drop old backends

plugins/org.chromium.sdk.wipbackend.wk118685/src/org/chromium/sdk/internal/wip/EvaluateHack.java

-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-package org.chromium.sdk.internal.wip;
-
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Map;
-import java.util.concurrent.atomic.AtomicInteger;
-
-import org.chromium.sdk.JsEvaluateContext;
-import org.chromium.sdk.JsEvaluateContext.ResultOrException;
-import org.chromium.sdk.RelayOk;
-import org.chromium.sdk.SyncCallback;
-import org.chromium.sdk.internal.wip.WipExpressionBuilder.ValueNameBuilder;
-import org.chromium.sdk.internal.wip.WipRelayRunner.ProcessException;
-import org.chromium.sdk.internal.wip.WipRelayRunner.Step;
-import org.chromium.sdk.internal.wip.WipValueBuilder.SerializableValue;
-import org.chromium.sdk.internal.wip.protocol.input.runtime.CallFunctionOnData;
-import org.chromium.sdk.internal.wip.protocol.input.runtime.EvaluateData;
-import org.chromium.sdk.internal.wip.protocol.input.runtime.RemoteObjectValue;
-import org.chromium.sdk.internal.wip.protocol.output.WipParamsWithResponse;
-import org.chromium.sdk.internal.wip.protocol.output.runtime.CallArgumentParam;
-import org.chromium.sdk.internal.wip.protocol.output.runtime.CallFunctionOnParams;
-import org.chromium.sdk.internal.wip.protocol.output.runtime.EvaluateParams;
-import org.chromium.sdk.util.GenericCallback;
-import org.chromium.sdk.util.RelaySyncCallback;
-
-/**
- * Helper class that implements evaluate with additional context and
- * destination group id operation. This implementation is a hack because it adds (injects)
- * a property to the global object and works with its properties. The normal approach is when
- * the protocol itself supports this operation. As it hopefully will.
- */
-public class EvaluateHack {
-
-  private final WipTabImpl tabImpl;
-  private final AtomicInteger uniqueIdCounter = new AtomicInteger(0);
-  private boolean objectInjected = false;
-
-  public EvaluateHack(WipTabImpl tabImpl) {
-    this.tabImpl = tabImpl;
-  }
-
-  /**
-   * Implements evaluate with additional context and destination group id operation.
-   * The implementation modifies a global object.
-   * @param destinationValueLoader value loader that corresponds to the destination group
-   * @param evaluateCommandHandler provides a particular request type
-   */
-  public RelayOk evaluateAsync(String expression, ValueNameBuilder valueNameBuidler,
-      Map<String, ? extends SerializableValue> additionalContext,
-      WipValueLoader destinationValueLoader, EvaluateCommandHandler<?> evaluateCommandHandler,
-      final JsEvaluateContext.EvaluateCallback callback, SyncCallback syncCallback) {
-
-    RelaySyncCallback relaySyncCallback = new RelaySyncCallback(syncCallback);
-
-    final EvaluateSession evaluateSession = new EvaluateSession(expression, valueNameBuidler,
-        additionalContext, destinationValueLoader, evaluateCommandHandler);
-
-    final RelaySyncCallback.Guard guard = relaySyncCallback.newGuard();
-
-    GenericCallback<Void> postEnsureCallback = new GenericCallback<Void>() {
-          @Override
-          public void success(Void value) {
-            RelayOk relayOk = evaluateSession.run(callback, guard.getRelay());
-            guard.discharge(relayOk);
-          }
-
-          @Override
-          public void failure(Exception exception) {
-            if (callback != null) {
-              callback.failure(exception);
-            }
-          }
-        };
-
-    return ensureObjectInjected(postEnsureCallback, guard.asSyncCallback());
-  }
-
-  /**
-   * Provides an actual evaluate request. It may or may not refer to a particular call frame
-   * or deal with other details that are out of scope of this class.
-   *
-   * @param <DATA> type of request's response
-   */
-  public interface EvaluateCommandHandler<DATA> {
-    WipParamsWithResponse<DATA> createRequest(String patchedUserExpression,
-        WipValueLoader destinationValueLoader);
-
-    ResultOrException processResult(DATA response, WipValueLoader destinationValueLoader,
-        ValueNameBuilder valueNameBuidler);
-
-    /**
-     * Return the same exception or wraps it with a more high-level error details.
-     * @return not null
-     */
-    Exception processFailure(Exception cause);
-  }
-
-  synchronized void pageReloaded() {
-    objectInjected = false;
-  }
-
-  /**
-   * Corresponds to a one evaluate operation. Holds most of parameters. It does following:
-   * <ol>
-   *   <li>creates a temporary object inside the main injected object,
-   *   <li>puts all values from additional context thus making it a 'with' object,
-   *   <li>evaluates user expression inside the 'with' operator,
-   *   <li>returns result to a user callback,
-   *   <li>deletes the temporary object.
-   * </ol>
-   *
-   * It uses {@link WipRelayRunner} as an engine.
-   */
-  private class EvaluateSession {
-    private final String userExpression;
-    private final ValueNameBuilder valueNameBuidler;
-    private final Map<String, ? extends SerializableValue> additionalContext;
-    private final WipValueLoader destinationValueLoader;
-    private final EvaluateCommandHandler<?> evaluateCommandHandler;
-
-    private final String dataId = "d" + uniqueIdCounter.incrementAndGet();
-
-    EvaluateSession(String expression, ValueNameBuilder valueNameBuidler,
-        Map<String, ? extends SerializableValue> additionalContext,
-        WipValueLoader destinationValueLoader, EvaluateCommandHandler<?> evaluateCommandHandler) {
-      this.userExpression = expression;
-      this.valueNameBuidler = valueNameBuidler;
-      this.additionalContext = additionalContext;
-      this.destinationValueLoader = destinationValueLoader;
-      this.evaluateCommandHandler = evaluateCommandHandler;
-    }
-
-    RelayOk run(final JsEvaluateContext.EvaluateCallback callback, RelaySyncCallback relay) {
-      WipRelayRunner.Step<ResultOrException> step = createFillDataObjectStep();
-
-      GenericCallback<ResultOrException> innerCallback;
-      if (callback == null) {
-        innerCallback = null;
-      } else {
-        innerCallback = new GenericCallback<ResultOrException>() {
-          @Override public void success(ResultOrException value) {
-            callback.success(value);
-          }
-          @Override public void failure(Exception exception) {
-            callback.failure(exception);
-          }
-        };
-      }
-
-      return WipRelayRunner.run(tabImpl.getCommandProcessor(), step,
-          innerCallback, relay);
-    }
-
-    /**
-     * Sends request that create a temporary object and fills it with user values.
-     * User values are passed as 1. 'this', 2. additional arguments to the function.
-     */
-    private WipRelayRunner.Step<ResultOrException> createFillDataObjectStep() {
-      if (additionalContext.isEmpty()) {
-        throw new IllegalArgumentException("Empty context");
-      }
-
-      StringBuilder assigmentBuilder = new StringBuilder();
-      StringBuilder parametersBuilder = new StringBuilder();
-
-      String thisObjectId = null;
-      final List<CallArgumentParam> additionalObjectIds = new ArrayList<CallArgumentParam>(0);
-      String tempObjectRef = GLOBAL_VARIABLE_NAME + ".data." + dataId + ".";
-      for (Map.Entry<String, ? extends SerializableValue> entry : additionalContext.entrySet()) {
-        SerializableValue jsValueBase = entry.getValue();
-        String commandParamName;
-        if (thisObjectId == null && jsValueBase.getRefId() != null) {
-          commandParamName = "this";
-          thisObjectId = jsValueBase.getRefId();
-        } else {
-          commandParamName = "p" + additionalObjectIds.size();
-          CallArgumentParam callArgumentParam = jsValueBase.createCallArgumentParam();
-          if (callArgumentParam == null) {
-            throw new IllegalArgumentException("Cannot serialize additional context property " +
-                entry.getKey());
-          }
-          additionalObjectIds.add(callArgumentParam);
-          if (parametersBuilder.length() != 0) {
-            parametersBuilder.append(", ");
-          }
-          parametersBuilder.append(commandParamName);
-        }
-        assigmentBuilder.append(tempObjectRef + entry.getKey() + " = " + commandParamName + ";\n");
-      }
-      if (thisObjectId == null) {
-        // TODO: remove this limitation in protocol.
-        throw new IllegalArgumentException("At least one additional parameter must be an object");
-      }
-
-      final String functionText = "function(" + parametersBuilder + ") { " +
-          GLOBAL_VARIABLE_NAME + ".data." + dataId + " = {};\n" +
-          assigmentBuilder + "}";
-
-      final String thisObjectIdFinal = thisObjectId;
-
-      return new WipRelayRunner.SendStepWithResponse<CallFunctionOnData, ResultOrException>() {
-        @Override
-        public WipParamsWithResponse<CallFunctionOnData> getParams() {
-          List<CallArgumentParam> arguments;
-          if (additionalObjectIds.isEmpty()) {
-            arguments = null;
-          } else {
-            arguments = additionalObjectIds;
-          }
-          return new CallFunctionOnParams(thisObjectIdFinal, functionText, arguments, null, true);
-        }
-
-        @Override
-        public Step<ResultOrException> processResponse(CallFunctionOnData response) {
-          if (response.wasThrown() == Boolean.TRUE) {
-            return createHandleErrorStep(response.result());
-          }
-          return createEvaluateStep(evaluateCommandHandler);
-        }
-
-        @Override
-        public Exception processFailure(Exception cause) {
-          return cause;
-        }
-      };
-    }
-
-    private <EVAL_DATA> WipRelayRunner.Step<ResultOrException> createEvaluateStep(
-        final EvaluateCommandHandler<EVAL_DATA> commandHandler) {
-      return new WipRelayRunner.SendStepWithResponse<EVAL_DATA, ResultOrException>() {
-        @Override
-        public WipParamsWithResponse<EVAL_DATA> getParams() {
-          String script = "with (" + GLOBAL_VARIABLE_NAME + ".data." + dataId +
-              ") { return (" + userExpression + "); }";
-          String wrappedExpression = "(function() {" + script +"})()";
-
-          WipParamsWithResponse<EVAL_DATA> paramsWithResponse = commandHandler.createRequest(
-              wrappedExpression, destinationValueLoader);
-
-          return paramsWithResponse;
-        }
-
-        @Override
-        public Step<ResultOrException> processResponse(EVAL_DATA response) {
-          ResultOrException resultOrException =
-              commandHandler.processResult(response, destinationValueLoader, valueNameBuidler);
-
-          clearTempObjectAsync();
-
-          return WipRelayRunner.createFinalStep(resultOrException);
-        }
-
-        @Override
-        public Exception processFailure(Exception cause) {
-          return commandHandler.processFailure(cause);
-        }
-      };
-    }
-
-    /**
-     * Clears the temporary object. It is done asynchronously, outside the main relay, because
-     * user shouldn't wait for its result.
-     */
-    private void clearTempObjectAsync() {
-      String script = "delete " + GLOBAL_VARIABLE_NAME + ".data." + dataId + ";";
-      String deleteDataExpression = "(function() {" + script +"})()";
-      EvaluateParams evaluateParams =
-          new EvaluateParams(deleteDataExpression, null, null, null, null, true);
-      tabImpl.getCommandProcessor().send(evaluateParams, (WipCommandCallback) null, null);
-    }
-
-    /**
-     * An alternative spin-off in the relay, that handles an exception we ran into.
-     * The additional step is needed because the exception message is only available from
-     * its 'message' pseudo-property (a getter).
-     */
-    private Step<ResultOrException> createHandleErrorStep(final RemoteObjectValue remoteObjectValue) {
-      return new WipRelayRunner.SendStepWithResponse<CallFunctionOnData, ResultOrException>() {
-        @Override
-        public WipParamsWithResponse<CallFunctionOnData> getParams() {
-          String functionText = "function() { return String(this.message); }";
-          return new CallFunctionOnParams(remoteObjectValue.objectId(), functionText, null, null, true);
-        }
-
-        @Override
-        public Step<ResultOrException> processResponse(CallFunctionOnData response)
-            throws ProcessException {
-          throw new ProcessException("Helper script failed on remote: " +
-              response.result().value());
-        }
-
-        @Override
-        public Exception processFailure(Exception cause) {
-          return cause;
-        }
-      };
-    }
-  }
-
-  /**
-   * Makes sure that we injected a helper object inside a global object.
-   * This cannot be implemented as step in {@link WipRelayRunner}, because the method
-   * is synchronized and cannot undergo required control inversion.
-   */
-  private synchronized RelayOk ensureObjectInjected(GenericCallback<Void> callback,
-      SyncCallback syncCallback) {
-    if (objectInjected) {
-      callback.success(null);
-      return RelaySyncCallback.finish(syncCallback);
-    } else {
-      objectInjected = true;
-      return injectObject(callback, syncCallback);
-    }
-  }
-
-  private RelayOk injectObject(final GenericCallback<Void> callback, SyncCallback syncCallback) {
-    // 'data' is for temporary objects.
-    // 'code' is for utility methods.
-    String injectedObjectText = "{ data: {}, code: {}}";
-    String expression = "(function() { " + GLOBAL_VARIABLE_NAME + " = " + injectedObjectText +
-        " ; })()";
-
-    EvaluateParams evaluateParams = new EvaluateParams(expression, null, false, null, null, true);
-
-    GenericCallback<EvaluateData> wrappedCallback = new GenericCallback<EvaluateData>() {
-      @Override
-      public void success(EvaluateData value) {
-        // TODO: check result.
-        callback.success(null);
-      }
-
-      @Override
-      public void failure(Exception exception) {
-        callback.failure(new Exception("Failed to inject evaluate helper script into remote VM",
-            exception));
-      }
-    };
-
-    return tabImpl.getCommandProcessor().send(evaluateParams, wrappedCallback, syncCallback);
-  }
-
-  private static final String GLOBAL_VARIABLE_NAME = "_com_chromium_debug_helper";
-}