/**
* @param catalogTracker
* @param serverName
* @return List of user regions installed on this server (does not include catalog regions).
* @throws IOException
*/
public static NavigableMap<HRegionInfo, Result> getServerUserRegions(
CatalogTracker catalogTracker, final ServerName serverName) throws IOException {
final NavigableMap<HRegionInfo, Result> hris = new TreeMap<HRegionInfo, Result>();
// Fill the above hris map with entries from .META. that have the passed
// servername.
CollectingVisitor<Result> v =
new CollectingVisitor<Result>() {
@Override
void add(Result r) {
if (r == null || r.isEmpty()) return;
ServerName sn = getServerNameFromCatalogResult(r);
if (sn != null && sn.equals(serverName)) this.results.add(r);
}
};
fullScan(catalogTracker, v);
List<Result> results = v.getResults();
if (results != null && !results.isEmpty()) {
// Convert results to Map keyed by HRI
for (Result r : results) {
Pair<HRegionInfo, ServerName> p = parseCatalogResult(r);
if (p != null && p.getFirst() != null) hris.put(p.getFirst(), r);
}
}
return hris;
}
/**
* Checks if the specified table exists. Looks at the META table hosted on the specified server.
*
* @param catalogTracker
* @param tableName table to check
* @return true if the table exists in meta, false if not
* @throws IOException
*/
public static boolean tableExists(CatalogTracker catalogTracker, String tableName)
throws IOException {
if (tableName.equals(HTableDescriptor.ROOT_TABLEDESC.getNameAsString())
|| tableName.equals(HTableDescriptor.META_TABLEDESC.getNameAsString())) {
// Catalog tables always exist.
return true;
}
final byte[] tableNameBytes = Bytes.toBytes(tableName);
// Make a version of ResultCollectingVisitor that only collects the first
CollectingVisitor<HRegionInfo> visitor =
new CollectingVisitor<HRegionInfo>() {
private HRegionInfo current = null;
@Override
public boolean visit(Result r) throws IOException {
this.current = parseHRegionInfoFromCatalogResult(r, HConstants.REGIONINFO_QUALIFIER);
if (this.current == null) {
LOG.warn("No serialized HRegionInfo in " + r);
return true;
}
if (!isInsideTable(this.current, tableNameBytes)) return false;
// Else call super and add this Result to the collection.
super.visit(r);
// Stop collecting regions from table after we get one.
return false;
}
@Override
void add(Result r) {
// Add the current HRI.
this.results.add(this.current);
}
};
fullScan(catalogTracker, visitor, getTableStartRowForMeta(tableNameBytes));
// If visitor has results >= 1 then table exists.
return visitor.getResults().size() >= 1;
}
