1 files changed, 165 insertions, 0 deletions
diff --git a/container-core/src/main/java/com/yahoo/container/core/config/ApplicationBundleLoader.java b/container-core/src/main/java/com/yahoo/container/core/config/ApplicationBundleLoader.java
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+++ b/container-core/src/main/java/com/yahoo/container/core/config/ApplicationBundleLoader.java
@@ -0,0 +1,165 @@
+// Copyright 2020 Oath Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.container.core.config;
+
+import com.yahoo.config.FileReference;
+import com.yahoo.container.Container;
+import com.yahoo.filedistribution.fileacquirer.FileAcquirer;
+import com.yahoo.osgi.Osgi;
+import org.osgi.framework.Bundle;
+import org.osgi.framework.wiring.BundleRevision;
+
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.logging.Logger;
+import java.util.stream.Collectors;
+
+/**
+ * Manages the set of installed and active/inactive bundles.
+ *
+ * @author gjoranv
+ * @author Tony Vaagenes
+ */
+public class ApplicationBundleLoader {
+
+    /* Map of file refs of active bundles (not scheduled for uninstall) to the installed bundle.
+     *
+     * Used to:
+     * 1. Avoid installing already installed bundles. Just an optimization, installing the same bundle location is a NOP
+     * 2. Start bundles (all are started every time)
+     * 3. Calculate the set of bundles to uninstall
+     */
+    private final Map<FileReference, Bundle> reference2Bundle = new LinkedHashMap<>();
+
+    private final Logger log = Logger.getLogger(ApplicationBundleLoader.class.getName());
+    private final Osgi osgi;
+
+    // A custom bundle installer for non-disk bundles, to be used for testing
+    private BundleInstaller customBundleInstaller = null;
+
+    public ApplicationBundleLoader(Osgi osgi) {
+        this.osgi = osgi;
+    }
+
+    /**
+     * Installs the given set of bundles and returns the set of bundles that is no longer used
+     * by the application, and should therefore be scheduled for uninstall.
+     */
+    public synchronized Set<Bundle> useBundles(List<FileReference> newFileReferences) {
+
+        Set<FileReference> obsoleteReferences = getObsoleteFileReferences(newFileReferences);
+        Set<Bundle> bundlesToUninstall = getObsoleteBundles(obsoleteReferences);
+        log.info("Bundles to schedule for uninstall: " + bundlesToUninstall);
+
+        osgi.allowDuplicateBundles(bundlesToUninstall);
+        removeInactiveFileReferences(obsoleteReferences);
+
+        installBundles(newFileReferences);
+        startBundles();
+        log.info(installedBundlesMessage());
+
+        return bundlesToUninstall;
+    }
+
+    private Set<FileReference> getObsoleteFileReferences(List<FileReference> newReferences) {
+        Set<FileReference> obsoleteReferences = new HashSet<>(reference2Bundle.keySet());
+        obsoleteReferences.removeAll(newReferences);
+        return obsoleteReferences;
+    }
+
+
+    /**
+     * Returns the bundles that will not be retained by the new application generation.
+     */
+    private Set<Bundle> getObsoleteBundles(Set<FileReference> obsoleteReferences) {
+        return obsoleteReferences.stream().map(reference2Bundle::get).collect(Collectors.toSet());
+    }
+
+    private void removeInactiveFileReferences(Set<FileReference> fileReferencesToRemove) {
+        fileReferencesToRemove.forEach(reference2Bundle::remove);
+    }
+
+    private void installBundles(List<FileReference> references) {
+        Set<FileReference> bundlesToInstall = new HashSet<>(references);
+
+        // This is just an optimization, as installing a bundle with the same location id returns the already installed bundle.
+        bundlesToInstall.removeAll(reference2Bundle.keySet());
+
+        if (!bundlesToInstall.isEmpty()) {
+            FileAcquirer fileAcquirer = Container.get().getFileAcquirer();
+            boolean hasFileDistribution = (fileAcquirer != null);
+            if (hasFileDistribution) {
+                installWithFileDistribution(bundlesToInstall, new FileAcquirerBundleInstaller(fileAcquirer));
+            } else if (customBundleInstaller != null) {
+                installWithFileDistribution(bundlesToInstall, customBundleInstaller);
+            } else {
+                log.warning("Can't retrieve bundles since file distribution is disabled.");
+            }
+        }
+    }
+
+    private void installWithFileDistribution(Set<FileReference> bundlesToInstall, BundleInstaller bundleInstaller) {
+        for (FileReference reference : bundlesToInstall) {
+            try {
+                log.info("Installing bundle with reference '" + reference.value() + "'");
+                List<Bundle> bundles = bundleInstaller.installBundles(reference, osgi);
+
+                // Throw if more than one bundle was installed, which means that the X-JDisc-Preinstall-Bundle header was used.
+                // However, if the OSGi framework is only a test framework, this rule does not apply.
+                if (bundles.size() > 1  && osgi.hasFelixFramework()) {
+                    throw new RuntimeException("Bundle '" + bundles.get(0).getSymbolicName() + "' tried to pre-install other bundles.");
+                }
+                reference2Bundle.put(reference, bundles.get(0));
+            }
+            catch(Exception e) {
+                throw new RuntimeException("Could not install bundle with reference '" + reference + "'", e);
+            }
+        }
+    }
+
+    /**
+     * Resolves and starts (calls the Bundles BundleActivator) all bundles. Bundle resolution must take place
+     * after all bundles are installed to ensure that the framework can resolve dependencies between bundles.
+     */
+    private void startBundles() {
+        for (var bundle : reference2Bundle.values()) {
+            try {
+                if ( ! isFragment(bundle))
+                    bundle.start();  // NOP for already ACTIVE bundles
+            } catch(Exception e) {
+                throw new RuntimeException("Could not start bundle '" + bundle.getSymbolicName() + "'", e);
+            }
+        }
+    }
+
+    private boolean isFragment(Bundle bundle) {
+        BundleRevision bundleRevision = bundle.adapt(BundleRevision.class);
+        if (bundleRevision == null)
+            throw new NullPointerException("Null bundle revision means that bundle has probably been uninstalled: " +
+                                           bundle.getSymbolicName() + ":" + bundle.getVersion());
+        return (bundleRevision.getTypes() & BundleRevision.TYPE_FRAGMENT) != 0;
+    }
+
+    private String installedBundlesMessage() {
+        StringBuilder sb = new StringBuilder("Installed bundles: {" );
+        for (Bundle b : osgi.getBundles())
+            sb.append("[" + b.getBundleId() + "]" + b.getSymbolicName() + ":" + b.getVersion() + ", ");
+        sb.setLength(sb.length() - 2);
+        sb.append("}");
+        return sb.toString();
+    }
+
+    // Only for testing
+    void useCustomBundleInstaller(BundleInstaller bundleInstaller) {
+        customBundleInstaller = bundleInstaller;
+    }
+
+    // Only for testing
+    List<FileReference> getActiveFileReferences() {
+        return new ArrayList<>(reference2Bundle.keySet());
+    }
+
+}