| /********************************************************************** |
| // @@@ START COPYRIGHT @@@ |
| // |
| // Licensed to the Apache Software Foundation (ASF) under one |
| // or more contributor license agreements. See the NOTICE file |
| // distributed with this work for additional information |
| // regarding copyright ownership. The ASF licenses this file |
| // to you 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. |
| // |
| // @@@ END COPYRIGHT @@@ |
| **********************************************************************/ |
| #ifndef ExPack_h |
| #define ExPack_h |
| |
| /* -*-C++-*- |
| ****************************************************************************** |
| * |
| * File: ExPack.h |
| * Description: Pack Operator |
| * |
| * Created: 6/16/97 |
| * Language: C++ |
| * |
| * |
| * |
| * |
| ****************************************************************************** |
| */ |
| |
| #include "ex_stdh.h" |
| #include "ComTdb.h" |
| #include "ex_tcb.h" |
| #include "ex_expr.h" |
| |
| // External forward declarations |
| // |
| class ExSimpleSQLBuffer; |
| |
| #include "ComTdbPackRows.h" |
| |
| // ----------------------------------------------------------------------- |
| // Classes defined in this file |
| // ----------------------------------------------------------------------- |
| class ExPackRowsTdb; |
| |
| // ----------------------------------------------------------------------- |
| // Classes referenced in this file |
| // ----------------------------------------------------------------------- |
| class ex_tcb; |
| |
| // ----------------------------------------------------------------------- |
| // ExPackRowsTdb |
| // ----------------------------------------------------------------------- |
| class ExPackRowsTdb : public ComTdbPackRows |
| { |
| public: |
| |
| // --------------------------------------------------------------------- |
| // Constructor is only called to instantiate an object used for |
| // retrieval of the virtual table function pointer of the class while |
| // unpacking. An empty constructor is enough. |
| // --------------------------------------------------------------------- |
| NA_EIDPROC ExPackRowsTdb() |
| {} |
| |
| NA_EIDPROC virtual ~ExPackRowsTdb() |
| {} |
| |
| // --------------------------------------------------------------------- |
| // Build a TCB for this TDB. Redefined in the Executor project. |
| // --------------------------------------------------------------------- |
| NA_EIDPROC virtual ex_tcb *build(ex_globals *globals); |
| |
| private: |
| // --------------------------------------------------------------------- |
| // !!!!!!! IMPORTANT -- NO DATA MEMBERS ALLOWED IN EXECUTOR TDB !!!!!!!! |
| // ********************************************************************* |
| // The Executor TDB's are only used for the sole purpose of providing a |
| // way to supplement the Compiler TDB's (in comexe) with methods whose |
| // implementation depends on Executor objects. This is done so as to |
| // decouple the Compiler from linking in Executor objects unnecessarily. |
| // |
| // When a Compiler generated TDB arrives at the Executor, the same data |
| // image is "cast" as an Executor TDB after unpacking. Therefore, it is |
| // a requirement that a Compiler TDB has the same object layout as its |
| // corresponding Executor TDB. As a result of this, all Executor TDB's |
| // must have absolutely NO data members, but only member functions. So, |
| // if you reach here with an intention to add data members to a TDB, ask |
| // yourself two questions: |
| // |
| // 1. Are those data members Compiler-generated? |
| // If yes, put them in the ComTdbPackRows instead. |
| // If no, they should probably belong to someplace else (like TCB). |
| // |
| // 2. Are the classes those data members belong defined in the executor |
| // project? |
| // If your answer to both questions is yes, you might need to move |
| // the classes to the comexe project. |
| // --------------------------------------------------------------------- |
| }; |
| |
| |
| class ExPackRowsTcb : public ex_tcb |
| { |
| friend class ExPackRowsTdb; |
| friend class ExPackPrivateState; |
| |
| public: |
| |
| // The various states of a request for the Pack work methods. |
| enum workState |
| { |
| // The request has been sent to the child. |
| STARTED_, |
| |
| // The request has not yet been sent to the child. |
| EMPTY_, |
| |
| // A cancel request has been sent to the child for this request. |
| CANCELLED_ |
| }; |
| |
| // Constructor |
| // Construct a TCB node from the given TDB. This constructor is |
| // called during the build phase by ExPackRowsTdb::build(). |
| // It: |
| // - allocates the sql buffer pool |
| // - allocates the ATP's for its child's down queue. |
| // - allocates the up and down queues used to communicate |
| // with the parent. |
| // - allocates the private state associated with each entry of the |
| // parents down queue. |
| // - initializes local state. |
| // - fixes up all expressions. |
| // |
| NA_EIDPROC |
| ExPackRowsTcb(const ExPackRowsTdb& packTdb, |
| const ex_tcb& childTdb, |
| ex_globals* glob); |
| |
| // Destructor |
| NA_EIDPROC |
| ~ExPackRowsTcb(); |
| |
| // Free up any run-time resources. |
| NA_EIDPROC |
| void freeResources(); |
| |
| // Register all the pack subtasks with the scheduler. |
| NA_EIDPROC |
| void registerSubtasks(); |
| |
| // The basic work method for a TCB. Pack does not use this method. |
| NA_EIDPROC |
| ExWorkProcRetcode work(); |
| |
| // Work method to pass requests from parent down to child. |
| NA_EIDPROC |
| ExWorkProcRetcode workDown(); |
| |
| // Work method to recieve results from child, process and pass up to parent |
| // when the packed record has been formed or there is EOD. |
| NA_EIDPROC |
| ExWorkProcRetcode workUp(); |
| |
| // Work method called by workUp() to return rows when we form a fully packed |
| // record or get an EOD before that. |
| NA_EIDPROC |
| ExWorkProcRetcode workReturnRow(); |
| |
| // Stub to workUp() used by scheduler. |
| NA_EIDPROC |
| // warning elimination (removed "inline") |
| static ExWorkProcRetcode sWorkUp(ex_tcb *tcb) |
| { |
| return ((ExPackRowsTcb *) tcb)->workUp(); |
| } |
| |
| // Stub to workDown() used by scheduler. |
| NA_EIDPROC |
| // warning elimination (removed "inline") |
| static ExWorkProcRetcode sWorkDown(ex_tcb *tcb) |
| { |
| return ((ExPackRowsTcb *) tcb)->workDown(); |
| } |
| |
| // Stub to processCancel() used by scheduler. |
| NA_EIDPROC |
| // warning elimination (removed "inline") |
| static ExWorkProcRetcode sCancel(ex_tcb *tcb) |
| { |
| return ((ExPackRowsTcb *) tcb)->processCancel(); |
| } |
| |
| // Return the parent queue pair. |
| NA_EIDPROC |
| // warning elimination (removed "inline") |
| ex_queue_pair getParentQueue() const { return qParent_; } |
| |
| // Return a reference to the Pack TDB associated with this Pack TCB. |
| NA_EIDPROC |
| inline ExPackRowsTdb& packTdb() const |
| { |
| return (ExPackRowsTdb &) tdb; |
| } |
| |
| // Return the selection predicate. |
| NA_EIDPROC |
| inline ex_expr* predExpr() { return packTdb().predExpr_; } |
| |
| // Return the packing expression. |
| NA_EIDPROC |
| inline ex_expr* packExpr() { return packTdb().packExpr_; } |
| |
| // Pack has one child. |
| NA_EIDPROC |
| virtual Int32 numChildren() const { return 1; } |
| |
| // Return the child of the pack node by position. |
| NA_EIDPROC |
| virtual const ex_tcb* getChild(Int32 pos) const |
| { |
| if(pos == 0) return childTcb_; |
| return NULL; |
| } |
| |
| protected: |
| |
| // The child TCB of this Transpose node. |
| const ex_tcb* childTcb_; |
| |
| // The queue pair used to communicate with the parent node. |
| ex_queue_pair qParent_; |
| |
| // The queue pair used to communicate with the child node. |
| ex_queue_pair qChild_; |
| |
| // Next parent down queue entry to process. |
| queue_index nextRqst_; |
| |
| // Buffer pool used to allocated tupps for the packed columns. |
| ExSimpleSQLBuffer* pool_; |
| |
| // Send next request down to children. (called by workDown()) |
| NA_EIDPROC |
| void start(); |
| |
| // Send EOD to parent. (called when child return Q_NO_DATA in queue) |
| NA_EIDPROC |
| void stop(); |
| |
| // Process cancel requests. (called when parent cancel its request) |
| NA_EIDPROC |
| ExWorkProcRetcode processCancel(); |
| |
| }; |
| |
| // ----------------------------------------------------------------------- |
| // Private state |
| // ----------------------------------------------------------------------- |
| class ExPackPrivateState : public ex_tcb_private_state |
| { |
| friend class ExPackRowsTcb; |
| |
| tupp packTupp_; |
| ExPackRowsTcb::workState childState_; |
| Int64 matchCount_; |
| |
| NA_EIDPROC |
| void init(); |
| |
| public: |
| |
| NA_EIDPROC |
| ExPackPrivateState(const ExPackRowsTcb* tcb); |
| |
| NA_EIDPROC |
| ~ExPackPrivateState(); |
| |
| NA_EIDPROC |
| ex_tcb_private_state* allocate_new(const ex_tcb* tcb); |
| |
| NA_EIDPROC |
| void printPackTupp(); |
| |
| }; |
| |
| #endif |
| |