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Hilbish/job.go

501 lines
10 KiB

package main
import (
"bytes"
"errors"
"fmt"
"io"
"os"
"os/exec"
"sync"
"syscall"
"hilbish/util"
rt "github.com/arnodel/golua/runtime"
)
var jobs *jobHandler
var jobMetaKey = rt.StringValue("hshjob")
// #interface jobs
// #property cmd The user entered command string for the job.
// #property running Whether the job is running or not.
// #property id The ID of the job in the job table
// #property pid The Process ID
// #property exitCode The last exit code of the job.
// #property stdout The standard output of the job. This just means the normal logs of the process.
// #property stderr The standard error stream of the process. This (usually) includes error messages of the job.
// The Job type describes a Hilbish job.
type job struct {
cmd string
running bool
id int
pid int
exitCode int
once bool
args []string
// save path for a few reasons, one being security (lmao) while the other
// would just be so itll be the same binary command always (path changes)
path string
handle *exec.Cmd
cmdout io.Writer
cmderr io.Writer
stdout *bytes.Buffer
stderr *bytes.Buffer
ud *rt.UserData
}
func (j *job) start() error {
if j.handle == nil || j.once {
// cmd cant be reused so make a new one
cmd := exec.Cmd{
Path: j.path,
Args: j.args,
}
j.setHandle(&cmd)
}
// bgProcAttr is defined in execfile_<os>.go, it holds a procattr struct
// in a simple explanation, it makes signals from hilbish (sigint)
// not go to it (child process)
j.handle.SysProcAttr = bgProcAttr
// reset output buffers
j.stdout.Reset()
j.stderr.Reset()
// make cmd write to both standard output and output buffers for lua access
j.handle.Stdout = io.MultiWriter(j.cmdout, j.stdout)
j.handle.Stderr = io.MultiWriter(j.cmderr, j.stderr)
if !j.once {
j.once = true
}
err := j.handle.Start()
proc := j.getProc()
j.pid = proc.Pid
j.running = true
hooks.Emit("job.start", rt.UserDataValue(j.ud))
return err
}
func (j *job) stop() {
// finish will be called in exec handle
proc := j.getProc()
if proc != nil {
proc.Kill()
}
}
func (j *job) finish() {
j.running = false
hooks.Emit("job.done", rt.UserDataValue(j.ud))
}
func (j *job) wait() {
j.handle.Wait()
}
func (j *job) setHandle(handle *exec.Cmd) {
j.handle = handle
j.args = handle.Args
j.path = handle.Path
if handle.Stdout != nil {
j.cmdout = handle.Stdout
}
if handle.Stderr != nil {
j.cmderr = handle.Stderr
}
}
func (j *job) getProc() *os.Process {
handle := j.handle
if handle != nil {
return handle.Process
}
return nil
}
// #interface jobs
// #member
// start()
// Starts running the job.
func luaStartJob(t *rt.Thread, c *rt.GoCont) (rt.Cont, error) {
if err := c.Check1Arg(); err != nil {
return nil, err
}
j, err := jobArg(c, 0)
if err != nil {
return nil, err
}
if !j.running {
err := j.start()
exit := handleExecErr(err)
j.exitCode = int(exit)
j.finish()
}
return c.Next(), nil
}
// #interface jobs
// #member
// stop()
// Stops the job from running.
func luaStopJob(t *rt.Thread, c *rt.GoCont) (rt.Cont, error) {
if err := c.Check1Arg(); err != nil {
return nil, err
}
j, err := jobArg(c, 0)
if err != nil {
return nil, err
}
if j.running {
j.stop()
j.finish()
}
return c.Next(), nil
}
// #interface jobs
// #member
// foreground()
// Puts a job in the foreground. This will cause it to run like it was
// executed normally and wait for it to complete.
func luaForegroundJob(t *rt.Thread, c *rt.GoCont) (rt.Cont, error) {
if err := c.Check1Arg(); err != nil {
return nil, err
}
j, err := jobArg(c, 0)
if err != nil {
return nil, err
}
if !j.running {
return nil, errors.New("job not running")
}
// lua code can run in other threads and goroutines, so this exists
jobs.foreground = true
// this is kinda funny
// background continues the process incase it got suspended
err = j.background()
if err != nil {
return nil, err
}
err = j.foreground()
if err != nil {
return nil, err
}
jobs.foreground = false
return c.Next(), nil
}
// #interface jobs
// #member
// background()
// Puts a job in the background. This acts the same as initially running a job.
func luaBackgroundJob(t *rt.Thread, c *rt.GoCont) (rt.Cont, error) {
if err := c.Check1Arg(); err != nil {
return nil, err
}
j, err := jobArg(c, 0)
if err != nil {
return nil, err
}
if !j.running {
return nil, errors.New("job not running")
}
err = j.background()
if err != nil {
return nil, err
}
return c.Next(), nil
}
type jobHandler struct {
jobs map[int]*job
latestID int
foreground bool // if job currently in the foreground
mu *sync.RWMutex
}
func newJobHandler() *jobHandler {
return &jobHandler{
jobs: make(map[int]*job),
latestID: 0,
mu: &sync.RWMutex{},
}
}
func (j *jobHandler) add(cmd string, args []string, path string) *job {
j.mu.Lock()
defer j.mu.Unlock()
j.latestID++
jb := &job{
cmd: cmd,
running: false,
id: j.latestID,
args: args,
path: path,
cmdout: os.Stdout,
cmderr: os.Stderr,
stdout: &bytes.Buffer{},
stderr: &bytes.Buffer{},
}
jb.ud = jobUserData(jb)
j.jobs[j.latestID] = jb
hooks.Emit("job.add", rt.UserDataValue(jb.ud))
return jb
}
func (j *jobHandler) getLatest() *job {
j.mu.RLock()
defer j.mu.RUnlock()
return j.jobs[j.latestID]
}
func (j *jobHandler) disown(id int) error {
j.mu.RLock()
if j.jobs[id] == nil {
return errors.New("job doesnt exist")
}
j.mu.RUnlock()
j.mu.Lock()
delete(j.jobs, id)
j.mu.Unlock()
return nil
}
func (j *jobHandler) stopAll() {
j.mu.RLock()
defer j.mu.RUnlock()
for _, jb := range j.jobs {
// on exit, unix shell should send sighup to all jobs
if jb.running {
proc := jb.getProc()
proc.Signal(syscall.SIGHUP)
jb.wait() // waits for program to exit due to sighup
}
}
}
// #interface jobs
// background job management
/*
Manage interactive jobs in Hilbish via Lua.
Jobs are the name of background tasks/commands. A job can be started via
interactive usage or with the functions defined below for use in external runners. */
func (j *jobHandler) loader(rtm *rt.Runtime) *rt.Table {
jobMethods := rt.NewTable()
jFuncs := map[string]util.LuaExport{
"stop": {luaStopJob, 1, false},
"start": {luaStartJob, 1, false},
"foreground": {luaForegroundJob, 1, false},
"background": {luaBackgroundJob, 1, false},
}
util.SetExports(l, jobMethods, jFuncs)
jobMeta := rt.NewTable()
jobIndex := func(t *rt.Thread, c *rt.GoCont) (rt.Cont, error) {
j, _ := jobArg(c, 0)
arg := c.Arg(1)
val := jobMethods.Get(arg)
if val != rt.NilValue {
return c.PushingNext1(t.Runtime, val), nil
}
keyStr, _ := arg.TryString()
switch keyStr {
case "cmd": val = rt.StringValue(j.cmd)
case "running": val = rt.BoolValue(j.running)
case "id": val = rt.IntValue(int64(j.id))
case "pid": val = rt.IntValue(int64(j.pid))
case "exitCode": val = rt.IntValue(int64(j.exitCode))
case "stdout": val = rt.StringValue(string(j.stdout.Bytes()))
case "stderr": val = rt.StringValue(string(j.stderr.Bytes()))
}
return c.PushingNext1(t.Runtime, val), nil
}
jobMeta.Set(rt.StringValue("__index"), rt.FunctionValue(rt.NewGoFunction(jobIndex, "__index", 2, false)))
l.SetRegistry(jobMetaKey, rt.TableValue(jobMeta))
jobFuncs := map[string]util.LuaExport{
"all": {j.luaAllJobs, 0, false},
"last": {j.luaLastJob, 0, false},
"get": {j.luaGetJob, 1, false},
"add": {j.luaAddJob, 3, false},
"disown": {j.luaDisownJob, 1, false},
}
luaJob := rt.NewTable()
util.SetExports(rtm, luaJob, jobFuncs)
return luaJob
}
func jobArg(c *rt.GoCont, arg int) (*job, error) {
j, ok := valueToJob(c.Arg(arg))
if !ok {
return nil, fmt.Errorf("#%d must be a job", arg + 1)
}
return j, nil
}
func valueToJob(val rt.Value) (*job, bool) {
u, ok := val.TryUserData()
if !ok {
return nil, false
}
j, ok := u.Value().(*job)
return j, ok
}
func jobUserData(j *job) *rt.UserData {
jobMeta := l.Registry(jobMetaKey)
return rt.NewUserData(j, jobMeta.AsTable())
}
// #interface jobs
// get(id) -> @Job
// Get a job object via its ID.
// --- @param id number
// --- @returns Job
func (j *jobHandler) luaGetJob(t *rt.Thread, c *rt.GoCont) (rt.Cont, error) {
j.mu.RLock()
defer j.mu.RUnlock()
if err := c.Check1Arg(); err != nil {
return nil, err
}
jobID, err := c.IntArg(0)
if err != nil {
return nil, err
}
job := j.jobs[int(jobID)]
if job == nil {
return c.Next(), nil
}
return c.PushingNext(t.Runtime, rt.UserDataValue(job.ud)), nil
}
// #interface jobs
// add(cmdstr, args, execPath)
// Adds a new job to the job table. Note that this does not immediately run it.
// --- @param cmdstr string
// --- @param args table
// --- @param execPath string
func (j *jobHandler) luaAddJob(t *rt.Thread, c *rt.GoCont) (rt.Cont, error) {
if err := c.CheckNArgs(3); err != nil {
return nil, err
}
cmd, err := c.StringArg(0)
if err != nil {
return nil, err
}
largs, err := c.TableArg(1)
if err != nil {
return nil, err
}
execPath, err := c.StringArg(2)
if err != nil {
return nil, err
}
var args []string
util.ForEach(largs, func(k rt.Value, v rt.Value) {
if v.Type() == rt.StringType {
args = append(args, v.AsString())
}
})
jb := j.add(cmd, args, execPath)
return c.PushingNext1(t.Runtime, rt.UserDataValue(jb.ud)), nil
}
// #interface jobs
// all() -> table<@Job>
// Returns a table of all job objects.
// --- @returns table<Job>
func (j *jobHandler) luaAllJobs(t *rt.Thread, c *rt.GoCont) (rt.Cont, error) {
j.mu.RLock()
defer j.mu.RUnlock()
jobTbl := rt.NewTable()
for id, job := range j.jobs {
jobTbl.Set(rt.IntValue(int64(id)), rt.UserDataValue(job.ud))
}
return c.PushingNext1(t.Runtime, rt.TableValue(jobTbl)), nil
}
// #interface jobs
// disown(id)
// Disowns a job. This deletes it from the job table.
// --- @param id number
func (j *jobHandler) luaDisownJob(t *rt.Thread, c *rt.GoCont) (rt.Cont, error) {
if err := c.Check1Arg(); err != nil {
return nil, err
}
jobID, err := c.IntArg(0)
if err != nil {
return nil, err
}
err = j.disown(int(jobID))
if err != nil {
return nil, err
}
return c.Next(), nil
}
// #interface jobs
// last() -> @Job
// Returns the last added job from the table.
// --- @returns Job
func (j *jobHandler) luaLastJob(t *rt.Thread, c *rt.GoCont) (rt.Cont, error) {
j.mu.RLock()
defer j.mu.RUnlock()
job := j.jobs[j.latestID]
if job == nil { // incase we dont have any jobs yet
return c.Next(), nil
}
return c.PushingNext1(t.Runtime, rt.UserDataValue(job.ud)), nil
}