001 /*
002 // $Id: //open/mondrian/src/main/mondrian/rolap/ResultLoader.java#2 $
003 // This software is subject to the terms of the Common Public License
004 // Agreement, available at the following URL:
005 // http://www.opensource.org/licenses/cpl.html.
006 // Copyright (C) 2003-2008 Julian Hyde
007 // All Rights Reserved.
008 // You must accept the terms of that agreement to use this software.
009 //
010 // jhyde, Feb 21, 2003
011 */
012 package mondrian.rolap;
013
014 import mondrian.olap.Util;
015
016 import java.sql.ResultSet;
017 import java.sql.SQLException;
018 import java.util.ArrayList;
019 import java.util.List;
020
021 /**
022 * Loader to be iterated to load all results from database.
023 *
024 * @version $Id: //open/mondrian/src/main/mondrian/rolap/ResultLoader.java#2 $
025 * @author luis f. canals
026 */
027 public class ResultLoader {
028 private final List<Target> targets;
029 private final int enumTargetCount;
030 private final ResultSet resultSet;
031 private final boolean execQuery;
032 private final String message;
033 private final List<List<RolapMember>> partialResult, newPartialResult;
034 private final SqlStatement stmt;
035
036 private final int[] srcMemberIdxes;
037
038 int currPartialResultIdx = 0;
039
040 public ResultLoader(
041 final int enumTargetCount,
042 final List<Target> targets,
043 final SqlStatement stmt,
044 final ResultSet resultSet,
045 final boolean execQuery,
046 final List<List<RolapMember>> partialResult,
047 final List<List<RolapMember>> newPartialResult)
048 throws SQLException
049 {
050 this.targets = targets;
051 this.enumTargetCount = enumTargetCount;
052 this.stmt = stmt;
053 this.resultSet = resultSet;
054 this.execQuery = execQuery;
055 this.partialResult = partialResult;
056 this.newPartialResult = newPartialResult;
057 this.srcMemberIdxes =
058 enumTargetCount > 0
059 ? new int[enumTargetCount]
060 : null;
061 this.message = "Populating member cache with members for " + targets;
062 }
063
064
065 public boolean loadResult() throws SQLException {
066 boolean moreRows = true;
067 /*
068 if (limit > 0 && limit < ++fetchCount) {
069 throw MondrianResource.instance().MemberFetchLimitExceeded
070 .ex((long) limit);
071 }
072 */
073 if (enumTargetCount == 0) {
074 int column = 0;
075 for (Target target : targets) {
076 target.removeCurrMember();
077 column = target.addRow(resultSet, column);
078 }
079 } else {
080 int firstEnumTarget = 0;
081 for (; firstEnumTarget < targets.size(); firstEnumTarget++) {
082 if (targets.get(firstEnumTarget).getSrcMembers() != null) {
083 break;
084 }
085 }
086 List<RolapMember> partialRow;
087 if (execQuery) {
088 partialRow = null;
089 } else {
090 partialRow = partialResult.get(currPartialResultIdx);
091 }
092 resetCurrMembers(partialRow);
093 addTargets(
094 0, firstEnumTarget, enumTargetCount, srcMemberIdxes,
095 resultSet, message);
096 if (newPartialResult != null) {
097 savePartialResult(newPartialResult);
098 }
099 }
100
101 if (execQuery) {
102 moreRows = resultSet.next();
103 if (moreRows) {
104 ++stmt.rowCount;
105 }
106 } else {
107 currPartialResultIdx++;
108 moreRows = currPartialResultIdx < partialResult.size();
109 }
110 return moreRows;
111 }
112
113
114 /**
115 * Closes internal statement.
116 */
117 public void close() {
118 if (this.stmt != null) {
119 this.stmt.close();
120 }
121 }
122
123
124 /**
125 * Handles error
126 */
127 public void handle(Exception e) {
128 if (stmt != null) {
129 stmt.handle(e);
130 } else {
131 throw Util.newError(e, message);
132 }
133 }
134
135 //
136 // Private stuff -------------------------------
137 //
138
139 /**
140 * Sets the current member for those targets that retrieve their column
141 * values from native sql.
142 *
143 * @param partialRow if set, previously cached result set
144 */
145 private void resetCurrMembers(List<RolapMember> partialRow) {
146 int nativeTarget = 0;
147 for (Target target : targets) {
148 if (target.getSrcMembers() == null) {
149 if (partialRow != null) {
150 target.setCurrMember(partialRow.get(nativeTarget++));
151 } else {
152 target.removeCurrMember();
153 }
154 }
155 }
156 }
157
158 /**
159 * Recursively forms the cross product of a row retrieved through sql
160 * with each of the targets that contains an enumerated set of members.
161 *
162 * @param currEnumTargetIdx current enum target that recursion
163 * is being applied on
164 * @param currTargetIdx index within the list of a targets that
165 * currEnumTargetIdx corresponds to
166 * @param nEnumTargets number of targets that have enumerated members
167 * @param srcMemberIdxes for each enumerated target, the current member
168 * to be retrieved to form the current cross product row
169 * @param resultSet result set corresponding to rows retrieved through
170 * native sql
171 * @param message Message to issue on failure
172 */
173 private void addTargets(
174 int currEnumTargetIdx, int currTargetIdx, int nEnumTargets,
175 int[] srcMemberIdxes, ResultSet resultSet, String message) {
176
177 Target currTarget = targets.get(currTargetIdx);
178 for (int i = 0; i < currTarget.getSrcMembers().size(); i++) {
179 srcMemberIdxes[currEnumTargetIdx] = i;
180 if (currEnumTargetIdx < nEnumTargets - 1) {
181 int nextTargetIdx = currTargetIdx + 1;
182 for (; nextTargetIdx < targets.size(); nextTargetIdx++) {
183 if (targets.get(nextTargetIdx).getSrcMembers() != null) {
184 break;
185 }
186 }
187 addTargets(
188 currEnumTargetIdx + 1, nextTargetIdx, nEnumTargets,
189 srcMemberIdxes, resultSet, message);
190 } else {
191 int column = 0;
192 int enumTargetIdx = 0;
193 for (Target target : targets) {
194 if (target.getSrcMembers() == null) {
195 try {
196 column = target.addRow(resultSet, column);
197 } catch (Throwable e) {
198 throw Util.newError(e, message);
199 }
200 } else {
201 RolapMember member = target.getSrcMembers().get(
202 srcMemberIdxes[enumTargetIdx++]);
203 target.add(member);
204 }
205 }
206 }
207 }
208 }
209
210 /**
211 * Retrieves the current members fetched from the targets executed
212 * through sql and form tuples, adding them to partialResult
213 *
214 * @param partialResult list containing the columns and rows corresponding
215 * to data fetched through sql
216 */
217 private void savePartialResult(List<List<RolapMember>> partialResult) {
218 List<RolapMember> row = new ArrayList<RolapMember>();
219 for (Target target : targets) {
220 if (target.getSrcMembers() == null) {
221 row.add(target.getCurrMember());
222 }
223 }
224 partialResult.add(row);
225 }
226
227 }
228
229 // End ResultLoader.java