RandomSec/main/src/com/google/refine/InterProjectModel.java

/*

Copyright 2010, Google Inc.
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:

    * Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following disclaimer
in the documentation and/or other materials provided with the
distribution.
    * Neither the name of Google Inc. nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,           
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY           
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

*/

package com.google.refine;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;

import com.google.refine.expr.ExpressionUtils;
import com.google.refine.expr.HasFieldsListImpl;
import com.google.refine.expr.WrappedRow;
import com.google.refine.model.Column;
import com.google.refine.model.Project;
import com.google.refine.model.Row;

public class InterProjectModel {
    static public class ProjectJoin {
        final public long   fromProjectID;
        final public String fromProjectColumnName;
        final public long   toProjectID;
        final public String toProjectColumnName;
        
        final public Map<Object, List<Integer>> valueToRowIndices = 
            new HashMap<Object, List<Integer>>();
        
        ProjectJoin(
            long   fromProjectID,
            String fromProjectColumnName,
            long   toProjectID,
            String toProjectColumnName
        ) {
            this.fromProjectID = fromProjectID;
            this.fromProjectColumnName = fromProjectColumnName;
            this.toProjectID = toProjectID;
            this.toProjectColumnName = toProjectColumnName;
        }
        
        public HasFieldsListImpl getRows(Object value) {
            if (ExpressionUtils.isNonBlankData(value) && valueToRowIndices.containsKey(value)) {
                Project toProject = ProjectManager.singleton.getProject(toProjectID);
                if (toProject != null) {
                    HasFieldsListImpl rows = new HasFieldsListImpl();
                    for (Integer r : valueToRowIndices.get(value)) {
                        Row row = toProject.rows.get(r);
                        rows.add(new WrappedRow(toProject, r, row));
                    }
                    
                    return rows;
                }
            }
            return null;
        }
    }
    
    protected Map<String, ProjectJoin> _joins = new HashMap<String, ProjectJoin>();
    
    /**
     * Compute the ProjectJoin based on combination key, return the cached one from the HashMap if already computed
     * 
     * @param fromProject
     * @param fromColumn
     * @param toProject
     * @param toColumn
     * @return
     */
    public ProjectJoin getJoin(String fromProject, String fromColumn, String toProject, String toColumn) {
        String key = fromProject + ";" + fromColumn + ";" + toProject + ";" + toColumn;
        if (!_joins.containsKey(key)) {
            ProjectJoin join = new ProjectJoin(
                ProjectManager.singleton.getProjectID(fromProject), 
                fromColumn, 
                ProjectManager.singleton.getProjectID(toProject), 
                toColumn
            );
            
            computeJoin(join);
            
            synchronized (_joins) {
                _joins.put(key, join);
            }
        }
        
        return _joins.get(key);
    }
    
    public void flushJoinsInvolvingProject(long projectID) {
        synchronized (_joins) {
            for (Iterator<Entry<String, ProjectJoin>> it = _joins.entrySet().iterator(); it.hasNext();) {
                Entry<String, ProjectJoin> entry = it.next();
                ProjectJoin join = entry.getValue();
                if (join.fromProjectID == projectID || join.toProjectID == projectID) {
                    it.remove();
                }
            }
        }
    }

    public void flushJoinsInvolvingProjectColumn(long projectID, String columnName) {
        synchronized (_joins) {
            for (Iterator<Entry<String, ProjectJoin>> it = _joins.entrySet().iterator(); it.hasNext();) {
                Entry<String, ProjectJoin> entry = it.next();
                ProjectJoin join = entry.getValue();
                if (join.fromProjectID == projectID && join.fromProjectColumnName.equals(columnName) || 
                        join.toProjectID == projectID && join.toProjectColumnName.equals(columnName)) {
                    it.remove();
                }
            }
        }
    }

    protected void computeJoin(ProjectJoin join) {
        if (join.fromProjectID < 0 || join.toProjectID < 0) {
            return;
        }
        
        Project fromProject = ProjectManager.singleton.getProject(join.fromProjectID);
        Project toProject = ProjectManager.singleton.getProject(join.toProjectID);
        if (fromProject == null || toProject == null) {
            return;
        }
        
        Column fromColumn = fromProject.columnModel.getColumnByName(join.fromProjectColumnName);
        Column toColumn = toProject.columnModel.getColumnByName(join.toProjectColumnName);
        if (fromColumn == null || toColumn == null) {
            return;
        }
        
        for (Row fromRow : fromProject.rows) {
            Object value = fromRow.getCellValue(fromColumn.getCellIndex());
            if (ExpressionUtils.isNonBlankData(value) && !join.valueToRowIndices.containsKey(value)) {
                join.valueToRowIndices.put(value, new ArrayList<Integer>());
            }
        }
        
        int count = toProject.rows.size();
        for (int r = 0; r < count; r++) {
            Row toRow = toProject.rows.get(r);
            
            Object value = toRow.getCellValue(toColumn.getCellIndex());
            if (ExpressionUtils.isNonBlankData(value) && join.valueToRowIndices.containsKey(value)) {
                join.valueToRowIndices.get(value).add(r);
            }
        }
    }
}