if ttl = 0 then entry stored infinitely

src/main/java/org/redisson/RedissonMapCache.java

@@ -194,6 +194,13 @@ public class RedissonMapCache<K, V> extends RedissonMap<K, V> implements RMapCac
 
     @Override
     public Future<V> putIfAbsentAsync(K key, V value, long ttl, TimeUnit unit) {
+        if (ttl < 0) {
+            throw new IllegalArgumentException("TTL can't be negative");
+        }
+        if (ttl == 0) {
+            return putIfAbsentAsync(key, value);
+        }
+
         if (unit == null) {
             throw new NullPointerException("TimeUnit param can't be null");
         }
@@ -274,6 +281,13 @@ public class RedissonMapCache<K, V> extends RedissonMap<K, V> implements RMapCac
 
     @Override
     public Future<V> putAsync(K key, V value, long ttl, TimeUnit unit) {
+        if (ttl < 0) {
+            throw new IllegalArgumentException("TTL can't be negative");
+        }
+        if (ttl == 0) {
+            return putAsync(key, value);
+        }
+
         if (unit == null) {
             throw new NullPointerException("TimeUnit param can't be null");
         }

src/main/java/org/redisson/RedissonSetCache.java

@@ -330,6 +330,13 @@ public class RedissonSetCache<V> extends RedissonExpirable implements RSetCache<
 
     @Override
     public Future<Boolean> addAsync(V value, long ttl, TimeUnit unit) {
+        if (ttl < 0) {
+            throw new IllegalArgumentException("TTL can't be negative");
+        }
+        if (ttl == 0) {
+            return addAsync(value);
+        }
+
         if (unit == null) {
             throw new NullPointerException("TimeUnit param can't be null");
         }

src/main/java/org/redisson/core/RMapCache.java

@@ -38,8 +38,37 @@ import java.util.concurrent.TimeUnit;
  */
 public interface RMapCache<K, V> extends RMap<K, V>, RMapCacheAsync<K, V> {
 
+    /**
+     * If the specified key is not already associated
+     * with a value, associate it with the given value.
+     * <p/>
+     * Stores value mapped by key with specified time to live.
+     * Entry expires after specified time to live.
+     * If the map previously contained a mapping for
+     * the key, the old value is replaced by the specified value.
+     *
+     * @param key
+     * @param value
+     * @param ttl - time to live for key\value entry.
+     *              If <code>0</code> then stores infinitely.
+     * @param unit
+     * @return previous associated value
+     */
     V putIfAbsent(K key, V value, long ttl, TimeUnit unit);
 
+    /**
+     * Stores value mapped by key with specified time to live.
+     * Entry expires after specified time to live.
+     * If the map previously contained a mapping for
+     * the key, the old value is replaced by the specified value.
+     *
+     * @param key
+     * @param value
+     * @param ttl - time to live for key\value entry.
+     *              If <code>0</code> then stores infinitely.
+     * @param unit
+     * @return previous associated value
+     */
     V put(K key, V value, long ttl, TimeUnit unit);
 
     /**

src/main/java/org/redisson/core/RMapCacheAsync.java

@@ -40,8 +40,37 @@ import io.netty.util.concurrent.Future;
  */
 public interface RMapCacheAsync<K, V> extends RMapAsync<K, V> {
 
+    /**
+     * If the specified key is not already associated
+     * with a value, associate it with the given value.
+     * <p/>
+     * Stores value mapped by key with specified time to live.
+     * Entry expires after specified time to live.
+     * If the map previously contained a mapping for
+     * the key, the old value is replaced by the specified value.
+     *
+     * @param key
+     * @param value
+     * @param ttl - time to live for key\value entry.
+     *              If <code>0</code> then stores infinitely.
+     * @param unit
+     * @return previous associated value
+     */
     Future<V> putIfAbsentAsync(K key, V value, long ttl, TimeUnit unit);
 
+    /**
+     * Stores value mapped by key with specified time to live.
+     * Entry expires after specified time to live.
+     * If the map previously contained a mapping for
+     * the key, the old value is replaced by the specified value.
+     *
+     * @param key
+     * @param value
+     * @param ttl - time to live for key\value entry.
+     *              If <code>0</code> then stores infinitely.
+     * @param unit
+     * @return previous associated value
+     */
     Future<V> putAsync(K key, V value, long ttl, TimeUnit unit);
 
     /**

src/main/java/org/redisson/core/RSetCache.java

@@ -41,6 +41,18 @@ import java.util.concurrent.TimeUnit;
  */
 public interface RSetCache<V> extends Set<V>, RExpirable, RSetCacheAsync<V> {
 
+    /**
+     * Stores value with specified time to live.
+     * Value expires after specified time to live.
+     *
+     * @param key
+     * @param value
+     * @param ttl - time to live for key\value entry.
+     *              If <code>0</code> then stores infinitely.
+     * @param unit
+     * @return <code>true</code> if value has been added. <code>false</code>
+     *          if value already been in collection.
+     */
     boolean add(V value, long ttl, TimeUnit unit);
 
     /**

src/main/java/org/redisson/core/RSetCacheAsync.java

@@ -28,6 +28,18 @@ import io.netty.util.concurrent.Future;
  */
 public interface RSetCacheAsync<V> extends RCollectionAsync<V> {
 
+    /**
+     * Stores value with specified time to live.
+     * Value expires after specified time to live.
+     *
+     * @param key
+     * @param value
+     * @param ttl - time to live for key\value entry.
+     *              If <code>0</code> then stores infinitely.
+     * @param unit
+     * @return <code>true</code> if value has been added. <code>false</code>
+     *          if value already been in collection.
+     */
     Future<Boolean> addAsync(V value, long ttl, TimeUnit unit);
 
     /**