/*
* Returns the relative path of the dir this cache will be localized in
* relative path that this cache will be localized in. For
* hdfs://hostname:port/absolute_path -- the relative path is
* hostname/absolute path -- if it is just /absolute_path -- then the
* relative path is hostname of DFS this mapred cluster is running
* on/absolute_path
*/
public static String makeRelative(URI cache, Configuration conf) throws IOException {
String host = cache.getHost();
if (host == null) {
host = cache.getScheme();
}
if (host == null) {
URI defaultUri = FileSystem.get(conf).getUri();
host = defaultUri.getHost();
if (host == null) {
host = defaultUri.getScheme();
}
}
String path = host + cache.getPath();
path = path.replace(":/", "/"); // remove windows device colon
return path;
}
private static Path checkCacheStatusValidity(
Configuration conf,
URI cache,
long confFileStamp,
CacheStatus cacheStatus,
FileStatus fileStatus,
boolean isArchive)
throws IOException {
FileSystem fs = FileSystem.get(cache, conf);
// Has to be
if (!ifExistsAndFresh(conf, fs, cache, confFileStamp, cacheStatus, fileStatus)) {
throw new IOException(
"Stale cache file: " + cacheStatus.localizedLoadPath + " for cache-file: " + cache);
}
LOG.info(
String.format(
"Using existing cache of %s->%s", cache.toString(), cacheStatus.localizedLoadPath));
return cacheStatus.localizedLoadPath;
}
private static FileSystem getFileSystem(URI cache, Configuration conf) throws IOException {
String fileSysName = getFileSysName(cache);
if (fileSysName != null) return FileSystem.getNamed(fileSysName, conf);
else return FileSystem.get(conf);
}
/**
* Returns the status of a given cache file on hdfs.
*
* @param conf configuration
* @param cache cache file
* @return FileStatus object of the file
* @throws IOException
*/
public static FileStatus getFileStatus(Configuration conf, URI cache) throws IOException {
FileSystem fileSystem = FileSystem.get(cache, conf);
Path filePath = new Path(cache.getPath());
return fileSystem.getFileStatus(filePath);
}
/**
* Returns mtime of a given cache file on hdfs.
*
* @param conf configuration
* @param cache cache file
* @return mtime of a given cache file on hdfs
* @throws IOException
*/
public static long getTimestamp(Configuration conf, URI cache) throws IOException {
FileSystem fileSystem = FileSystem.get(cache, conf);
Path filePath = new Path(cache.getPath());
return fileSystem.getFileStatus(filePath).getModificationTime();
}
