Implements isOpen() / close() methods on RemoteCollection

exist-core/src/main/java/org/exist/util/Leasable.java

@@ -24,6 +24,7 @@
 import net.jcip.annotations.ThreadSafe;
 
 import javax.annotation.Nullable;
+import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.locks.ReentrantReadWriteLock;
 import java.util.function.Consumer;
 
@@ -135,17 +136,30 @@ public boolean isLeased() {
         }
     }
 
+    public boolean isClosed() {
+        lock.readLock().lock();
+        try {
+            return Leasable.this.closed;
+        } finally {
+            lock.readLock().unlock();
+        }
+    }
+
     /**
      * Represents a lease of the leasable object.
      */
     public class Lease implements AutoCloseable {
+        private final AtomicBoolean leaseClosed = new AtomicBoolean();
 
         /**
          * Access to the leased object.
          *
          * @return the leased object.
          */
         public T get() {
+            if (leaseClosed.get()) {
+                throw new IllegalLeasableState("Lease is closed");
+            }
             lock.readLock().lock();
             try {
                 if (closed) {
@@ -167,26 +181,32 @@ public T get() {
          */
         @Override
         public void close() {
-            lock.writeLock().lock();
-            try {
-                if (closed) {
-                    throw new IllegalLeasableState("Object is closed");
-                }
-
-                if(leases == 0) {
-                    throw new IllegalLeasableState("Lease was already returned");
-                }
-
-                leases--;
-
-                if (leases == 0 && closer != null) {
-                    closer.accept(object);
-                    closed = true;
+            if (leaseClosed.compareAndSet(false, true)) {
+                lock.writeLock().lock();
+                try {
+                    if (Leasable.this.closed) {
+                        throw new IllegalLeasableState("Object is closed");
+                    }
+
+                    if(leases == 0) {
+                        throw new IllegalLeasableState("Lease was already returned");
+                    }
+
+                    leases--;
+
+                    if (leases == 0 && closer != null) {
+                        closer.accept(object);
+                        Leasable.this.closed = true;
+                    }
+                } finally {
+                    lock.writeLock().unlock();
                 }
-            } finally {
-                lock.writeLock().unlock();
             }
         }
+
+        public boolean isClosed() {
+            return leaseClosed.get();
+        }
     }
 
     /**

exist-core/src/main/java/org/exist/xmldb/AbstractRemoteResource.java

@@ -27,7 +27,6 @@
 import java.util.zip.Inflater;
 
 import com.evolvedbinary.j8fu.lazy.LazyVal;
-import org.apache.xmlrpc.XmlRpcException;
 
 import org.apache.xmlrpc.client.XmlRpcClient;
 import org.exist.security.Permission;
@@ -52,7 +51,6 @@
 
 public abstract class AbstractRemoteResource extends AbstractRemote
         implements EXistResource, ExtendedResource, Resource {
-    protected final Leasable<XmlRpcClient>.Lease xmlRpcClientLease;
     protected final XmldbURI path;
     private String mimeType;
 
@@ -67,9 +65,8 @@ public abstract class AbstractRemoteResource extends AbstractRemote
     Date dateCreated = null;
     Date dateModified = null;
 
-    protected AbstractRemoteResource(final Leasable<XmlRpcClient>.Lease xmlRpcClientLease, final RemoteCollection parent, final XmldbURI documentName, final String mimeType) {
+    protected AbstractRemoteResource(final RemoteCollection parent, final XmldbURI documentName, final String mimeType) {
         super(parent);
-        this.xmlRpcClientLease = xmlRpcClientLease;
         if (documentName.numSegments() > 1) {
             this.path = documentName;
         } else {
@@ -162,11 +159,7 @@ public void setLastModificationTime(final Date dateModified) throws XMLDBExcepti
             params.add(path.toString());
             params.add(dateModified.getTime());
 
-            try {
-                xmlRpcClientLease.get().execute("setLastModified", params);
-            } catch (final XmlRpcException e) {
-                throw new XMLDBException(ErrorCodes.UNKNOWN_ERROR, e.getMessage(), e);
-            }
+            collection.execute("setLastModified", params);
 
             this.dateModified = dateModified;
         }
@@ -282,7 +275,7 @@ protected void getRemoteContentIntoLocalFile(final OutputStream os, final boolea
             final TemporaryFileManager tempFileManager = TemporaryFileManager.getInstance();
             final VirtualTempPath tempFile = new VirtualTempPath(getInMemorySize(properties), tempFileManager);
 
-            Map<?, ?> table = (Map<?, ?>) xmlRpcClientLease.get().execute(command, params);
+            Map<?, ?> table = (Map<?, ?>) collection.execute(command, params);
 
             final String method;
             final boolean useLongOffset;
@@ -329,7 +322,7 @@ protected void getRemoteContentIntoLocalFile(final OutputStream os, final boolea
                     params.clear();
                     params.add(table.get("handle"));
                     params.add(useLongOffset ? Long.toString(offset) : Integer.valueOf((int) offset));
-                    table = (Map<?, ?>) xmlRpcClientLease.get().execute(method, params);
+                    table = (Map<?, ?>) collection.execute(method, params);
                     offset = useLongOffset ? Long.parseLong((String) table.get("offset")) : ((Integer) table.get("offset"));
                     data = (byte[]) table.get("data");
 
@@ -359,8 +352,6 @@ protected void getRemoteContentIntoLocalFile(final OutputStream os, final boolea
             }
 
             contentFile = tempFile;
-        } catch (final XmlRpcException xre) {
-            throw new XMLDBException(ErrorCodes.INVALID_RESOURCE, xre.getMessage(), xre);
         } catch (final IOException | DataFormatException e) {
             throw new XMLDBException(ErrorCodes.VENDOR_ERROR, e.getMessage(), e);
         }
@@ -493,20 +484,16 @@ protected long getStreamLengthInternal(final Object obj)
             final List<Object> params = new ArrayList<>();
             params.add(path.toString());
             params.add(getProperties());
-            try {
-                final Map<?, ?> table = (Map<?, ?>) xmlRpcClientLease.get().execute("describeResource", params);
-                if (table.containsKey("content-length-64bit")) {
-                    final Object o = table.get("content-length-64bit");
-                    if (o instanceof Long) {
-                        retval = ((Long) o);
-                    } else {
-                        retval = Long.parseLong((String) o);
-                    }
+            final Map<?, ?> table = (Map<?, ?>) collection.execute("describeResource", params);
+            if (table.containsKey("content-length-64bit")) {
+                final Object o = table.get("content-length-64bit");
+                if (o instanceof Long) {
+                    retval = ((Long) o);
                 } else {
-                    retval = ((Integer) table.get("content-length"));
+                    retval = Long.parseLong((String) o);
                 }
-            } catch (final XmlRpcException xre) {
-                throw new XMLDBException(ErrorCodes.INVALID_RESOURCE, xre.getMessage(), xre);
+            } else {
+                retval = ((Integer) table.get("content-length"));
             }
         }
 
@@ -567,7 +554,6 @@ public final void close() {
                     contentFile.close();
                     contentFile = null;
                 }
-                xmlRpcClientLease.close();
             } finally {
                 closed = true;
             }

exist-core/src/main/java/org/exist/xmldb/RemoteBinaryResource.java

@@ -54,12 +54,12 @@ public class RemoteBinaryResource
     private BlobId blobId = null;
     private MessageDigest contentDigest = null;
 
-    public RemoteBinaryResource(final Leasable<XmlRpcClient>.Lease xmlRpcClientLease, final RemoteCollection parent, final XmldbURI documentName) throws XMLDBException {
-        super(xmlRpcClientLease, parent, documentName, MimeType.BINARY_TYPE.getName());
+    public RemoteBinaryResource(final RemoteCollection parent, final XmldbURI documentName) throws XMLDBException {
+        super(parent, documentName, MimeType.BINARY_TYPE.getName());
     }
 
-    public RemoteBinaryResource(final Leasable<XmlRpcClient>.Lease xmlRpcClientLease, final RemoteCollection parent, final XmldbURI documentName, final String type, final byte[] content) throws XMLDBException {
-        super(xmlRpcClientLease, parent, documentName, MimeType.BINARY_TYPE.getName());
+    public RemoteBinaryResource(final RemoteCollection parent, final XmldbURI documentName, final String type, final byte[] content) throws XMLDBException {
+        super(parent, documentName, MimeType.BINARY_TYPE.getName());
         this.type = type;
         this.content = content;
     }
@@ -149,20 +149,16 @@ public MessageDigest getContentDigest(final DigestType digestType) throws XMLDBE
         params.add(path.toString());
         params.add(digestType.getCommonNames()[0]);
 
-        try {
-            final Map result = (Map) xmlRpcClientLease.get().execute("getContentDigest", params);
-            final String digestAlgorithm = (String)result.get("digest-algorithm");
-            final byte[] digest = (byte[])result.get("digest");
+        final Map result = (Map) collection.execute("getContentDigest", params);
+        final String digestAlgorithm = (String)result.get("digest-algorithm");
+        final byte[] digest = (byte[])result.get("digest");
 
-            final MessageDigest messageDigest = new MessageDigest(DigestType.forCommonName(digestAlgorithm), digest);
-            if (this.contentDigest == null) {
-                this.contentDigest = messageDigest;
-            }
-            return messageDigest;
-
-        } catch (final XmlRpcException xre) {
-            throw new XMLDBException(ErrorCodes.INVALID_RESOURCE, xre.getMessage(), xre);
+        final MessageDigest messageDigest = new MessageDigest(DigestType.forCommonName(digestAlgorithm), digest);
+        if (this.contentDigest == null) {
+            this.contentDigest = messageDigest;
         }
+        return messageDigest;
+
     }
 
     public void setContentDigest(final MessageDigest contentDigest) {

exist-core/src/main/java/org/exist/xmldb/RemoteCallSite.java

@@ -0,0 +1,41 @@
+/*
+ * eXist Open Source Native XML Database
+ * Copyright (C) 2019 The eXist Project
+ * http://exist-db.org
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+package org.exist.xmldb;
+
+import org.xmldb.api.base.XMLDBException;
+
+import java.util.List;
+
+/**
+ * Represents a remote method call site.
+ */
+@FunctionalInterface
+public interface RemoteCallSite {
+    /**
+     * Executes the given {@code methodName} with the given {@code parameters} and returns the result. In case of
+     * an error a {@link XMLDBException} will be thrown.
+     *
+     * @param methodName the method name to be invoked
+     * @param parameters the list of method arguments
+     * @return the result of the method
+     * @throws XMLDBException in case of the invocation fails
+     */
+    Object execute(String methodName, List<Object> parameters) throws XMLDBException;
+}