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The following commit(s) were added to refs/heads/main by this push:
new 3d6072ad4d API: Add CharSequenceMap (#9047)
3d6072ad4d is described below
commit 3d6072ad4d94ba8fb83fcecfdaa2a2a326e99e15
Author: Anton Okolnychyi <[email protected]>
AuthorDate: Thu Nov 16 15:41:29 2023 -0800
API: Add CharSequenceMap (#9047)
---
.../org/apache/iceberg/util/CharSequenceMap.java | 220 +++++++++++++++++++++
.../apache/iceberg/util/TestCharSequenceMap.java | 202 +++++++++++++++++++
2 files changed, 422 insertions(+)
diff --git a/api/src/main/java/org/apache/iceberg/util/CharSequenceMap.java
b/api/src/main/java/org/apache/iceberg/util/CharSequenceMap.java
new file mode 100644
index 0000000000..98da48ed59
--- /dev/null
+++ b/api/src/main/java/org/apache/iceberg/util/CharSequenceMap.java
@@ -0,0 +1,220 @@
+/*
+ * 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.iceberg.util;
+
+import java.io.Serializable;
+import java.util.Collection;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Set;
+import java.util.stream.Collectors;
+import org.apache.iceberg.relocated.com.google.common.collect.Maps;
+import org.apache.iceberg.relocated.com.google.common.collect.Sets;
+
+/**
+ * A map that uses char sequences as keys.
+ *
+ * <p>This implementation wraps provided keys into {@link CharSequenceWrapper}
for consistent
+ * hashing and equals behavior. This ensures that objects of different types
that represent the same
+ * sequence of characters are treated as equal keys in the map.
+ *
+ * <p>Note: This map is not designed for concurrent modification by multiple
threads. However, it
+ * supports safe concurrent reads, assuming there are no concurrent writes.
+ *
+ * <p>Note: This map does not support null keys.
+ *
+ * @param <V> the type of values
+ */
+public class CharSequenceMap<V> implements Map<CharSequence, V>, Serializable {
+
+ private static final long serialVersionUID = 1L;
+ private static final ThreadLocal<CharSequenceWrapper> WRAPPERS =
+ ThreadLocal.withInitial(() -> CharSequenceWrapper.wrap(null));
+
+ private final Map<CharSequenceWrapper, V> wrapperMap;
+
+ private CharSequenceMap() {
+ this.wrapperMap = Maps.newHashMap();
+ }
+
+ public static <T> CharSequenceMap<T> create() {
+ return new CharSequenceMap<>();
+ }
+
+ @Override
+ public int size() {
+ return wrapperMap.size();
+ }
+
+ @Override
+ public boolean isEmpty() {
+ return wrapperMap.isEmpty();
+ }
+
+ @Override
+ public boolean containsKey(Object key) {
+ if (key instanceof CharSequence) {
+ CharSequenceWrapper wrapper = WRAPPERS.get();
+ boolean result = wrapperMap.containsKey(wrapper.set((CharSequence) key));
+ wrapper.set(null); // don't hold a reference to the key
+ return result;
+ }
+
+ return false;
+ }
+
+ @Override
+ public boolean containsValue(Object value) {
+ return wrapperMap.containsValue(value);
+ }
+
+ @Override
+ public V get(Object key) {
+ if (key instanceof CharSequence) {
+ CharSequenceWrapper wrapper = WRAPPERS.get();
+ V result = wrapperMap.get(wrapper.set((CharSequence) key));
+ wrapper.set(null); // don't hold a reference to the value
+ return result;
+ }
+
+ return null;
+ }
+
+ @Override
+ public V put(CharSequence key, V value) {
+ return wrapperMap.put(CharSequenceWrapper.wrap(key), value);
+ }
+
+ @Override
+ public V remove(Object key) {
+ if (key instanceof CharSequence) {
+ CharSequenceWrapper wrapper = WRAPPERS.get();
+ V result = wrapperMap.remove(wrapper.set((CharSequence) key));
+ wrapper.set(null); // don't hold a reference to the value
+ return result;
+ }
+
+ return null;
+ }
+
+ @Override
+ public void putAll(Map<? extends CharSequence, ? extends V> otherMap) {
+ otherMap.forEach(this::put);
+ }
+
+ @Override
+ public void clear() {
+ wrapperMap.clear();
+ }
+
+ @Override
+ public Set<CharSequence> keySet() {
+ CharSequenceSet keySet = CharSequenceSet.empty();
+
+ for (CharSequenceWrapper wrapper : wrapperMap.keySet()) {
+ keySet.add(wrapper.get());
+ }
+
+ return keySet;
+ }
+
+ @Override
+ public Collection<V> values() {
+ return wrapperMap.values();
+ }
+
+ @Override
+ public Set<Entry<CharSequence, V>> entrySet() {
+ Set<Entry<CharSequence, V>> entrySet = Sets.newHashSet();
+
+ for (Entry<CharSequenceWrapper, V> entry : wrapperMap.entrySet()) {
+ entrySet.add(new CharSequenceEntry<>(entry));
+ }
+
+ return entrySet;
+ }
+
+ @Override
+ public boolean equals(Object other) {
+ if (this == other) {
+ return true;
+ } else if (other == null || getClass() != other.getClass()) {
+ return false;
+ }
+
+ CharSequenceMap<?> that = (CharSequenceMap<?>) other;
+ return Objects.equals(wrapperMap, that.wrapperMap);
+ }
+
+ @Override
+ public int hashCode() {
+ return Objects.hashCode(wrapperMap);
+ }
+
+ @Override
+ public String toString() {
+ return
entrySet().stream().map(this::toString).collect(Collectors.joining(", ", "{",
"}"));
+ }
+
+ private String toString(Entry<CharSequence, V> entry) {
+ CharSequence key = entry.getKey();
+ V value = entry.getValue();
+ return key + "=" + (value == this ? "(this Map)" : value);
+ }
+
+ private static class CharSequenceEntry<V> implements Entry<CharSequence, V> {
+ private final Entry<CharSequenceWrapper, V> inner;
+
+ private CharSequenceEntry(Entry<CharSequenceWrapper, V> inner) {
+ this.inner = inner;
+ }
+
+ @Override
+ public CharSequence getKey() {
+ return inner.getKey().get();
+ }
+
+ @Override
+ public V getValue() {
+ return inner.getValue();
+ }
+
+ @Override
+ public int hashCode() {
+ return inner.hashCode();
+ }
+
+ @Override
+ public boolean equals(Object other) {
+ if (this == other) {
+ return true;
+ } else if (other == null || getClass() != other.getClass()) {
+ return false;
+ }
+
+ CharSequenceEntry<?> that = (CharSequenceEntry<?>) other;
+ return inner.equals(that.inner);
+ }
+
+ @Override
+ public V setValue(V value) {
+ throw new UnsupportedOperationException("Cannot set value");
+ }
+ }
+}
diff --git a/api/src/test/java/org/apache/iceberg/util/TestCharSequenceMap.java
b/api/src/test/java/org/apache/iceberg/util/TestCharSequenceMap.java
new file mode 100644
index 0000000000..47d686d3ab
--- /dev/null
+++ b/api/src/test/java/org/apache/iceberg/util/TestCharSequenceMap.java
@@ -0,0 +1,202 @@
+/*
+ * 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.iceberg.util;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
+import org.apache.iceberg.relocated.com.google.common.collect.ImmutableList;
+import org.apache.iceberg.relocated.com.google.common.collect.ImmutableMap;
+import org.junit.jupiter.api.Test;
+
+public class TestCharSequenceMap {
+
+ @Test
+ public void testEmptyMap() {
+ CharSequenceMap<String> map = CharSequenceMap.create();
+ assertThat(map).isEmpty();
+ assertThat(map).hasSize(0);
+ assertThat(map).doesNotContainKey("key");
+ assertThat(map).doesNotContainValue("value");
+ assertThat(map.values()).isEmpty();
+ assertThat(map.keySet()).isEmpty();
+ assertThat(map.entrySet()).isEmpty();
+ }
+
+ @Test
+ public void testDifferentCharSequenceImplementations() {
+ CharSequenceMap<String> map = CharSequenceMap.create();
+ map.put("abc", "value1");
+ map.put(new StringBuffer("def"), "value2");
+ assertThat(map).containsEntry(new StringBuilder("abc"), "value1");
+ assertThat(map).containsEntry("def", "value2");
+ }
+
+ @Test
+ public void testPutAndGet() {
+ CharSequenceMap<String> map = CharSequenceMap.create();
+ map.put("key1", "value1");
+ assertThat(map).containsEntry("key1", "value1");
+ }
+
+ @Test
+ public void testRemove() {
+ CharSequenceMap<String> map = CharSequenceMap.create();
+ map.put("key1", "value1");
+ map.remove(new StringBuilder("key1"));
+ assertThat(map).doesNotContainKey("key1");
+ assertThat(map).isEmpty();
+ }
+
+ @Test
+ public void testPutAll() {
+ CharSequenceMap<String> map = CharSequenceMap.create();
+ map.putAll(ImmutableMap.of("key1", "value1", "key2", "value2"));
+ assertThat(map).containsEntry("key1", "value1");
+ assertThat(map).containsEntry("key2", "value2");
+ }
+
+ @Test
+ public void testClear() {
+ CharSequenceMap<String> map = CharSequenceMap.create();
+ map.put("key1", "value1");
+ map.clear();
+ assertThat(map).isEmpty();
+ }
+
+ @Test
+ public void testValues() {
+ CharSequenceMap<String> map = CharSequenceMap.create();
+ map.put("key1", "value1");
+ map.put("key2", "value2");
+ assertThat(map.values()).containsAll(ImmutableList.of("value1", "value2"));
+ }
+
+ @Test
+ public void testEntrySet() {
+ CharSequenceMap<String> map = CharSequenceMap.create();
+ map.put("key1", "value1");
+ map.put(new StringBuilder("key2"), "value2");
+ assertThat(map.entrySet()).hasSize(2);
+ }
+
+ @Test
+ public void testEquals() {
+ CharSequenceMap<String> map1 = CharSequenceMap.create();
+ map1.put(new StringBuilder("key"), "value");
+
+ CharSequenceMap<String> map2 = CharSequenceMap.create();
+ map2.put("key", "value");
+
+ assertThat(map1).isEqualTo(map2);
+ }
+
+ @Test
+ public void testHashCode() {
+ CharSequenceMap<String> map1 = CharSequenceMap.create();
+ map1.put(new StringBuilder("key"), "value");
+
+ CharSequenceMap<String> map2 = CharSequenceMap.create();
+ map2.put("key", "value");
+
+ assertThat(map1.hashCode()).isEqualTo(map2.hashCode());
+ }
+
+ @Test
+ public void testToString() {
+ CharSequenceMap<String> map = CharSequenceMap.create();
+
+ // empty map
+ assertThat(map.toString()).isEqualTo("{}");
+
+ // single entry
+ map.put("key1", "value1");
+ assertThat(map.toString()).isEqualTo("{key1=value1}");
+
+ // multiple entries
+ map.put("key2", "value2");
+ map.put("key3", "value3");
+ String toStringResult = map.toString();
+ assertThat(toStringResult).contains("key1=value1", "key2=value2",
"key3=value3");
+ }
+
+ @Test
+ public void testComputeIfAbsent() {
+ CharSequenceMap<String> map = CharSequenceMap.create();
+
+ String result1 = map.computeIfAbsent("key1", key -> "computedValue1");
+ assertThat(result1).isEqualTo("computedValue1");
+ assertThat(map).containsEntry("key1", "computedValue1");
+
+ // verify existing key is not affected
+ String result2 = map.computeIfAbsent("key1", key -> "newValue");
+ assertThat(result2).isEqualTo("computedValue1");
+ assertThat(map).containsEntry("key1", "computedValue1");
+ }
+
+ @Test
+ public void testMerge() {
+ CharSequenceMap<String> map = CharSequenceMap.create();
+ map.put("key1", "value1");
+ map.put("key2", "value2");
+
+ // merge with an existing key
+ map.merge(new StringBuilder("key1"), "newValue", (oldVal, newVal) ->
oldVal + newVal);
+ assertThat(map).containsEntry("key1", "value1newValue");
+
+ // merge with a non-existing key
+ map.merge(new StringBuffer("key3"), "value3", (oldVal, newVal) -> oldVal +
newVal);
+ assertThat(map).containsEntry("key3", "value3");
+
+ // merge with null BiFunction should replace the value
+ map.merge("key2", "replacedValue", (oldVal, newVal) -> null);
+ assertThat(map).doesNotContainKey("key2");
+
+ // merge when old value is null (should add new value)
+ map.remove("key1");
+ map.merge("key1", "reAddedValue", (oldVal, newVal) -> oldVal + newVal);
+ assertThat(map).containsEntry("key1", "reAddedValue");
+ }
+
+ @Test
+ public void testConcurrentReadAccess() throws InterruptedException {
+ CharSequenceMap<String> map = CharSequenceMap.create();
+ map.put("key1", "value1");
+ map.put("key2", "value2");
+ map.put("key3", "value3");
+
+ int numThreads = 10;
+ ExecutorService executorService = Executors.newFixedThreadPool(numThreads);
+
+ // read the map from multiple threads to ensure thread-local wrappers are
used
+ for (int i = 0; i < numThreads; i++) {
+ executorService.submit(
+ () -> {
+ assertThat(map.get("key1")).isEqualTo("value1");
+ assertThat(map.get("key2")).isEqualTo("value2");
+ assertThat(map.get("key3")).isEqualTo("value3");
+ });
+ }
+
+ executorService.shutdown();
+ assertThat(executorService.awaitTermination(1, TimeUnit.MINUTES)).isTrue();
+ }
+}
