JS debug logger: add last messages, don't use busy wait

platform/script-debugger/backend/src/debugger/util.kt

@@ -19,6 +19,7 @@ import com.intellij.openapi.application.ApplicationManager
 import com.intellij.openapi.util.io.FileUtil
 import com.intellij.openapi.util.io.FileUtilRt
 import com.intellij.openapi.util.registry.Registry
+import com.intellij.util.concurrency.AppExecutorUtil
 import com.intellij.util.io.CharSequenceBackedByChars
 import com.intellij.util.io.addChannelListener
 import io.netty.buffer.ByteBuf
@@ -28,14 +29,74 @@ import java.io.File
 import java.io.FileOutputStream
 import java.nio.CharBuffer
 import java.text.SimpleDateFormat
-import java.util.concurrent.ConcurrentLinkedQueue
+import java.util.concurrent.Future
+import java.util.concurrent.LinkedBlockingQueue
+import java.util.concurrent.TimeUnit
 
 internal class LogEntry(val message: Any, val marker: String) {
   internal val time = System.currentTimeMillis()
 }
 
-class MessagingLogger internal constructor(private val queue: ConcurrentLinkedQueue<LogEntry>) {
-  internal @Volatile var closed = false
+class MessagingLogger internal constructor(debugFile: String) {
+  private val processFuture: Future<*>
+  private val queue = LinkedBlockingQueue<LogEntry>()
+
+  init {
+    processFuture = ApplicationManager.getApplication().executeOnPooledThread {
+      val file = File(FileUtil.expandUserHome(debugFile))
+      FileUtilRt.createParentDirs(file)
+      val out = FileOutputStream(file)
+      val writer = out.writer()
+      writer.write("[\n")
+      writer.flush()
+      val fileChannel = out.channel
+
+      val dateFormatter = SimpleDateFormat("HH.mm.ss,SSS")
+
+      try {
+        while (true) {
+          val entry = queue.take()
+
+          writer.write("""{"timestamp": "${dateFormatter.format(entry.time)}", """)
+          val message = entry.message
+          when (message) {
+            is CharSequence -> {
+              writer.write("\"${entry.marker}\": ")
+              writer.flush()
+
+              if (message is CharSequenceBackedByChars) {
+                fileChannel.write(message.byteBuffer)
+              }
+              else {
+                fileChannel.write(Charsets.UTF_8.encode(CharBuffer.wrap(message)))
+              }
+
+              writer.write("},\n")
+              writer.flush()
+            }
+            is ByteBuf -> {
+              writer.write("\"${entry.marker}\": ")
+              writer.flush()
+
+              message.getBytes(message.readerIndex(), out, message.readableBytes())
+              message.release()
+
+              writer.write("},\n")
+              writer.flush()
+            }
+            else -> throw RuntimeException("Unknown message type")
+          }
+        }
+      }
+      catch (e: InterruptedException) {
+      }
+      finally {
+        writer.write("]")
+        writer.flush()
+        out.close()
+      }
+    }
+  }
 
   fun add(inMessage: CharSequence, marker: String = "IN") {
     queue.add(LogEntry(inMessage, marker))
@@ -46,7 +107,9 @@ class MessagingLogger internal constructor(private val queue: ConcurrentLinkedQu
   }
 
   fun close() {
-    closed = true
+    AppExecutorUtil.getAppScheduledExecutorService().schedule(fun() {
+      processFuture.cancel(true)
+    }, 1, TimeUnit.SECONDS)
   }
 
   fun closeOnChannelClose(channel: Channel) {
@@ -63,71 +126,12 @@ class MessagingLogger internal constructor(private val queue: ConcurrentLinkedQu
 
 fun createDebugLogger(@PropertyKey(resourceBundle = Registry.REGISTRY_BUNDLE) key: String, suffix: String = ""): MessagingLogger? {
   var debugFile = Registry.stringValue(key)
-  if (debugFile.isNullOrEmpty()) {
+  if (debugFile.isEmpty()) {
     return null
   }
 
-  if (!suffix.isNullOrEmpty()) {
+  if (!suffix.isEmpty()) {
     debugFile = debugFile.replace(".json", suffix + ".json")
   }
-  return createDebugLoggerWithFile(debugFile)
-}
-
-fun createDebugLoggerWithFile(debugFile: String): MessagingLogger? {
-  val queue = ConcurrentLinkedQueue<LogEntry>()
-  val logger = MessagingLogger(queue)
-  ApplicationManager.getApplication().executeOnPooledThread {
-    val file = File(FileUtil.expandUserHome(debugFile))
-    FileUtilRt.createParentDirs(file)
-    val out = FileOutputStream(file)
-    val writer = out.writer()
-    writer.write("[\n")
-    writer.flush()
-    val fileChannel = out.channel
-
-    val dateFormatter = SimpleDateFormat("HH.mm.ss,SSS")
-
-    while (true) {
-      val entry = queue.poll() ?: if (logger.closed) {
-        break
-      }
-      else {
-        continue
-      }
-
-      writer.write("""{"timestamp": "${dateFormatter.format(entry.time)}", """)
-      val message = entry.message
-      when (message) {
-        is CharSequence -> {
-          writer.write("\"${entry.marker}\": ")
-          writer.flush()
-
-          if (message is CharSequenceBackedByChars) {
-            fileChannel.write(message.byteBuffer)
-          }
-          else {
-            fileChannel.write(Charsets.UTF_8.encode(CharBuffer.wrap(message)))
-          }
-
-          writer.write("},\n")
-          writer.flush()
-        }
-        is ByteBuf -> {
-          writer.write("\"${entry.marker}\": ")
-          writer.flush()
-
-          message.getBytes(message.readerIndex(), out, message.readableBytes())
-          message.release()
-
-          writer.write("},\n")
-          writer.flush()
-        }
-        else -> throw RuntimeException("Unknown message type")
-      }
-    }
-    writer.write("]")
-    writer.flush()
-    out.close()
-  }
-  return logger
+  return MessagingLogger(debugFile)
 }