Examples with GeneratedClass org.apache.derby.iapi.services.loader.GeneratedClass used on opensource projects

Example 1 with GeneratedClass

use of org.apache.derby.iapi.services.loader.GeneratedClass in project derby by apache.

the class GenericPreparedStatement method getActivation.

/**
 * Get a new activation instance.
 *
 * @exception StandardException thrown if finished.
 */
public Activation getActivation(LanguageConnectionContext lcc, boolean scrollable) throws StandardException {
    Activation ac;
    synchronized (this) {
        GeneratedClass gc = getActivationClass();
        if (gc == null) {
            rePrepare(lcc);
            gc = getActivationClass();
        }
        ac = new GenericActivationHolder(lcc, gc, this, scrollable);
        inUseCount++;
    }
    // DERBY-2689. Close unused activations-- this method should be called
    // when I'm not holding a lock on a prepared statement to avoid
    // deadlock.
    lcc.closeUnusedActivations();
    Activation parentAct = null;
    StatementContext stmctx = lcc.getStatementContext();
    if (stmctx != null) {
        // If not null, parentAct represents one of 1) the activation of a
        // calling statement and this activation corresponds to a statement
        // inside a stored procedure or function, and 2) the activation of
        // a statement that performs a substatement, e.g. trigger body
        // execution.
        parentAct = stmctx.getActivation();
    }
    ac.setParentActivation(parentAct);
    return ac;
}

Example 2 with GeneratedClass

use of org.apache.derby.iapi.services.loader.GeneratedClass in project derby by apache.

the class GenericStorablePreparedStatement method loadGeneratedClass.

// ///////////////////////////////////////////////////////////
// 
// STORABLEPREPAREDSTATEMENT INTERFACE
// 
// ///////////////////////////////////////////////////////////
/**
 * Load up the class from the saved bytes.
 *
 * @exception StandardException on error
 */
public void loadGeneratedClass() throws StandardException {
    LanguageConnectionContext lcc = (LanguageConnectionContext) getContext(LanguageConnectionContext.CONTEXT_ID);
    ClassFactory classFactory = lcc.getLanguageConnectionFactory().getClassFactory();
    GeneratedClass gc = classFactory.loadGeneratedClass(className, byteCode);
    /*
		** No special try catch logic to write out bad classes
		** here.  We don't expect any problems, and in any 
		** event, we don't have the class builder available
		** here.
		*/
    setActivationClass(gc);
}

Example 3 with GeneratedClass

use of org.apache.derby.iapi.services.loader.GeneratedClass in project derby by apache.

the class StatementNode method generate.

/**
 * Do code generation for this statement.
 *
 * @param byteCode	the generated byte code for this statement.
 *			if non-null, then the byte code is saved
 *			here.
 *
 * @return		A GeneratedClass for this statement
 *
 * @exception StandardException		Thrown on error
 */
public GeneratedClass generate(ByteArray byteCode) throws StandardException {
    // start the new activation class.
    // it starts with the Execute method
    // and the appropriate superclass (based on
    // statement type, from inspecting the queryTree).
    int nodeChoice = activationKind();
    /* RESOLVE: Activation hierarchy was way too complicated
		 * and added no value.  Simple thing to do was to simply
		 * leave calling code alone and to handle here and to
		 * eliminate unnecessary classes.
		 */
    String superClass;
    switch(nodeChoice) {
        case NEED_CURSOR_ACTIVATION:
            superClass = ClassName.CursorActivation;
            break;
        case NEED_DDL_ACTIVATION:
            return getClassFactory().loadGeneratedClass("org.apache.derby.impl.sql.execute.ConstantActionActivation", null);
        case NEED_NOTHING_ACTIVATION:
        case NEED_ROW_ACTIVATION:
        case NEED_PARAM_ACTIVATION:
            superClass = ClassName.BaseActivation;
            break;
        default:
            throw StandardException.newException(SQLState.LANG_UNAVAILABLE_ACTIVATION_NEED, String.valueOf(nodeChoice));
    }
    ActivationClassBuilder generatingClass = new ActivationClassBuilder(superClass, getCompilerContext());
    // Create the method that generates the ResultSet tree used when
    // executing this statement. Implements the abstract method
    // BaseActivation.createResultSet().
    MethodBuilder mbWorker = generatingClass.getClassBuilder().newMethodBuilder(Modifier.PROTECTED, ClassName.ResultSet, "createResultSet");
    mbWorker.addThrownException(ClassName.StandardException);
    // Generate the complete ResultSet tree for this statement.
    // This step may add statements into the execute method
    // for per-execution actions.
    generate(generatingClass, mbWorker);
    mbWorker.methodReturn();
    mbWorker.complete();
    // wrap up the activation class definition
    // generate on the tree gave us back the newExpr
    // for getting a result set on the tree.
    // we put it in a return statement and stuff
    // it in the execute method of the activation.
    // The generated statement is the expression:
    // the activation class builder takes care of constructing it
    // for us, given the resultSetExpr to use.
    // return (this.resultSet = #resultSetExpr);
    generatingClass.finishExecuteMethod();
    // wrap up the constructor by putting a return at the end of it
    generatingClass.finishConstructor();
    try {
        // cook the completed class into a real class
        // and stuff it into activationClass
        GeneratedClass activationClass = generatingClass.getGeneratedClass(byteCode);
        return activationClass;
    } catch (StandardException e) {
        String msgId = e.getMessageId();
        if (SQLState.GENERATED_CLASS_LIMIT_EXCEEDED.equals(msgId) || SQLState.GENERATED_CLASS_LINKAGE_ERROR.equals(msgId)) {
            throw StandardException.newException(SQLState.LANG_QUERY_TOO_COMPLEX, e);
        }
        throw e;
    }
}

Example 4 with GeneratedClass

use of org.apache.derby.iapi.services.loader.GeneratedClass in project derby by apache.

the class GenericLanguageConnectionContext method lookupStatement.

/**
 * See if a given statement has already been compiled for this user, and
 * if so use its prepared statement. Returns null if not found.
 *
 * @exception StandardException thrown if lookup goes wrong.
 * @return the prepared statement for the given string, null
 *  if none was found.
 */
public PreparedStatement lookupStatement(GenericStatement statement) throws StandardException {
    CacheManager statementCache = getLanguageConnectionFactory().getStatementCache();
    if (statementCache == null)
        return null;
    // statement caching disable when in DDL mode
    if (dataDictionaryInWriteMode()) {
        return null;
    }
    Cacheable cachedItem = statementCache.find(statement);
    CachedStatement cs = (CachedStatement) cachedItem;
    GenericPreparedStatement ps = cs.getPreparedStatement();
    synchronized (ps) {
        if (ps.upToDate()) {
            GeneratedClass ac = ps.getActivationClass();
            // Check to see if the statement was prepared before some change
            // in the class loading set. If this is the case then force it to be invalid
            int currentClasses = getLanguageConnectionFactory().getClassFactory().getClassLoaderVersion();
            if (ac.getClassLoaderVersion() != currentClasses) {
                ps.makeInvalid(DependencyManager.INTERNAL_RECOMPILE_REQUEST, this);
            }
        // note that the PreparedStatement is not kept in the cache. This is because
        // having items kept in the cache that ultimately are held onto by
        // user code is impossible to manage. E.g. an open ResultSet would hold onto
        // a PreparedStatement (through its activation) and the user can allow
        // this object to be garbage collected. Pushing a context stack is impossible
        // in garbage collection as it may deadlock with the open connection and
        // the context manager assumes a singel current thread per context stack
        }
    }
    statementCache.release(cachedItem);
    return ps;
}

Example 5 with GeneratedClass

use of org.apache.derby.iapi.services.loader.GeneratedClass in project derby by apache.

the class ExecSPSNode method generate.

/**
 * Do code generation for this statement.  Overrides
 * the normal generation path in StatementNode.
 *
 * @param	ignored - ignored (he he)
 *
 * @return		A GeneratedClass for this statement
 *
 * @exception StandardException		Thrown on error
 */
@Override
public GeneratedClass generate(ByteArray ignored) throws StandardException {
    // table during stale sps recompilation later in the getPreparedstatement() call.
    if (spsd.isValid() == false) {
        getLanguageConnectionContext().commitNestedTransaction();
        getLanguageConnectionContext().beginNestedTransaction(true);
    }
    /*
		** The following does a prepare on the underlying
		** statement if necessary.  The returned statement
		** is valid and its class is loaded up.
		*/
    ps = spsd.getPreparedStatement();
    /*
		** Set the saved constants from the prepared statement.
		** Put them in the compilation context -- this is where
		** they are expected.
		*/
    getCompilerContext().setSavedObjects(ps.getSavedObjects());
    getCompilerContext().setCursorInfo(ps.getCursorInfo());
    GeneratedClass gc = ps.getActivationClass();
    return gc;
}