基于SCache分布式锁实现

package org.scache.cache.redis; import org.scache.serialization.ISerializer; import redis.clients.jedis.BinaryClient.LIST_POSITION; import redis.clients.jedis.JedisPool; import java.io.Serializable; import java.util.*; /** * Redis的 {@link List}实现 * * @author 君枫 * @since 2014-8-15 下午2:21:06 */ @SuppressWarnings("unchecked") class RedisList<T extends Serializable> extends AbstractRedisObject implements List<T> { private static final int batchSize = 50; RedisList(String listName, JedisPool jedisPool, ISerializer serializer) { super(listName, jedisPool, serializer); } @Override public int size() { return getJedis().llen(redisKeyByteArray).intValue(); } @Override public boolean isEmpty() { return size() == 0; } @Override public boolean contains(Object o) { return indexOf(o) != -1; } @Override public Iterator<T> iterator() { return listIterator(0); } @Override public ListIterator<T> listIterator(final int ind) { return new ListIterator<T>() { private int currentIndex = ind - 1; private boolean removeExecuted; @Override public boolean hasNext() { int size = size(); return currentIndex + 1 < size && size > 0; } @Override public T next() { if (!hasNext()) { throw new NoSuchElementException("No such element at index " + currentIndex); } currentIndex++; removeExecuted = false; return RedisList.this.get(currentIndex); } @Override public void remove() { if (removeExecuted) { throw new IllegalStateException("Element been already deleted"); } RedisList.this.remove(currentIndex); currentIndex--; removeExecuted = true; } @Override public boolean hasPrevious() { int size = size(); return currentIndex - 1 < size && size > 0 && currentIndex >= 0; } @Override public T previous() { if (!hasPrevious()) { throw new NoSuchElementException("No such element at index " + currentIndex); } removeExecuted = false; T res = RedisList.this.get(currentIndex); currentIndex--; return res; } @Override public int nextIndex() { return currentIndex + 1; } @Override public int previousIndex() { return currentIndex; } @Override public void set(T e) { if (currentIndex >= size() - 1) { throw new IllegalStateException(); } RedisList.this.set(currentIndex, e); } @Override public void add(T e) { RedisList.this.add(currentIndex + 1, e); currentIndex++; } }; } @Override public Object[] toArray() { List<T> list = subList(0, size()); return list.toArray(); } @Override public <V> V[] toArray(V[] a) { List<T> list = subList(0, size()); return list.toArray(a); } @Override public boolean add(T e) { return getJedis().rpush(redisKeyByteArray, serialize(e)) > 0; } @Override public boolean remove(Object o) { return remove(o, 1); } protected boolean remove(final Object o, final int count) { return getJedis().lrem(redisKeyByteArray, count, serialize((T) o)) > 0; } @Override public boolean containsAll(Collection<?> c) { if (isEmpty()) { return false; } Collection<Object> copy = new ArrayList<Object>(c); int to = div(size(), batchSize); for (int i = 0; i < to; i++) { List<byte[]> byteList = getJedis().lrange(redisKeyByteArray, i * batchSize, i * batchSize + batchSize - 1); List<T> list = deserializeValue(byteList); for (Iterator<Object> iterator = copy.iterator(); iterator.hasNext(); ) { Object obj = iterator.next(); int index = list.indexOf(obj); if (index != -1) { iterator.remove(); } } } return copy.isEmpty(); } @Override public boolean addAll(Collection<? extends T> c) { return getJedis().rpush(redisKeyByteArray, serializeValue((List<T>) c)) >= c.size(); } @Override public boolean addAll(int index, Collection<? extends T> c) { if (index > 0) { byte[] lastElemnt = getByteArray(index - 1); byte[] currentElemnt; for (T v : c) { currentElemnt = serialize(v); getJedis().linsert(redisKeyByteArray, LIST_POSITION.AFTER, lastElemnt, currentElemnt); lastElemnt = currentElemnt; } } else if (index == 0) { Collections.reverse((List<?>) c); byte[][] bytes = serializeValue((Collection<T>) c); getJedis().lpush(redisKeyByteArray, bytes); } else return false; return true; } @Override public boolean removeAll(Collection<?> c) { boolean flag = true; for (Object o : c) { if (!remove(o)) flag = false; } return flag; } @Override public boolean retainAll(Collection<?> c) { boolean changed = false; for (Iterator<T> iterator = iterator(); iterator.hasNext(); ) { T object = iterator.next(); if (!c.contains(object)) { iterator.remove(); changed = true; } } return changed; } @Override public void clear() { getJedis().del(redisKeyByteArray); } @Override public T get(int index) { return deserialize(getJedis().lindex(redisKeyByteArray, index)); } protected byte[] getByteArray(int index) { checkIndex(index, size()); return getJedis().lindex(redisKeyByteArray, index); } @Override public T set(int index, T element) { checkIndex(index, size()); T old = get(index); getJedis().lset(redisKeyByteArray, index, serialize(element)); return old; } @Override public void add(int index, T element) { if (index > 0) { getJedis().linsert(redisKeyByteArray, LIST_POSITION.AFTER, getByteArray(index - 1), serialize(element)); } else if (index == 0) { getJedis().lpush(redisKeyByteArray, serialize(element)); } } private void checkIndex(int index, int size) { if (!isInRange(index, size)) throw new IndexOutOfBoundsException("index: " + index + " but current size: " + size); } private boolean isInRange(int index, int size) { return index >= 0 && index < size; } T removeFromLeft(int index, int size) { List<byte[]> byteList = getJedis().lrange(redisKeyByteArray, 0, index); getJedis().ltrim(redisKeyByteArray, index + 1, size - 1);// 只保留另一半 T removed = deserialize(byteList.remove(index)); Collections.reverse(byteList); byte[][] reversedBytes = new byte[byteList.size()][]; byteList.toArray(reversedBytes);