- Gregg Allman
MemoryStream
MemoryStream Methods
| MemoryStream() | Constructor for the MemoryStream class |
| Size() | Returns the current size of the binary memory buffer |
| BytesAvailable() | Virtual method to return the number of bytes available to read before end of buffer |
| Pos() | Virtual method to return the current position within the memory buffer |
| SetPos() | Virtual method to set the current position within the memory buffer |
| DirectAccess() | Virtual method to return true since Direct Access I/O is available for memory buffers |
| EndOfStream() | Virtual method to return true if currently at end of stream |
| Clear() | Clears some or all of current contents of (writable) memory buffer and sets position to end of stream |
| Encrypt() | Encrypts the memory buffer with optional user keys |
| Decrypt() | Decrypts the (previously encrypted) memory buffer with optional user keys |
| Read() | Virtual method to read a single 8 byte integer from the memory buffer |
| Read() | Virtual method to read a single "small" integer from the memory buffer (1, 2 or 4 bytes) |
| Read() | Virtual method to read a single float from the memory buffer (4 or 8 bytes) |
| Read() | Virtual method to read a text string from the memory buffer (default length or specific length) |
| Read() | Virtual method to read a boolean from the memory buffer |
| Read() | Virtual method to read a binary buffer (stream) from the memory buffer |
| Write() | Virtual method to write a single 8 byte integer to the memory buffer |
| Write() | Virtual method to write a single "small" integer to the memory buffer (1, 2 or 4 bytes) |
| Write() | Virtual method to write a single float to the memory buffer (4 or 8 bytes) |
| Write() | Virtual method to write a single text string (default or specific length) to the memory buffer |
| Write() | Virtual method to write a single boolean to the memory buffer |
| Write() | Virtual method to write a binary buffer (stream) to the memory buffer |
Derived Classes
None
See Also
Class Hierarchy, FileStream, SocketStream, FilterStream, StreamException
public method MemoryStream(int IOMode = StreamIO.ReadWriteMode, int BufferSize = 32767)
Parameters
IOMode
Indicates type of I/O which is valid (Write or ReadWrite)
BufferSize
Initial size of the INTERNAL memory buffer
Return Value
None
Description
Constructor for the MemoryStream class. The I/O mode (WriteMode or ReadWriteMode) is specified along with the initial INTERNAL size of the memory buffer. This buffer size can increase as needed when data is written to it. Note that the internal memory buffer size is NOT typically the same as the value returned by the Size() method or BytesAvailable() method. These methods apply to the actual data which has been written into the memory buffer, not the maximum internal size of the buffer which contains the data written into this stream. The MemoryStream object comes out of this constructor with an empty buffer, thus a "Size()" of zero and "BytesAvailable()" of zero.
The default I/O mode for memory buffers is ReadWriteMode.
MemoryStream Class
public virtual method<int> Size()
Parameters
None
Return Value
Number of bytes in memory buffer
Description
Returns the total number of bytes currentlly in the memory buffer, accounting for all stream I/O already performed into the buffer..
MemoryStream 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 memory buffer. It is based on the current pointer position and the total size of the buffer.
MemoryStream 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 memory buffer (one based). The next read or write operation takes place at this position.
MemoryStream 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 memory buffer (one based). The next read or write operation will take place at this position.
MemoryStream 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 memory buffers.
MemoryStream 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 memory buffer to read, this method returns true and false if there are one or more bytes available to read.
MemoryStream Class
public method Clear(int Position = 1)
Parameters
Position
One based starting position for clear operation
Return Value
None
Description
Method to clear the contents of the memory buffer and reset the current position to the end of the remaining buffer. If position is one (default), it clears the entire contents of the buffer. If the stream is specified as "Read", this method will fire a StreamException.
MemoryStream Class
public method Encrypt(int ApplicationKey = 0)
Parameters
ApplicationKey
Key that the caller of the method can pass in to further protect the contents (default of 0)
Return Value
None
Description
This instance method performs an internal encryption process on the memory buffer. It encrypts from the current buffer position to the end of the buffer. Therefore, it is important that the caller set the correct position within the memory buffer before it is encrypted and then subsequently when it is decrypted.
Encryption is performed by an internal algorithm that is not RSA compatible, and Aztec Development Group does not guarantee its effectiveness. It is not intended for use with highly secret encryption requirements such as might be needed for military or government applications. This method is simply intended for situations where it is useful or necessary to prevent those who could potentially see the data from quickly knowing its contents. It would likely take an encryption expert a reasonable amount of time to break the code generated by the multi-level internal algorithm, and it would be mostly unbreakable by someone who is not an expert.
In addition to the internal default encryption which is performed, the user can optionally pass in an application key. The method performs further processing on the memory buffer given the application key, and it helps to protect the contents of the buffer further. The encrypted buffer cannot be successfully decrypted unless that same key is used.
MemoryStream Class
public method Decrypt(int ApplicationKey = 0)
Parameters
ApplicationKey
Key that the caller of the method can pass in to decrypt the string (default of 0)
Return Value
None
Description
This instance method performs an internal decryption process on the memory buffer (that has presumably already been encrypted using the same key that was passed in). It decrypts from the current buffer position to the end of the buffer. Therefore, it is important that the caller set the correct position within the memory buffer before it is decrypted to match the same buffer position as when it was encrypted. It is also important that the same application key be used for decryption that was used for the original encryption process of this buffer.
Encryption is performed by an internal algorithm that is not RSA compatible, and Aztec Development Group does not guarantee its effectiveness. It is not intended for use with highly secret encryption requirements such as might be needed for military or government applications. This method is simply intended for situations where it is useful or necessary to prevent those who could potentially see the data from quickly knowing its contents. It would likely take an encryption expert a reasonable amount of time to break the code generated by the multi-level internal algorithm, and it would be mostly unbreakable by someone who is not an expert.
In addition to the internal default encryption which is performed, the user can optionally pass in an application key. The method performs further processing on the memory buffer given the application key, and it helps to protect the contents of the buffer further. The encrypted buffer cannot be successfully decrypted unless that same key is used.
MemoryStream 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 memory stream and copy the value into the IntBucket.
If the stream is specified as "WriteMode", this method will fire a StreamException.
MemoryStream 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 memory stream 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.
MemoryStream 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 memory buffer 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 buffer 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.
MemoryStream 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 memory buffer 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 buffer (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 buffer 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.
MemoryStream 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 memory buffer 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 buffer 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.
MemoryStream 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 memory buffer 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 buffer 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.
MemoryStream 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 memory stream.
If the stream is specified as "ReadMode", this method will fire a StreamException.
MemoryStream 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 memory stream. 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.
MemoryStream 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 memory buffer. 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.
MemoryStream 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 memory buffer. If the "EmbedLength" flag is true, the length of the string is embedded in the buffer before the text string itself (as a 4 byte integer). By default, the entire string is written to the buffer, 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.
MemoryStream 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 memory buffer. It is written as a one byte integer value repesenting the enumeration index.
If the stream is specified as "ReadMode", this method will fire a StreamException.
MemoryStream 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 memory buffer. 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 buffer (at current buffer 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.
MemoryStream Class