first commit for openGauss server

src/gausskernel/runtime/vecexecutor/vecnode/vecresult.cpp

@@ -0,0 +1,248 @@
+/*
+ * Portions Copyright (c) 2020 Huawei Technologies Co.,Ltd.
+ * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * openGauss is licensed under Mulan PSL v2.
+ * You can use this software according to the terms and conditions of the Mulan PSL v2.
+ * You may obtain a copy of Mulan PSL v2 at:
+ *
+ *          http://license.coscl.org.cn/MulanPSL2
+ *
+ * THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
+ * EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
+ * MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
+ * See the Mulan PSL v2 for more details.
+ * ---------------------------------------------------------------------------------------
+ *
+ * vecresult.cpp
+ *  support for constant nodes needing special code.
+ *
+ * IDENTIFICATION
+ *        Code/src/gausskernel/runtime/vecexecutor/vecnode/vecresult.cpp
+ *
+ * ---------------------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+#include "knl/knl_variable.h"
+
+#include "vecexecutor/vecexecutor.h"
+#include "executor/executor.h"
+#include "vecexecutor/vecnoderesult.h"
+#include "utils/memutils.h"
+#include "vecexecutor/vectorbatch.h"
+
+/* ----------------------------------------------------------------
+ *		ExecVecResult(node)
+ *
+ *		returns the tuples from the outer plan which satisfy the
+ *		qualification clause.  Since result nodes with right
+ *		subtrees are never planned, we ignore the right subtree
+ *		entirely (for now).. -cim 10/7/89
+ *
+ *		The qualification containing only constant clauses are
+ *		checked first before any processing is done. It always returns
+ *		'nil' if the constant qualification is not satisfied.
+ * ----------------------------------------------------------------
+ */
+VectorBatch* ExecVecResult(VecResultState* node)
+{
+    PlanState* outer_plan = NULL;
+    ExprContext* expr_context = NULL;
+    VectorBatch* batch = NULL;
+    VectorBatch* res_batch = NULL;
+    List* qual = node->ps.qual;
+
+    expr_context = node->ps.ps_ExprContext;
+
+    /*
+     * check constant qualifications like (2 > 1), if not already done
+     */
+    if (node->rs_checkqual) {
+        bool qual_result = ExecQual((List*)node->resconstantqual, expr_context, false);
+        node->rs_checkqual = false;
+        if (!qual_result) {
+            node->rs_done = true;
+            /*
+             * Mark this constant qualification check failure for future corner cases. Currently only used in GDS
+             * foreign scan
+             */
+            u_sess->exec_cxt.exec_result_checkqual_fail = true;
+            return NULL;
+        }
+    }
+
+    Assert(node->ps.ps_TupFromTlist == false);
+
+    /*
+     * Reset per-tuple memory context to free any expression evaluation
+     * storage allocated in the previous tuple cycle.  Note this can't happen
+     * until we're done projecting out tuples from a scan tuple.
+     */
+    ResetExprContext(expr_context);
+
+    /*
+     * if rs_done is true then it means that we were asked to return a
+     * constant tuple and we already did the last time ExecResult() was
+     * called, OR that we failed the constant qual check. Either way, now we
+     * are through.
+     */
+    while (!node->rs_done) {
+        outer_plan = outerPlanState(node);
+        if (outer_plan != NULL) {
+            /*
+             * retrieve tuples from the outer plan until there are no more.
+             */
+            batch = VectorEngine(outer_plan);
+
+            if (BatchIsNull(batch)) {
+                return NULL;
+            }
+
+            /*
+             * prepare to compute projection expressions, which will expect to
+             * access the input tuples as varno OUTER.
+             */
+            expr_context->ecxt_outerbatch = batch;
+            if (list_length(qual) != 0) {
+                expr_context->ecxt_scanbatch = batch;
+
+                ScalarVector* p_vector = ExecVecQual(qual, expr_context, false);
+                if (unlikely(p_vector == NULL))
+                    continue;
+
+                batch->Pack(expr_context->ecxt_scanbatch->m_sel);
+            }
+        } else {
+            /*
+             * if we don't have an outer plan, then we are just generating the
+             * results from a constant target list.  Do it only once.
+             */
+            node->rs_done = true;
+        }
+
+        /*
+         * form the result tuple using ExecProject(), and return it --- unless
+         * the projection produces an empty set, in which case we must loop
+         * back to see if there are more outer_plan tuples.
+         */
+        res_batch = ExecVecProject(node->ps.ps_ProjInfo);
+
+        if (batch != NULL) {
+            res_batch->m_rows = Min(res_batch->m_rows, batch->m_rows);
+        }
+
+        res_batch->FixRowCount();
+        return res_batch;
+    }
+
+    return NULL;
+}
+
+/* ----------------------------------------------------------------
+ *		ExecInitResult
+ *
+ *		Creates the run-time state information for the result node
+ *		produced by the planner and initializes outer relations
+ *		(child nodes).
+ * ----------------------------------------------------------------
+ */
+VecResultState* ExecInitVecResult(VecResult* node, EState* estate, int eflags)
+{
+    VecResultState* res_state = NULL;
+    ScalarDesc desc;
+
+    /* check for unsupported flags */
+    Assert(!(eflags & (EXEC_FLAG_MARK | EXEC_FLAG_BACKWARD)) || outerPlan(node) != NULL);
+
+    /*
+     * create state structure
+     */
+    res_state = makeNode(VecResultState);
+    res_state->ps.plan = (Plan*)node;
+    res_state->ps.state = estate;
+    res_state->ps.vectorized = true;
+    res_state->ps.type = T_VecResultState;
+
+    res_state->rs_done = false;
+    res_state->rs_checkqual = (node->resconstantqual == NULL) ? false : true;
+
+    /*
+     * Miscellaneous initialization
+     *
+     * create expression context for node
+     */
+    ExecAssignExprContext(estate, &res_state->ps);
+
+    res_state->ps.ps_TupFromTlist = false;
+
+    /*
+     * tuple table initialization
+     */
+    ExecInitResultTupleSlot(estate, &res_state->ps);
+
+    /*
+     * initialize child expressions
+     */
+    res_state->ps.targetlist = (List*)ExecInitVecExpr((Expr*)node->plan.targetlist, (PlanState*)res_state);
+    res_state->ps.qual = (List*)ExecInitVecExpr((Expr*)node->plan.qual, (PlanState*)res_state);
+
+    res_state->resconstantqual = ExecInitExpr((Expr*)node->resconstantqual, (PlanState*)res_state);
+
+    /*
+     * initialize child nodes
+     */
+    outerPlanState(res_state) = ExecInitNode(outerPlan(node), estate, eflags);
+
+    /*
+     * we don't use inner plan
+     */
+    Assert(innerPlan(node) == NULL);
+
+    /*
+     * initialize tuple type and projection info
+     */
+    ExecAssignResultTypeFromTL(&res_state->ps);
+    res_state->ps.ps_ProjInfo = ExecBuildVecProjectionInfo(
+        res_state->ps.targetlist, node->plan.qual, res_state->ps.ps_ExprContext, res_state->ps.ps_ResultTupleSlot, NULL);
+
+    ExecAssignVectorForExprEval(res_state->ps.ps_ExprContext);
+
+    return res_state;
+}
+
+/* ----------------------------------------------------------------
+ *		ExecEndResult
+ *
+ *		frees up storage allocated through C routines
+ * ----------------------------------------------------------------
+ */
+void ExecEndVecResult(VecResultState* node)
+{
+    /*
+     * Free the exprcontext
+     */
+    ExecFreeExprContext(&node->ps);
+
+    (void)ExecClearTuple(node->ps.ps_ResultTupleSlot);
+    /*
+     * shut down subplans
+     */
+    ExecEndNode(outerPlanState(node));
+}
+
+void ExecReScanVecResult(VecResultState* node)
+{
+    node->rs_done = false;
+    node->ps.ps_TupFromTlist = false;
+    node->rs_checkqual = (node->resconstantqual == NULL) ? false : true;
+
+    /*
+     * If chgParam of subnode is not null then plan will be re-scanned by
+     * first ExecProcNode.
+     */
+    if (node->ps.lefttree && node->ps.lefttree->chgParam == NULL) {
+        VecExecReScan(node->ps.lefttree);
+    }
+}