Propagate nullness knowledge

Keys and values are known to be non-null. Conditions are known to be nullable. Signed-off-by: Robert Varga <[email protected]>
PANTHEONtech · Jan 25, 2025 · 31b47da · 31b47da
1 parent 0076327
commit 31b47da
Show file tree

Hide file tree

Showing 9 changed files with 64 additions and 53 deletions.
diff --git a/triemap/src/main/java/tech/pantheon/triemap/CNode.java b/triemap/src/main/java/tech/pantheon/triemap/CNode.java
@@ -22,6 +22,7 @@
 import static tech.pantheon.triemap.PresencePredicate.PRESENT;
 
 import java.util.concurrent.ThreadLocalRandom;
+import org.eclipse.jdt.annotation.NonNull;
 import org.eclipse.jdt.annotation.Nullable;
 
 final class CNode<K, V> extends MainNode<K, V> {
@@ -54,8 +55,8 @@ private CNode(final Gen gen, final int bitmap, final Branch<K, V>... array) {
         this(gen, 0, (Branch<K, V>[]) EMPTY_ARRAY);
     }
 
-    static <K, V> MainNode<K, V> dual(final SNode<K, V> first, final K key, final V value, final int hc,
-        final int initLev, final Gen gen) {
+    static <K, V> MainNode<K, V> dual(final SNode<K, V> first, final @NonNull K key, final @NonNull V value,
+            final int hc, final int initLev, final Gen gen) {
         final var second = new SNode<>(key, value, hc);
         final var fhc = first.hc();
 
@@ -89,7 +90,7 @@ static <K, V> MainNode<K, V> dual(final SNode<K, V> first, final K key, final V
         }
     }
 
-    Object lookup(final TrieMap<K, V> ct, final Gen startGen, final int hc, final K key, final int lev,
+    Object lookup(final TrieMap<K, V> ct, final Gen startGen, final int hc, final @NonNull K key, final int lev,
             final INode<K, V> parent) {
         // 1) a multinode
         final int idx = hc >>> lev & 0x1f;
@@ -115,8 +116,8 @@ Object lookup(final TrieMap<K, V> ct, final Gen startGen, final int hc, final K
         }
     }
 
-    boolean insert(final MutableTrieMap<K, V> ct, final Gen startGen, final int hc, final K key, final V val,
-            final int lev, final INode<K, V> parent) {
+    boolean insert(final MutableTrieMap<K, V> ct, final Gen startGen, final int hc, final @NonNull K key,
+            final @NonNull V val, final int lev, final INode<K, V> parent) {
         // 1) a multiway node
         final int idx = hc >>> lev & 0x1f;
         final int flag = 1 << idx;
@@ -141,7 +142,7 @@ boolean insert(final MutableTrieMap<K, V> ct, final Gen startGen, final int hc,
     }
 
     boolean insert(final MutableTrieMap<K, V> ct, final INode<K, V> in, final int pos, final SNode<K, V> sn,
-            final K key, final V val, final int hc, final int lev) {
+            final @NonNull K key, final @NonNull V val, final int hc, final int lev) {
         final CNode<K, V> next;
         if (!sn.matches(hc, key)) {
             final var rn = gen == in.gen ? this : renewed(ct, gen);
@@ -152,15 +153,15 @@ boolean insert(final MutableTrieMap<K, V> ct, final INode<K, V> in, final int po
         return in.gcasWrite(ct, next);
     }
 
-    boolean insert(final MutableTrieMap<K, V> ct, final INode<K, V> in, final int pos, final int flag, final K key,
-            final V val, final int hc) {
+    boolean insert(final MutableTrieMap<K, V> ct, final INode<K, V> in, final int pos, final int flag,
+            final @NonNull K key, final @NonNull V val, final int hc) {
         final var ngen = in.gen;
         final var rn = gen == ngen ? this : renewed(ct, ngen);
         return in.gcasWrite(ct, rn.toInsertedAt(this, ngen, pos, flag, key, val, hc));
     }
 
-    @Nullable Result<V> insertIf(final MutableTrieMap<K, V> ct, final Gen startGen, final int hc, final K key,
-            final V val, final Object cond, final int lev, final INode<K, V> parent) {
+    @Nullable Result<V> insertIf(final MutableTrieMap<K, V> ct, final Gen startGen, final int hc, final @NonNull K key,
+            final @NonNull V val, final @Nullable Object cond, final int lev, final INode<K, V> parent) {
         // 1) a multiway node
         final int idx = hc >>> lev & 0x1f;
         final int flag = 1 << idx;
@@ -190,7 +191,8 @@ boolean insert(final MutableTrieMap<K, V> ct, final INode<K, V> in, final int po
     }
 
     private @Nullable Result<V> insertIf(final MutableTrieMap<K, V> ct, final INode<K, V> in, final int pos,
-            final SNode<K, V> sn, final K key, final V val, final int hc, final Object cond, final int lev) {
+            final SNode<K, V> sn, final @NonNull K key, final @NonNull V val, final int hc, final @Nullable Object cond,
+            final int lev) {
         if (!sn.matches(hc, key)) {
             if (cond == null || cond == ABSENT) {
                 final var ngen = in.gen;
@@ -208,8 +210,8 @@ boolean insert(final MutableTrieMap<K, V> ct, final INode<K, V> in, final int po
         return Result.empty();
     }
 
-    @Nullable Result<V> remove(final MutableTrieMap<K, V> ct, final Gen startGen, final int hc, final K key,
-            final Object cond, final int lev, final INode<K, V> parent) {
+    @Nullable Result<V> remove(final MutableTrieMap<K, V> ct, final Gen startGen, final int hc, final @NonNull K key,
+            final @Nullable Object cond, final int lev, final INode<K, V> parent) {
         final int idx = hc >>> lev & 0x1f;
         final int flag = 1 << idx;
         if ((bitmap & flag) == 0) {
@@ -345,12 +347,13 @@ private CNode<K, V> updatedAt(final int pos, final Branch<K, V> nn, final Gen ng
         return toUpdatedAt(this, pos, nn, ngen);
     }
 
-    private CNode<K, V> updatedAt(final int pos, final K key, final V val, final int hc, final Gen ngen) {
+    private CNode<K, V> updatedAt(final int pos, final @NonNull K key, final @NonNull V val, final int hc,
+            final Gen ngen) {
         return updatedAt(pos, new SNode<>(key, val, hc), ngen);
     }
 
-    private CNode<K, V> toInsertedAt(final CNode<K, V> prev, final Gen ngen, final int pos, final int flag, final K key,
-            final V value, final int hc) {
+    private CNode<K, V> toInsertedAt(final CNode<K, V> prev, final Gen ngen, final int pos, final int flag,
+            final @NonNull K key, final @NonNull V value, final int hc) {
         final int len = array.length;
         final var narr = newArray(len + 1);
         System.arraycopy(array, 0, narr, 0, pos);

diff --git a/triemap/src/main/java/tech/pantheon/triemap/DefaultEntry.java b/triemap/src/main/java/tech/pantheon/triemap/DefaultEntry.java
@@ -16,6 +16,7 @@
 package tech.pantheon.triemap;
 
 import java.util.Map.Entry;
+import org.eclipse.jdt.annotation.NonNull;
 
 /**
  * Our {@link Entry} implementations are immutable by default.
@@ -27,15 +28,15 @@
  */
 sealed interface DefaultEntry<K, V> extends Entry<K, V> permits AbstractEntry, EntryNode {
 
-    K key();
+    @NonNull K key();
 
     @Override
     @Deprecated
     default K getKey() {
         return key();
     }
 
-    V value();
+    @NonNull V value();
 
     @Override
     @Deprecated

diff --git a/triemap/src/main/java/tech/pantheon/triemap/INode.java b/triemap/src/main/java/tech/pantheon/triemap/INode.java
@@ -119,7 +119,8 @@ private TryGcas(final Gcas<K, V> prev) {
         this.gen = gen;
     }
 
-    INode(final INode<K, V> prev, final SNode<K, V> sn, final K key, final V val, final int hc, final int lev) {
+    INode(final INode<K, V> prev, final SNode<K, V> sn, final @NonNull K key, final @NonNull V val, final int hc,
+            final int lev) {
         this(prev.gen, CNode.dual(sn, key, val, hc, lev + LEVEL_BITS, prev.gen));
     }
 
@@ -229,7 +230,7 @@ public int elementSize(final ImmutableTrieMap<K, V> ct) {
      * @return null if no value has been found, RESTART if the operation was not successful, or any other value
      *         otherwise
      */
-    Object lookup(final TrieMap<K, V> ct, final Gen startGen, final int hc, final K key, final int lev,
+    Object lookup(final TrieMap<K, V> ct, final Gen startGen, final int hc, final @NonNull K key, final int lev,
             final INode<K, V> parent) {
         final var m = gcasRead(ct);
 
@@ -257,8 +258,8 @@ Object lookup(final TrieMap<K, V> ct, final Gen startGen, final int hc, final K
      *
      * @return true if successful, false otherwise
      */
-    boolean insert(final MutableTrieMap<K, V> ct, final Gen startGen, final int hc, final K key, final V val,
-            final int lev, final INode<K, V> parent) {
+    boolean insert(final MutableTrieMap<K, V> ct, final Gen startGen, final int hc, final @NonNull K key,
+            final @NonNull V val, final int lev, final INode<K, V> parent) {
         final var m = gcasRead(ct);
         if (m instanceof CNode<K, V> cn) {
             return cn.insert(ct, startGen, hc, key, val, lev, this);
@@ -282,8 +283,8 @@ boolean insert(final MutableTrieMap<K, V> ct, final Gen startGen, final int hc,
      *            other value `val` - key must be bound to `val`
      * @return null if unsuccessful, Result(V) otherwise (indicating previous value bound to the key)
      */
-    @Nullable Result<V> insertIf(final MutableTrieMap<K, V> ct, final Gen startGen, final int hc, final K key,
-            final V val, final Object cond, final int lev, final INode<K, V> parent) {
+    @Nullable Result<V> insertIf(final MutableTrieMap<K, V> ct, final Gen startGen, final int hc, final @NonNull K key,
+            final @NonNull V val, final Object cond, final int lev, final INode<K, V> parent) {
         final var m = gcasRead(ct);
         if (m instanceof CNode<K, V> cn) {
             return cn.insertIf(ct, startGen, hc, key, val, cond, lev, this);
@@ -308,8 +309,8 @@ boolean insert(final MutableTrieMap<K, V> ct, final Gen startGen, final int hc,
      * @return null if not successful, an Result indicating the previous
      *         value otherwise
      */
-    @Nullable Result<V> remove(final MutableTrieMap<K, V> ct, final Gen startGen, final int hc, final K key,
-            final Object cond, final int lev, final INode<K, V> parent) {
+    @Nullable Result<V> remove(final MutableTrieMap<K, V> ct, final Gen startGen, final int hc, final @NonNull K key,
+            final @Nullable Object cond, final int lev, final INode<K, V> parent) {
         final var m = gcasRead(ct);
         if (m instanceof CNode<K, V> cn) {
             final var res = cn.remove(ct, startGen, hc, key, cond, lev, this);

diff --git a/triemap/src/main/java/tech/pantheon/triemap/LNodeEntries.java b/triemap/src/main/java/tech/pantheon/triemap/LNodeEntries.java
@@ -18,6 +18,7 @@
 import static tech.pantheon.triemap.PresencePredicate.ABSENT;
 import static tech.pantheon.triemap.PresencePredicate.PRESENT;
 
+import org.eclipse.jdt.annotation.NonNull;
 import org.eclipse.jdt.annotation.Nullable;
 
 /**
@@ -32,7 +33,7 @@
 abstract sealed class LNodeEntries<K, V> extends LNodeEntry<K, V> {
     // Visible for testing
     static final class Single<K, V> extends LNodeEntries<K, V> {
-        Single(final K key, final V value) {
+        Single(final @NonNull K key, final @NonNull V value) {
             super(key, value);
         }
 
@@ -51,7 +52,7 @@ private static final class Multiple<K, V> extends LNodeEntries<K, V> {
             this(entry.key(), entry.value(), null);
         }
 
-        Multiple(final K key, final V value, final LNodeEntries<K, V> next) {
+        Multiple(final @NonNull K key, final @NonNull V value, final LNodeEntries<K, V> next) {
             super(key, value);
             this.next = next;
         }
@@ -62,11 +63,12 @@ LNodeEntries<K, V> next() {
         }
     }
 
-    LNodeEntries(final K key, final V value) {
+    LNodeEntries(final @NonNull K key, final @NonNull V value) {
         super(key, value);
     }
 
-    static <K,V> LNodeEntries<K, V> of(final K k1, final V v1, final K k2, final V v2) {
+    static <K,V> LNodeEntries<K, V> of(final @NonNull K k1, final @NonNull V v1,
+            final @NonNull K k2, final @NonNull V v2) {
         return new Multiple<>(k1, v1, new Single<>(k2, v2));
     }
 
@@ -78,19 +80,19 @@ static <K,V> LNodeEntries<K, V> of(final K k1, final V v1, final K k2, final V v
      */
     abstract LNodeEntries<K, V> next();
 
-    final @Nullable V lookup(final K key) {
+    final @Nullable V lookup(final @NonNull K key) {
         final var entry = findEntry(key);
         return entry != null ? entry.value() : null;
     }
 
-    final boolean insert(final MutableTrieMap<K, V> ct, final INode<K, V> in, final LNode<K, V> ln, final K key,
-            final V val) {
+    final boolean insert(final MutableTrieMap<K, V> ct, final INode<K, V> in, final LNode<K, V> ln,
+            final @NonNull K key, final @NonNull V val) {
         final var entry = findEntry(key);
         return in.gcasWrite(ct, entry == null ? toInserted(ln, key, val) : toReplaced(ln, entry, val));
     }
 
-    @Nullable Result<V> insertIf(final MutableTrieMap<K, V> ct, final INode<K, V> in, final LNode<K, V> ln, final K key,
-            final V val, final Object cond) {
+    @Nullable Result<V> insertIf(final MutableTrieMap<K, V> ct, final INode<K, V> in, final LNode<K, V> ln,
+            final @NonNull K key, final @NonNull V val, final Object cond) {
         final var entry = findEntry(key);
         if (entry == null) {
             return cond != null && cond != ABSENT || in.gcasWrite(ct, toInserted(ln, key, val)) ? Result.empty() : null;
@@ -103,8 +105,8 @@ final boolean insert(final MutableTrieMap<K, V> ct, final INode<K, V> in, final
         return Result.empty();
     }
 
-    @Nullable Result<V> remove(final MutableTrieMap<K, V> ct, final INode<K, V> in, final LNode<K, V> ln, final K key,
-            final Object cond, final int hc) {
+    @Nullable Result<V> remove(final MutableTrieMap<K, V> ct, final INode<K, V> in, final LNode<K, V> ln,
+            final @NonNull K key, final @Nullable Object cond, final int hc) {
         final var entry = findEntry(key);
         if (entry == null) {
             // Key was not found, hence no modification is needed
@@ -127,22 +129,22 @@ final boolean insert(final MutableTrieMap<K, V> ct, final INode<K, V> in, final
         return in.gcasWrite(ct, next) ? entry.toResult() : null;
     }
 
-    private LNode<K, V> toInserted(final LNode<K, V> ln, final K key, final V val) {
+    private LNode<K, V> toInserted(final LNode<K, V> ln, final @NonNull K key, final @NonNull V val) {
         return new LNode<>(ln, insertEntry(key, val), ln.size + 1);
     }
 
-    private LNode<K, V> toReplaced(final LNode<K, V> ln, final LNodeEntry<K, V> entry, final V val) {
+    private LNode<K, V> toReplaced(final LNode<K, V> ln, final LNodeEntry<K, V> entry, final @NonNull V val) {
         return new LNode<>(ln, replace(entry, val), ln.size);
     }
 
     // Visible for testing
-    final LNodeEntries<K, V> replace(final LNodeEntry<K, V> entry, final V value) {
+    final LNodeEntries<K, V> replace(final LNodeEntry<K, V> entry, final @NonNull V value) {
         final var removed = removeEntry(entry);
         return removed == null ? new Single<>(entry.key(), value) : new Multiple<>(entry.key(), value, removed);
     }
 
     // Visible for testing
-    final @Nullable LNodeEntry<K, V> findEntry(final K key) {
+    final @Nullable LNodeEntry<K, V> findEntry(final @NonNull K key) {
         // We do not perform recursion on purpose here, so we do not run out of stack if the key hashing fails.
         var entry = this;
         do {
@@ -157,7 +159,7 @@ final LNodeEntries<K, V> replace(final LNodeEntry<K, V> entry, final V value) {
     }
 
     // Visible for testing
-    final LNodeEntries<K, V> insertEntry(final K key, final V value) {
+    final LNodeEntries<K, V> insertEntry(final @NonNull K key, final @NonNull V value) {
         return new Multiple<>(key, value, this);
     }
 

diff --git a/triemap/src/main/java/tech/pantheon/triemap/LNodeEntry.java b/triemap/src/main/java/tech/pantheon/triemap/LNodeEntry.java
@@ -27,10 +27,10 @@
  * @param <V> the type of value
  */
 abstract sealed class LNodeEntry<K, V> extends AbstractEntry<K, V> permits LNodeEntries {
-    private final K key;
-    private final V value;
+    private final @NonNull K key;
+    private final @NonNull V value;
 
-    LNodeEntry(final K key, final V value) {
+    LNodeEntry(final @NonNull K key, final @NonNull V value) {
         this.key = key;
         this.value = value;
     }

diff --git a/triemap/src/main/java/tech/pantheon/triemap/MutableIterator.java b/triemap/src/main/java/tech/pantheon/triemap/MutableIterator.java
@@ -83,7 +83,8 @@ public K key() {
          */
         @Override
         public V value() {
-            return newValue != null ? newValue : delegate.value();
+            final var val = newValue;
+            return val != null ? val : delegate.value();
         }
 
         /**

diff --git a/triemap/src/main/java/tech/pantheon/triemap/MutableTrieMap.java b/triemap/src/main/java/tech/pantheon/triemap/MutableTrieMap.java
@@ -23,6 +23,7 @@
 import java.lang.invoke.MethodHandles;
 import java.lang.invoke.VarHandle;
 import org.eclipse.jdt.annotation.NonNull;
+import org.eclipse.jdt.annotation.Nullable;
 
 /**
  * A mutable TrieMap.
@@ -106,7 +107,7 @@ public V replace(final K key, final V value) {
         return insertIf(k, requireNonNull(value), PRESENT).orNull();
     }
 
-    private @NonNull Result<V> insertIf(final K key, final V value, final Object cond) {
+    private @NonNull Result<V> insertIf(final @NonNull K key, final @NonNull V value, final @Nullable Object cond) {
         final int hc = computeHash(key);
 
         Result<V> res;
@@ -119,7 +120,7 @@ public V replace(final K key, final V value) {
         return res;
     }
 
-    private @NonNull Result<V> removeIf(final K key, final Object cond) {
+    private @NonNull Result<V> removeIf(final @NonNull K key, final @Nullable Object cond) {
         final int hc = computeHash(key);
 
         Result<V> res;

diff --git a/triemap/src/main/java/tech/pantheon/triemap/SNode.java b/triemap/src/main/java/tech/pantheon/triemap/SNode.java
@@ -18,7 +18,7 @@
 import org.eclipse.jdt.annotation.NonNull;
 import org.eclipse.jdt.annotation.Nullable;
 
-record SNode<K, V>(K key, V value, int hc) implements Branch<K, V>, EntryNode<K, V> {
+record SNode<K, V>(@NonNull K key, @NonNull V value, int hc) implements Branch<K, V>, EntryNode<K, V> {
     SNode(final TNode<K, V> tn) {
         this(tn.key, tn.value, tn.hc);
     }

diff --git a/triemap/src/main/java/tech/pantheon/triemap/TNode.java b/triemap/src/main/java/tech/pantheon/triemap/TNode.java
@@ -15,13 +15,15 @@
  */
 package tech.pantheon.triemap;
 
+import org.eclipse.jdt.annotation.NonNull;
+
 final class TNode<K, V> extends MainNode<K, V> implements EntryNode<K, V> {
-    final K key;
-    final V value;
+    final @NonNull K key;
+    final @NonNull V value;
     final int hc;
 
     // Visible for testing
-    TNode(final CNode<K, V> prev, final K key, final V value, final int hc) {
+    TNode(final CNode<K, V> prev, final @NonNull K key, final @NonNull V value, final int hc) {
         super(prev);
         this.key = key;
         this.value = value;
@@ -32,7 +34,7 @@ final class TNode<K, V> extends MainNode<K, V> implements EntryNode<K, V> {
         this(prev, sn.key(), sn.value(), sn.hc());
     }
 
-    TNode(final LNode<K, V> prev, final K key, final V value, final int hc) {
+    TNode(final LNode<K, V> prev, final @NonNull K key, final @NonNull V value, final int hc) {
         super(prev);
         this.key = key;
         this.value = value;