Remove unnecessary nullness annotations (fixes #337)

caffeine/src/jmh/java/com/github/benmanes/caffeine/cache/BasicCache.java

@@ -15,7 +15,6 @@
  */
 package com.github.benmanes.caffeine.cache;
 
-import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 /**
@@ -26,13 +25,13 @@
 public interface BasicCache<K, V> {
 
   /** Returns the value stored in the cache, or null if not present. */
-  @Nullable V get(@NonNull K key);
+  @Nullable V get(K key);
 
   /** Stores the value into the cache, replacing an existing mapping if present. */
-  void put(@NonNull K key, @NonNull V value);
+  void put(K key, V value);
 
   /** Removes the entry from the cache, if present. */
-  void remove(@NonNull K key);
+  void remove(K key);
 
   /** Invalidates all entries from the cache. */
   void clear();

caffeine/src/main/java/com/github/benmanes/caffeine/cache/AsyncCache.java

@@ -23,7 +23,6 @@
 import java.util.function.BiFunction;
 import java.util.function.Function;
 
-import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 /**
@@ -50,7 +49,7 @@ public interface AsyncCache<K, V> {
    * @throws NullPointerException if the specified key is null
    */
   @Nullable
-  CompletableFuture<V> getIfPresent(@NonNull K key);
+  CompletableFuture<V> getIfPresent(K key);
 
   /**
    * Returns the future associated with {@code key} in this cache, obtaining that value from
@@ -70,9 +69,7 @@ public interface AsyncCache<K, V> {
    * @return the current (existing or computed) future value associated with the specified key
    * @throws NullPointerException if the specified key or mappingFunction is null
    */
-  @NonNull
-  CompletableFuture<V> get(@NonNull K key,
-      @NonNull Function<? super K, ? extends V> mappingFunction);
+  CompletableFuture<V> get(K key, Function<? super K, ? extends V> mappingFunction);
 
   /**
    * Returns the future associated with {@code key} in this cache, obtaining that value from
@@ -95,9 +92,8 @@ CompletableFuture<V> get(@NonNull K key,
    * @throws RuntimeException or Error if the mappingFunction does when constructing the future,
    *         in which case the mapping is left unestablished
    */
-  @NonNull
-  CompletableFuture<V> get(@NonNull K key,
-      @NonNull BiFunction<? super K, Executor, CompletableFuture<V>> mappingFunction);
+  CompletableFuture<V> get(K key,
+      BiFunction<? super K, Executor, CompletableFuture<V>> mappingFunction);
 
   /**
    * Returns the future of a map of the values associated with {@code keys}, creating or retrieving
@@ -122,9 +118,8 @@ CompletableFuture<V> get(@NonNull K key,
    * @throws RuntimeException or Error if the mappingFunction does so, in which case the mapping is
    *         left unestablished
    */
-  @NonNull
-  CompletableFuture<Map<K, V>> getAll(@NonNull Iterable<? extends @NonNull K> keys,
-      @NonNull Function<Set<? extends @NonNull K>, @NonNull Map<K, V>> mappingFunction);
+  CompletableFuture<Map<K, V>> getAll(Iterable<? extends K> keys,
+      Function<Set<? extends K>, Map<K, V>> mappingFunction);
 
   /**
    * Returns the future of a map of the values associated with {@code keys}, creating or retrieving
@@ -149,9 +144,8 @@ CompletableFuture<Map<K, V>> getAll(@NonNull Iterable<? extends @NonNull K> keys
    * @throws RuntimeException or Error if the mappingFunction does so, in which case the mapping is
    *         left unestablished
    */
-  @NonNull
-  CompletableFuture<Map<K, V>> getAll(@NonNull Iterable<? extends @NonNull K> keys,
-      @NonNull BiFunction<Set<? extends @NonNull K>, Executor, CompletableFuture<Map<K, V>>> mappingFunction);
+  CompletableFuture<Map<K, V>> getAll(Iterable<? extends K> keys,
+      BiFunction<Set<? extends K>, Executor, CompletableFuture<Map<K, V>>> mappingFunction);
 
   /**
    * Associates {@code value} with {@code key} in this cache. If the cache previously contained a
@@ -165,7 +159,7 @@ CompletableFuture<Map<K, V>> getAll(@NonNull Iterable<? extends @NonNull K> keys
    * @param valueFuture value to be associated with the specified key
    * @throws NullPointerException if the specified key or value is null
    */
-  void put(@NonNull K key, @NonNull CompletableFuture<V> valueFuture);
+  void put(K key, CompletableFuture<V> valueFuture);
 
   /**
    * Returns a view of the entries stored in this cache as a thread-safe map. Modifications made to
@@ -182,8 +176,7 @@ CompletableFuture<Map<K, V>> getAll(@NonNull Iterable<? extends @NonNull K> keys
    *
    * @return a thread-safe view of this cache supporting all of the optional {@link Map} operations
    */
-  @NonNull
-  ConcurrentMap<@NonNull K, @NonNull CompletableFuture<V>> asMap();
+  ConcurrentMap<K, CompletableFuture<V>> asMap();
 
   /**
    * Returns a view of the entries stored in this cache as a synchronous {@link Cache}. A mapping is
@@ -193,6 +186,5 @@ CompletableFuture<Map<K, V>> getAll(@NonNull Iterable<? extends @NonNull K> keys
    *
    * @return a thread-safe synchronous view of this cache
    */
-  @NonNull
   Cache<K, V> synchronous();
 }

caffeine/src/main/java/com/github/benmanes/caffeine/cache/AsyncCacheLoader.java

@@ -24,8 +24,6 @@
 import java.util.function.BiFunction;
 import java.util.function.Function;
 
-import org.checkerframework.checker.nullness.qual.NonNull;
-
 /**
  * Computes or retrieves values asynchronously, based on a key, for use in populating a
  * {@link AsyncLoadingCache}.
@@ -57,8 +55,7 @@ public interface AsyncCacheLoader<K, V> {
    *         treated like any other {@code Exception} in all respects except that, when it is
    *         caught, the thread's interrupt status is set
    */
-  @NonNull
-  CompletableFuture<V> asyncLoad(@NonNull K key, @NonNull Executor executor) throws Exception;
+  CompletableFuture<V> asyncLoad(K key, Executor executor) throws Exception;
 
   /**
    * Asynchronously computes or retrieves the values corresponding to {@code keys}. This method is
@@ -82,9 +79,8 @@ public interface AsyncCacheLoader<K, V> {
    *         treated like any other {@code Exception} in all respects except that, when it is
    *         caught, the thread's interrupt status is set
    */
-  @NonNull
-  default CompletableFuture<Map<@NonNull K, @NonNull V>> asyncLoadAll(
-      @NonNull Set<? extends @NonNull K> keys, @NonNull Executor executor) throws Exception {
+  default CompletableFuture<Map<K, V>> asyncLoadAll(
+      Set<? extends K> keys, Executor executor) throws Exception {
     throw new UnsupportedOperationException();
   }
 
@@ -106,9 +102,7 @@ public interface AsyncCacheLoader<K, V> {
    *         treated like any other {@code Exception} in all respects except that, when it is
    *         caught, the thread's interrupt status is set
    */
-  @NonNull
-  default CompletableFuture<V> asyncReload(
-      @NonNull K key, @NonNull V oldValue, @NonNull Executor executor) throws Exception {
+  default CompletableFuture<V> asyncReload(K key, V oldValue, Executor executor) throws Exception {
     return asyncLoad(key, executor);
   }
 
@@ -128,7 +122,6 @@ default CompletableFuture<V> asyncReload(
    * @return an asynchronous cache loader that delegates to the supplied {@code mappingFunction}
    * @throws NullPointerException if the mappingFunction is null
    */
-  @NonNull
   static <K, V> AsyncCacheLoader<K, V> bulk(Function<Set<? extends K>, Map<K, V>> mappingFunction) {
     return CacheLoader.bulk(mappingFunction);
   }
@@ -149,7 +142,6 @@ static <K, V> AsyncCacheLoader<K, V> bulk(Function<Set<? extends K>, Map<K, V>>
    * @return an asynchronous cache loader that delegates to the supplied {@code mappingFunction}
    * @throws NullPointerException if the mappingFunction is null
    */
-  @NonNull
   static <K, V> AsyncCacheLoader<K, V> bulk(
       BiFunction<Set<? extends K>, Executor, CompletableFuture<Map<K, V>>> mappingFunction) {
     requireNonNull(mappingFunction);

caffeine/src/main/java/com/github/benmanes/caffeine/cache/AsyncLoadingCache.java

@@ -18,8 +18,6 @@
 import java.util.Map;
 import java.util.concurrent.CompletableFuture;
 
-import org.checkerframework.checker.nullness.qual.NonNull;
-
 /**
  * A semi-persistent mapping from keys to values. Values are automatically loaded by the cache
  * asynchronously, and are stored in the cache until either evicted or manually invalidated.
@@ -49,8 +47,7 @@ public interface AsyncLoadingCache<K, V> extends AsyncCache<K, V> {
    * @throws RuntimeException or Error if the {@link AsyncCacheLoader} does when constructing the
    *         future, in which case the mapping is left unestablished
    */
-  @NonNull
-  CompletableFuture<V> get(@NonNull K key);
+  CompletableFuture<V> get(K key);
 
   /**
    * Returns the future of a map of the values associated with {@code keys}, creating or retrieving
@@ -78,8 +75,7 @@ public interface AsyncLoadingCache<K, V> extends AsyncCache<K, V> {
    *         {@link AsyncCacheLoader#asyncLoadAll} returns {@code null}, or fails when constructing
    *         the future, in which case the mapping is left unestablished
    */
-  @NonNull
-  CompletableFuture<Map<K, V>> getAll(@NonNull Iterable<? extends @NonNull K> keys);
+  CompletableFuture<Map<K, V>> getAll(Iterable<? extends K> keys);
 
   /**
    * Returns a view of the entries stored in this cache as a synchronous {@link LoadingCache}. A
@@ -89,7 +85,6 @@ public interface AsyncLoadingCache<K, V> extends AsyncCache<K, V> {
    *
    * @return a thread-safe synchronous view of this cache
    */
-  @NonNull
   @Override
   LoadingCache<K, V> synchronous();
 }

caffeine/src/main/java/com/github/benmanes/caffeine/cache/BoundedLocalCache.java

@@ -70,7 +70,6 @@
 import java.util.function.Predicate;
 import java.util.function.Supplier;
 
-import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 import com.github.benmanes.caffeine.cache.Async.AsyncExpiry;
@@ -752,13 +751,13 @@ void evictFromMain(int candidates) {
       K victimKey = victim.getKey();
       K candidateKey = candidate.getKey();
       if (victimKey == null) {
-        @NonNull Node<K, V> evict = victim;
+        Node<K, V> evict = victim;
         victim = victim.getNextInAccessOrder();
         evictEntry(evict, RemovalCause.COLLECTED, 0L);
         continue;
       } else if (candidateKey == null) {
         candidates--;
-        @NonNull Node<K, V> evict = candidate;
+        Node<K, V> evict = candidate;
         candidate = candidate.getPreviousInAccessOrder();
         evictEntry(evict, RemovalCause.COLLECTED, 0L);
         continue;
@@ -3529,7 +3528,7 @@ final class BoundedEviction implements Eviction<K, V> {
       @Override public boolean isWeighted() {
         return isWeighted;
       }
-      @Override public OptionalInt weightOf(@NonNull K key) {
+      @Override public OptionalInt weightOf(K key) {
         requireNonNull(key);
         if (!isWeighted) {
           return OptionalInt.empty();

caffeine/src/main/java/com/github/benmanes/caffeine/cache/Buffer.java

@@ -17,8 +17,6 @@
 
 import java.util.function.Consumer;
 
-import org.checkerframework.checker.nullness.qual.NonNull;
-
 /**
  * A multiple-producer / single-consumer buffer that rejects new elements if it is full or
  * fails spuriously due to contention. Unlike a queue and stack, a buffer does not guarantee an
@@ -50,15 +48,15 @@ static <E> Buffer<E> disabled() {
    * @param e the element to add
    * @return {@code 1} if the buffer is full, {@code -1} if the CAS failed, or {@code 0} if added
    */
-  int offer(@NonNull E e);
+  int offer(E e);
 
   /**
    * Drains the buffer, sending each element to the consumer for processing. The caller must ensure
    * that a consumer has exclusive read access to the buffer.
    *
    * @param consumer the action to perform on each element
    */
-  void drainTo(@NonNull Consumer<E> consumer);
+  void drainTo(Consumer<E> consumer);
 
   /**
    * Returns the number of elements residing in the buffer.

caffeine/src/main/java/com/github/benmanes/caffeine/cache/Cache.java

@@ -21,8 +21,8 @@
 import java.util.function.Function;
 
 import org.checkerframework.checker.index.qual.NonNegative;
-import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
+import org.checkerframework.checker.nullness.qual.PolyNull;
 
 import com.github.benmanes.caffeine.cache.stats.CacheStats;
 
@@ -50,7 +50,7 @@ public interface Cache<K, V> {
    * @throws NullPointerException if the specified key is null
    */
   @Nullable
-  V getIfPresent(@NonNull K key);
+  V getIfPresent(K key);
 
   /**
    * Returns the value associated with the {@code key} in this cache, obtaining that value from the
@@ -77,8 +77,8 @@ public interface Cache<K, V> {
    * @throws RuntimeException or Error if the mappingFunction does so, in which case the mapping is
    *         left unestablished
    */
-  @Nullable
-  V get(@NonNull K key, @NonNull Function<? super K, ? extends V> mappingFunction);
+  @PolyNull
+  V get(K key, Function<? super K, ? extends @PolyNull V> mappingFunction);
 
   /**
    * Returns a map of the values associated with the {@code keys} in this cache. The returned map
@@ -91,8 +91,7 @@ public interface Cache<K, V> {
    * @return the unmodifiable mapping of keys to values for the specified keys found in this cache
    * @throws NullPointerException if the specified collection is null or contains a null element
    */
-  @NonNull
-  Map<@NonNull K, @NonNull V> getAllPresent(@NonNull Iterable<? extends K> keys);
+  Map<K, V> getAllPresent(Iterable<? extends K> keys);
 
   /**
    * Returns a map of the values associated with the {@code keys}, creating or retrieving those
@@ -118,9 +117,8 @@ public interface Cache<K, V> {
    * @throws RuntimeException or Error if the mappingFunction does so, in which case the mapping is
    *         left unestablished
    */
-  @NonNull
-  Map<K, V> getAll(@NonNull Iterable<? extends @NonNull K> keys,
-      @NonNull Function<Set<? extends @NonNull K>, @NonNull Map<K, V>> mappingFunction);
+  Map<K, V> getAll(Iterable<? extends K> keys,
+      Function<Set<? extends K>, Map<K, V>> mappingFunction);
 
   /**
    * Associates the {@code value} with the {@code key} in this cache. If the cache previously
@@ -134,7 +132,7 @@ Map<K, V> getAll(@NonNull Iterable<? extends @NonNull K> keys,
    * @param value value to be associated with the specified key
    * @throws NullPointerException if the specified key or value is null
    */
-  void put(@NonNull K key, @NonNull V value);
+  void put(K key, V value);
 
   /**
    * Copies all of the mappings from the specified map to the cache. The effect of this call is
@@ -146,7 +144,7 @@ Map<K, V> getAll(@NonNull Iterable<? extends @NonNull K> keys,
    * @throws NullPointerException if the specified map is null or the specified map contains null
    *         keys or values
    */
-  void putAll(@NonNull Map<? extends @NonNull K,? extends @NonNull V> map);
+  void putAll(Map<? extends K,? extends V> map);
 
   /**
    * Discards any cached value for the {@code key}. The behavior of this operation is undefined for
@@ -155,7 +153,7 @@ Map<K, V> getAll(@NonNull Iterable<? extends @NonNull K> keys,
    * @param key the key whose mapping is to be removed from the cache
    * @throws NullPointerException if the specified key is null
    */
-  void invalidate(@NonNull K key);
+  void invalidate(K key);
 
   /**
    * Discards any cached values for the {@code keys}. The behavior of this operation is undefined
@@ -164,7 +162,7 @@ Map<K, V> getAll(@NonNull Iterable<? extends @NonNull K> keys,
    * @param keys the keys whose associated values are to be removed
    * @throws NullPointerException if the specified collection is null or contains a null element
    */
-  void invalidateAll(@NonNull Iterable<? extends @NonNull K> keys);
+  void invalidateAll(Iterable<? extends K> keys);
 
   /**
    * Discards all entries in the cache. The behavior of this operation is undefined for an entry
@@ -192,7 +190,6 @@ Map<K, V> getAll(@NonNull Iterable<? extends @NonNull K> keys,
    *
    * @return the current snapshot of the statistics of this cache
    */
-  @NonNull
   CacheStats stats();
 
   /**
@@ -210,8 +207,7 @@ Map<K, V> getAll(@NonNull Iterable<? extends @NonNull K> keys,
    *
    * @return a thread-safe view of this cache supporting all of the optional {@link Map} operations
    */
-  @NonNull
-  ConcurrentMap<@NonNull K, @NonNull V> asMap();
+  ConcurrentMap<K, V> asMap();
 
   /**
    * Performs any pending maintenance operations needed by the cache. Exactly which activities are
@@ -226,6 +222,5 @@ Map<K, V> getAll(@NonNull Iterable<? extends @NonNull K> keys,
    *
    * @return access to inspect and perform advanced operations based on the cache's characteristics
    */
-  @NonNull
   Policy<K, V> policy();
 }