feature: Switch to using Bloop Rifle and backport all improvements

Scala CLI uses a fork of Bloop by default and that fork has added a bunch of improvements especially connected to using domain sockets, which should work much nicer in our case. IT also solves the issue of having multiple Bloop servers on one machine, but with different users.

This might sometimes lead to using 2 bloop servers on one machine, which take up memory uneccesarily. To fix that I decided to backport most of the fixes from the fork, add bloop rifle and deprecate launcher.

.github/workflows/ci.yml

@@ -37,7 +37,7 @@ jobs:
       - uses: graalvm/setup-graalvm@v1
         with:
           version: '22.3.0'
-          java-version: '11'
+          java-version: '17'
           github-token: ${{ secrets.GITHUB_TOKEN }}
 
       - name: Tests
@@ -58,7 +58,7 @@ jobs:
       - uses: graalvm/setup-graalvm@v1
         with:
           version: '22.3.0'
-          java-version: '11'
+          java-version: '17'
           github-token: ${{ secrets.GITHUB_TOKEN }}
 
       - name: Tests
@@ -88,7 +88,7 @@ jobs:
       - uses: graalvm/setup-graalvm@v1
         with:
           version: '22.3.0'
-          java-version: '11'
+          java-version: '17'
           github-token: ${{ secrets.GITHUB_TOKEN }}
           components: 'native-image'
 
@@ -104,7 +104,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest, windows-latest, macOS-12]
-        jdk: ["22.3.0", "11"]
+        jdk: ["22.3.0", "17"]
 
     name: Test ${{ matrix.os }} -- ${{ matrix.jdk }}
     env:
@@ -118,15 +118,15 @@ jobs:
 
       - uses: coursier/setup-action@v1
         with:
-          jvm: 'temurin:11.0.18'
-        if: matrix.jdk == '11'
+          jvm: 'temurin:17'
+        if: matrix.jdk == '17'
 
       - uses: coursier/cache-action@v6
 
       - uses: graalvm/setup-graalvm@v1
         with:
           version: ${{ matrix.jdk }}
-          java-version: '11'
+          java-version: '17'
         if: matrix.jdk == '22.3.0'
 
       - uses: actions/setup-node@v4
@@ -146,6 +146,7 @@ jobs:
               "frontend/test:compile; \
               backend/test; \
               docs/compile; \
+              bloopRifle/test; \
               frontend/testOnly bloop.ScalaVersionsSpec; \
               frontend/testOnly -bloop.ScalaVersionsSpec; \
               frontend/runMain bloop.util.CommandsDocGenerator --test; \

bloop-rifle/src/main/scala/bloop/rifle/BloopRifle.scala

@@ -0,0 +1,187 @@
+package bloop.rifle
+
+import bloop.rifle.internal.{Operations, Util}
+
+import java.io.{ByteArrayOutputStream, OutputStream}
+import java.nio.file.Path
+import java.util.concurrent.ScheduledExecutorService
+
+import scala.concurrent.Future
+
+object BloopRifle {
+
+  /**
+   * Checks whether a bloop server is running at this host / port.
+   *
+   * @param host
+   * @param port
+   * @param logger
+   * @return
+   *   Whether a server is running or not.
+   */
+  def check(
+      config: BloopRifleConfig,
+      logger: BloopRifleLogger
+  ): Boolean = {
+    def check() =
+      Operations.check(
+        config.address,
+        logger
+      )
+    check()
+  }
+
+  /**
+   * Starts a new bloop server.
+   *
+   * @param config
+   * @param scheduler
+   * @param logger
+   * @return
+   *   A future, that gets completed when the server is done starting (and can thus be used).
+   */
+  def startServer(
+      config: BloopRifleConfig,
+      scheduler: ScheduledExecutorService,
+      logger: BloopRifleLogger,
+      version: String,
+      bloopJava: String
+  ): Future[Unit] =
+    config.classPath(version) match {
+      case Left(ex) => Future.failed(new Exception("Error getting Bloop class path", ex))
+      case Right((cp, isScalaCliBloop)) =>
+        logger.info("Starting compilation server")
+        logger.debug(
+          s"Starting Bloop $version at ${config.address.render} using JVM $bloopJava"
+        )
+        object IntValue {
+          def unapply(s: String): Option[Int] =
+            // no String.toIntOption in Scala 2.12.x
+            try Some(s.toInt)
+            catch {
+              case _: NumberFormatException => None
+            }
+        }
+        val bloopServerSupportsFileTruncating =
+          isScalaCliBloop && {
+            version.takeWhile(c => c.isDigit || c == '.').split('.') match {
+              case Array(IntValue(maj), IntValue(min), IntValue(patch), _ @_*) =>
+                import scala.math.Ordering.Implicits._
+                Seq(maj, min, patch) >= Seq(1, 4, 20)
+              case _ =>
+                false
+            }
+          }
+        Operations.startServer(
+          config.address,
+          bloopJava,
+          config.javaOpts,
+          cp.map(_.toPath),
+          config.workingDir,
+          scheduler,
+          config.startCheckPeriod,
+          config.startCheckTimeout,
+          logger,
+          bloopServerSupportsFileTruncating = bloopServerSupportsFileTruncating
+        )
+    }
+
+  /**
+   * Opens a BSP connection to a running bloop server.
+   *
+   * Starts a thread to read output from the nailgun connection, and another one to pass input to
+   * it.
+   *
+   * @param logger
+   * @return
+   *   A [[BspConnection]] object, that can be used to close the connection.
+   */
+  def bsp(
+      config: BloopRifleConfig,
+      workingDir: Path,
+      logger: BloopRifleLogger
+  ): BspConnection = {
+
+    val bspSocketOrPort = config.bspSocketOrPort.map(_()).getOrElse {
+      BspConnectionAddress.Tcp("127.0.0.1", Util.randomPort())
+    }
+
+    val inOpt = config.bspStdin
+
+    val out = config.bspStdout.getOrElse(OutputStream.nullOutputStream())
+    val err = config.bspStderr.getOrElse(OutputStream.nullOutputStream())
+
+    Operations.bsp(
+      config.address,
+      bspSocketOrPort,
+      workingDir,
+      inOpt,
+      out,
+      err,
+      logger
+    )
+  }
+
+  def exit(
+      config: BloopRifleConfig,
+      workingDir: Path,
+      logger: BloopRifleLogger
+  ): Int = {
+
+    val out = config.bspStdout.getOrElse(OutputStream.nullOutputStream())
+    val err = config.bspStderr.getOrElse(OutputStream.nullOutputStream())
+
+    Operations.exit(
+      config.address,
+      workingDir,
+      out,
+      err,
+      logger
+    )
+  }
+
+  def getCurrentBloopVersion(
+      config: BloopRifleConfig,
+      logger: BloopRifleLogger,
+      workdir: Path,
+      scheduler: ScheduledExecutorService
+  ): Either[BloopAboutFailure, BloopServerRuntimeInfo] = {
+    val isRunning = BloopRifle.check(config, logger)
+
+    if (isRunning) {
+      val bufferedOStream = new ByteArrayOutputStream
+      Operations.about(
+        config.address,
+        workdir,
+        bufferedOStream,
+        OutputStream.nullOutputStream(),
+        logger,
+        scheduler
+      )
+      val bloopAboutOutput = new String(bufferedOStream.toByteArray)
+      VersionUtil
+        .parseBloopAbout(bloopAboutOutput)
+        .toRight(ParsingFailed(bloopAboutOutput))
+    } else
+      Left(BloopNotRunning)
+  }
+
+  sealed abstract class BloopAboutFailure extends Product with Serializable {
+    def message: String
+  }
+  case object BloopNotRunning extends BloopAboutFailure {
+    def message = "not running"
+  }
+  final case class ParsingFailed(bloopAboutOutput: String) extends BloopAboutFailure {
+    def message = s"failed to parse output: '$bloopAboutOutput'"
+  }
+
+  final case class BloopServerRuntimeInfo(
+      bloopVersion: BloopVersion,
+      jvmVersion: Int,
+      javaHome: String
+  ) {
+    def message: String =
+      s"version $bloopVersion, JVM $jvmVersion under $javaHome"
+  }
+}