Make logger group repeated exceptions (e.g. "(x100) message")

Author: IlyaMuravjov

utbot-junit-contest/build.gradle

@@ -160,6 +160,8 @@ dependencies {
     }
     implementation group: 'org.apache.commons', name: 'commons-exec', version: '1.2'
     implementation group: 'io.github.microutils', name: 'kotlin-logging', version: kotlinLoggingVersion
+    implementation group: 'org.apache.logging.log4j', name: 'log4j-api', version: log4j2Version
+    implementation group: 'org.apache.logging.log4j', name: 'log4j-core', version: log4j2Version
     implementation group: 'org.jsoup', name: 'jsoup', version: '1.6.2'
     implementation 'org.jetbrains.kotlinx:kotlinx-serialization-json:1.4.1'
     implementation group: 'com.google.guava', name: 'guava', version: guavaVersion

utbot-junit-contest/src/main/kotlin/org/utbot/contest/usvm/ContestUsvm.kt

@@ -28,6 +28,7 @@ import org.utbot.contest.usvm.converter.toExecutableId
 import org.utbot.contest.usvm.jc.JcContainer
 import org.utbot.contest.usvm.jc.JcContainer.Companion.CONTEST_TEST_EXECUTION_TIMEOUT
 import org.utbot.contest.usvm.jc.JcTestExecutor
+import org.utbot.contest.usvm.log.ErrorCountingLoggerAppender
 import org.utbot.framework.codegen.domain.ProjectType
 import org.utbot.framework.codegen.domain.RuntimeExceptionTestsBehaviour
 import org.utbot.framework.codegen.domain.junitByVersion
@@ -63,6 +64,8 @@ fun runUsvmGeneration(
     expectedExceptions: ExpectedExceptionsForClass,
     methodNameFilter: String? = null // For debug purposes you can specify method name
 ): StatsForClass = runBlocking {
+    ErrorCountingLoggerAppender.resetOccurrenceCounter()
+
     val testsByMethod: MutableMap<ExecutableId, MutableList<UtExecution>> = mutableMapOf()
 
     val timeBudgetMs = timeLimitSec * 1000

utbot-junit-contest/src/main/kotlin/org/utbot/contest/usvm/log/ErrorCountingLoggerAppender.kt

@@ -0,0 +1,83 @@
+package org.utbot.contest.usvm.log
+
+import org.apache.logging.log4j.Level
+import org.apache.logging.log4j.LogManager
+import org.apache.logging.log4j.core.Appender
+import org.apache.logging.log4j.core.Core
+import org.apache.logging.log4j.core.LogEvent
+import org.apache.logging.log4j.core.LoggerContext
+import org.apache.logging.log4j.core.config.plugins.Plugin
+import org.apache.logging.log4j.core.config.plugins.PluginFactory
+import org.apache.logging.log4j.core.layout.PatternLayout
+import org.apache.logging.log4j.core.appender.AbstractAppender
+import org.apache.logging.log4j.core.config.Property
+import org.apache.logging.log4j.core.config.plugins.PluginAttribute
+import org.apache.logging.log4j.core.impl.ThrowableProxy
+import org.apache.logging.log4j.message.Message
+import org.apache.logging.log4j.message.SimpleMessage
+import java.util.concurrent.ConcurrentHashMap
+
+@Plugin(
+    name = "ErrorCountingAppender",
+    category = Core.CATEGORY_NAME,
+    elementType = Appender.ELEMENT_TYPE,
+    printObject = true
+)
+class ErrorCountingLoggerAppender(name: String, private val delegateAppenderName: String) : AbstractAppender(
+    name,
+    null,
+    PatternLayout.createDefaultLayout(),
+    false,
+    Property.EMPTY_ARRAY
+) {
+
+    private val delegate: Appender by lazy {
+        (LogManager.getContext(false) as LoggerContext)
+            .configuration
+            .getAppender(delegateAppenderName)
+    }
+
+    companion object {
+        private val occurrenceCountsToLogAt =
+            generateSequence(1) { it * 10 }.take(10).toList() + listOf(2, 5, 50, 500)
+        private val errorOccurrenceCounts: MutableMap<Any, Int> = ConcurrentHashMap<Any, Int>()
+
+        @PluginFactory
+        @JvmStatic
+        fun createAppender(
+            @PluginAttribute("name") name: String,
+            @PluginAttribute("delegateAppender") delegateAppenderName: String
+        ) = ErrorCountingLoggerAppender(name, delegateAppenderName)
+
+        fun resetOccurrenceCounter() {
+            errorOccurrenceCounts.keys.toList().forEach { errorOccurrenceCounts[it] = 0 }
+        }
+    }
+
+    override fun append(event: LogEvent) {
+        if (event.level >= Level.INFO) {
+            delegate.append(event)
+            return
+        }
+
+        val key = event.thrown?.stackTrace?.firstOrNull() ?: event.message.formattedMessage
+        val alreadyLogged = key in errorOccurrenceCounts
+        val count = (errorOccurrenceCounts[key] ?: 0) + 1
+        errorOccurrenceCounts[key] = count
+
+        if (!alreadyLogged) {
+            delegate.append(event)
+        } else if (count in occurrenceCountsToLogAt) {
+            val modifiedMessage = "(x$count) ${event.message.formattedMessage}${
+                event.thrown?.let { e ->
+                    "\n${e.javaClass.name}: ${e.message}\n\tat ${e.stackTrace.firstOrNull()}" 
+                }.orEmpty()
+            }"
+            delegate.append(object : LogEvent by event {
+                override fun getMessage(): Message = SimpleMessage(modifiedMessage)
+                override fun getThrown(): Throwable? = null
+                override fun getThrownProxy(): ThrowableProxy? = null
+            })
+        }
+    }
+}

utbot-junit-contest/src/main/resources/log4j2.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<Configuration>
+<Configuration packages="org.utbot.contest.usvm.log">
     <Appenders>
         <File name="FrameworkAppender"
               append="false"
@@ -9,9 +9,11 @@
             <PatternLayout pattern="%d{HH:mm:ss.SSS} | %-5level | %c{1} | %msg%n"/>
         </File>
 
-        <Console name="Console" target="SYSTEM_OUT">
+        <Console name="ActualConsole" target="SYSTEM_OUT">
             <PatternLayout pattern="%d{HH:mm:ss.SSS} | %-5level | %msg%n"/>
         </Console>
+
+        <ErrorCountingAppender name="Console" delegateAppender="ActualConsole"/>
     </Appenders>
     <Loggers>
         <Logger name="org.utbot.contest" level="debug">