001 /**
002 *
003 */
004 package org.wdssii.core;
005
006 import java.util.Date;
007 import java.util.HashMap;
008 import java.util.HashSet;
009 import java.util.Map;
010 import java.util.Set;
011 import java.util.SortedMap;
012 import java.util.TreeMap;
013
014 // import org.apache.commons.logging.Log;
015 // import org.apache.commons.logging.LogFactory;
016
017 /**
018 * the Index class connects to a data source and provides access to real-time
019 * products as they come in.
020 *
021 * @author Lakshman
022 * @version $Id: Index.java,v 1.6 2006/12/29 21:15:12 lakshman Exp $
023 * @see IndexRecord
024 */
025 public abstract class Index {
026 // private static Log log = LogFactory.getLog(Index.class);
027
028 /**
029 * Create a brand-new Index with these listeners attached.
030 */
031 public abstract Index newInstance(String path,
032 Set<IndexRecordListener> listeners) throws DataUnavailableException;
033
034 /**
035 * The update() method will be called periodically. The implementation is
036 * allowed to ignore update() calls that happen at inconvenient times.
037 */
038 public abstract void update();
039
040 /** datatype to TreeMap<time,record> */
041 private HashMap<String, TreeMap<Date, IndexRecord>> timestamps = new HashMap<String, TreeMap<Date, IndexRecord>>();
042
043 private HashMap<String, IndexRecord> records = new HashMap<String, IndexRecord>();
044
045 private HashMap<String, HashSet<String>> selections = new HashMap<String, HashSet<String>>();
046
047 private HashSet<String> datatypes = new HashSet<String>();
048
049 private Set<IndexRecordListener> listeners = null;
050
051 private String indexLocation = null;
052
053 /** the directory in which this index.xml or index.lb is located */
054 public String getIndexLocation() {
055 return indexLocation;
056 }
057
058 public Index(String indexLocation, Set<IndexRecordListener> listeners) {
059 this.indexLocation = indexLocation;
060 this.listeners = listeners;
061 }
062
063 /** Register a listener to be notified about new records in this index. */
064 public void addRecordListener(IndexRecordListener listener) {
065 listeners.add(listener);
066 }
067
068 public void addRecord(IndexRecord rec) {
069 // form the selections to create the keys
070 String[] sels = new String[3];
071 sels[0] = rec.getDataType(); // dt
072 sels[1] = rec.getSubType();
073 sels[2] = rec.getTimeStamp();
074
075 addSelection(getKey(sels, 0, 0), sels[1]);
076 addSelection(getKey(sels, 0, 1), sels[2]);
077 addRecord(getKey(sels, 0, 2), rec); // everything to record
078
079 datatypes.add(sels[0]);
080
081 addRecByTypeTime(rec.getTime(), sels[0], rec);
082
083 for (IndexRecordListener listener : listeners) {
084 listener.handleRecord(rec);
085 }
086 }
087
088 void addRecByTypeTime(Date time, String dt, IndexRecord rec) {
089 TreeMap<Date, IndexRecord> tm = timestamps.get(dt);
090 if (tm == null) {
091 tm = new TreeMap<Date, IndexRecord>();
092 timestamps.put(dt, tm);
093 }
094 tm.put(time, rec);
095 }
096
097 private String getKey(String[] sels, int start, int last) {
098 StringBuilder b = new StringBuilder();
099 for (int i = start; i <= last; ++i) {
100 b.append(sels[i]);
101 b.append(" ");
102 }
103 return b.toString();
104 }
105
106 // note that from is INCLUSIVE and to is EXCLUSIVE
107
108 public Map<Date, IndexRecord> getRecordsByTypeTime(String dt, Date from,
109 Date to) {
110 TreeMap<Date, IndexRecord> tm = timestamps.get(dt);
111 if (tm == null)
112 return null;
113
114 SortedMap<Date, IndexRecord> sm = null;
115 if (from != null) {
116 if (to != null)
117 sm = tm.subMap(from, to);
118 else
119 sm = tm.tailMap(from);
120 } else {
121 if (to != null)
122 sm = tm.headMap(to);
123 else
124 sm = tm;
125 }
126 return (sm);
127 }
128
129 public IndexRecord getFirstRecordByTime(String dt) {
130 TreeMap<Date, IndexRecord> tm = timestamps.get(dt);
131 if (tm == null)
132 return null;
133 return tm.get(tm.firstKey());
134 }
135
136 public IndexRecord getLastRecordByTime(String dt) {
137 TreeMap<Date, IndexRecord> tm = timestamps.get(dt);
138 if (tm == null)
139 return null;
140 return tm.get(tm.lastKey());
141 }
142
143 public int numRecordsByTime(String dt) {
144 TreeMap<Date, IndexRecord> tm = timestamps.get(dt);
145 if (tm == null)
146 return -1;
147 return (tm.size());
148 }
149
150 private void addSelection(String key, String s) {
151 HashSet<String> inmap = selections.get(key);
152 if (inmap == null) {
153 inmap = new HashSet<String>();
154 selections.put(key, inmap);
155 }
156 inmap.add(s);
157 }
158
159 private void addRecord(String key, IndexRecord rec) {
160 records.put(key, rec);
161 }
162
163 public IndexRecord getRecord(String[] selections) {
164 return getRecord(getKey(selections, 0, 2));
165 }
166
167 public IndexRecord getRecord(String key) {
168 return records.get(key);
169 }
170
171 public Set<String> getDataTypes() {
172 return datatypes;
173 }
174
175 public Set<String> getNextSelection(String[] selections) {
176 return getNextSelection(getKey(selections, 0, selections.length - 1));
177 }
178
179 public Set<String> getNextSelection(String key) {
180 return selections.get(key);
181 }
182
183 }