Server overview

Table of Contents

• About the server
  • Inbound connections
  • Error handling
  • The routing table
  • Logging

About the server

tanzer::server is the central locus of activity where acceptance of inbound connections, handling of errors server-wide, request routing, and logging occurs.

Inbound connections

Inbound connections are serviced by tanzer::server::accept, which creates a new tanzer::session object, binds the connection to the new session, and delegates all I/O events to the socket as appropriate.

Error handling

All I/O events other than those relegated to background operations initiated by [chan copy] go through tanzer::server::respond; as such, any errors that are raised can be logged and actioned upon as appropriate without having to force every request handler or client worry about logging concerns.

The routing table

The default routing table is a flat list of tanzer::router::entry objects that are managed by tanzer::router. When the server accepts a new request, it loops over each entry in the route table, in search of the first route that matches the criteria for servicing the request. For each route, the server interrogates the request object to determine if the route matches the request. In terms of implementation details, this is serviced by ::tanzer::request::matches.

The manner in which ::tanzer::request::matches determines the ability of a route to service a request is as follows, in the following order:

1. The request method must match that of the route.
2. The Host: header must match that of the route.
3. The request URI must match the path glob pattern of the route, including any positional path arguments.

A route must match all these criteria in order to service a request.

Logging

The default logging facility is ::tanzer::logger::default, a simple function which outputs informational log lines to standard output, and any error objects raised to the server.

An alternate logger can be provided which must accept two subcommands: log and err. The log subcommand requires a request object, and a response object. The err subcommand simply accepts any error provided, be it a string, or a servable error produced by the facilities in tanzer::error.