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in repository https://gitbox.apache.org/repos/asf/dubbo-hessian-lite.git
The following commit(s) were added to refs/heads/master by this push:
new cc4fb8a9 Allocate init capacity directly according to the expected
size to avoid resize. (#95)
cc4fb8a9 is described below
commit cc4fb8a91035e6410abf0820ff630082693dcb2b
Author: Ares_xue <[email protected]>
AuthorDate: Sat Sep 20 11:13:17 2025 +0800
Allocate init capacity directly according to the expected size to avoid
resize. (#95)
---
.../caucho/hessian/io/CollectionDeserializer.java | 14 +++----
.../com/caucho/hessian/io/MapDeserializer.java | 10 ++---
.../com/alibaba/com/caucho/hessian/io/MapUtil.java | 46 ++++++++++++++++++++++
3 files changed, 56 insertions(+), 14 deletions(-)
diff --git
a/hessian-lite/src/main/java/com/alibaba/com/caucho/hessian/io/CollectionDeserializer.java
b/hessian-lite/src/main/java/com/alibaba/com/caucho/hessian/io/CollectionDeserializer.java
index 459435a4..3d1447cb 100644
---
a/hessian-lite/src/main/java/com/alibaba/com/caucho/hessian/io/CollectionDeserializer.java
+++
b/hessian-lite/src/main/java/com/alibaba/com/caucho/hessian/io/CollectionDeserializer.java
@@ -78,7 +78,7 @@ public class CollectionDeserializer extends
AbstractListDeserializer {
@Override
public Object readList(AbstractHessianInput in, int length, Class<?>
expectType) throws IOException {
- Collection list = createList();
+ Collection list = createList(length);
in.addRef(list);
@@ -106,7 +106,7 @@ public class CollectionDeserializer extends
AbstractListDeserializer {
@Override
public Object readLengthList(AbstractHessianInput in, int length, Class<?>
expectType) throws IOException {
- Collection list = createList();
+ Collection list = createList(length);
in.addRef(list);
@@ -125,12 +125,12 @@ public class CollectionDeserializer extends
AbstractListDeserializer {
return list;
}
- private Collection createList()
+ private Collection createList(int expectedSize)
throws IOException {
Collection list = null;
if (_type == null)
- list = new ArrayList();
+ list = new ArrayList(expectedSize);
else if (!_type.isInterface()) {
try {
list = (Collection) _type.newInstance();
@@ -142,11 +142,9 @@ public class CollectionDeserializer extends
AbstractListDeserializer {
} else if (SortedSet.class.isAssignableFrom(_type))
list = new TreeSet();
else if (Set.class.isAssignableFrom(_type))
- list = new HashSet();
- else if (List.class.isAssignableFrom(_type))
- list = new ArrayList();
+ list = new HashSet(MapUtil.capacity(expectedSize));
else if (Collection.class.isAssignableFrom(_type))
- list = new ArrayList();
+ list = new ArrayList(expectedSize);
else {
try {
list = (Collection) _type.newInstance();
diff --git
a/hessian-lite/src/main/java/com/alibaba/com/caucho/hessian/io/MapDeserializer.java
b/hessian-lite/src/main/java/com/alibaba/com/caucho/hessian/io/MapDeserializer.java
index f7a9a4e7..45f99d4c 100644
---
a/hessian-lite/src/main/java/com/alibaba/com/caucho/hessian/io/MapDeserializer.java
+++
b/hessian-lite/src/main/java/com/alibaba/com/caucho/hessian/io/MapDeserializer.java
@@ -150,7 +150,7 @@ public class MapDeserializer extends
AbstractMapDeserializer {
Object[] fields)
throws IOException {
String[] fieldNames = (String[]) fields;
- Map<Object, Object> map = createMap();
+ Map<Object, Object> map = createMap(fieldNames.length);
int ref = in.addRef(map);
@@ -163,13 +163,11 @@ public class MapDeserializer extends
AbstractMapDeserializer {
return map;
}
- private Map createMap()
+ private Map createMap(int expectedSize)
throws IOException {
- if (_type == null)
- return new HashMap();
- else if (_type.equals(Map.class))
- return new HashMap();
+ if (_type == null || _type.equals(Map.class) ||
_type.equals(HashMap.class))
+ return new HashMap(MapUtil.capacity(expectedSize));
else if (_type.equals(SortedMap.class))
return new TreeMap();
else {
diff --git
a/hessian-lite/src/main/java/com/alibaba/com/caucho/hessian/io/MapUtil.java
b/hessian-lite/src/main/java/com/alibaba/com/caucho/hessian/io/MapUtil.java
new file mode 100644
index 00000000..185c922d
--- /dev/null
+++ b/hessian-lite/src/main/java/com/alibaba/com/caucho/hessian/io/MapUtil.java
@@ -0,0 +1,46 @@
+/*
+ * 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 com.alibaba.com.caucho.hessian.io;
+
+
+class MapUtil {
+
+ private static final int MAX_POWER_OF_TWO = 1 << (Integer.SIZE - 2);
+
+ /**
+ * @see java.util.HashMap#DEFAULT_INITIAL_CAPACITY
+ */
+ private static final int DEFAULT_INITIAL_CAPACITY = 1 << 4;
+
+ protected static int capacity(int expectedSize) {
+ if (expectedSize < 0) {
+ return DEFAULT_INITIAL_CAPACITY;
+ }
+
+ if (expectedSize < 3) {
+ return expectedSize + 1;
+ }
+ if (expectedSize < MAX_POWER_OF_TWO) {
+ // This is the calculation used in JDK8 to resize when a putAll
+ // happens; it seems to be the most conservative calculation we
+ // can make. 0.75 is the default load factor.
+ return (int) ((float) expectedSize / 0.75F + 1.0F);
+ }
+ return Integer.MAX_VALUE;
+ }
+
+}
