public void map(
Text key, LongWritable value, OutputCollector<K, LongWritable> collector, Reporter reporter)
throws IOException {
String name = key.toString();
long size = value.get();
long seed = Long.parseLong(name);
if (size == 0) return;
reporter.setStatus("opening " + name);
FSDataInputStream in = fs.open(new Path(DATA_DIR, name));
try {
for (int i = 0; i < SEEKS_PER_FILE; i++) {
// generate a random position
long position = Math.abs(random.nextLong()) % size;
// seek file to that position
reporter.setStatus("seeking " + name);
in.seek(position);
byte b = in.readByte();
// check that byte matches
byte checkByte = 0;
// advance random state to that position
random.setSeed(seed);
for (int p = 0; p <= position; p += check.length) {
reporter.setStatus("generating data for " + name);
if (fastCheck) {
checkByte = (byte) random.nextInt(Byte.MAX_VALUE);
} else {
random.nextBytes(check);
checkByte = check[(int) (position % check.length)];
}
}
assertEquals(b, checkByte);
}
} finally {
in.close();
}
}
