fix(analyze-command): properly close PackageManager instances

analyzer/src/main/kotlin/PackageManager.kt

@@ -19,6 +19,7 @@
 
 package org.ossreviewtoolkit.analyzer
 
+import java.io.Closeable
 import java.io.File
 import java.nio.file.FileSystems
 import java.nio.file.Path
@@ -62,7 +63,7 @@ abstract class PackageManager(
     val analysisRoot: File,
     val analyzerConfig: AnalyzerConfiguration,
     val repoConfig: RepositoryConfiguration
-) {
+) : Closeable {
     companion object {
         private val PACKAGE_MANAGER_DIRECTORIES = setOf(
             // Ignore intermediate build system directories.
@@ -361,6 +362,11 @@ abstract class PackageManager(
             }
         }
     }
+
+    /**
+     * [PackageManager] implementations should override this method if they need to close resources.
+     */
+    override fun close() = Unit
 }
 
 /**

plugins/commands/analyzer/src/main/kotlin/AnalyzerCommand.kt

@@ -228,5 +228,9 @@ class AnalyzerCommand : OrtCommand(
         val issues = analyzerRun.result.getAllIssues().flatMap { it.value }
         SeverityStatsPrinter(terminal, resolutionProvider).stats(issues)
             .print().conclude(ortConfig.severeIssueThreshold, 2)
+
+        for (packageManager in info.managedFiles.keys) {
+            packageManager.close()
+        }
     }
 }

plugins/package-managers/gradle/src/main/kotlin/Gradle.kt

@@ -290,4 +290,9 @@ class Gradle(
             }
         }
     }
+
+    override fun close() {
+        // Silently close the [MvnSupport] instance.
+        maven.use {}
+    }
 }

plugins/package-managers/maven/src/main/kotlin/Maven.kt

@@ -164,6 +164,11 @@ class Maven(
 
         return listOf(ProjectAnalyzerResult(project, emptySet(), issues))
     }
+
+    override fun close() {
+        // Silently close the [MvnSupport] instance.
+        mvn.use {}
+    }
 }
 
 /**

plugins/package-managers/maven/src/main/kotlin/utils/MavenSupport.kt

@@ -19,6 +19,7 @@
 
 package org.ossreviewtoolkit.plugins.packagemanagers.maven.utils
 
+import java.io.Closeable
 import java.io.File
 import java.net.URI
 
@@ -108,7 +109,7 @@ fun Artifact.identifier() = "$groupId:$artifactId:$version"
 private val File?.safePath: String
     get() = this?.invariantSeparatorsPath ?: "<unknown file>"
 
-class MavenSupport(private val workspaceReader: WorkspaceReader) {
+class MavenSupport(private val workspaceReader: WorkspaceReader) : Closeable {
     companion object {
         private val PACKAGING_TYPES = setOf(
             // Core packaging types, see https://maven.apache.org/pom.html#packaging.
@@ -814,6 +815,10 @@ class MavenSupport(private val workspaceReader: WorkspaceReader) {
             legacySupport.session = null
         }
     }
+
+    override fun close() {
+        remoteArtifactCache.close()
+    }
 }
 
 /**

plugins/package-managers/sbt/src/funTest/assets/projects/target-scala-2.12-projects_2.12-0.1.0-SNAPSHOT.pom

@@ -0,0 +1,20 @@
+<?xml version='1.0' encoding='UTF-8'?>
+<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://maven.apache.org/POM/4.0.0">
+    <modelVersion>4.0.0</modelVersion>
+    <groupId>default</groupId>
+    <artifactId>projects_2.12</artifactId>
+    <packaging>jar</packaging>
+    <description>projects</description>
+    <version>0.1.0-SNAPSHOT</version>
+    <name>projects</name>
+    <organization>
+        <name>default</name>
+    </organization>
+    <dependencies>
+        <dependency>
+            <groupId>org.scala-lang</groupId>
+            <artifactId>scala-library</artifactId>
+            <version>2.12.16</version>
+        </dependency>
+    </dependencies>
+</project>

plugins/package-managers/sbt/src/funTest/assets/projects/target/streams/_global/ivyConfiguration/_global/streams/out

@@ -0,0 +1,3 @@
+[debug] Other repositories:
+[debug] Default repositories:
+[debug] Using inline dependencies specified in Scala.

plugins/package-managers/sbt/src/funTest/assets/projects/target/streams/_global/makePom/_global/streams/out

@@ -0,0 +1 @@
+[info] Wrote /home/tn/workspace/netomi/ort/plugins/package-managers/sbt/src/funTest/assets/projects/target/scala-2.12/projects_2.12-0.1.0-SNAPSHOT.pom

utils/common/src/main/kotlin/DiskCache.kt

@@ -21,6 +21,7 @@ package org.ossreviewtoolkit.utils.common
 
 import com.jakewharton.disklrucache.DiskLruCache
 
+import java.io.Closeable
 import java.io.File
 import java.io.IOException
 
@@ -46,7 +47,7 @@ class DiskCache(
      * Duration in seconds that cache entries are valid.
      */
     private val maxCacheEntryAgeInSeconds: Long
-) {
+) : Closeable {
     companion object {
         const val INDEX_FULL_KEY = 0
         const val INDEX_TIMESTAMP = 1
@@ -144,4 +145,8 @@ class DiskCache(
     }
 
     private fun currentTimeInSeconds() = System.currentTimeMillis() / 1000L
+
+    override fun close() {
+        diskLruCache.close()
+    }
 }