/**
* Returns longest common path for the given list of files.
*
* @param files list of files.
* @return longest common path
*/
private static String commonPathForFiles(final List<String> files) {
if (files == null || files.isEmpty()) {
return "";
}
final int total = files.size();
final String[][] folders = new String[total][];
int shortest = Integer.MAX_VALUE;
for (int i = 0; i < total; i++) {
final Path path = new Path(files.get(i));
folders[i] = Path.getPathWithoutSchemeAndAuthority(path).toString().split(PATH_SEPARATOR);
shortest = Math.min(shortest, folders[i].length);
}
int latest;
out:
for (latest = 0; latest < shortest; latest++) {
final String current = folders[0][latest];
for (int i = 1; i < folders.length; i++) {
if (!current.equals(folders[i][latest])) {
break out;
}
}
}
final Path path = new Path(files.get(0));
final URI uri = path.toUri();
final String pathString = buildPath(folders[0], latest);
return new Path(uri.getScheme(), uri.getAuthority(), pathString).toString();
}
private FileSelection expandSelection(DrillFileSystem fs, FileSelection selection)
throws IOException {
if (metaDataFileExists(fs, selection.getFirstPath(fs))) {
FileStatus metaRootDir = selection.getFirstPath(fs);
Path metaFilePath = getMetadataPath(metaRootDir);
// get the metadata for the directory by reading the metadata file
ParquetTableMetadata_v1 metadata = Metadata.readBlockMeta(fs, metaFilePath.toString());
List<String> fileNames = Lists.newArrayList();
for (ParquetFileMetadata file : metadata.files) {
fileNames.add(file.path);
}
// when creating the file selection, set the selection root in the form /a/b instead of
// file:/a/b. The reason is that the file names above have been created in the form
// /a/b/c.parquet and the format of the selection root must match that of the file names
// otherwise downstream operations such as partition pruning can break.
Path metaRootPath = Path.getPathWithoutSchemeAndAuthority(metaRootDir.getPath());
return new FileSelection(
fileNames, metaRootPath.toString(), metadata /* save metadata for future use */);
} else {
// don't expand yet; ParquetGroupScan's metadata gathering operation
// does that.
return selection;
}
}
@Override
public Path getPathWithoutSchemeAndAuthority(Path path) {
return Path.getPathWithoutSchemeAndAuthority(path);
}