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提供 core 模块下的 text 中布隆过滤器的单过滤器多哈希函数支持

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Looly
2025-11-26 17:35:20 +08:00
parent 4d4bf08fc1
commit 7393f66d06
2 changed files with 18 additions and 17 deletions
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27
hutool-core/src/main/java/cn/hutool/v7/core/text/bloom/FuncFilter.java
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@@ -22,7 +22,7 @@ import java.io.Serial;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.function.Function;
import java.util.function.ToIntFunction;
/**
* 基于Hash函数方法的{@link BloomFilter}
@@ -37,31 +37,31 @@ public class FuncFilter extends AbstractFilter {
/**
* 创建FuncFilter
*
* @param size 最大值
* @param size 最大值
* @param hashFuncs Hash函数
* @return FuncFilter
*/
@SafeVarargs
public static FuncFilter of(final int size, final Function<String, Number>... hashFuncs) {
public static FuncFilter of(final int size, final ToIntFunction<String>... hashFuncs) {
return new FuncFilter(size, hashFuncs);
}
// 允许接收多个哈希函数
private final List<Function<String, Number>> hashFuncs;
private final List<ToIntFunction<String>> hashFuncs;
/**
* @param size 最大值
* @param size 最大值
* @param hashFuncs Hash函数
*/
@SafeVarargs
public FuncFilter(final int size, final Function<String, Number>... hashFuncs) {
public FuncFilter(final int size, final ToIntFunction<String>... hashFuncs) {
super(size);
Assert.notEmpty(hashFuncs, "Hash functions must not be empty");
this.hashFuncs = Collections.unmodifiableList(Arrays.asList(hashFuncs));
}
/**
*兼容父类，如果存在多个哈希函数，就使用第一个
* 兼容父类，如果存在多个哈希函数，就使用第一个
*
* @param str 字符串
*/
@@ -72,18 +72,18 @@ public class FuncFilter extends AbstractFilter {
/**
*
* @param str 字符串
* @param str 字符串
* @param hashFunc 哈希函数
* @return HashCode 指定哈希函数的计算结果
*/
public int hash(final String str, final Function<String, Number> hashFunc) {
public int hash(final String str, final ToIntFunction<String> hashFunc) {
// 通过位运算获取正数
return (hashFunc.apply(str).intValue() & 0x7FFFFFFF) % size;
return (hashFunc.applyAsInt(str) & 0x7FFFFFFF) % size;
}
@Override
public boolean contains(final String str) {
for (final Function<String, Number> hashFunc : hashFuncs) {
for (final ToIntFunction<String> hashFunc : hashFuncs) {
if (!bitSet.get(hash(str, hashFunc))) {
return false;
}
@@ -94,8 +94,9 @@ public class FuncFilter extends AbstractFilter {
@Override
public boolean add(final String str) {
boolean add = false;
for (final Function<String, Number> hashFunc : hashFuncs) {
int hash = hash(str, hashFunc);
int hash;
for (final ToIntFunction<String> hashFunc : hashFuncs) {
hash = hash(str, hashFunc);
if (!bitSet.get(hash)) {
bitSet.set(hash);
add = true;

8
hutool-core/src/test/java/cn/hutool/v7/core/text/bloom/BitMapBloomFilterTest.java
View File

@@ -65,7 +65,7 @@ public class BitMapBloomFilterTest {
@Test
public void combinedMultiHashTest() {
FuncFilter multiHashFuncFilter = FuncFilter.of(SIZE,
final FuncFilter multiHashFuncFilter = FuncFilter.of(SIZE,
HashUtil::bkdrHash,
HashUtil::apHash,
HashUtil::djbHash
@@ -84,9 +84,9 @@ public class BitMapBloomFilterTest {
HashUtil::djbHash
);
String s1 = "你好世界";
String s2 = "双亲委派";
String s3 = "测试工程师";
final String s1 = "你好世界";
final String s2 = "双亲委派";
final String s3 = "测试工程师";
filter.add(s1);
filter.add(s2);