Protocol Buffers » History » Version 2
Nevcairiel, 05/06/2010 02:55 PM
| 1 | 1 | Nevcairiel | h1. Protocol Buffers |
|---|---|---|---|
| 2 | 1 | Nevcairiel | |
| 3 | 1 | Nevcairiel | "Google Protocol Buffers":http://code.google.com/apis/protocolbuffers/ is an open binary serialization format created by Google. |
| 4 | 1 | Nevcairiel | This page describes an attempt to create an alternate language and platform neutral protocol for Quassel using the Protocol Buffers format. |
| 5 | 1 | Nevcairiel | |
| 6 | 2 | Nevcairiel | The initial plan was to use JSON for an alternate protocol, but using Protocol Buffers has some distinct advantages, so this is the successor of that idea. |
| 7 | 2 | Nevcairiel | |
| 8 | 1 | Nevcairiel | h2. Why Protocol Buffers? |
| 9 | 1 | Nevcairiel | |
| 10 | 1 | Nevcairiel | ?? |
| 11 | 1 | Nevcairiel | Protocol buffers are Google's language-neutral, platform-neutral, extensible mechanism for serializing structured data – *think XML, but smaller, faster, and simpler* |
| 12 | 1 | Nevcairiel | ?? |
| 13 | 1 | Nevcairiel | |
| 14 | 1 | Nevcairiel | Protocol buffers are not just a format definition, but also include code generation for many different languages. |
| 15 | 1 | Nevcairiel | |
| 16 | 1 | Nevcairiel | This offers several advantages, one being a absolutely clear defined, self-describing protocol, instead of protocol based on conventions and possibly outdated documentation. |
| 17 | 1 | Nevcairiel | Additionally, protocol buffers are a binary protocol, with highly optimized implementations in several languages. Official support by Google for C++, Java and Python, as well as third party extension for many other popular languages, including PHP, Obj-C, Perl, JS, and many more. |
| 18 | 1 | Nevcairiel | |
| 19 | 1 | Nevcairiel | h2. Protocol definition |
| 20 | 1 | Nevcairiel | |
| 21 | 1 | Nevcairiel | Note: The protocol is still being actively worked on. |
| 22 | 1 | Nevcairiel | The outlined protocol definitions are not final, and just listed here for documentation. |
| 23 | 1 | Nevcairiel | |
| 24 | 1 | Nevcairiel | h3. Message Container |
| 25 | 1 | Nevcairiel | |
| 26 | 1 | Nevcairiel | Every Message has to be wrapped in a container, since we otherwise can't determine the message type. This is done by the "QuasselServerMessage" and "QuasselClientMessage" message types. This design is modeled around the Protocol Buffers "Union Types":http://code.google.com/apis/protocolbuffers/docs/techniques.html#union example. |
| 27 | 1 | Nevcairiel | |
| 28 | 1 | Nevcairiel | QuasselServerMessage are messages the server sends, while QuasselClientMessage are messages the client sends. |
| 29 | 1 | Nevcairiel | |
| 30 | 1 | Nevcairiel | <pre> |
| 31 | 1 | Nevcairiel | message QuasselServerMessage { |
| 32 | 1 | Nevcairiel | enum MessageType { |
| 33 | 1 | Nevcairiel | ERROR = 0, // Generic message for errors |
| 34 | 1 | Nevcairiel | SUCCESS = 1, // Generic message for success |
| 35 | 1 | Nevcairiel | SESSION_STATE = 2, // State of current session, sent after init |
| 36 | 1 | Nevcairiel | ... |
| 37 | 1 | Nevcairiel | } |
| 38 | 1 | Nevcairiel | required MessageType type = 1; |
| 39 | 1 | Nevcairiel | |
| 40 | 1 | Nevcairiel | optional ErrorMessage errorMessage = 100; |
| 41 | 1 | Nevcairiel | optional SuccessMessage successMessage = 101; |
| 42 | 1 | Nevcairiel | optional SessionState sessionState = 102; |
| 43 | 1 | Nevcairiel | ... |
| 44 | 1 | Nevcairiel | } |
| 45 | 1 | Nevcairiel | </pre> |
| 46 | 1 | Nevcairiel | |
| 47 | 1 | Nevcairiel | <pre> |
| 48 | 1 | Nevcairiel | message QuasselClientMessage { |
| 49 | 1 | Nevcairiel | enum MessageType { |
| 50 | 1 | Nevcairiel | REQUEST = 0, // Generic Request message (request init, request login, request backlog, etc..) |
| 51 | 1 | Nevcairiel | ... |
| 52 | 1 | Nevcairiel | } |
| 53 | 1 | Nevcairiel | required MessageType type = 1; |
| 54 | 1 | Nevcairiel | |
| 55 | 1 | Nevcairiel | optional RequestMessage request = 2; |
| 56 | 1 | Nevcairiel | ... |
| 57 | 1 | Nevcairiel | } |
| 58 | 1 | Nevcairiel | </pre> |
| 59 | 1 | Nevcairiel | |
| 60 | 1 | Nevcairiel | Once the protocol is better defined, the full protocol files will be available here. |