pgwire

This library implements PostgreSQL Wire Protocol, and provide essential APIs to write PostgreSQL comptible servers and clients.

This library is a work in progress and in its relatively early stage. There is no guarantee for API stability. I'm constantly introducing break changes during this period. And also sorry for lack of API docs, examples may get you familiar with its usage.

Status

• Message format
• Backend TCP/TLS server on Tokio
• Frontend-Backend interaction over TCP
  • SSL Request and Response
  • Startup
    • No authentication
    • Clear-text password authentication
    • Md5 Password authentication
    • SASL SCRAM authentication
      • SCRAM-SHA-256
      • SCRAM-SHA-256-PLUS
  • Simple Query and Response
  • Extended Query and Response
    • Parse
    • Bind
    • Execute
    • Describe
    • Sync
  • Termination
  • Cancel
  • Error and Notice
  • Copy
• APIs
  • Startup APIs
    • AuthSource API, fetching and hashing passwords
    • Server parameters API, ready but not very good
  • Simple Query API
  • Extended Query API
    • QueryParser API, for transforming prepared statement
    • PortalStore API, for caching statements and portals
  • ResultSet builder/encoder API
  • Query Cancellation API
  • Error and Notice API

Usage

Server/Backend

To use pgwire in your server application, you will need to implement two key components: startup processor* and query processor. For query processing, there are two kinds of queries: simple and extended. In simple mode, the sql command is passed to postgresql server as a string. In extended query mode, a sql command follows parse-bind-describe(optional)-execute lifecycle.

Examples are provided to demo the very basic usage of pgwire on server side:

• examples/sqlite.rs: uses an in-memory sqlite database at its core and serves it with postgresql protocol.
• examples/gluesql.rs: uses an in-memory gluesql at its core and serves it with postgresql protocol.
• examples/server.rs: demos a server that always returns fixed results.
• examples/secure_server.rs: demos a server with ssl support and always returns fixed results.

Client/Frontend

I think in most case you do not need pgwire to build a postgresql client, existing postgresql client like rust-postgres should fit your scenarios. Please rise an issue if there is a scenario.

Projects using pgwire

• GreptimeDB: Cloud-native time-series database
• sqld: A server frontend for libSQL
• risinglight: OLAP database system for educational purpose

License

This library is released under MIT/Apache dual license.