direct Access I/O is available for files |
| EndOfStream() | Virtual method to return true if currently at end of stream |
| Read() | Virtual method to read a single 8 byte integer from the file |
| Read() | Virtual method to read a single "small" integer from the file (1, 2 or 4 bytes) |
| Read() | Virtual method to read a single float from the file (4 or 8 bytes) |
| Read() | Virtual method to read a text string from the file (default length or specific length) |
| Read() | Virtual method to read a boolean from the file |
| Read() | Virtual method to read a binary buffer (stream) from the file |
| Write() | Virtual method to write a single 8 byte integer to the file |
| Write() | Virtual method to write a single "small" integer to the file (1, 2 or 4 bytes) |
| Write() | Virtual method to write a single float to the file (4 or 8 bytes) |
| Write() | Virtual method to write a single text string (default or specific length) |
| Write() | Virtual method to write a single boolean to the file |
| Write() | Virtual method to write a binary buffer (stream) to the file |
Derived Classes
None
See Also
Class Hierarchy, MemoryStream, SocketStream, FilterStream, StreamException, File
public method FileStream(string FileName, int IOMode = StreamIO.ReadMode, bool truncate = true, bool append = false, int BufferSize = 32767)
Parameters
FileName
File name to be used for I/O operations
IOMode
Indicates mode of I/O which is valid
Truncate
Clears the contents of the file for Write or ReadWrite modes
Append
Append data to file if true
BufferSize
Size of the internal memory buffer
Return Value
None
Description
Constructor for the FileStream class. The I/O mode (ReadMode, WriteMode or ReadWriteMode) is specified along with the file name to be associated with the I/O operations for this file stream. The file should contain a fully qualified path.
The truncate flag, the append flag and the buffer size are used when the file is opened using the Open() method. The file itself is not validated or opened in this constructor.
FileStream Class
public method FileStream(File FileRef, int IOMode = StreamIO.ReadMode, bool truncate = true, bool append = false, int BufferSize = 32767)
Parameters
FileRef
File object specifying file to be used for I/O operations
IOMode
Indicates mode of I/O which is valid
Truncate
Clears the contents of the file for Write or ReadWrite modes
Append
Append data to file if true
BufferSize
Size of the internal memory buffer
Return Value
None
Description
Constructor for the FileStream class. The I/O mode (ReadMode, WriteMode or ReadWriteMode) is specified along with the 'File' object which specifies the file name to be associated with the I/O operations for this file stream.
The truncate flag, the append flag and the buffer size are used when the file is opened using the Open() method. The file itself is not validated or opened in this constructor.
FileStream Class
public method<File> File()
Parameters
None
Return Value
Returns File object associated with file stream or null
Description
Returns the File object which contains the file name associated with this file stream. If the "file name" version of the constructor was used, this method will return null.
FileStream Class
public method<string> FileName()
Parameters
None
Return Value
Returns the file name
Description
Returns the file name associated with this file stream.
FileStream Class
public virtual method<bool> Open(bool FireException = true)
Parameters
FireException
If true, fires exception if error or file not found
Return Value
Returns true if file opened successfully
Description
Thie method opens the file associated with this file stream. If the IOType is 'ReadWrite' or 'Write' and the truncate flag was true in the constructor, the contents of the file are cleared. If the append flag is true, the file pointer is adjusted to the end of the file, otherwise the pointer is set at the beginning of the stream.
If the file is opened successfully, the method returns true. If the file does not exist or there was an access error, the method will fire a StreamException, as long as the FireException flag is true. If it's false, the method simply returns false.
FileStream Class
public virtual method Flush()
Parameters
None
Return Value
None
Description
This method flushes the contents of the internal memory buffers to the file. A StreamException is fired if an error occurs.
FileStream Class
public virtual method Close()
Parameters
None
Return Value
None
Description
This method flushes the contents of the internal memory buffers to the file and then closes the file. A StreamException is fired if an error occurs.
No more stream I/O can be performed on the file once it is closed.
FileStream Class
public virtual method<int> Size()
Parameters
None
Return Value
Number of bytes in file
Description
Returns the total number of bytes currentlly in the file (based on original file size plus adjustments based on all read and write operations performed on the stream).
FileStream Class
public virtual method<int> BytesAvailable()
Parameters
None
Return Value
Number of bytes available to read
Description
Returns the number of bytes available to read from the file. It is based on the current pointer position and the total size of the file.
FileStream Class
public virtual method<int> Pos()
Parameters
None
Return Value
Current read/write pointer position
Description
Virtual method to return the current pointer position within the file (one based). The next read or write operation takes place at this position.
FileStream Class
public virtual method<bool> SetPos(int PointerPosition)
Parameters
PointerPosition
One based position in stream to read/write
Return Value
true if successful
Description
Virtual method to set the current read/write pointer position with the file (one based). The next read or write operation will take place at this position.
FileStream Class
public virtual method<bool> DirectAccess()
Parameters
None
Return Value
Returns true
Description
Virtual method to return the direct access mode, which is always 'true' for files.
FileStream Class
public virtual method<bool> EndOfStream()
Parameters
None
Return Value
Returns true if at end of stream
Description
Virtual method to return the value of the "end of stream" flag. If there are no bytes available in the file to read, this method returns true and false if there are one or more bytes available to read.
FileStream Class
public virtual method Read(int ref IntBucket, bool PeekOnly = false)
Parameters
IntBucket
Integer reference to receive the value
PeekOnly
If true, peek without reading/removing
Return Value
None
Description
Virtual method to read a single binary 8 byte integer value from the file and copy the value into the IntBucket.
If the stream is specified as "WriteMode", this method will fire a StreamException.
FileStream Class
public virtual method Read(int ref IntBucket, SmallInt IntSizeEnum, bool IsSigned = true, bool PeekOnly = false)
Parameters
IntBucket
Integer reference to receive the value
IntSizeEnum
Enumeration to indicate 1, 2 or 4 byte integer
IsSigned
Treat as signed integer If true, and unsigned if false (default is false)
PeekOnly
Peek without reading/removing if true (default is false)
Return Value
None
Description
Virtual method to read a single "small" binary integer value from the file and copy the value into the IntBucket. The size of the integer read operation is specified by IntSizeEnum, and represents 1, 2 or 4 bytes. The "IsSigned" flag is also used to affect how the binary integer buffer is interpreted, signed or unsiged.
If the stream is specified as "WriteMode", this method will fire a StreamException.
FileStream Class
public virtual method Read(float ref FloatBucket, bool Read32BitFloat = false, bool PeekOnly = false)
Parameters
FloatBucket
Float reference to receive the value
Read32BitFloat
Read 32 bit (4 byte) float if true (default is false)
PeekOnly
If true, read without advancing pointer
Return Value
None
Description
Virtual method to read a single binary floating point value from the file and copy the value into the FloatBucket. The default size of the float read operation is 8 bytes, but can be changed to 4 bytes by setting the "Read32BitFloat" flag. If the "PeekOnly" flag is true, the value is read but the file pointer position is not advanced, so the next read operation will read the same data.
If the stream is specified as "WriteMode", this method will fire a StreamException.
FileStream Class
public virtual method Read(string ref StringBucket, bool ExtractLength = true, int ReadSize = 0, bool PeekOnly = false)
Parameters
StringBucket
String reference to receive the value
ExtractLength
Read the string length from the stream if true
ReadSize
Size of the read operation if ExtractLength is false
PeekOnly
If true, read without advancing pointer
Return Value
None
Description
Virtual method to read a single string from the file and copy the value into the StringBucket. This supports reading a variable length string, and there are two ways of handling this. If the "ExtractLength" flag is true, the size of the string is actually read from the file (as a 4 byte integer) and then the string read operation is dictacted by that size. If the "ExtractLength" flag is false, the "ReadSize" value is then used to dictate the length of the string to be read.
If the "PeekOnly" flag is true, the value is read but the file pointer position is not advanced, so the next read operation will read the same data.
If the stream is specified as "WriteMode", this method will fire a StreamException.
FileStream Class
public virtual method Read(bool ref BoolBucket, bool PeekOnly = false)
Parameters
BoolBucket
Boolean reference to receive the value
PeekOnly
If true, read without advancing pointer
Return Value
None
Description
Virtual method to read a single binary boolean value from the file and copy the value into the BoolBucket. It is read as a one byte value. If the "PeekOnly" flag is true, the value is read but the file pointer position is not advanced, so the next read operation will read the same data.
If the stream is specified as "WriteMode", this method will fire a StreamException.
FileStream Class
public virtual method Read(StreamIO StreamBucket, int ReadSize = 0, bool PeekOnly = false)
Parameters
StreamBucket
Stream reference to receive the data
ReadSize
Size of the binary read operation
PeekOnly
If true, read without advancing pointer
Return Value
None
Description
Virtual method to read a binary block of data from the file and write it into the target stream (StreamBucket). The size of the read operation is specified. If the target stream supports "random access", the data is written at the current pointer position within that target stream. If the "PeekOnly" flag is true, the value is read but the file pointer position is not advanced, so the next read operation will read the same data.
If the ReadSize is specified as zero, the read operation goes all the way to the end of this stream.
If the stream is specified as "WriteMode", this method will fire a StreamException.
FileStream Class
public virtual method Write(int Value)
Parameters
Value
Integer value to be written
Return Value
None
Description
Virtual method to write a single 8 byte binary integer value to the file.
If the stream is specified as "ReadMode", this method will fire a StreamException.
FileStream Class
public virtual method Write(int Value, SmallInt IntSizeEnum)
Parameters
Value
Integer value to be written
IntSizeEnum
Enumeration to indicate 1, 2 or 4 byte integer
Return Value
None
Description
Virtual method to write a single "small" binary integer value to the file. The size of the integer write operation is specified by IntSizeEnum, and represents 1, 2 or 4 bytes. The integer value must fit within one of the two valid ranges for the integer size that was specified. For each integer size, there is a valid "signed" range and a separate value "unsigned" range. Refer to the 'int' class documention for more details.
If the stream is specified as "ReadMode", this method will fire a StreamException.
FileStream Class
public virtual method Write(float Value, bool Write32BitFloat = false)
Parameters
Value
Float value to be written
Write32BitFloat
Write 32 bit (4 byte) float if true (default is false)
Return Value
None
Description
Virtual method to write a single binary floating point value to the file. The default size of the float write operation is 8 bytes, but can be changed to 4 bytes by setting the "Write32BitFloat" flag. If the "Write32BitFlag" is set, the floating point value must fit within the valid range for a 4 byte float. Refer to the 'float' class documention for more details.
If the stream is specified as "ReadMode", this method will fire a StreamException.
FileStream Class
public virtual method Write(string Value, bool EmbedLength = true, int OverrideLength = 0)
Parameters
Value
String value to be written to stream
EmbedLength
If true, embed string length into stream before the string
OverrideLength
Override length for string to be written
Return Value
None
Description
Virtual method to write a single string to the file. If the "EmbedLength" flag is true, the length of the string is embedded in the file before the text string itself (as a 4 byte integer). By default, the entire string is written to the file, but if "OverrideLength" is greater than zero, then the override length will be used instead.
If the stream is specified as "ReadMode", this method will fire a StreamException.
FileStream Class
public virtual method Write(bool Value)
Parameters
Value
Boolean value to be written
Return Value
None
Description
Virtual method to write a single binary boolean value to the file. It is written as a one byte value.
If the stream is specified as "ReadMode", this method will fire a StreamException.
FileStream Class
public virtual method Write(StreamIO SourceStream, int WriteSize = 0)
Parameters
SourceStream
Source stream reference
WriteSize
Size of the binary write operation
Return Value
None
Description
Virtual method to read a binary block of data from the source stream and write it into this file. The size of the read and write operation is specified by "WriteSize". If the source stream supports "random access", the data is read from the current pointer position within that source stream and then written into this file (at current file pointer position). If the WriteSize is specified as zero, the read operation from the source stream goes all the way to the end of that stream.
If the stream is specified as "ReadMode", this method will fire a StreamException.
FileStream Class