using [java] fanx.interop::Interop
using [java] java.lang::IllegalThreadStateException as JIllegalThreadStateException
using [java] java.lang::Process as JProcess
using [java] java.lang::ProcessBuilder as JProcessBuilder
using [java] java.util::Map$Entry as JEntry
using concurrent::Actor
using concurrent::ActorPool
** Process manages spawning external OS processes.
** Goes one better than the standard 'sys::Process' as this constantly stream keyboard input to the new process.
class Process2 {
private JProcess? jProc
** The 'ActorPool' used to control the in / out / err stream threads.
** Leave as 'null' to create a default 'ActorPool'.
ActorPool? actorPool {
set { checkRun; &actorPool = it }
}
** Command argument list used to launch process.
** The first item is the executable itself, then rest are the parameters.
Str[] command {
set { checkRun; &command = it }
}
** Working directory of process.
File? dir {
set { checkRun; &dir = it }
}
** If true, then stderr is redirected to the output stream configured via the 'out' field, and the 'err'
** field is ignored. The default is true.
Bool mergeErr := true {
set { checkRun; &mergeErr = it }
}
** The output stream used to sink the process stdout.
** Default is to send to `Env.out`. If set to null, then output is silently consumed like /dev/null.
OutStream? out := Env.cur.out {
set { checkRun; &out = it }
}
** The output stream used to sink the process stderr.
** Default is to send to `Env.err`.
** If set to 'null', then output is silently consumed like /dev/null.
** Note this field is ignored if `mergeErr` is set true, in which case stderr goes to the stream configured via 'out'.
OutStream? err := Env.cur.err {
set { checkRun; &err = it }
}
** The input stream used to source the process stdin.
** If 'null', then the new process will block if it attempts to read stdin. Default is null.
InStream? in := null {
set { checkRun; &in = it }
}
** Environment variables to pass to new process as a mutable map of string key/value pairs.
** This map is initialised with the current process environment.
Str:Str env {
set { checkRun; &env = it }
}
@NoDoc
Duration throttle := 20ms // ~ 1 Jiffy
** Construct a Process instanced used to launch an external OS process with the specified command arguments.
** The first item in the 'cmd' list is the executable itself, then rest are the parameters.
new make(Str[] cmd := Str[,], File? dir := null) {
this.command = cmd
this.dir = dir
&env = Str:Str[:]
itr := JProcessBuilder((Str[]) Str#.emptyList).environment.entrySet.iterator
while (itr.hasNext) {
entry := (JEntry) itr.next
&env[entry.getKey] = entry.getValue
}
}
** Spawn this process.
** See `join` to wait until the process has finished and get the exit code.
** Return this.
This run() {
checkRun
builder := JProcessBuilder(command)
envMap := builder.environment
env.each |v, k| {
envMap.put(k, v)
}
if (dir != null)
builder.directory(Interop.toJava(dir))
if (mergeErr)
builder.redirectErrorStream(true)
jProc = builder.start
stdInStream := Interop.toFan(jProc.getOutputStream, 0)
stdOutStream := Interop.toFan(jProc.getInputStream, 0)
stdErrStream := Interop.toFan(jProc.getErrorStream, 0)
&actorPool = actorPool ?: ActorPool() { it.name = "Process: ${command.first}" }
// now launch threads to pipe std in, out, and err
PipeInToOut(actorPool, this, this.in, stdInStream, throttle).pipe
PipeInToOut(actorPool, this, stdOutStream, this.out, throttle).pipe
if (!mergeErr)
PipeInToOut(actorPool, this, stdErrStream, this.err, throttle).pipe
return this
}
** Wait for this process to exit and return the exit code.
** This method may only be called once after 'run'.
Int join() {
if (jProc == null) throw Err("Process not running")
try return jProc.waitFor
finally {
actorPool.stop
&in = null
&out = null
&err = null
jProc = null
}
}
** Kill this process. Returns this.
This kill() {
if (jProc == null) throw Err("Process not running")
try {
jProc.destroy
return this
}
finally {
actorPool.stop
&in = null
&out = null
&err = null
jProc = null
}
}
Bool isAlive() {
// hacky to use exception for flow control, but there
// doesn't seem to be any other way to check state
try {
jProc.exitValue
} catch (Err err) {
if (Interop.toJava(err) is JIllegalThreadStateException)
return true
}
return false
}
private Void checkRun() {
if (jProc != null) throw Err.make("Process already run")
}
private Void checkNotRun() {
if (jProc == null) throw Err.make("Process has not been created")
}
}
const class PipeInToOut {
private const Synchronized thread
private const Unsafe inStreamRef
private const Unsafe outStreamRef
private const Unsafe processRef
private const Duration throttle
new make(ActorPool actorPool, Process2 process, InStream? inStream, OutStream? outStream, Duration throttle) {
this.thread = Synchronized(actorPool)
this.outStreamRef = Unsafe(outStream)
this.inStreamRef = Unsafe(inStream)
this.processRef = Unsafe(process)
this.throttle = throttle
}
This pipe() {
thread.async |->| {
inStream := (InStream? ) inStreamRef .val
outStream := (OutStream?) outStreamRef.val
process := (Process2) processRef.val
if (inStream != null)
while (process.isAlive) {
// read whole characters
while (inStream.avail > 0) {
ch := inStream.readChar
if (ch != null)
outStream?.writeChar(ch)
}
outStream?.flush
// lets not hammer the thread waiting for key inputs!
Actor.sleep(throttle)
}
}
return this
}
}
