public int getPartition(WritablePoint key, LongWritable value, int numReduceTasks) {
int grid = (int) Math.sqrt(numReduceTasks);
minlat = conf.getDouble(OSMMapper.MINLAT, 0);
minlon = conf.getDouble(OSMMapper.MINLON, 0);
maxlat = conf.getDouble(OSMMapper.MAXLAT, 0);
maxlon = conf.getDouble(OSMMapper.MAXLON, 0);
double w = (maxlon - minlon) / grid;
double h = (maxlat - minlat) / grid;
int ret = -1;
for (int i = 0; i < grid; i++) {
double comp = minlat + (double) (i + 1) * h;
if (key.getY() < comp) {
ret = i * grid; // determine highside value
break;
}
}
if (ret == -1) {
// We had a slight double imprecision problem assume we didn't properly arrive at maxlat
ret = grid * grid - grid;
}
for (int i = 0; i < grid; i++) {
if (key.getX() < minlon + (double) (i + 1) * w) {
ret = ret + i;
return ret; // determine lowside value
}
}
ret = ret + grid - 1;
return ret;
}
public void map(Object key, Text value, Context context)
throws IOException, InterruptedException {
int start = 0;
while (start < value.getLength()) {
// Find the start of a node
start = value.find("node", start);
if (start == -1) break;
// Find the id of that node
start = value.find(" id", start);
if (start == -1) break;
start += 5;
int c = ':';
StringBuilder temp = new StringBuilder();
for (; start < value.getLength(); start++) {
c = value.charAt(start);
if (c != '"') temp.append(c);
else break;
}
if (start > value.getLength()) break;
try {
id.set(Long.parseLong(temp.toString()));
} catch (NumberFormatException e) {
// My Job isn't to worry about java not having unsigned values because they are stupid
id.set(404);
}
start = value.find(" lat", start);
if (start == -1) break;
start += 6;
c = ':';
temp.delete(0, temp.length());
for (; start < value.getLength(); start++) {
c = value.charAt(start);
if (c != '"') temp.append((char) c);
else break;
}
if (start > value.getLength()) break;
node.setY(Double.parseDouble(temp.toString()));
if (node.getY() < minlat || node.getY() > maxlat) {
continue; // Don't care about nodes outside our area of interest
}
start = value.find(" lon", start);
if (start == -1) break;
start += 6;
c = ':';
temp.delete(0, temp.length());
for (; start < value.getLength(); start++) {
c = value.charAt(start);
if (c != '"') temp.append((char) c);
else break;
}
if (start > value.getLength()) break;
node.setX(Double.parseDouble(temp.toString()));
if (node.getX() < minlon || node.getX() > maxlon)
continue; // Don't care about nodes outside our area of interest
context.write(node, id);
}
}
