[jacodb-core] In JarFacade, avoid caching JarEntries returned by JarFile (#303)

Some implementations of JarEntry are inner classes referencing their JarFiles
for doing some internal checks,e.g., on getting input stream. Such caching
may require the JarFiles to always be open. To address the issue, copies
of all JarEntries should be cached.

Author: Saloed

jacodb-core/src/main/kotlin/org/jacodb/impl/fs/Jars.kt

@@ -17,6 +17,7 @@
 package org.jacodb.impl.fs
 
 import jetbrains.exodus.util.LightByteArrayOutputStream
+import org.jacodb.impl.util.asSequence
 import java.io.InputStream
 import java.io.OutputStream
 import java.util.jar.Attributes
@@ -43,9 +44,9 @@ class JarFacade(private val runtimeVersion: Int, private val getter: () -> JarFi
         getter().use { jarFile ->
             isJmod = jarFile?.name?.endsWith(".jmod") ?: false
             isMultiReleaseEnabledInManifest = jarFile?.manifest?.mainAttributes?.getValue(MULTI_RELEASE).toBoolean()
-            entries = jarFile?.entries()?.toList()?.filter {
+            entries = jarFile?.entries()?.asSequence()?.filter {
                 it.name.endsWith(".class") && !it.name.contains("module-info")
-            }?.associateBy { it.name }
+            }?.associate { it.name to JarEntry(it) }
         }
     }
 
@@ -85,8 +86,8 @@ class JarFacade(private val runtimeVersion: Int, private val getter: () -> JarFi
             val jarFile = getter() ?: return emptyMap()
             return jarFile.use {
                 val buffer = ByteArray(DEFAULT_BUFFER_SIZE * 8)
-                classes.map { it.key to jarFile.getInputStream(it.value).use { it.readBytes(buffer) } }
-            }.toMap()
+                classes.entries.associate { it.key to jarFile.getInputStream(it.value).use { it.readBytes(buffer) } }
+            }
         }
 
 }

jacodb-core/src/main/kotlin/org/jacodb/impl/util/SequenceUtil.kt

@@ -16,6 +16,18 @@
 
 package org.jacodb.impl.util
 
+import java.util.*
+
 inline fun <T> Sequence(crossinline it: () -> Iterable<T>): Sequence<T> = object : Sequence<T> {
     override fun iterator(): Iterator<T> = it().iterator()
+}
+
+fun <T> Enumeration<T>?.asSequence(): Sequence<T> {
+    if (this == null) return emptySequence()
+    return object : Sequence<T> {
+        override fun iterator(): Iterator<T> = object : Iterator<T> {
+            override fun hasNext() = this@asSequence.hasMoreElements()
+            override fun next(): T = this@asSequence.nextElement()
+        }
+    }
 }

jacodb-core/src/test/kotlin/org/jacodb/testing/JarFacadeTest.kt

@@ -16,9 +16,14 @@
 
 package org.jacodb.testing
 
+import kotlinx.coroutines.runBlocking
+import org.jacodb.impl.JcRamErsSettings
 import org.jacodb.impl.fs.JarFacade
 import org.jacodb.impl.fs.parseRuntimeVersion
-import org.junit.jupiter.api.Assertions.*
+import org.jacodb.impl.jacodb
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.Assertions.assertNotNull
+import org.junit.jupiter.api.Assertions.assertTrue
 import org.junit.jupiter.api.Test
 import org.junit.jupiter.api.condition.EnabledOnJre
 import org.junit.jupiter.api.condition.JRE
@@ -93,4 +98,15 @@ class JarFacadeTest {
         assertTrue(javaBase.classes.contains("java.lang.String"))
         assertNotNull(javaBase.inputStreamOf("java.lang.String"))
     }
+
+    @Test
+    fun `load bouncycastle`(): Unit = runBlocking {
+        val jar = cookJar("https://repo1.maven.org/maven2/org/bouncycastle/bcpg-jdk18on/1.78.1/bcpg-jdk18on-1.78.1.jar")
+        val db = jacodb {
+            persistenceImpl(JcRamErsSettings)
+            loadByteCode(listOf(jar.toFile()))
+        }.apply { awaitBackgroundJobs() }
+        val cp = db.classpath(listOf(jar.toFile()))
+        assertTrue(cp.locations.flatMap { location -> location.classes.values }.isNotEmpty())
+    }
 }

jacodb-core/src/test/kotlin/org/jacodb/testing/persistence/incrementality/IncrementalDbTest.kt

@@ -19,15 +19,12 @@ package org.jacodb.testing.persistence.incrementality
 import kotlinx.coroutines.runBlocking
 import org.jacodb.api.jvm.ext.findClass
 import org.jacodb.testing.WithDb
+import org.jacodb.testing.cookJar
+import org.jacodb.testing.createTempJar
 import org.junit.jupiter.api.Assertions
 import org.junit.jupiter.api.Test
-import java.net.URL
 import java.nio.file.Files
-import java.nio.file.Files.createDirectories
-import java.nio.file.Path
 import java.nio.file.StandardCopyOption
-import kotlin.io.path.Path
-import kotlin.io.path.createTempDirectory
 
 class IncrementalDbTest {
 
@@ -55,16 +52,4 @@ class IncrementalDbTest {
         db.awaitBackgroundJobs()
         Assertions.assertTrue(bc1 contentEquals cp.findClass("com.github.penemue.keap.PriorityQueue").bytecode())
     }
-
-    private fun cookJar(link: String): Path {
-        val url = URL(link)
-        val result = createTempJar(url.file)
-        Files.copy(url.openStream(), result, StandardCopyOption.REPLACE_EXISTING)
-        return result
-    }
-
-    private fun createTempJar(name: String) =
-        Path(createTempDirectory("jcdb-temp-jar").toString(), name).also {
-            createDirectories(it.parent)
-        }
 }

jacodb-core/src/testFixtures/kotlin/org/jacodb/testing/Jars.kt

@@ -0,0 +1,37 @@
+/*
+ *  Copyright 2022 UnitTestBot contributors (utbot.org)
+ * <p>
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ * <p>
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+package org.jacodb.testing
+
+import java.net.URL
+import java.nio.file.Files
+import java.nio.file.Files.createDirectories
+import java.nio.file.Path
+import java.nio.file.StandardCopyOption
+import kotlin.io.path.Path
+import kotlin.io.path.createTempDirectory
+
+fun cookJar(link: String): Path {
+    val url = URL(link)
+    val result = createTempJar(url.file)
+    Files.copy(url.openStream(), result, StandardCopyOption.REPLACE_EXISTING)
+    return result
+}
+
+fun createTempJar(name: String) =
+    Path(createTempDirectory("jcdb-temp-jar").toString(), name).also {
+        createDirectories(it.parent)
+    }