public int compareTo(BigramWritable bw) {
int cmp = leftBigram.compareTo(bw.leftBigram);
if (cmp != 0) return cmp;
else return rightBigram.compareTo(bw.rightBigram);
}
/** Delete the dst files/dirs which do not exist in src */
private static void deleteNonexisting(
FileSystem dstfs,
FileStatus dstroot,
Path dstsorted,
FileSystem jobfs,
Path jobdir,
JobConf jobconf,
Configuration conf)
throws IOException {
if (!dstroot.isDir()) {
throw new IOException(
"dst must be a directory when option "
+ Options.DELETE.cmd
+ " is set, but dst (= "
+ dstroot.getPath()
+ ") is not a directory.");
}
// write dst lsr results
final Path dstlsr = new Path(jobdir, "_distcp_dst_lsr");
final SequenceFile.Writer writer =
SequenceFile.createWriter(
jobfs,
jobconf,
dstlsr,
Text.class,
FileStatus.class,
SequenceFile.CompressionType.NONE);
try {
// do lsr to get all file statuses in dstroot
final Stack<FileStatus> lsrstack = new Stack<FileStatus>();
for (lsrstack.push(dstroot); !lsrstack.isEmpty(); ) {
final FileStatus status = lsrstack.pop();
if (status.isDir()) {
for (FileStatus child : dstfs.listStatus(status.getPath())) {
String relative = makeRelative(dstroot.getPath(), child.getPath());
writer.append(new Text(relative), child);
lsrstack.push(child);
}
}
}
} finally {
checkAndClose(writer);
}
// sort lsr results
final Path sortedlsr = new Path(jobdir, "_distcp_dst_lsr_sorted");
SequenceFile.Sorter sorter =
new SequenceFile.Sorter(
jobfs, new Text.Comparator(), Text.class, FileStatus.class, jobconf);
sorter.sort(dstlsr, sortedlsr);
// compare lsr list and dst list
SequenceFile.Reader lsrin = null;
SequenceFile.Reader dstin = null;
try {
lsrin = new SequenceFile.Reader(jobfs, sortedlsr, jobconf);
dstin = new SequenceFile.Reader(jobfs, dstsorted, jobconf);
// compare sorted lsr list and sorted dst list
final Text lsrpath = new Text();
final FileStatus lsrstatus = new FileStatus();
final Text dstpath = new Text();
final Text dstfrom = new Text();
final FsShell shell = new FsShell(conf);
final String[] shellargs = {"-rmr", null};
boolean hasnext = dstin.next(dstpath, dstfrom);
for (; lsrin.next(lsrpath, lsrstatus); ) {
int dst_cmp_lsr = dstpath.compareTo(lsrpath);
for (; hasnext && dst_cmp_lsr < 0; ) {
hasnext = dstin.next(dstpath, dstfrom);
dst_cmp_lsr = dstpath.compareTo(lsrpath);
}
if (dst_cmp_lsr == 0) {
// lsrpath exists in dst, skip it
hasnext = dstin.next(dstpath, dstfrom);
} else {
// lsrpath does not exist, delete it
String s = new Path(dstroot.getPath(), lsrpath.toString()).toString();
if (shellargs[1] == null || !isAncestorPath(shellargs[1], s)) {
shellargs[1] = s;
int r = 0;
try {
r = shell.run(shellargs);
} catch (Exception e) {
throw new IOException("Exception from shell.", e);
}
if (r != 0) {
throw new IOException(
"\"" + shellargs[0] + " " + shellargs[1] + "\" returns non-zero value " + r);
}
}
}
}
} finally {
checkAndClose(lsrin);
checkAndClose(dstin);
}
}