@Override
protected void map(
BytesWritable key,
ArrayWritable value,
Mapper<BytesWritable, ArrayWritable, BytesWritable, TextArrayWritable>.Context context)
throws IOException, InterruptedException {
Map<String, Report> reports = new LinkedHashMap<String, Report>();
Writable[] repts = value.get();
if (repts.length == 0 || !(repts[0] instanceof Text)) {
System.out.println("error: bad input.");
return; // bail out more drastically
}
Text[] repts_as_text = (Text[]) repts;
for (Text t : repts_as_text) {
Report r = Report.createFromString(t.toString());
reports.put(r.getMetadata().getOpIdString(), r);
}
Text[] indexed = indexGraph(reports);
TextArrayWritable output = new TextArrayWritable();
output.set(indexed);
context.write(key, output);
}
/**
* Indexes a set of reports, using Start and End tags output is a list of entries of the form: A:
* time1,time2,time3
*
* <p>If no matches, will return an empty array
*/
@SuppressWarnings("unchecked")
public static Text[] indexGraph(Map<String, Report> reports) {
org.apache.commons.collections.MultiMap index =
new org.apache.commons.collections.MultiHashMap();
// map from start tag to opIds of nodes containing the ends
for (Map.Entry<String, Report> report : reports.entrySet()) {
Report start = report.getValue();
List<String> starts = start.get("Start");
if (starts != null) {
for (String s : starts) {
Report end = findMatchingEnd(reports, start, s);
if (end == null) continue;
List<String> endTL = end.get("Timestamp");
List<String> staTL = start.get("Timestamp");
if (staTL != null && endTL != null && staTL.size() > 0 && endTL.size() > 0) {
// FIXME: perhaps parse more cleverly?
double startT = Double.parseDouble(staTL.get(0));
double endT = Double.parseDouble(endTL.get(0));
Long diff = new Long((long) (1000 * (endT - startT)));
index.put(s, diff);
}
}
}
}
Text[] out = new Text[index.size()];
int i = 0;
for (Object k : index.keySet()) {
StringBuilder sb = new StringBuilder();
sb.append(k.toString());
sb.append(' ');
Collection coll = (Collection) index.get(k);
for (Object v : coll) {
assert v instanceof Long : "how did a non-Long get into my collection?";
sb.append(v.toString());
sb.append(",");
}
sb.deleteCharAt(sb.length() - 1);
Text t = new Text(sb.toString());
out[i++] = t;
}
return out;
}
// do a BFS find closest report to start with endTag
static Report findMatchingEnd(Map<String, Report> reports, Report start, String endTag) {
LinkedList<Report> bfsQ = new LinkedList<Report>();
Set<String> seen = new HashSet<String>();
bfsQ.add(start);
while (!bfsQ.isEmpty()) {
Report cur = bfsQ.poll();
List<String> ends = cur.get("End");
if (ends != null && ends.contains(endTag)) return cur;
List<String> outlinks = start.get(XtrExtract.OUTLINK_FIELD);
if (outlinks == null) return null;
for (String s : outlinks) {
if (seen.contains(s)) continue;
else seen.add(s);
Report r = reports.get(s);
if (r != null) bfsQ.add(r);
}
}
return null;
}
