| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.cassandra.db.lifecycle; |
| |
| import java.util.*; |
| |
| import com.google.common.base.Predicate; |
| import com.google.common.collect.*; |
| |
| import org.apache.cassandra.io.sstable.format.SSTableReader; |
| import org.apache.cassandra.utils.Throwables; |
| |
| import static com.google.common.base.Predicates.*; |
| import static com.google.common.collect.Iterables.any; |
| import static com.google.common.collect.Iterables.concat; |
| import static com.google.common.collect.Iterables.filter; |
| import static com.google.common.collect.Iterables.getFirst; |
| import static org.apache.cassandra.utils.Throwables.merge; |
| |
| class Helpers |
| { |
| /** |
| * update the contents of a set with the provided sets, ensuring that the items to remove are |
| * really present, and that the items to add are not (unless we're also removing them) |
| * @return a new set with the contents of the provided one modified |
| */ |
| static <T> Set<T> replace(Set<T> original, Set<T> remove, Iterable<T> add) |
| { |
| return ImmutableSet.copyOf(replace(identityMap(original), remove, add).keySet()); |
| } |
| |
| /** |
| * update the contents of an "identity map" with the provided sets, ensuring that the items to remove are |
| * really present, and that the items to add are not (unless we're also removing them) |
| * @return a new identity map with the contents of the provided one modified |
| */ |
| static <T> Map<T, T> replace(Map<T, T> original, Set<T> remove, Iterable<T> add) |
| { |
| // ensure the ones being removed are the exact same ones present |
| for (T reader : remove) |
| assert original.get(reader) == reader; |
| |
| // ensure we don't already contain any we're adding, that we aren't also removing |
| assert !any(add, and(not(in(remove)), in(original.keySet()))) : String.format("original:%s remove:%s add:%s", original.keySet(), remove, add); |
| |
| Map<T, T> result = |
| identityMap(concat(add, filter(original.keySet(), not(in(remove))))); |
| |
| assert result.size() == original.size() - remove.size() + Iterables.size(add) : |
| String.format("Expecting new size of %d, got %d while replacing %s by %s in %s", |
| original.size() - remove.size() + Iterables.size(add), result.size(), remove, add, original.keySet()); |
| return result; |
| } |
| |
| /** |
| * A convenience method for encapsulating this action over multiple SSTableReader with exception-safety |
| * @return accumulate if not null (with any thrown exception attached), or any thrown exception otherwise |
| */ |
| static void setupOnline(Iterable<SSTableReader> readers) |
| { |
| for (SSTableReader reader : readers) |
| reader.setupOnline(); |
| } |
| |
| /** |
| * A convenience method for encapsulating this action over multiple SSTableReader with exception-safety |
| * @return accumulate if not null (with any thrown exception attached), or any thrown exception otherwise |
| */ |
| static Throwable setReplaced(Iterable<SSTableReader> readers, Throwable accumulate) |
| { |
| for (SSTableReader reader : readers) |
| { |
| try |
| { |
| reader.setReplaced(); |
| } |
| catch (Throwable t) |
| { |
| accumulate = merge(accumulate, t); |
| } |
| } |
| return accumulate; |
| } |
| |
| /** |
| * assert that none of these readers have been replaced |
| */ |
| static void checkNotReplaced(Iterable<SSTableReader> readers) |
| { |
| for (SSTableReader reader : readers) |
| assert !reader.isReplaced(); |
| } |
| |
| static Throwable markObsolete(List<LogTransaction.Obsoletion> obsoletions, Throwable accumulate) |
| { |
| if (obsoletions == null || obsoletions.isEmpty()) |
| return accumulate; |
| |
| for (LogTransaction.Obsoletion obsoletion : obsoletions) |
| { |
| try |
| { |
| obsoletion.reader.markObsolete(obsoletion.tidier); |
| } |
| catch (Throwable t) |
| { |
| accumulate = merge(accumulate, t); |
| } |
| } |
| return accumulate; |
| } |
| |
| static Throwable prepareForObsoletion(Iterable<SSTableReader> readers, LogTransaction txnLogs, List<LogTransaction.Obsoletion> obsoletions, Throwable accumulate) |
| { |
| for (SSTableReader reader : readers) |
| { |
| try |
| { |
| obsoletions.add(new LogTransaction.Obsoletion(reader, txnLogs.obsoleted(reader))); |
| } |
| catch (Throwable t) |
| { |
| accumulate = Throwables.merge(accumulate, t); |
| } |
| } |
| return accumulate; |
| } |
| |
| static Throwable abortObsoletion(List<LogTransaction.Obsoletion> obsoletions, Throwable accumulate) |
| { |
| if (obsoletions == null || obsoletions.isEmpty()) |
| return accumulate; |
| |
| for (LogTransaction.Obsoletion obsoletion : obsoletions) |
| { |
| try |
| { |
| obsoletion.tidier.abort(); |
| } |
| catch (Throwable t) |
| { |
| accumulate = merge(accumulate, t); |
| } |
| } |
| return accumulate; |
| } |
| |
| /** |
| * @return the identity function, as a Map, with domain of the provided values |
| */ |
| static <T> Map<T, T> identityMap(Iterable<T> values) |
| { |
| ImmutableMap.Builder<T, T> builder = ImmutableMap.<T, T>builder(); |
| for (T t : values) |
| builder.put(t, t); |
| return builder.build(); |
| } |
| |
| /** |
| * @return an Iterable of the union if the sets, with duplicates being represented by their first encountered instance |
| * (as defined by the order of set provision) |
| */ |
| static <T> Iterable<T> concatUniq(Set<T>... sets) |
| { |
| List<Predicate<T>> notIn = new ArrayList<>(sets.length); |
| for (Set<T> set : sets) |
| notIn.add(not(in(set))); |
| List<Iterable<T>> results = new ArrayList<>(sets.length); |
| for (int i = 0 ; i < sets.length ; i++) |
| results.add(filter(sets[i], and(notIn.subList(0, i)))); |
| return concat(results); |
| } |
| |
| /** |
| * @return a Predicate yielding true for an item present in NONE of the provided sets |
| */ |
| static <T> Predicate<T> notIn(Set<T>... sets) |
| { |
| return not(orIn(sets)); |
| } |
| |
| /** |
| * @return a Predicate yielding true for an item present in ANY of the provided sets |
| */ |
| static <T> Predicate<T> orIn(Collection<T>... sets) |
| { |
| Predicate<T>[] orIn = new Predicate[sets.length]; |
| for (int i = 0 ; i < orIn.length ; i++) |
| orIn[i] = in(sets[i]); |
| return or(orIn); |
| } |
| |
| /** |
| * filter out (i.e. remove) matching elements |
| * @return filter, filtered to only those elements that *are not* present in *any* of the provided sets (are present in none) |
| */ |
| static <T> Iterable<T> filterOut(Iterable<T> filter, Set<T>... inNone) |
| { |
| return filter(filter, notIn(inNone)); |
| } |
| |
| /** |
| * filter in (i.e. retain) |
| * |
| * @return filter, filtered to only those elements that *are* present in *any* of the provided sets |
| */ |
| static <T> Iterable<T> filterIn(Iterable<T> filter, Set<T>... inAny) |
| { |
| return filter(filter, orIn(inAny)); |
| } |
| |
| static Set<SSTableReader> emptySet() |
| { |
| return Collections.emptySet(); |
| } |
| |
| static <T> T select(T t, Collection<T> col) |
| { |
| if (col instanceof Set && !col.contains(t)) |
| return null; |
| return getFirst(filter(col, equalTo(t)), null); |
| } |
| |
| static <T> T selectFirst(T t, Collection<T> ... sets) |
| { |
| for (Collection<T> set : sets) |
| { |
| T select = select(t, set); |
| if (select != null) |
| return select; |
| } |
| return null; |
| } |
| |
| static <T> Predicate<T> idIn(Set<T> set) |
| { |
| return idIn(identityMap(set)); |
| } |
| |
| static <T> Predicate<T> idIn(final Map<T, T> identityMap) |
| { |
| return new Predicate<T>() |
| { |
| public boolean apply(T t) |
| { |
| return identityMap.get(t) == t; |
| } |
| }; |
| } |
| |
| } |