support sending back rows changed

Previously we would only return a result for sql commands that were
selct statements. This diff makes `DatabasePeerManager` aware of what
commands are being executed and returns a result set appropriate to that
command.

Note: We are returning a result for all commands (including ones that do
not normally contain results like CREATE TABLE). We do this so that the
inspector interface will not remove the command.

Closes #82

stetho/src/main/java/com/facebook/stetho/Stetho.java

@@ -1,3 +1,5 @@
+// Copyright 2015-present Facebook. All Rights Reserved.
+
 package com.facebook.stetho;
 
 import com.facebook.stetho.inspector.database.DefaultDatabaseFilesProvider;
@@ -26,6 +28,7 @@
 import com.facebook.stetho.inspector.protocol.module.DOM;
 import com.facebook.stetho.inspector.protocol.module.DOMStorage;
 import com.facebook.stetho.inspector.protocol.module.Database;
+import com.facebook.stetho.inspector.protocol.module.DatabaseConstants;
 import com.facebook.stetho.inspector.protocol.module.Debugger;
 import com.facebook.stetho.inspector.protocol.module.HeapProfiler;
 import com.facebook.stetho.inspector.protocol.module.Inspector;
@@ -115,7 +118,7 @@ public Iterable<ChromeDevtoolsDomain> get() {
         modules.add(new Profiler());
         modules.add(new Runtime());
         modules.add(new Worker());
-        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
+        if (Build.VERSION.SDK_INT >= DatabaseConstants.MIN_API_LEVEL) {
           modules.add(new Database(context, new DefaultDatabaseFilesProvider(context)));
         }
         return modules;

stetho/src/main/java/com/facebook/stetho/inspector/database/DatabasePeerManager.java

@@ -11,16 +11,19 @@
 import java.util.ArrayList;
 import java.util.List;
 
+import android.annotation.TargetApi;
 import android.content.Context;
 import android.database.Cursor;
 import android.database.sqlite.SQLiteDatabase;
 import android.database.sqlite.SQLiteException;
+import android.database.sqlite.SQLiteStatement;
 
 import com.facebook.stetho.common.Util;
 import com.facebook.stetho.inspector.helper.ChromePeerManager;
 import com.facebook.stetho.inspector.helper.PeerRegistrationListener;
 import com.facebook.stetho.inspector.jsonrpc.JsonRpcPeer;
 import com.facebook.stetho.inspector.protocol.module.Database;
+import com.facebook.stetho.inspector.protocol.module.DatabaseConstants;
 
 @ThreadSafe
 public class DatabasePeerManager extends ChromePeerManager {
@@ -129,17 +132,67 @@ public <T> T executeSQL(String databaseName, String query, ExecuteResultHandler<
     Util.throwIfNull(handler);
     SQLiteDatabase database = openDatabase(databaseName);
     try {
-      Cursor cursor = database.rawQuery(query, null);
-      try {
-        return handler.handleResult(cursor);
-      } finally {
-        cursor.close();
+      String firstWord = getFirstWord(query);
+
+      if (firstWord.equalsIgnoreCase("UPDATE") || firstWord.equalsIgnoreCase("DELETE")) {
+        return executeUpdateDelete(database, query, handler);
+      } else if (firstWord.equalsIgnoreCase("INSERT")) {
+        return executeInsert(database, query, handler);
+      } else if (firstWord.equalsIgnoreCase("SELECT")) {
+        return executeSelect(database, query, handler);
+      } else {
+        return executeRawQuery(database, query, handler);
       }
+
     } finally {
       database.close();
     }
   }
 
+  private static String getFirstWord(String s) {
+    s.trim();
+    int firstSpace = s.indexOf(' ');
+    return firstSpace >= 0 ? s.substring(0, firstSpace) : s;
+  }
+
+  @TargetApi(DatabaseConstants.MIN_API_LEVEL)
+  private <T> T executeUpdateDelete(
+      SQLiteDatabase database,
+      String query,
+      ExecuteResultHandler<T> handler) {
+    SQLiteStatement statement = database.compileStatement(query);
+    int count = statement.executeUpdateDelete();
+    return handler.handleUpdateDelete(count);
+  }
+
+  private <T> T executeInsert(
+      SQLiteDatabase database,
+      String query,
+      ExecuteResultHandler<T> handler) {
+    SQLiteStatement statement = database.compileStatement(query);
+    long count = statement.executeInsert();
+    return handler.handleInsert(count);
+  }
+
+  private <T> T executeSelect(
+      SQLiteDatabase database,
+      String query,
+      ExecuteResultHandler<T> handler) {
+    Cursor cursor = database.rawQuery(query, null);
+    try {
+      return handler.handleSelect(cursor);
+    } finally {
+      cursor.close();
+    }
+  }
+
+  private <T> T executeRawQuery(
+      SQLiteDatabase database,
+      String query,
+      ExecuteResultHandler<T> handler) {
+    database.execSQL(query);
+    return handler.handleRawQuery();
+  }
   private SQLiteDatabase openDatabase(String databaseName) throws SQLiteException {
     Util.throwIfNull(databaseName);
     File databaseFile = mContext.getDatabasePath(databaseName);
@@ -151,7 +204,13 @@ private SQLiteDatabase openDatabase(String databaseName) throws SQLiteException
   }
 
   public interface ExecuteResultHandler<T> {
-    public T handleResult(Cursor result) throws SQLiteException;
+    public T handleRawQuery() throws SQLiteException;
+
+    public T handleSelect(Cursor result) throws SQLiteException;
+
+    public T handleInsert(long insertedId) throws SQLiteException;
+
+    public T handleUpdateDelete(int count) throws SQLiteException;
   }
 
   private final PeerRegistrationListener mPeerRegistrationListener =

stetho/src/main/java/com/facebook/stetho/inspector/protocol/module/Database.java

@@ -5,6 +5,7 @@
 import com.facebook.stetho.inspector.database.DatabaseFilesProvider;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.List;
 
 import android.annotation.TargetApi;
@@ -85,12 +86,38 @@ public JsonRpcResult executeSQL(JsonRpcPeer peer, JSONObject params) {
       return mDatabasePeerManager.executeSQL(request.databaseId, request.query,
           new DatabasePeerManager.ExecuteResultHandler<ExecuteSQLResponse>() {
         @Override
-        public ExecuteSQLResponse handleResult(Cursor result) throws SQLiteException {
+        public ExecuteSQLResponse handleRawQuery() throws SQLiteException {
+          ExecuteSQLResponse response = new ExecuteSQLResponse();
+          // This is done because the inspector UI likes to delete rows if you give them no
+          // name/value list
+          response.columnNames = Arrays.asList("success");
+          response.values = Arrays.asList((Object) "true");
+          return response;
+        }
+
+        @Override
+        public ExecuteSQLResponse handleSelect(Cursor result) throws SQLiteException {
           ExecuteSQLResponse response = new ExecuteSQLResponse();
           response.columnNames = Arrays.asList(result.getColumnNames());
           response.values = flattenRows(result, MAX_EXECUTE_RESULTS);
           return response;
         }
+
+        @Override
+        public ExecuteSQLResponse handleInsert(long insertedId) throws SQLiteException {
+          ExecuteSQLResponse response = new ExecuteSQLResponse();
+          response.columnNames = Arrays.asList("ID of last inserted row");
+          response.values = Arrays.asList((Object) insertedId);
+          return response;
+        }
+
+        @Override
+        public ExecuteSQLResponse handleUpdateDelete(int count) throws SQLiteException {
+          ExecuteSQLResponse response = new ExecuteSQLResponse();
+          response.columnNames = Arrays.asList("Modified rows");
+          response.values = Arrays.asList((Object) count);
+          return response;
+        }
       });
     } catch (SQLiteException e) {
       Error error = new Error();

stetho/src/main/java/com/facebook/stetho/inspector/protocol/module/DatabaseConstants.java

@@ -0,0 +1,13 @@
+// Copyright 2015-present Facebook. All Rights Reserved.
+
+package com.facebook.stetho.inspector.protocol.module;
+
+import android.os.Build;
+
+public interface DatabaseConstants {
+
+  /**
+   * Minimum API version required to use the {@link Database}.
+   */
+  public static final int MIN_API_LEVEL = Build.VERSION_CODES.HONEYCOMB;
+}