Working on connection management stuff.

Got rid of pool.close() and introduced pool.closeConnectionsNow and pool.closeConnectionsWhenNotInUse

CHANGELOG.md

@@ -1,6 +1,13 @@
 Changelog
 =========
 
+v0.12.0
+-------
+* Breaking change: ConnectionPool.close() has been renamed to ConnectionPool.closeConnectionsNow.
+It is a dangerous method to call as it closes all connections even if they are in the middle
+of an operation. ConnectionPool.closeConnectionsWhenNotInUse has been added, which is much
+safer.
+
 v0.11.0
 -------
 * Added support for packets larger than 16 MB. ConnectionPool's constructor has a new parameter,

README.md

@@ -90,6 +90,8 @@ Things to do
 
 * Compression
 * COM_SEND_LONG_DATA
+* CLIENT_MULTI_STATEMENTS and CLIENT_MULTI_RESULTS for stored procedures
+* More connection pool management (close after timeout, change pool size...)
 * Better handling of various data types, especially BLOBs, which behave differently when using straight queries and prepared queries.
 * Implement the rest of mysql's commands
 * Handle character sets properly? Currently defaults to UTF8 for the connection character set. Is it

lib/src/connection.dart

@@ -22,6 +22,7 @@ class _Connection {
   final Buffer _compressedHeaderBuffer;
   Buffer _dataBuffer;
   bool _readyForHeader = true;
+  bool _closeRequested = false;
 
   int _packetNumber = 0;
 
@@ -56,6 +57,15 @@ class _Connection {
     if (_socket != null) {
       _socket.close();
     }
+    _pool._removeConnection(this);
+  }
+
+  void closeWhenFinished() {
+    if (_inUse) {
+      _closeRequested = true;
+    } else {
+      close();
+    }
   }
 
   bool get inUse => _inUse;
@@ -216,11 +226,15 @@ class _Connection {
     if (autoRelease && !inTransaction) { 
       log.finest("Response finished for #$number, setting handler to null and waiting to release and reuse");
       new Future.delayed(new Duration(seconds: 0), () {
+        if (_closeRequested) {
+          close();
+          return;
+        }
         if (_inUse) {
           log.finest("Releasing and reusing connection #$number");
           _inUse = false;
           _handler = null;
-          _pool._newReuseConnection(this);
+          _pool._reuseConnectionForQueuedOperations(this);
         }
       });
     } else {

lib/src/connection_pool.dart

@@ -99,18 +99,16 @@ class ConnectionPool extends Object with _ConnectionHelpers implements Queriable
     _pool.remove(cnx);
   }
 
-/**
+  /**
    * Attempts to continue using a connection. If the connection isn't managed
    * by this pool, or if the connection is already in use, nothing happens.
    * 
    * If there are operations which have been queued in this pool, starts
    * to execute that operation. 
    * 
    * Otherwise, nothing happens.
-   * 
-   * //TODO rename to something like processQueuedOperations??
    */
-  _newReuseConnection(_Connection cnx) {
+  _reuseConnectionForQueuedOperations(_Connection cnx) {
     if (!_pool.contains(cnx)) {
       _log.warning("reuseConnection called for unmanaged connection");
       return;
@@ -138,19 +136,38 @@ class ConnectionPool extends Object with _ConnectionHelpers implements Queriable
 //    });
 //  }
 
-/**
-   * Closes all open connections. 
-   * 
+  /**
+   * Closes all open connections immediately. It doesn't wait for operations to complete.
+   *
    * WARNING: this will probably break things.
    */
-  void close() {
+  void closeConnectionsNow() {
     for (_Connection cnx in _pool) {
       if (cnx != null) {
         cnx.close();
       }
     }
   }
 
+  /**
+   * Closes all connections as soon as they are no longer in use.
+   *
+   * Retained connections will only be closed once they have been released.
+   * Connection which are in use by a transaction will only be closed
+   * once the transaction has completed.
+   *
+   * Any operations which are initiated after calling this method will be
+   * executed on new connections, even if the current operations haven't
+   * yet finished when the operation is queued.
+   */
+  void closeConnectionsWhenNotInUse() {
+    for (_Connection cnx in _pool) {
+      if (cnx != null) {
+        cnx.closeWhenFinished();
+      }
+    }
+  }
+
   Future<Results> query(String sql) {
     _log.info("Running query: ${sql}");
 

lib/src/retained_connection.dart

@@ -64,7 +64,7 @@ class _RetainedConnectionImpl extends _RetainedConnectionBase implements Retaine
 
     _cnx.inTransaction = false;
     _cnx.release();
-    _pool._newReuseConnection(_cnx);
+    _pool._reuseConnectionForQueuedOperations(_cnx);
   }
 
   void _checkReleased() {

lib/src/transaction.dart

@@ -32,7 +32,7 @@ class _TransactionImpl extends _RetainedConnectionBase implements Transaction {
       .then((results) {
         _cnx.inTransaction = false;
         _cnx.release();
-        _pool._newReuseConnection(_cnx);
+        _pool._reuseConnectionForQueuedOperations(_cnx);
         return results;
       });
   }
@@ -46,7 +46,7 @@ class _TransactionImpl extends _RetainedConnectionBase implements Transaction {
       .then((results) {
         _cnx.inTransaction = false;
         _cnx.release();
-        _pool._newReuseConnection(_cnx);
+        _pool._reuseConnectionForQueuedOperations(_cnx);
         return results;
       });
   }