Function

Summary

Asynchronously fills a buffer with bytes read from an async-io-state.

Package

comm

Signature

async-io-state-read-buffer async-io-state buffer callback &key start end timeout error-callback user-info

Arguments

async-io-state

An async-io-state.

buffer

A cl:base-string or an 8-bit cl:simple-array.

callback

A function designator for a function of 3 arguments.

start

A lower bounding index designator for buffer.

end

An upper bounding index designator for buffer.

timeout

nil or a positive real.

error-callback

A function designator for a function of 3 arguments, or nil.

user-info

A Lisp object.

Values

None.

Description

The function async-io-state-read-buffer asynchronously fills the buffer buffer between start and end with bytes read from async-io-state. When buffer is full (between start and end) or the read-timeout of async-io-state has passed, the callback is called like this:

callback async-io-state buffer number-of-bytes-read

If an error occurs during the I/O operation and error-callback is non-nil, then error-callback is called with these same arguments:

error-callback async-io-state buffer number-of-bytes-read

If error-callback is nil, then callback is called, so it should check for errors using async-io-state-read-status.

The default value of start is 0. The default value of end is the length of buffer.

If the operation does not finish within the state's read-timeout period then state's read-status is set to :timeout and callback is called.

If timeout or user-info are supplied then they set read-timeout and user-info in async-io-state for this and subsequent operations.

If another read operation on the state is in progress, an error is signaled.

See also

async-io-state-write-buffer
async-io-state-read-with-checking
The Async-I/O-State API