Add auto completions support interface for debug console. (microsoft#168)

Author: yaohaizh

com.microsoft.java.debug.core/src/main/java/com/microsoft/java/debug/core/adapter/ErrorCode.java

@@ -30,7 +30,8 @@ public enum ErrorCode {
     VM_TERMINATED(1013),
     LAUNCH_IN_TERMINAL_FAILURE(1014),
     STEP_FAILURE(1015),
-    RESTARTFRAME_FAILURE(1016);
+    RESTARTFRAME_FAILURE(1016),
+    COMPLETIONS_FAILURE(1017);
 
     private int id;
 

com.microsoft.java.debug.core/src/main/java/com/microsoft/java/debug/core/adapter/ICompletionsProvider.java

@@ -0,0 +1,35 @@
+/*******************************************************************************
+ * Copyright (c) 2018 Microsoft Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Microsoft Corporation - initial API and implementation
+ *******************************************************************************/
+
+package com.microsoft.java.debug.core.adapter;
+
+import java.util.List;
+
+import com.microsoft.java.debug.core.protocol.Types.CompletionItem;
+import com.sun.jdi.StackFrame;
+
+public interface ICompletionsProvider extends IProvider {
+
+    /**
+     * Complete the code snippet on the target frame.
+     *
+     * @param frame
+     *            the target frame that the completions on
+     * @param snippet
+     *            the code snippet text
+     * @param line
+     *            the line number of the operation happens inside the snippet
+     * @param column
+     *            the column number of the operation happens inside the snippet
+     * @return a list of {@link CompletionItem}
+     */
+    List<CompletionItem> codeComplete(StackFrame frame, String snippet, int line, int column);
+}

com.microsoft.java.debug.core/src/main/java/com/microsoft/java/debug/core/adapter/handler/CompletionsHandler.java

@@ -0,0 +1,74 @@
+/*******************************************************************************
+* Copyright (c) 2018 Microsoft Corporation and others.
+* All rights reserved. This program and the accompanying materials
+* are made available under the terms of the Eclipse Public License v1.0
+* which accompanies this distribution, and is available at
+* http://www.eclipse.org/legal/epl-v10.html
+*
+* Contributors:
+*     Microsoft Corporation - initial API and implementation
+*******************************************************************************/
+
+package com.microsoft.java.debug.core.adapter.handler;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.CompletionException;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import com.microsoft.java.debug.core.Configuration;
+import com.microsoft.java.debug.core.adapter.AdapterUtils;
+import com.microsoft.java.debug.core.adapter.ErrorCode;
+import com.microsoft.java.debug.core.adapter.ICompletionsProvider;
+import com.microsoft.java.debug.core.adapter.IDebugAdapterContext;
+import com.microsoft.java.debug.core.adapter.IDebugRequestHandler;
+import com.microsoft.java.debug.core.adapter.variables.StackFrameReference;
+import com.microsoft.java.debug.core.protocol.Messages.Response;
+import com.microsoft.java.debug.core.protocol.Requests;
+import com.microsoft.java.debug.core.protocol.Requests.Arguments;
+import com.microsoft.java.debug.core.protocol.Requests.Command;
+import com.microsoft.java.debug.core.protocol.Requests.CompletionsArguments;
+import com.microsoft.java.debug.core.protocol.Responses;
+import com.microsoft.java.debug.core.protocol.Types.CompletionItem;
+import com.sun.jdi.IncompatibleThreadStateException;
+import com.sun.jdi.ThreadReference;
+
+public class CompletionsHandler implements IDebugRequestHandler {
+
+    private static final Logger logger = Logger.getLogger(Configuration.LOGGER_NAME);
+
+    @Override
+    public List<Command> getTargetCommands() {
+        return Arrays.asList(Requests.Command.COMPLETIONS);
+    }
+
+    @Override
+    public CompletableFuture<Response> handle(Command command, Arguments arguments, Response response, IDebugAdapterContext context) {
+        CompletionsArguments completionsArgs = (CompletionsArguments) arguments;
+        StackFrameReference stackFrameReference = (StackFrameReference) context.getRecyclableIdPool().getObjectById(completionsArgs.frameId);
+
+        if (stackFrameReference == null) {
+            return AdapterUtils.createAsyncErrorResponse(response, ErrorCode.COMPLETIONS_FAILURE,
+                    String.format("Completions: cannot find the stack frame with frameID %s", completionsArgs.frameId));
+        }
+
+        return CompletableFuture.supplyAsync(() -> {
+            try {
+                ICompletionsProvider completionsProvider = context.getProvider(ICompletionsProvider.class);
+                if (completionsProvider != null) {
+                    ThreadReference thread = stackFrameReference.getThread();
+
+                    List<CompletionItem> res = completionsProvider.codeComplete(thread.frame(stackFrameReference.getDepth()), completionsArgs.text,
+                            completionsArgs.line, completionsArgs.column);
+                    response.body = new Responses.CompletionsResponseBody(res);
+                }
+                return response;
+            } catch (IncompatibleThreadStateException e) {
+                logger.log(Level.WARNING, String.format("Cannot provide code completions because of %s.", e.toString()), e);
+                throw new CompletionException(e);
+            }
+        });
+    }
+}

com.microsoft.java.debug.core/src/main/java/com/microsoft/java/debug/core/adapter/handler/InitializeRequestHandler.java

@@ -50,6 +50,7 @@ public CompletableFuture<Messages.Response> handle(Requests.Command command, Req
         caps.supportsConditionalBreakpoints = true;
         caps.supportsSetVariable = true;
         caps.supportTerminateDebuggee = true;
+        caps.supportsCompletionsRequest = true;
         caps.supportsRestartFrame = true;
         Types.ExceptionBreakpointFilter[] exceptionFilters = {
             Types.ExceptionBreakpointFilter.UNCAUGHT_EXCEPTION_FILTER,

com.microsoft.java.debug.core/src/main/java/com/microsoft/java/debug/core/protocol/Requests.java

@@ -263,6 +263,13 @@ public static class RestartFrameArguments extends Arguments {
         public int frameId;
     }
 
+    public static class CompletionsArguments extends Arguments {
+        public int frameId;
+        public String text;
+        public int line;
+        public int column;
+    }
+
     public static enum Command {
         INITIALIZE("initialize", InitializeArguments.class),
         LAUNCH("launch", LaunchArguments.class),
@@ -285,6 +292,7 @@ public static enum Command {
         SETEXCEPTIONBREAKPOINTS("setExceptionBreakpoints", SetExceptionBreakpointsArguments.class),
         SETFUNCTIONBREAKPOINTS("setFunctionBreakpoints", SetFunctionBreakpointsArguments.class),
         EVALUATE("evaluate", EvaluateArguments.class),
+        COMPLETIONS("completions", CompletionsArguments.class),
         RUNINTERMINAL("runInTerminal", RunInTerminalRequestArguments.class),
         REDEFINECLASSES("redefineClasses", RedefineClassesArguments.class),
         UNSUPPORTED("", Arguments.class);

com.microsoft.java.debug.core/src/main/java/com/microsoft/java/debug/core/protocol/Responses.java

@@ -172,6 +172,21 @@ public EvaluateResponseBody(String value, int ref, String type, int indexedVaria
         }
     }
 
+    public static class CompletionsResponseBody extends ResponseBody {
+        public Types.CompletionItem[] targets;
+
+        /**
+         * Constructor.
+         */
+        public CompletionsResponseBody(List<Types.CompletionItem> items) {
+            if (items == null) {
+                targets = new Types.CompletionItem[0];
+            } else {
+                targets = items.toArray(new Types.CompletionItem[0]);
+            }
+        }
+    }
+
     public static class SetBreakpointsResponseBody extends ResponseBody {
         public Types.Breakpoint[] breakpoints;
 

com.microsoft.java.debug.core/src/main/java/com/microsoft/java/debug/core/protocol/Types.java

@@ -190,6 +190,23 @@ public FunctionBreakpoint(String name) {
         }
     }
 
+    public static class CompletionItem {
+        public String label;
+        public String text;
+        public String type;
+
+        public int start;
+        public int number;
+
+        public CompletionItem() {
+        }
+
+        public CompletionItem(String label, String text) {
+            this.label = label;
+            this.text = text;
+        }
+    }
+
     public static class ExceptionBreakpointFilter {
         public static final String UNCAUGHT_EXCEPTION_FILTER_NAME = "uncaught";
         public static final String CAUGHT_EXCEPTION_FILTER_NAME = "caught";
@@ -215,6 +232,7 @@ public static class Capabilities {
         public boolean supportsHitConditionalBreakpoints;
         public boolean supportsConditionalBreakpoints;
         public boolean supportsEvaluateForHovers;
+        public boolean supportsCompletionsRequest;
         public boolean supportsRestartFrame;
         public boolean supportsSetVariable;
         public boolean supportsRestartRequest;