[jboss-jira] [JBoss JIRA] (JGRP-2218) New buffers

[Bela Ban (JIRA)]

     [ https://issues.jboss.org/browse/JGRP-2218?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Bela Ban updated JGRP-2218:
---------------------------
    Description: 
h3. Goal
Change payload in {{Message}} from byte[] arrays to a {{Buffer}} interface which can have multiple implementations.

h3. Motivation
Currently, having to pass a byte[] array to a message leads to unnecessary copying:
* When an application has a ref to an NIO (direct) {{ByteBuffer}}, the bytes in the byte buffer have to be copied into a byte[] array and then set in the message
* When the application sends around byte[] arrays, but also wants to add some additional metadata, e.g. type (1000-byte requests/responses), it needs to create a new byte[] array of (say) 1001 bytes and copy the data (1000 bytes) plus the request type (1 byte) into the new copy. Example: {{MPerf}} and {{UPerf}}

h3. Design
Instead of copying, the application creates an instance of {{Buffer}} and sets the buffer in {{Message}}. The {{Buffer}} is then passed all the way down into the transport where it is marshalled and sent. There can be a number of buffer implementations, e.g.
* {{ArrayBuffer}}: wraps a byte[] array with an offset and length
* {{NioDirectBuffer}}: wraps an NIO direct {{ByteBuffer}}
* {{NioHeapBuffer}}: wraps an NIO heap-based {{ByteBuffer}}
* {{CompositeBuffer}}: wraps multiple Buffers. E.g. type (1 byte) and data (1000 bytes) as described above
* {{IntBuffer}}: a single integer
* {{PartialBuffer}}: a ref to a {{Buffer}}, with an offset and length

The {{Buffer}} interface has methods {{size()}}, {{writeTo(DataOutput)}}, {{readFrom(DataInput)}}, possibly also {{acquire()}} and {{release()}} (for ref-counting).

Each buffer impl has an ID and it should be possible to register new impls. A {{BufferFactory}} maintains a mapping between IDs and impl classes.

When marshalling a {{Buffer}}, the ID is written first, followed by the buffer's {{writeTo()}} method. When reading buffers, the {{BufferFactory}} is used to create instances from IDs.

h4. Fragmentation
When fragmenting a buffer, the fragments are instances of {{PartialBuffer}} which maintains an offset and length over an underlying buffer. When marshalling a {{PartialBuffer}}, only the part between offset and offset+length is written to the output stream.


  was:
h3. Goal
Change payload in {{Message}} from byte[] arrays to a {{Buffer}} interface which can have multiple implementations.

h3. Motivation
Currently, having to pass a byte[] array to a message leads to unnecessary copying:
* When an application has a ref to an NIO (direct) {{ByteBuffer}}, the bytes in the byte buffer have to be copied into a byte[] array and then set in the message
* When the application sends around byte[] arrays, but also wants to add some additional metadata, e.g. type (1000-byte requests/responses), it needs to create a new byte[] array of (say) 1001 bytes and copy the data (1000 bytes) plus the request type (1 byte) into the new copy. Example: {{MPerf}} and {{UPerf}}

h3. Design
Instead of copying, the application creates an instance of {{Buffer}} and sets the buffer in {{Message}}. The {{Buffer}} is then passed all the way down into the transport where it is marshalled and sent. There can be a number of buffer implementations, e.g.
* {{ArrayBuffer}}: wraps a byte[] array with an offset and length
* {{NioDirectBuffer}}: wraps an NIO direct {{ByteBuffer}}
* {{NioHeapBuffer}}: wraps an NIO heap-based {{ByteBuffer}}
* {{CompositeBuffer}}: wraps multiple Buffers. E.g. type (1 byte) and data (1000 bytes) as described above
* {{IntBuffer}}: a single integer
* {{PartialBuffer}}: a ref to a {{Buffer}}, with an offset and length

The {{Buffer}} interface has methods {{size()}}, {{writeTo(DataOutput)}}, {{readFrom(DataInput)}}, possibly also {{acquire()}} and {{release()}} (for ref-counting).

Each buffer impl has an ID and it should be possible to register new impls. A {{BufferFactory}} maintains a mapping between IDs and impl classes.

When marshalling a {{Buffer}}, the ID is written first, followed by the buffer's {{writeTo()}} method. When reading buffers, the {{BufferFactory}} is used to create instances from IDs.





> New buffers
> -----------
>
>                 Key: JGRP-2218
>                 URL: https://issues.jboss.org/browse/JGRP-2218
>             Project: JGroups
>          Issue Type: Feature Request
>            Reporter: Bela Ban
>            Assignee: Bela Ban
>             Fix For: 5.0
>
>
> h3. Goal
> Change payload in {{Message}} from byte[] arrays to a {{Buffer}} interface which can have multiple implementations.
> h3. Motivation
> Currently, having to pass a byte[] array to a message leads to unnecessary copying:
> * When an application has a ref to an NIO (direct) {{ByteBuffer}}, the bytes in the byte buffer have to be copied into a byte[] array and then set in the message
> * When the application sends around byte[] arrays, but also wants to add some additional metadata, e.g. type (1000-byte requests/responses), it needs to create a new byte[] array of (say) 1001 bytes and copy the data (1000 bytes) plus the request type (1 byte) into the new copy. Example: {{MPerf}} and {{UPerf}}
> h3. Design
> Instead of copying, the application creates an instance of {{Buffer}} and sets the buffer in {{Message}}. The {{Buffer}} is then passed all the way down into the transport where it is marshalled and sent. There can be a number of buffer implementations, e.g.
> * {{ArrayBuffer}}: wraps a byte[] array with an offset and length
> * {{NioDirectBuffer}}: wraps an NIO direct {{ByteBuffer}}
> * {{NioHeapBuffer}}: wraps an NIO heap-based {{ByteBuffer}}
> * {{CompositeBuffer}}: wraps multiple Buffers. E.g. type (1 byte) and data (1000 bytes) as described above
> * {{IntBuffer}}: a single integer
> * {{PartialBuffer}}: a ref to a {{Buffer}}, with an offset and length
> The {{Buffer}} interface has methods {{size()}}, {{writeTo(DataOutput)}}, {{readFrom(DataInput)}}, possibly also {{acquire()}} and {{release()}} (for ref-counting).
> Each buffer impl has an ID and it should be possible to register new impls. A {{BufferFactory}} maintains a mapping between IDs and impl classes.
> When marshalling a {{Buffer}}, the ID is written first, followed by the buffer's {{writeTo()}} method. When reading buffers, the {{BufferFactory}} is used to create instances from IDs.
> h4. Fragmentation
> When fragmenting a buffer, the fragments are instances of {{PartialBuffer}} which maintains an offset and length over an underlying buffer. When marshalling a {{PartialBuffer}}, only the part between offset and offset+length is written to the output stream.



--
This message was sent by Atlassian JIRA
(v7.2.3#72005)