Thanks for the more verbose comments. These are very helpful.
----- Original Message ----- From: "Daniel John Debrunner" <[EMAIL PROTECTED]> To: "derby-dev" <derby-dev@db.apache.org> Sent: Thursday, January 20, 2005 11:21 AM Subject: [PATCH] Cleanup of special function nodes > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > I'll apply this patch by next Monday if there are no objections. > > This patch replaces two compile time query tree nodes > CurrentUserNode.java and CurrentIsolationNode.java with a single node > SpecialFunctionNode.java. > > The driving force behind this is footprint, the Java class file format > imposes a penalty for multiple classes as String constants such as > method names, signatures and class names are repeated in each class. > E.g. if each class has a toString() method then each class will have the > constants 'java/lang/String', 'toString' etc. In addition the jar file > format has a per-class overhead. Thus moving common functionality into a > single class can reduce footprint. > > In this case the classes CurrentUserNode (3801 bytes) and > CurrentIsolation (2757) are replaced with a single class > SpecialFunctionNode (4208). > > The downside to moving functionality into single classes is that > typically more conditional code (if or switch statements) have to be > executed at runtime, and thus performance can degrade. Thus a decision > to consolidate should depend on the situation. The general rule of thumb > has been that additional conditional logic at SQL compile time is not an > issue, but is an issue at SQL execution time. Obviously in the case of > SQL execution time it depends on how frequently the piece of code is > likely to be executed by a typical application. Another consideration is > how much visual complexity is added by combining classes, if the code is > easier to understand in multiple classes then it should remain so. > > > I saw this opportunity to consolidate classes when chaging > IDENITY_VALUE_LOCAL to use Long instead of BigDecimal for the JSR 169 > preperation work. That function was implemented in CurrentUserNode.java > which seemed misleading, and then I saw that node implemented other > non-user releated functions. Looking around in the other Nodes I saw a > pattern of special functions with near identical nodes. A blatent > example was CurrentIsolationNode where it was obviously copied from > CurrentUserNode as most of the comments still indicated CurrentUserNode. > > Thus I created SpecialFunctionNode and made it have correct up to date > comments. It handles Special SQL functions which seem to have a pattern > of being implemented as a method call in LanguageConnectionContext, > though I believe other functions could be added here which are > implemented as method calls in Activation. Basically a SQL special > function returns state of the connection (session) or of the statement. > > Other Nodes I think could be consolidated into SpecialFunctionNodes are: > > GetCurrentConnectionNode - though this functionality should be removed, > it has been replaced by the standard jdbc:default:connection. There is > only one internal use of it at the moment. > > CurrentDatetimeOperatorNode - a little more involved, as some setup > state manipulation has to be added. > > > Hope this the type of explaination that shahbaz chaudhary was looking for. > > Dan. > > svn status outpur > > M java\engine\org\apache\derby\impl\sql\compile\NodeFactoryImpl.java > M java\engine\org\apache\derby\impl\sql\compile\C_NodeNames.java > M > java\engine\org\apache\derby\impl\sql\compile\ColumnDefinitionNode.java > M java\engine\org\apache\derby\impl\sql\compile\sqlgrammar.jj > M java\engine\org\apache\derby\iapi\sql\compile\C_NodeTypes.java > A > java\engine\org\apache\derby\impl\sql\compile\SpecialFunctionNode.java > D > java\engine\org\apache\derby\impl\sql\compile\CurrentIsolationNode.java > D java\engine\org\apache\derby\impl\sql\compile\CurrentUserNode.java > > > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1.2.5 (MingW32) > Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org > > iD8DBQFB8ATBIv0S4qsbfuQRAnPyAJsEsNy9xpnK3GBJVkCwaceho9WragCfXf+S > JToMu3+IEFk3zNGdmA06U4k= > =qRdp > -----END PGP SIGNATURE----- > ---------------------------------------------------------------------------- ---- > Index: java/engine/org/apache/derby/impl/sql/compile/NodeFactoryImpl.java > =================================================================== > --- java/engine/org/apache/derby/impl/sql/compile/NodeFactoryImpl.java (revision 125645) > +++ java/engine/org/apache/derby/impl/sql/compile/NodeFactoryImpl.java (working copy) > @@ -197,9 +197,6 @@ > case C_NodeTypes.GROUP_BY_LIST: > return C_NodeNames.GROUP_BY_LIST_NAME; > > - case C_NodeTypes.CURRENT_ISOLATION_NODE: > - return C_NodeNames.CURRENT_ISOLATION_NAME; > - > case C_NodeTypes.ORDER_BY_LIST: > return C_NodeNames.ORDER_BY_LIST_NAME; > > @@ -420,8 +417,14 @@ > case C_NodeTypes.CURRENT_DATETIME_OPERATOR_NODE: > return C_NodeNames.CURRENT_DATETIME_OPERATOR_NODE_NAME; > > + case C_NodeTypes.USER_NODE: > case C_NodeTypes.CURRENT_USER_NODE: > - return C_NodeNames.CURRENT_USER_NODE_NAME; > + case C_NodeTypes.SESSION_USER_NODE: > + case C_NodeTypes.SYSTEM_USER_NODE: > + case C_NodeTypes.CURRENT_ISOLATION_NODE: > + case C_NodeTypes.IDENTITY_VAL_NODE: > + case C_NodeTypes.CURRENT_SCHEMA_NODE: > + return C_NodeNames.SPECIAL_FUNCTION_NODE_NAME; > > case C_NodeTypes.IS_NODE: > return C_NodeNames.IS_NODE_NAME; > Index: java/engine/org/apache/derby/impl/sql/compile/C_NodeNames.java > =================================================================== > --- java/engine/org/apache/derby/impl/sql/compile/C_NodeNames.java (revision 125645) > +++ java/engine/org/apache/derby/impl/sql/compile/C_NodeNames.java (working copy) > @@ -94,13 +94,11 @@ > > static final String CURRENT_DATETIME_OPERATOR_NODE_NAME = "org.apache.derby.impl.sql.compile.CurrentDatetimeOperatorNode"; > > - static final String CURRENT_ISOLATION_NAME = "org.apache.derby.impl.sql.compile.CurrentIsolationNode"; > - > static final String CURRENT_OF_NODE_NAME = "org.apache.derby.impl.sql.compile.CurrentOfNode"; > > static final String CURRENT_ROW_LOCATION_NODE_NAME = "org.apache.derby.impl.sql.compile.CurrentRowLocationNode"; > > - static final String CURRENT_USER_NODE_NAME = "org.apache.derby.impl.sql.compile.CurrentUserNode"; > + static final String SPECIAL_FUNCTION_NODE_NAME = "org.apache.derby.impl.sql.compile.SpecialFunctionNode"; > > static final String CURSOR_NODE_NAME = "org.apache.derby.impl.sql.compile.CursorNode"; > > Index: java/engine/org/apache/derby/impl/sql/compile/ColumnDefinitionNode.java > =================================================================== > --- java/engine/org/apache/derby/impl/sql/compile/ColumnDefinitionNode.java (revision 125645) > +++ java/engine/org/apache/derby/impl/sql/compile/ColumnDefinitionNode.java (working copy) > @@ -611,24 +611,27 @@ > (colType == StoredFormatIds.VARCHAR_TYPE_ID) || > (colType == StoredFormatIds.LONGVARCHAR_TYPE_ID)); > > - if (defaultNode instanceof CurrentUserNode) { > + if (defaultNode instanceof SpecialFunctionNode) { > > - defaultText = defaultText.toLowerCase(java.util.Locale.ENGLISH); > - if (defaultText.indexOf("user") != -1) > + switch (defaultNode.getNodeType()) > + { > + case C_NodeTypes.USER_NODE: > + case C_NodeTypes.CURRENT_USER_NODE: > + case C_NodeTypes.SESSION_USER_NODE: > + case C_NodeTypes.SYSTEM_USER_NODE: > // DB2 enforces min length of 8. > // Note also: any size under 30 gives a warning in DB2. > return (charCol && (columnDesc.getMaximumWidth() >= > DB2Limit.MIN_COL_LENGTH_FOR_CURRENT_USER)); > > - if ((defaultText.indexOf("schema") != -1) || > - (defaultText.indexOf("sqlid") != -1)) > + case C_NodeTypes.CURRENT_SCHEMA_NODE: > // DB2 enforces min length of 128. > return (charCol && (columnDesc.getMaximumWidth() >= > DB2Limit.MIN_COL_LENGTH_FOR_CURRENT_SCHEMA)); > - > - // else, function not allowed. > - return false; > - > + default: > + // else, function not allowed. > + return false; > + } > } > > } > Index: java/engine/org/apache/derby/impl/sql/compile/sqlgrammar.jj > =================================================================== > --- java/engine/org/apache/derby/impl/sql/compile/sqlgrammar.jj (revision 125645) > +++ java/engine/org/apache/derby/impl/sql/compile/sqlgrammar.jj (working copy) > @@ -92,7 +92,6 @@ > import org.apache.derby.impl.sql.compile.ValueNode; > import org.apache.derby.impl.sql.compile.ValueNodeList; > import org.apache.derby.impl.sql.compile.GroupByColumn; > -import org.apache.derby.impl.sql.compile.CurrentUserNode; > import org.apache.derby.impl.sql.compile.CurrentDatetimeOperatorNode; > import org.apache.derby.impl.sql.compile.CreateStatementNode; > import org.apache.derby.impl.sql.compile.AlterTableNode; > @@ -5511,8 +5510,7 @@ > <IDENTITY_VAL_LOCAL> <LEFT_PAREN> <RIGHT_PAREN> > { > return (ValueNode) nodeFactory.getNode( > - C_NodeTypes.CURRENT_USER_NODE, > - ReuseFactory.getInteger(CurrentUserNode.IDENTITY_VAL), > + C_NodeTypes.IDENTITY_VAL_NODE, > getContextManager()); > } > } > @@ -5742,8 +5740,7 @@ > <CURRENT> (<SCHEMA> | <SQLID>) > { > return (ValueNode) nodeFactory.getNode( > - C_NodeTypes.CURRENT_USER_NODE, > - ReuseFactory.getInteger(CurrentUserNode.SCHEMA), > + C_NodeTypes.CURRENT_SCHEMA_NODE, > getContextManager()); > } > | > @@ -6170,8 +6167,7 @@ > <USER> > { > return (ValueNode) nodeFactory.getNode( > - C_NodeTypes.CURRENT_USER_NODE, > - ReuseFactory.getInteger(CurrentUserNode.USER), > + C_NodeTypes.USER_NODE, > getContextManager()); > } > | > @@ -6179,15 +6175,13 @@ > { > return (ValueNode) nodeFactory.getNode( > C_NodeTypes.CURRENT_USER_NODE, > - ReuseFactory.getInteger(CurrentUserNode.CURRENT_USER), > getContextManager()); > } > | > <SESSION_USER> > { > return (ValueNode) nodeFactory.getNode( > - C_NodeTypes.CURRENT_USER_NODE, > - ReuseFactory.getInteger(CurrentUserNode.SESSION_USER), > + C_NodeTypes.SESSION_USER_NODE, > getContextManager()); > } > } > @@ -9210,16 +9204,14 @@ > <CURRENT> (<SCHEMA> | <SQLID>) > { > return (ValueNode) nodeFactory.getNode( > - C_NodeTypes.CURRENT_USER_NODE, > - ReuseFactory.getInteger(CurrentUserNode.SCHEMA), > + C_NodeTypes.CURRENT_SCHEMA_NODE, > getContextManager()); > } > | > <USER> > { > return (ValueNode) nodeFactory.getNode( > - C_NodeTypes.CURRENT_USER_NODE, > - ReuseFactory.getInteger(CurrentUserNode.USER), > + C_NodeTypes.USER_NODE, > getContextManager()); > } > | > Index: java/engine/org/apache/derby/iapi/sql/compile/C_NodeTypes.java > =================================================================== > --- java/engine/org/apache/derby/iapi/sql/compile/C_NodeTypes.java (revision 125645) > +++ java/engine/org/apache/derby/iapi/sql/compile/C_NodeTypes.java (working copy) > @@ -34,8 +34,8 @@ > static final int CURRENT_ROW_LOCATION_NODE = 2; > static final int GROUP_BY_LIST = 3; > static final int CURRENT_ISOLATION_NODE = 4; > - // 5 available; > - // 6 available > + static final int IDENTITY_VAL_NODE = 5; > + static final int CURRENT_SCHEMA_NODE = 6; > static final int ORDER_BY_LIST = 7; > static final int PREDICATE_LIST = 8; > static final int RESULT_COLUMN_LIST = 9; > @@ -137,8 +137,8 @@ > // 106 is available > static final int VIRTUAL_COLUMN_NODE = 107; > static final int CURRENT_DATETIME_OPERATOR_NODE = 108; > - static final int CURRENT_USER_NODE = 109; > - // 110 is available > + static final int CURRENT_USER_NODE = 109; // special function CURRENT_USER > + static final int USER_NODE = 110; // // special function USER > static final int IS_NODE = 111; > static final int LOCK_TABLE_NODE = 112; > // 113 > @@ -153,8 +153,8 @@ > static final int NORMALIZE_RESULT_SET_NODE = 122; > static final int SCROLL_INSENSITIVE_RESULT_SET_NODE = 123; > static final int DISTINCT_NODE = 124; > - // 125 available > - // 126 available > + static final int SESSION_USER_NODE = 125; // // special function SESSION_USER > + static final int SYSTEM_USER_NODE = 126; // // special function SYSTEM_USER > static final int TRIM_OPERATOR_NODE = 127; > // 128 is available > static final int SELECT_NODE = 129; > Index: java/engine/org/apache/derby/impl/sql/compile/SpecialFunctionNode.java > =================================================================== > --- java/engine/org/apache/derby/impl/sql/compile/SpecialFunctionNode.java (revision 0) > +++ java/engine/org/apache/derby/impl/sql/compile/SpecialFunctionNode.java (revision 0) > @@ -0,0 +1,224 @@ > +/* > + > + Derby - Class org.apache.derby.impl.sql.compile.SpecialFunctionNode > + > + Copyright 1999, 2005 The Apache Software Foundation or its licensors, as applicable. > + > + Licensed under the Apache License, Version 2.0 (the "License"); > + you may not use this file except in compliance with the License. > + You may obtain a copy of the License at > + > + http://www.apache.org/licenses/LICENSE-2.0 > + > + Unless required by applicable law or agreed to in writing, software > + distributed under the License is distributed on an "AS IS" BASIS, > + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. > + See the License for the specific language governing permissions and > + limitations under the License. > + > + */ > + > +package org.apache.derby.impl.sql.compile; > + > +import org.apache.derby.iapi.sql.compile.CompilerContext; > + > +import org.apache.derby.iapi.types.DataTypeDescriptor; > + > +import org.apache.derby.iapi.services.compiler.MethodBuilder; > +import org.apache.derby.iapi.services.compiler.LocalField; > + > +import org.apache.derby.iapi.services.sanity.SanityManager; > + > +import org.apache.derby.iapi.store.access.Qualifier; > + > +import org.apache.derby.impl.sql.compile.ExpressionClassBuilder; > + > +import java.lang.reflect.Modifier; > + > +import org.apache.derby.iapi.error.StandardException; > +import org.apache.derby.iapi.reference.ClassName; > +import org.apache.derby.iapi.services.classfile.VMOpcode; > +import org.apache.derby.iapi.sql.compile.C_NodeTypes; > + > + > +import java.sql.Types; > + > +import java.util.Vector; > + > +/** > + SpecialFunctionNode handles system SQL functions. > + A function value is either obtained by a method > + call off the LanguageConnectionContext or Activation. > + LanguageConnectionContext functions are state related to the connection. > + Activation functions are those related to the statement execution. > + > + Each SQL function takes no arguments and returns a SQLvalue. > + <P> > + Functions supported: > + <UL> > + <LI> USER > + <LI> CURRENT_USER > + <LI> SESSION_USER > + <LI> SYSTEM_USER > + <LI> CURRENT SCHEMA > + <LI> CURRENT ISOLATION > + <LI> IDENTITY_VAL_LOCAL > + > + </UL> > + > + > + <P> > + > + This node is used rather than some use of MethodCallNode for > + runtime performance. MethodCallNode does not provide a fast access > + to the current language connection or activatation, since it is geared > + towards user defined routines. > + > + > +*/ > +public class SpecialFunctionNode extends ValueNode > +{ > + /** > + Name of SQL function > + */ > + String sqlName; > + > + /** > + Java method name > + */ > + private String methodName; > + > + /** > + Return type of Java method. > + */ > + private String methodType; > + > + /** > + */ > + //private boolean isActivationCall; > + > + /** > + * Binding this special function means setting the result DataTypeServices. > + * In this case, the result type is based on the operation requested. > + * > + * @param fromList The FROM list for the statement. This parameter > + * is not used in this case. > + * @param subqueryList The subquery list being built as we find > + * SubqueryNodes. Not used in this case. > + * @param aggregateVector The aggregate vector being built as we find > + * AggregateNodes. Not used in this case. > + * > + * @return The new top of the expression tree. > + * > + * @exception StandardException Thrown on error > + */ > + public ValueNode bindExpression(FromList fromList, SubqueryList subqueryList, > + Vector aggregateVector) > + throws StandardException > + { DataTypeDescriptor dtd; > + int nodeType = getNodeType(); > + switch (nodeType) > + { > + case C_NodeTypes.USER_NODE: > + case C_NodeTypes.CURRENT_USER_NODE: > + case C_NodeTypes.SESSION_USER_NODE: > + case C_NodeTypes.SYSTEM_USER_NODE: > + switch (nodeType) > + { > + case C_NodeTypes.USER_NODE: sqlName = "USER"; break; > + case C_NodeTypes.CURRENT_USER_NODE: sqlName = "CURRENT_USER"; break; > + case C_NodeTypes.SESSION_USER_NODE: sqlName = "SESSION_USER"; break; > + case C_NodeTypes.SYSTEM_USER_NODE: sqlName = "SYSTEM_USER"; break; > + } > + methodName = "getAuthorizationId"; > + methodType = "java.lang.String"; > + dtd = DataTypeDescriptor.getBuiltInDataTypeDescriptor(Types.VARCHAR, false, 128); > + break; > + > + case C_NodeTypes.CURRENT_SCHEMA_NODE: > + sqlName = "CURRENT SCHEMA"; > + methodName = "getCurrentSchemaName"; > + methodType = "java.lang.String"; > + dtd = DataTypeDescriptor.getBuiltInDataTypeDescriptor(Types.VARCHAR, false, 128); > + break; > + > + case C_NodeTypes.IDENTITY_VAL_NODE: > + sqlName = "IDENTITY_VAL_LOCAL"; > + methodName = "getIdentityValue"; > + methodType = "java.lang.Long"; > + dtd = DataTypeDescriptor.getSQLDataTypeDescriptor("java.math.BigDecimal", 31, 0, true, 31); > + break; > + > + case C_NodeTypes.CURRENT_ISOLATION_NODE: > + sqlName = "CURRENT ISOLATION"; > + methodName = "getCurrentIsolationLevelStr"; > + methodType = "java.lang.String"; > + dtd = DataTypeDescriptor.getBuiltInDataTypeDescriptor(Types.CHAR, 2); > + break; > + default: > + if (SanityManager.DEBUG) > + { > + SanityManager.THROWASSERT("Invalid type for SpecialFunctionNode " + nodeType); > + } > + dtd = null; > + break; > + } > + > + checkReliability(sqlName, CompilerContext.USER_ILLEGAL ); > + setType(dtd); > + > + return this; > + } > + > + /** > + * Return the variant type for the underlying expression. > + All supported special functions are QUERY_INVARIANT > + > + * > + * @return The variant type for the underlying expression. > + */ > + protected int getOrderableVariantType() > + { > + return Qualifier.QUERY_INVARIANT; > + } > + > + /** > + Generate an expression that returns a DataValueDescriptor and > + calls a method off the language connection or the activation. > + * > + * @param acb The ExpressionClassBuilder for the class being built > + * @param mb The method the code to place the code > + * > + * > + * @exception StandardException Thrown on error > + */ > + public void generateExpression(ExpressionClassBuilder acb, > + MethodBuilder mb) > + throws StandardException > + { > + mb.pushThis(); > + mb.callMethod(VMOpcode.INVOKEINTERFACE, ClassName.Activation, "getLanguageConnectionContext", > + ClassName.LanguageConnectionContext, 0); > + > + mb.callMethod(VMOpcode.INVOKEINTERFACE, (String) null, methodName, methodType, 0); > + > + String fieldType = getTypeCompiler().interfaceName(); > + LocalField field = acb.newFieldDeclaration(Modifier.PRIVATE, fieldType); > + > + acb.generateDataValue(mb, getTypeCompiler(), field); > + } > + > + /* > + print the non-node subfields > + */ > + public String toString() { > + if (SanityManager.DEBUG) > + { > + return super.toString()+ sqlName; > + } > + else > + { > + return ""; > + } > + } > +} > Index: java/engine/org/apache/derby/impl/sql/compile/CurrentIsolationNode.java > =================================================================== > --- java/engine/org/apache/derby/impl/sql/compile/CurrentIsolationNode.java (revision 125645) > +++ java/engine/org/apache/derby/impl/sql/compile/CurrentIsolationNode.java (working copy) > @@ -1,136 +0,0 @@ > -/* > - > - Derby - Class org.apache.derby.impl.sql.compile.CurrentIsolationNode > - > - Copyright 2004 The Apache Software Foundation or its licensors, as applicable. > - > - Licensed under the Apache License, Version 2.0 (the "License"); > - you may not use this file except in compliance with the License. > - You may obtain a copy of the License at > - > - http://www.apache.org/licenses/LICENSE-2.0 > - > - Unless required by applicable law or agreed to in writing, software > - distributed under the License is distributed on an "AS IS" BASIS, > - WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. > - See the License for the specific language governing permissions and > - limitations under the License. > - > - */ > - > -package org.apache.derby.impl.sql.compile; > - > -import org.apache.derby.iapi.store.access.Qualifier; > -import org.apache.derby.iapi.error.StandardException; > -import org.apache.derby.iapi.types.DataTypeDescriptor; > -import org.apache.derby.iapi.services.compiler.MethodBuilder; > -import org.apache.derby.iapi.services.compiler.LocalField; > - > -import org.apache.derby.iapi.services.sanity.SanityManager; > - > -import org.apache.derby.iapi.services.classfile.VMOpcode; > -import org.apache.derby.iapi.reference.ClassName; > - > -import org.apache.derby.impl.sql.compile.ExpressionClassBuilder; > - > -import java.lang.reflect.Modifier; > - > -import java.sql.Types; > -import java.util.Vector; > - > -/** > - * The CurrentIsolationNode is for the CURRENT ISOLATION special register > - * > - * @author Jack Klebanoff > - */ > -public class CurrentIsolationNode extends ValueNode > -{ > - > - > - /** > - * Return the variant type for the underlying expression. > - * The variant type can be: > - * VARIANT - variant within a scan > - * (method calls and non-static field access) > - * SCAN_INVARIANT - invariant within a scan > - * (column references from outer tables) > - * QUERY_INVARIANT - invariant within the life of a query > - * (constant expressions) > - * > - * @return The variant type for the underlying expression. > - */ > - protected int getOrderableVariantType() > - { > - // CurrentDate, Time, Timestamp are invariant for the life of the query > - return Qualifier.QUERY_INVARIANT; > - } > - > - // > - // QueryTreeNode interface > - // > - > - /** > - * Binding this expression means setting the result DataTypeServices. > - * In this case, the result type is based on the operation requested. > - * > - * @param fromList The FROM list for the statement. This parameter > - * is not used in this case. > - * @param subqueryList The subquery list being built as we find > - * SubqueryNodes. Not used in this case. > - * @param aggregateVector The aggregate vector being built as we find > - * AggregateNodes. Not used in this case. > - * > - * @return The new top of the expression tree. > - * > - * @exception StandardException Thrown on error > - */ > - public ValueNode bindExpression(FromList fromList, SubqueryList subqueryList, > - Vector aggregateVector) > - throws StandardException > - { > - setType( DataTypeDescriptor.getBuiltInDataTypeDescriptor(Types.CHAR, 2)); > - return this; > - } > - > - /** > - * CurrentDatetimeOperatorNode is used in expressions. > - * The expression generated for it invokes a static method > - * on a special Cloudscape type to get the system time and > - * wrap it in the right java.sql type, and then wrap it > - * into the right shape for an arbitrary value, i.e. a column > - * holder. This is very similar to what constants do. > - * > - * @param acb The ExpressionClassBuilder for the class being built > - * @param mb The method the code to place the code > - * > - * > - * @exception StandardException Thrown on error > - */ > - public void generateExpression(ExpressionClassBuilder acb, > - MethodBuilder mb) > - throws StandardException > - { > - mb.pushThis(); > - mb.callMethod(VMOpcode.INVOKEINTERFACE, ClassName.Activation, "getLanguageConnectionContext", > - ClassName.LanguageConnectionContext, 0); > - mb.callMethod(VMOpcode.INVOKEINTERFACE, (String) null, "getCurrentIsolationLevelStr", "java.lang.String", 0); > - String fieldType = getTypeCompiler().interfaceName(); > - LocalField field = acb.newFieldDeclaration(Modifier.PRIVATE, fieldType); > - > - acb.generateDataValue(mb, getTypeCompiler(), field); > - } // end of generateExpression > - > - > - public String toString() > - { > - if (SanityManager.DEBUG) > - { > - return super.toString() + "\n"; > - } > - else > - { > - return ""; > - } > - } > - > -} > Index: java/engine/org/apache/derby/impl/sql/compile/CurrentUserNode.java > =================================================================== > --- java/engine/org/apache/derby/impl/sql/compile/CurrentUserNode.java (revision 125645) > +++ java/engine/org/apache/derby/impl/sql/compile/CurrentUserNode.java (working copy) > @@ -1,210 +0,0 @@ > -/* > - > - Derby - Class org.apache.derby.impl.sql.compile.CurrentUserNode > - > - Copyright 1999, 2004 The Apache Software Foundation or its licensors, as applicable. > - > - Licensed under the Apache License, Version 2.0 (the "License"); > - you may not use this file except in compliance with the License. > - You may obtain a copy of the License at > - > - http://www.apache.org/licenses/LICENSE-2.0 > - > - Unless required by applicable law or agreed to in writing, software > - distributed under the License is distributed on an "AS IS" BASIS, > - WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. > - See the License for the specific language governing permissions and > - limitations under the License. > - > - */ > - > -package org.apache.derby.impl.sql.compile; > - > -import org.apache.derby.iapi.sql.compile.CompilerContext; > - > -import org.apache.derby.iapi.sql.conn.LanguageConnectionContext; > - > -import org.apache.derby.iapi.sql.dictionary.DataDictionary; > - > -import org.apache.derby.iapi.types.DataTypeDescriptor; > - > -import org.apache.derby.iapi.services.compiler.MethodBuilder; > -import org.apache.derby.iapi.services.compiler.LocalField; > - > -import org.apache.derby.iapi.services.sanity.SanityManager; > - > -import org.apache.derby.iapi.store.access.Qualifier; > - > -import org.apache.derby.impl.sql.compile.ExpressionClassBuilder; > - > -import java.lang.reflect.Modifier; > - > -import org.apache.derby.iapi.error.StandardException; > -import org.apache.derby.iapi.reference.ClassName; > -import org.apache.derby.iapi.services.classfile.VMOpcode; > - > - > -import java.sql.Types; > - > -import java.util.Vector; > - > -/** > - * The CurrentUser operator is for the builtin USER, CURRENT_USER, > - * SESSION_USER, CURRENT SCHEMA AND IDENTITY_VAL_LOCAL() operations. > - * > - * @author jerry > - */ > -public class CurrentUserNode extends ValueNode > -{ > - > - public static final int USER = 0; > - public static final int CURRENT_USER = 1; > - public static final int SESSION_USER = 2; > - public static final int SYSTEM_USER = 3; > - public static final int SCHEMA = 4; > - public static final int IDENTITY_VAL = 5; > - > - private int whichType; > - > - public void init(Object whichType) > - { > - this.whichType = ((Integer) whichType).intValue(); > - > - if (SanityManager.DEBUG) > - { > - SanityManager.ASSERT(((this.whichType >= 0 && this.whichType <= 2) || > - this.whichType == 4 || this.whichType == 5), > - "whichType expected to be between 0 and 2 or 4 and 5"); > - } > - } > - > - // > - // QueryTreeNode interface > - // > - > - /** > - * Binding this expression means setting the result DataTypeServices. > - * In this case, the result type is based on the operation requested. > - * > - * @param fromList The FROM list for the statement. This parameter > - * is not used in this case. > - * @param subqueryList The subquery list being built as we find > - * SubqueryNodes. Not used in this case. > - * @param aggregateVector The aggregate vector being built as we find > - * AggregateNodes. Not used in this case. > - * > - * @return The new top of the expression tree. > - * > - * @exception StandardException Thrown on error > - */ > - public ValueNode bindExpression(FromList fromList, SubqueryList subqueryList, > - Vector aggregateVector) > - throws StandardException > - { > - String errorString = null; > - switch (whichType) > - { > - case USER: > - errorString = "USER"; > - break; > - > - case CURRENT_USER: > - errorString = "CURRENT_USER"; > - break; > - > - case SESSION_USER: > - errorString = "SESSION_USER"; > - break; > - > - case SYSTEM_USER: > - errorString = "SYSTEM_USER"; > - break; > - > - case SCHEMA: > - errorString = "CURRENT SCHEMA"; > - break; > - > - case IDENTITY_VAL: > - errorString = "IDENTITY_VAL_LOCAL"; > - break; > - } > - > - if (whichType == SCHEMA) > - checkReliability( errorString, CompilerContext.SCHEMA_ILLEGAL ); > - else > - checkReliability( errorString, CompilerContext.USER_ILLEGAL ); > - > - if (whichType == IDENTITY_VAL) > - setType(DataTypeDescriptor.getSQLDataTypeDescriptor("java.math.BigDecimal", 31, 0, true, 31)); > - else > - setType(DataTypeDescriptor.getBuiltInDataTypeDescriptor(Types.VARCHAR, false, 128)); > - > - return this; > - } > - > - /** > - * Return the variant type for the underlying expression. > - * The variant type can be: > - * VARIANT - variant within a scan > - * (method calls and non-static field access) > - * SCAN_INVARIANT - invariant within a scan > - * (column references from outer tables) > - * QUERY_INVARIANT - invariant within the life of a query > - * (constant expressions) > - * > - * @return The variant type for the underlying expression. > - */ > - protected int getOrderableVariantType() > - { > - // CurrentDate, Time, Timestamp are invariant for the life of the query > - return Qualifier.QUERY_INVARIANT; > - } > - > - /** > - * CurrentDatetimeOperatorNode is used in expressions. > - * The expression generated for it invokes a static method > - * on a special Cloudscape type to get the system time and > - * wrap it in the right java.sql type, and then wrap it > - * into the right shape for an arbitrary value, i.e. a column > - * holder. This is very similar to what constants do. > - * > - * @param acb The ExpressionClassBuilder for the class being built > - * @param mb The method the code to place the code > - * > - * > - * @exception StandardException Thrown on error > - */ > - public void generateExpression(ExpressionClassBuilder acb, > - MethodBuilder mb) > - throws StandardException > - { > - mb.pushThis(); > - mb.callMethod(VMOpcode.INVOKEINTERFACE, ClassName.Activation, "getLanguageConnectionContext", > - ClassName.LanguageConnectionContext, 0); > - if (whichType == IDENTITY_VAL) > - mb.callMethod(VMOpcode.INVOKEINTERFACE, (String) null, "getIdentityValue", "java.lang.Long", 0); > - else if (whichType == SCHEMA) > - mb.callMethod(VMOpcode.INVOKEINTERFACE, (String) null, "getCurrentSchemaName", "java.lang.String", 0); > - else > - mb.callMethod(VMOpcode.INVOKEINTERFACE, (String) null, "getAuthorizationId", "java.lang.String", 0); > - > - String fieldType = getTypeCompiler().interfaceName(); > - LocalField field = acb.newFieldDeclaration(Modifier.PRIVATE, fieldType); > - > - acb.generateDataValue(mb, getTypeCompiler(), field); > - } > - > - /* > - print the non-node subfields > - */ > - public String toString() { > - if (SanityManager.DEBUG) > - { > - return super.toString()+"whichType = "+whichType+"\n"; > - } > - else > - { > - return ""; > - } > - } > -} >
