@Override
public DrillTable create(String key) {
try {
FileSelection fileSelection = FileSelection.create(fs, config.getLocation(), key);
if (fileSelection == null) return null;
if (fileSelection.containsDirectories(fs)) {
for (FormatMatcher m : dirMatchers) {
try {
Object selection = m.isReadable(fileSelection);
if (selection != null)
return new DynamicDrillTable(plugin, storageEngineName, selection);
} catch (IOException e) {
logger.debug("File read failed.", e);
}
}
fileSelection = fileSelection.minusDirectories(fs);
}
for (FormatMatcher m : fileMatchers) {
Object selection = m.isReadable(fileSelection);
if (selection != null) return new DynamicDrillTable(plugin, storageEngineName, selection);
}
return null;
} catch (IOException e) {
logger.debug(
"Failed to create DrillTable with root {} and name {}", config.getLocation(), key, e);
}
return null;
}
@Override
public FormatSelection isReadable(DrillFileSystem fs, FileSelection selection)
throws IOException {
// TODO: we only check the first file for directory reading. This is because
if (selection.containsDirectories(fs)) {
if (isDirReadable(fs, selection.getFirstPath(fs))) {
return new FormatSelection(plugin.getConfig(), expandSelection(fs, selection));
}
}
return super.isReadable(fs, selection);
}
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;
}
}
@Test
public void testCreateReturnsNullWhenArgumentsAreIllegal() {
for (final Object statuses : new Object[] {null, EMPTY_STATUSES}) {
for (final Object files : new Object[] {null, EMPTY_FILES}) {
for (final Object root : new Object[] {null, EMPTY_ROOT}) {
final FileSelection selection =
FileSelection.create(
(List<FileStatus>) statuses, (List<String>) files, (String) root);
assertNull(selection);
}
}
}
}
public FileSelection minusDirectories(DrillFileSystem fs) throws IOException {
if (isExpanded()) {
return this;
}
Stopwatch timer = Stopwatch.createStarted();
final List<FileStatus> statuses = getStatuses(fs);
final int total = statuses.size();
final Path[] paths = new Path[total];
for (int i = 0; i < total; i++) {
paths[i] = statuses.get(i).getPath();
}
final List<FileStatus> allStats = fs.list(true, paths);
final List<FileStatus> nonDirectories =
Lists.newArrayList(
Iterables.filter(
allStats,
new Predicate<FileStatus>() {
@Override
public boolean apply(@Nullable FileStatus status) {
return !status.isDirectory();
}
}));
final FileSelection fileSel = create(nonDirectories, null, selectionRoot);
logger.debug(
"FileSelection.minusDirectories() took {} ms, numFiles: {}",
timer.elapsed(TimeUnit.MILLISECONDS),
total);
// fileSel will be null if we query an empty folder
if (fileSel != null) {
fileSel.setExpanded();
}
return fileSel;
}
@Override
public GroupScan createNewGroupScan(List<String> newFiles) throws IOException {
final FileSelection newSelection = FileSelection.create(null, newFiles, getBaseTableLocation());
final FileGroupScan newScan = ((FileGroupScan) scanRel.getGroupScan()).clone(newSelection);
return newScan;
}
