Labrea api

LaBrea API

In addition to almost anything you can do in lua, you have a few features made available to you via labrea itself:

labrea.usleep

This allows you to pause the execution of the calling thread by the given number of microseconds. This is useful to, for example, slow down a seek operation.

Example:

function before_lseek(...)
    labrea.usleep(500000) -- Sleep half a second
end

labrea.invoke

When writing an around_wrapper, this allows you invoke the original function that was being called.

Example:

function around_read(f, fd, buf, size)
    return labrea.invoke(f, fd, buf, size)
end

labrea.set_errno

Here, you can adjust the errno value so your errors become meaningful.

Example:

function around_write(f, fd, buf, size)
    set_errno(28) -- ENOSPC
    return -1
end

labrea.reinit

Instructs labrea to reinitialize the script mappings for all overridden functions.

You'd use this when your function made changes to the scripting envrionment as a whole, such as loading a new library at runtime that changes all of your bindings.

Example:

function after_listen(...)
    loadfile("/some/path/started_listening.lua")()
    labrea.reinit()
end

labrea.tostring

Converts a pointer to a null terminated string to a lua string.

Only use this when you're sure you're looking at a null terminated string.

Example:

function before_open(path, ...)
    io.stderr:write(string.format("Opening '%s'\n", labrea.tostring(path)))
end