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/* NSC -- new Scala compiler
* Copyright 2005-2006 LAMP/EPFL
* @author Martin Odersky
*/
// $Id$
package scala.tools.nsc
import java.io._
import java.net._
object CompileSocket {
/** The prefix of the port identification file, which is followed by the port number */
private val dirName = "scalac-compile-server-port"
/** The vm-part of the command to start a new scala compile server */
private val vmCommand =
System.getProperty("scala.home") match {
case null => "scala"
case dirname =>
val trial = new File(new File(dirname, "bin"), "scala")
if(trial.canRead)
trial.getPath
else
"scala"
}
/** The class name of the scala compile server */
private val serverClass = "scala.tools.nsc.CompileServer"
/** The temporary directory in which the port identification file is stored */
private val tmpDir = {
val totry = List(
Pair("scala.home", List("var", "scala-devel")),
Pair("user.home", List("tmp")),
Pair("java.io.tmpdir", Nil))
/** Expand a property-extensions pair into a complete File object */
def expand(trial: Pair[String, List[String]]): Option[File] = {
val Pair(topdirProp, extensions) = trial
val topdir = System.getProperty(topdirProp)
if(topdir == null)
return None
val fulldir =
extensions.foldLeft[File](new File(topdir))(
(dir,ext)=>new File(dir, ext))
Some(fulldir)
}
/** Write a test file to a directory to see if it is writable */
def dirWritable(dir: File): Boolean = {
dir.mkdirs
if(!dir.exists)
return false
val f = new File(dir, "caniwrite")
try {
f.createNewFile
if(!f.canWrite)
return false
f.delete
if(f.exists)
return false
} catch {
case _:java.io.IOException =>
f.delete
return false
}
return true
}
val potentials =
for {
val trial <- totry
val expanded = expand(trial)
!expanded.isEmpty
dirWritable(expanded.get)
}
yield expanded.get
if(potentials.isEmpty) {
Console.println("could not find a directory for port files")
exit(1)
} else {
val d = new File(potentials.head, dirName)
d.mkdirs
d
}
}
/** Maximum number of polls for an available port */
private val MaxAttempts = 100
/** Time (in ms) to sleep between two polls */
private val sleepTime = 20
/** The command which starts the compile server, given vm arguments
* @param vmArgs the argument string to be passed to the java or scala command
* the string must be either empty or start with a ' '.
*/
def serverCommand(vmArgs: String): String = vmCommand+vmArgs+" "+serverClass
/** The port identification file */
def portFile(port: int) = new File(tmpDir, port.toString())
/** Poll for a server port number; return -1 if none exists yet */
private def pollPort(): int = {
val hits = tmpDir.listFiles()
if (hits.length == 0) -1
else
try {
for (val i <- 1 until hits.length) hits(i).delete()
Integer.parseInt(hits(0).getName)
} catch {
case ex: Throwable =>
System.err.println(ex)
System.err.println("bad file in temp directory: "+hits(0).getAbsolutePath())
System.err.println("please remove the file and try again")
exit(1)
}
}
/** Get the port number to which a scala compile server is connected;
* If no server is running yet, create one
*/
def getPort(vmArgs: String): int = {
var attempts = 0;
var port = pollPort()
if (port < 0) {
Runtime.getRuntime().exec(serverCommand(vmArgs))
}
while (port < 0 && attempts < MaxAttempts) {
attempts = attempts + 1
Thread.sleep(sleepTime)
port = pollPort()
}
if (port < 0) {
System.err.println("cannot start server with command")
System.err.println(serverCommand(vmArgs))
exit(1)
}
port
}
/** Set the port number to which a scala compile server is connected */
def setPort(port: int): unit =
try {
val f = new PrintWriter(new FileOutputStream(portFile(port)))
f.println(new java.util.Random().nextInt.toString)
f.close()
} catch {
case ex: IOException =>
System.err.println("cannot create file: "+portFile(port).getAbsolutePath()+"; exiting")
throw new Error()
}
/** Delete the port number to which a scala compile server was connected */
def deletePort(port: int): unit = portFile(port).delete()
def getOrCreateSocket(vmArgs: String): Socket = {
val nAttempts = 9;
def getsock(attempts: int): Socket =
if (attempts == 0) {
System.err.println("unable to establish connection to server; exiting");
exit(1)
} else {
val port = getPort(vmArgs)
val hostName = InetAddress.getLocalHost().getHostName()
try {
new Socket(hostName, port)
} catch {
case e: IOException =>
System.err.println(e)
System.err.println("...connection attempt to server at port "+port+" failed; re-trying...")
if (attempts % 2 == 0) portFile(port).delete()
Thread.sleep(100)
val result = getsock(attempts - 1)
if (attempts == nAttempts)
System.err.println("...connection established at port "+port+"...")
result
}
}
getsock(nAttempts)
}
def getSocket(serverAdr: String): Socket = {
val cpos = serverAdr indexOf ':'
if (cpos < 0) {
System.err.println("malformed server address: "+serverAdr+"; exiting")
exit(1)
} else {
val hostName = serverAdr.substring(0, cpos)
val port = try {
Integer.parseInt(serverAdr.substring(cpos+1))
} catch {
case ex: Throwable =>
System.err.println("malformed server address: "+serverAdr+"; exiting")
exit(1)
}
getSocket(hostName, port)
}
}
def getSocket(hostName: String, port: int): Socket =
try {
new Socket(hostName, port)
} catch {
case e: IOException =>
System.err.println(
"unable to establish connection to server "+hostName+":"+port+"; exiting")
exit(1)
}
def getPassword(port: int): String = {
val f = new BufferedReader(new FileReader(portFile(port)))
val result = f.readLine()
f.close()
result
}
}
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