Filewatcher

[Immortalin]

Is your feature request related to a problem? Please describe.

Package managers often have a "watch" feature where code is automatically rebuilt and ran when the source is changed.

Something like https://github.com/watchexec/cargo-watch

Describe the solution you'd like

xmake watch command

Describe alternatives you've considered

N/A

Additional context

Each OS has different filewatcher APIs, use inotify on Linux, FSEvents on Mac, and ReadDirectoryChangesW for Windows. (BSD has something called kqueue but I am not sure)

[waruqi]

xmake does not need to provide the xmake watch command, but I will consider providing some api modules related to file watcher. With these api modules and custom tasks, you can easily implement any watch function by yourself, including xmake watch.

like this

task("watch")
     on_run(function (target)
         os.watchdir("src", function()
             -- do some thing
             os.exec("xmake build")
         end)
     end)

$ xmake watch

[OuYangPaste]

I used to implement similar features based on xmake plugin and entr, for private

[waruqi]

I have supported it in #2592 and add new xmake watch plugin command.

xmake watch plugin

Watch project directory and build project

$ xmake watch
watching /private/tmp/test/src/** ..
watching /private/tmp/test/* ..
/private/tmp/test/src/main.cpp modified
[ 25%]: ccache compiling.release src/main.cpp
[ 50%]: linking.release test
[100%]: build ok!

Watch the given directories

$ xmake watch -d src
$ xmake watch -d "src;tests/*"

Watch and run multiple given commands

$ xmake watch -c "xmake; xmake run"

Run an arbitrary command

$ xmake watch -- echo hello xmake!
$ xmake watch -- xmake run --help

Watch and run given lua script file

$ xmake watch -s /tmp/test.lua

Watch and build the given target

$ xmake watch -t targetname

Watch and run targets

$ xmake watch -r
$ xmake watch --run
[100%]: build ok!
hello world!

Watch modules

basic api

import("core.base.fwatcher")

function main(watchdir)
    print("watch %s ..", watchdir)
    fwatcher.add(watchdir)
    while true do
        local ok, event = fwatcher.wait(-1)
        if ok > 0 then
            print(event)
        end
    end
end

callback api

import("core.base.fwatcher")

function main(watchdir)
    print("watch %s ..", watchdir)
    fwatcher.watchdirs(watchdir, function (event)
        local status
        if event.type == fwatcher.ET_CREATE then
            status = "created"
        elseif event.type == fwatcher.ET_MODIFY then
            status = "modified"
        elseif event.type == fwatcher.ET_DELETE then
            status = "deleted"
        end
        print(event.path, status)
    end)
end

specific event callback api

import("core.base.fwatcher")

function main(watchdir)
    print("watch %s ..", watchdir)
    fwatcher.on_modified(watchdir, function (filepath)
        print(filepath, "modified")
    end)
end

import("core.base.fwatcher")

function main(watchdir)
    print("watch %s ..", watchdir)
    fwatcher.on_created(watchdir, function (filepath)
        print(filepath, "created")
    end)
end

import("core.base.fwatcher")

function main(watchdir)
    print("watch %s ..", watchdir)
    fwatcher.on_deleted(watchdir, function (filepath)
        print(filepath, "deleted")
    end)
end

[waruqi]

There are still some bugs in the fsevent based implementation on the mac, I will continue to improve it in the next few days.

[waruqi]

I have fixed all bugs and It is now fully available.