HeavyDBRelWriterImpl.java

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/*
 * Copyright 2023 HEAVY.AI, Inc.
 *
 * 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.calcite.rel.externalize;

import com.google.common.collect.ImmutableList;

import org.apache.calcite.avatica.util.Spacer;
import org.apache.calcite.linq4j.Ord;
import org.apache.calcite.plan.RelOptTable;
import org.apache.calcite.rel.RelNode;
import org.apache.calcite.rel.RelWriter;
import org.apache.calcite.rel.core.AggregateCall;
import org.apache.calcite.rel.logical.LogicalAggregate;
import org.apache.calcite.rel.metadata.RelColumnOrigin;
import org.apache.calcite.rel.metadata.RelMetadataQuery;
import org.apache.calcite.rex.RexInputRef;
import org.apache.calcite.rex.RexNode;
import org.apache.calcite.rex.RexShuttle;
import org.apache.calcite.sql.SqlExplainLevel;
import org.apache.calcite.util.Pair;
import org.checkerframework.checker.nullness.qual.Nullable;

import java.io.PrintWriter;
import java.util.*;

public class HeavyDBRelWriterImpl implements RelWriter {
  //~ Instance fields --------------------------------------------------------

  protected final PrintWriter pw;
  protected final SqlExplainLevel detailLevel;
  protected final boolean withIdPrefix;
  protected final Spacer spacer = new Spacer();
  private final List<Pair<String, @Nullable Object>> values = new ArrayList<>();

  //~ Constructors -----------------------------------------------------------

  public HeavyDBRelWriterImpl(PrintWriter pw) {
    this(pw, SqlExplainLevel.EXPPLAN_ATTRIBUTES, true);
  }

  public HeavyDBRelWriterImpl(
          PrintWriter pw, SqlExplainLevel detailLevel, boolean withIdPrefix) {
    this.pw = pw;
    this.detailLevel = detailLevel;
    this.withIdPrefix = withIdPrefix;
  }

  //~ Methods ----------------------------------------------------------------

  public Set<String> collectRelColumnOrigin(
          RelMetadataQuery mq, RelNode rel, int targetColumnIndex) {
    Set<RelColumnOrigin> columnOrigins = new HashSet<>();
    Map<String, Set<String>> originInfoMap = new HashMap<>();
    Set<String> originInfo = new HashSet<>();
    try {
      if (!rel.getInputs().isEmpty()) {
        RelNode sourceNode = rel.getInputs().size() == 1 ? rel.getInput(0) : rel;
        columnOrigins = mq.getColumnOrigins(sourceNode, targetColumnIndex);
      }
      for (RelColumnOrigin rco : columnOrigins) {
        RelOptTable relOptTable = rco.getOriginTable();
        String dbName = relOptTable.getQualifiedName().get(0);
        String tableName = relOptTable.getQualifiedName().get(1);
        String colName = relOptTable.getRowType()
                                 .getFieldList()
                                 .get(rco.getOriginColumnOrdinal())
                                 .getName();
        String key = "$" + targetColumnIndex;
        String info = "db:" + dbName + ",tableName:" + tableName + ",colName:" + colName;
        if (originInfoMap.containsKey(key)) {
          originInfoMap.get(key).add(info);
        } else {
          Set<String> originList = new HashSet<>();
          originList.add(info);
          originInfoMap.put(key, originList);
        }
      }
    } catch (Exception ex) {
      throw new RuntimeException("EXPLAIN CALCITE DETAILED error: " + ex.getMessage());
    }

    for (Map.Entry<String, Set<String>> entry : originInfoMap.entrySet()) {
      int index = 1;
      for (String colInfo : entry.getValue()) {
        if (entry.getValue().size() > 1) {
          originInfo.add(entry.getKey() + "-" + index + "->" + colInfo);
        } else {
          originInfo.add(entry.getKey() + "->" + colInfo);
        }
        index++;
      }
    }
    return originInfo;
  }

  protected void explain_(RelNode rel, List<Pair<String, @Nullable Object>> values) {
    List<RelNode> inputs = rel.getInputs();
    final RelMetadataQuery mq = rel.getCluster().getMetadataQuery();
    if (!mq.isVisibleInExplain(rel, detailLevel)) {
      // render children in place of this, at same level
      explainInputs(inputs);
      return;
    }

    StringBuilder s = new StringBuilder();
    spacer.spaces(s);
    if (withIdPrefix) {
      s.append(rel.getId()).append(":");
    }
    s.append(rel.getRelTypeName());
    if (detailLevel != SqlExplainLevel.NO_ATTRIBUTES) {
      int j = 0;
      for (Pair<String, @Nullable Object> value : values) {
        if (value.right instanceof RelNode) {
          continue;
        }
        if (j++ == 0) {
          s.append("(");
        } else {
          s.append(", ");
        }
        s.append(value.left).append("=[").append(value.right).append("]");
      }
      if (j > 0) {
        s.append(")");
      }
    }
    switch (detailLevel) {
      case ALL_ATTRIBUTES:
        s.append(": rowcount = ")
                .append(mq.getRowCount(rel))
                .append(", cumulative cost = ")
                .append(mq.getCumulativeCost(rel));
        break;
      default:
        break;
    }
    switch (detailLevel) {
      case NON_COST_ATTRIBUTES:
      case ALL_ATTRIBUTES:
        if (!withIdPrefix) {
          // If we didn't print the rel id at the start of the line, print
          // it at the end.
          s.append(", id = ").append(rel.getId());
        }
        break;
      default:
        break;
    }
    Set<String> originInfo = new HashSet<>();
    if (rel instanceof LogicalAggregate) {
      LogicalAggregate aggregate = (LogicalAggregate) rel;
      for (AggregateCall aggCall : aggregate.getAggCallList()) {
        for (int expressionIndex : aggCall.getArgList()) {
          originInfo.addAll(collectRelColumnOrigin(mq, rel, expressionIndex));
        }
      }
    } else {
      rel.accept(new RexShuttle() {
        @Override
        public RexNode visitInputRef(final RexInputRef inputRef) {
          originInfo.addAll(collectRelColumnOrigin(mq, rel, inputRef.getIndex()));
          return inputRef;
        }
      });
    }
    if (!originInfo.isEmpty()) {
      s.append("\t{");
      int index = 1;
      for (String info : originInfo) {
        s.append("[").append(info).append("]");
        if (index < originInfo.size()) {
          s.append(", ");
        }
        index++;
      }
      s.append("}");
    }
    pw.println(s);
    spacer.add(2);
    explainInputs(inputs);
    spacer.subtract(2);
  }

  private void explainInputs(List<RelNode> inputs) {
    for (RelNode input : inputs) {
      input.explain(this);
    }
  }

  @Override
  public final void explain(RelNode rel, List<Pair<String, @Nullable Object>> valueList) {
    explain_(rel, valueList);
  }

  @Override
  public SqlExplainLevel getDetailLevel() {
    return detailLevel;
  }

  @Override
  public RelWriter item(String term, @Nullable Object value) {
    values.add(Pair.of(term, value));
    return this;
  }

  @Override
  public RelWriter done(RelNode node) {
    assert checkInputsPresentInExplain(node);
    final List<Pair<String, @Nullable Object>> valuesCopy = ImmutableList.copyOf(values);
    values.clear();
    explain_(node, valuesCopy);
    pw.flush();
    return this;
  }

  private boolean checkInputsPresentInExplain(RelNode node) {
    int i = 0;
    if (values.size() > 0 && values.get(0).left.equals("subset")) {
      ++i;
    }
    for (RelNode input : node.getInputs()) {
      assert values.get(i).right == input;
      ++i;
    }
    return true;
  }

  public String simple() {
    final StringBuilder buf = new StringBuilder("(");
    for (Ord<Pair<String, @Nullable Object>> ord : Ord.zip(values)) {
      if (ord.i > 0) {
        buf.append(", ");
      }
      buf.append(ord.e.left).append("=[").append(ord.e.right).append("]");
    }
    buf.append(")");
    return buf.toString();
  }
}