C# BerkeleyDB.CursorConfig类代码示例

 public void GetCursur(string dbFileName, bool ifConfig)
 {
     HeapDatabaseConfig dbConfig = new HeapDatabaseConfig();
     dbConfig.Creation = CreatePolicy.IF_NEEDED;
     HeapDatabase db = HeapDatabase.Open(dbFileName, dbConfig);
     HeapRecordId rid = db.Append(
         new DatabaseEntry(BitConverter.GetBytes((int)1)));
     Cursor cursor;
     CursorConfig cursorConfig = new CursorConfig();
     cursorConfig.Priority = CachePriority.HIGH;
     if (ifConfig == false)
         cursor = db.Cursor();
     else
         cursor = db.Cursor(cursorConfig);
     cursor.Add(new KeyValuePair<DatabaseEntry, DatabaseEntry>(
         new DatabaseEntry(rid.toArray()),
         new DatabaseEntry(BitConverter.GetBytes((int)2))));
     Cursor dupCursor = cursor.Duplicate(false);
     Assert.IsNull(dupCursor.Current.Key);
     if (ifConfig)
         Assert.AreEqual(CachePriority.HIGH, dupCursor.Priority);
     dupCursor.Close();
     cursor.Close();
     db.Close();
 }

        // Get a cursor in CDS.
        public static void GetCursorInBtreeDBInCDS(
            string home, string name,
            CursorConfig cursorConfig,
            out DatabaseEnvironment env, out BTreeDatabase db,
            out BTreeCursor cursor)
        {
            string dbFileName = name + ".db";

            // Open an environment.
            DatabaseEnvironmentConfig envConfig =
                new DatabaseEnvironmentConfig();
            envConfig.Create = true;
            envConfig.UseCDB = true;
            envConfig.UseMPool = true;
            env = DatabaseEnvironment.Open(home, envConfig);

            /*
             * Open an btree database. The underlying database
             * should be opened with ReadUncommitted if the
             * cursor's isolation degree will be set to be 1.
             */
            BTreeDatabaseConfig dbConfig = new BTreeDatabaseConfig();
            dbConfig.Creation = CreatePolicy.IF_NEEDED;
            dbConfig.Env = env;

            if (cursorConfig.IsolationDegree == Isolation.DEGREE_ONE)
                dbConfig.ReadUncommitted = true;

            db = BTreeDatabase.Open(dbFileName, dbConfig);

            // Get a cursor in the transaction.
            cursor = db.Cursor(cursorConfig);
        }

        public void GetSecondaryCursurWithTxn(string home,
		    string name, bool ifCfg)
        {
            string dbFileName = name + ".db";
            SecondaryCursor cursor;

            // Open env.
            DatabaseEnvironmentConfig envConfig =
                new DatabaseEnvironmentConfig();
            envConfig.Create = true;
            envConfig.UseTxns = true;
            envConfig.UseMPool = true;
            DatabaseEnvironment env = DatabaseEnvironment.Open(home,
                envConfig);

            // Open primary/secondary database.
            Transaction txn = env.BeginTransaction();
            BTreeDatabaseConfig dbConfig = new BTreeDatabaseConfig();
            dbConfig.Creation = CreatePolicy.IF_NEEDED;
            dbConfig.Env = env;
            BTreeDatabase db = BTreeDatabase.Open(dbFileName,
                dbConfig, txn);

            SecondaryBTreeDatabaseConfig secDBConfig = new
                SecondaryBTreeDatabaseConfig(db,
                new SecondaryKeyGenDelegate(SecondaryKeyGen));
            secDBConfig.Env = env;
            SecondaryBTreeDatabase secDB =
                SecondaryBTreeDatabase.Open(dbFileName,
                secDBConfig, txn);

            for (int i = 0; i < 10; i++)
                db.Put(new DatabaseEntry(BitConverter.GetBytes(i)),
                    new DatabaseEntry(BitConverter.GetBytes((int)i)), txn);

            // Create secondary cursor.
            if (ifCfg == false)
                secDB.SecondaryCursor(txn);
            else if (ifCfg == true)
            {
                CursorConfig cursorConfig = new CursorConfig();
                cursorConfig.WriteCursor = false;
                cursor = secDB.SecondaryCursor(cursorConfig, txn);
                cursor.Close();
            }

            secDB.Close();
            db.Close();
            txn.Commit();
            env.Close();
        }

 public void TestConfig()
 {
     testName = "TestConfig";
     SetUpTest(false);
     /*
      * Configure the fields/properties and see if
      * they are updated successfully.
      */
     CursorConfig cursorConfig = new CursorConfig();
     XmlElement xmlElem = Configuration.TestSetUp(
         testFixtureName, testName);
     Config(xmlElem, ref cursorConfig, true);
     Confirm(xmlElem, cursorConfig, true);
 }

        public static void Config(XmlElement xmlElement, 
		    ref CursorConfig cursorConfig, bool compulsory)
        {
            Configuration.ConfigIsolation(xmlElement,
                "IsolationDegree", ref cursorConfig.IsolationDegree,
                compulsory);
            Configuration.ConfigCachePriority(xmlElement,
                "Priority", ref cursorConfig.Priority, compulsory);
            Configuration.ConfigBool(xmlElement,
                "SnapshotIsolation", ref cursorConfig.SnapshotIsolation,
                compulsory);
            Configuration.ConfigBool(xmlElement,
                "WriteCursor", ref cursorConfig.WriteCursor,
                compulsory);
        }

        public void TestPriority()
        {
            BTreeCursor cursor;
            BTreeDatabase db;
            CachePriority[] priorities;
            CursorConfig cursorConfig;
            DatabaseEnvironment env;

            cursorConfig = new CursorConfig();

            priorities = new CachePriority[5];
            priorities[0] = CachePriority.DEFAULT;
            priorities[1] = CachePriority.HIGH;
            priorities[2] = CachePriority.LOW;
            priorities[3] = CachePriority.VERY_HIGH;
            priorities[4] = CachePriority.VERY_LOW;

            testName = "TestPriority";
            testHome = testFixtureHome + "/" + testName;

            Configuration.ClearDir(testHome);

            for (int i = 0; i < 5; i++)
            {
                // Configure the cursor priority.
                cursorConfig.Priority = priorities[i];

                // Open a database to test a specified priority.
                GetCursorInBtreeDBInCDS(testHome, testName,
                    cursorConfig, out env, out db, out cursor);
                Assert.AreEqual(priorities[i], cursorConfig.Priority);
                cursor.Close();
                db.Close();
                env.Close();
            }
        }

        /*
         * This simply counts the number of records contained in the
         * database and returns the result. You can use this method
         * in three ways:
         *
         * First call it with an active txn handle.
         * Secondly, configure the cursor for dirty reads
         * Third, call countRecords AFTER the writer has committed
         * its transaction.
         *
         * If you do none of these things, the writer thread will
         * self-deadlock.
         *
         * Note that this method exists only for illustrative purposes.
         * A more straight-forward way to count the number of records in
         * a database is to use the Database.getStats() method.
         */
        private int CountRecords(Transaction txn)
        {
            int count = 0;
            Cursor cursor = null;

            try {
                // Get the cursor.
                CursorConfig cc = new CursorConfig();

                /*
                 * Isolation degree one is ignored if the
                 * database was not opened for uncommitted
                 * read support. TxnGuide opens its database
                 * in this way and TxnGuideInMemory does not.
                 */
                cc.IsolationDegree = Isolation.DEGREE_ONE;
                cursor = db.Cursor(cc, txn);
                while (cursor.MoveNext())
                    count++;
            } finally {
                if (cursor != null)
                    cursor.Close();
            }

            return count;
        }

 /// <summary>
 /// Create a secondary database cursor with the given configuration.
 /// </summary>
 /// <param name="cfg">
 /// The configuration properties for the cursor.
 /// </param>
 /// <returns>A newly created cursor</returns>
 public SecondaryCursor SecondaryCursor(CursorConfig cfg) {
     return SecondaryCursor(cfg, null);
 }

        public void ReadTxn()
        {
            // Get a new transaction for reading the db.
            TransactionConfig txnConfig =
                new TransactionConfig();
            txnConfig.Snapshot = true;
            readTxn = paramEnv.BeginTransaction(
                txnConfig);

            // Get a new cursor for putting record into db.
            CursorConfig cursorConfig = new CursorConfig();
            cursorConfig.WriteCursor = false;
            BTreeCursor cursor = paramDB.Cursor(
                cursorConfig, readTxn);

            // Continually reading record from db.
            try
            {
                Assert.IsTrue(cursor.MoveFirst());
                int i = 0;
                do
                {
                    Assert.AreEqual(
                        BitConverter.ToInt32(
                        cursor.Current.Key.Data, 0),
                        BitConverter.ToInt32(
                        cursor.Current.Value.Data, 0));
                } while (i <= 1000 && cursor.MoveNext());
            }
            catch (DeadlockException)
            {
            }
            finally
            {
                cursor.Close();
            }
        }

        public void TestPriority()
        {
            CachePriority[] priorities;
            CursorConfig cursorConfig;

            testName = "TestPriority";
            SetUpTest(true);
            cursorConfig = new CursorConfig();
            priorities = new CachePriority[6];
            priorities[0] = CachePriority.DEFAULT;
            priorities[1] = CachePriority.HIGH;
            priorities[2] = CachePriority.LOW;
            priorities[3] = CachePriority.VERY_HIGH;
            priorities[4] = CachePriority.VERY_LOW;
            priorities[5] = null;

            for (int i = 0; i < 6; i++) {
                if (priorities[i] != null) {
                    cursorConfig.Priority = priorities[i];
                    Assert.AreEqual(priorities[i], cursorConfig.Priority);
                }
                GetCursorWithConfig(testHome + "/" + testName + ".db",
                    DatabaseType.BTREE.ToString(), cursorConfig, DatabaseType.BTREE);
                GetCursorWithConfig(testHome + "/" + testName + ".db",
                    DatabaseType.HASH.ToString(), cursorConfig, DatabaseType.HASH);
                GetCursorWithConfig(testHome + "/" + testName + ".db",
                    DatabaseType.QUEUE.ToString(), cursorConfig, DatabaseType.QUEUE);
                GetCursorWithConfig(testHome + "/" + testName + ".db",
                    DatabaseType.RECNO.ToString(), cursorConfig, DatabaseType.RECNO);
            }
        }

        public static void GetCursorInBtreeDBInTDS(
		    string home, string name,
		    CursorConfig cursorConfig,
		    out DatabaseEnvironment env, out BTreeDatabase db,
		    out BTreeCursor cursor, out Transaction txn)
        {
            string dbFileName = name + ".db";

            Configuration.ClearDir(home);

            // Open an environment.
            DatabaseEnvironmentConfig envConfig =
                new DatabaseEnvironmentConfig();
            envConfig.Create = true;
            envConfig.UseMPool = true;
            envConfig.UseTxns = true;
            envConfig.NoMMap = false;
            envConfig.UseLocking = true;
            env = DatabaseEnvironment.Open(home, envConfig);

            // Begin a transaction.
            txn = env.BeginTransaction();

            /*
             * Open an btree database. The underlying database
             * should be opened with ReadUncommitted if the
             * cursor's isolation degree will be set to be 1.
             */
            BTreeDatabaseConfig dbConfig = new BTreeDatabaseConfig();
            dbConfig.Creation = CreatePolicy.IF_NEEDED;
            dbConfig.Env = env;
            if (cursorConfig != null &&
                cursorConfig.IsolationDegree == Isolation.DEGREE_ONE)
                dbConfig.ReadUncommitted = true;

            db = BTreeDatabase.Open(dbFileName, dbConfig, txn);

            // Get a cursor in the transaction.
            if (cursorConfig != null)
                cursor = db.Cursor(cursorConfig, txn);
            else
                cursor = db.Cursor(txn);
        }

 /// <summary>
 /// Create a database cursor with the given configuration.
 /// </summary>
 /// <param name="cfg">
 /// The configuration properties for the cursor.
 /// </param>
 /// <returns>A newly created cursor</returns>
 public Cursor Cursor(CursorConfig cfg)
 {
     return Cursor(cfg, null);
 }

 /// <summary>
 /// Create a transactionally protected database cursor with the given
 /// configuration.
 /// </summary>
 /// <param name="cfg">
 /// The configuration properties for the cursor.
 /// </param>
 /// <param name="txn">
 /// The transaction context in which the cursor may be used.
 /// </param>
 /// <returns>A newly created cursor</returns>
 public new HashCursor Cursor(CursorConfig cfg, Transaction txn)
 {
     return new HashCursor(
         db.cursor(Transaction.getDB_TXN(txn), cfg.flags), Pagesize);
 }

        public void TestWriteCursor()
        {
            BTreeCursor cursor;
            BTreeDatabase db;
            CursorConfig cursorConfig;
            DatabaseEnvironment env;

            testName = "TestWriteCursor";
            testHome = testFixtureHome + "/" + testName;

            Configuration.ClearDir(testHome);

            cursorConfig = new CursorConfig();
            cursorConfig.WriteCursor = true;

            GetCursorInBtreeDBInCDS(testHome, testName,
                cursorConfig, out env, out db, out cursor);

            /*
             * Add a record by cursor to the database. If the
             * WriteCursor doesn't work, exception will be
             * throwed in the environment which is configured
             * with DB_INIT_CDB.
             */
            try
            {
                AddOneByCursor(db, cursor);
            }
            catch (DatabaseException)
            {
                throw new TestException();
            }
            finally
            {
                cursor.Close();
                db.Close();
                env.Close();
            }
        }

        private void GetCursorWithConfig(string dbFile, string dbName, 
		    CursorConfig cfg, DatabaseType type)
        {
            Database db;
            Cursor cursor;
            Configuration.ClearDir(testHome);
            if (type == DatabaseType.BTREE) {
                BTreeDatabaseConfig dbConfig = new BTreeDatabaseConfig();
                dbConfig.Creation = CreatePolicy.IF_NEEDED;
                db = BTreeDatabase.Open(dbFile, dbName, dbConfig);
                cursor = ((BTreeDatabase)db).Cursor(cfg);
            } else if (type == DatabaseType.HASH) {
                HashDatabaseConfig dbConfig = new HashDatabaseConfig();
                dbConfig.Creation = CreatePolicy.IF_NEEDED;
                db = (HashDatabase)HashDatabase.Open(dbFile, dbName, dbConfig);
                cursor = ((HashDatabase)db).Cursor(cfg);
            } else if (type == DatabaseType.QUEUE) {
                QueueDatabaseConfig dbConfig = new QueueDatabaseConfig();
                dbConfig.Creation = CreatePolicy.IF_NEEDED;
                dbConfig.Length = 100;
                db = QueueDatabase.Open(dbFile, dbConfig);
                cursor = ((QueueDatabase)db).Cursor(cfg);
            } else if (type == DatabaseType.RECNO) {
                RecnoDatabaseConfig dbConfig = new RecnoDatabaseConfig();
                dbConfig.Creation = CreatePolicy.IF_NEEDED;
                db = RecnoDatabase.Open(dbFile, dbName, dbConfig);
                cursor = ((RecnoDatabase)db).Cursor(cfg);
            } else
                throw new TestException();

            if (cfg.Priority != null)
                Assert.AreEqual(cursor.Priority, cfg.Priority);
            else
                Assert.AreEqual(CachePriority.DEFAULT, cursor.Priority);

            Cursor dupCursor = cursor.Duplicate(false);
            Assert.AreEqual(cursor.Priority, dupCursor.Priority);
            cursor.Close();
            db.Close();
        }