/**
* Project: dubbo.registry.server
*
* File Created at Oct 18, 2010
* $Id: RouteRule.java 182348 2012-06-27 09:16:58Z tony.chenl $
*
* Copyright 1999-2100 Alibaba.com Corporation Limited.
* All rights reserved.
*
* This software is the confidential and proprietary information of
* Alibaba Company. ("Confidential Information"). You shall not
* disclose such Confidential Information and shall use it only in
* accordance with the terms of the license agreement you entered into
* with Alibaba.com.
*/
package com.alibaba.dubbo.registry.common.route;
import java.text.ParseException;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import com.alibaba.dubbo.common.utils.StringUtils;
import com.alibaba.dubbo.registry.common.domain.Route;
/**
* Rule分成两部分，When条件和Then条件。<br>
* 条件是一组键值（KV）对，表示匹配条件。条件包含的键值中的“值”（Value）可以有多个值，即是一个列表。<br>
* Rule的含义是，符合了When条件后，则进行Then条件的过虑。<br>
* 当然被When条件的符合的、被Then条件过滤的，也是一组KV，术语上我们就称为样本（Sample）吧。<br>
* 使用条件对样本进行的匹配的过程称为“过滤”（或称为“筛选”）（Filter）。
* 使用When条件过滤和使用Then条件过滤的样本，不需要是相同的集合。如在Dubbo中，分别对应的是Consumer和Provider。
* 对于RouteRule（路由规则）含义即，符合When条件的Consumer，则对Provider进行Then过滤，出来的Provide即是提供给这个Consumer的Provider。<br>
*
* Rule的字符串格式如下：<code>
* key1 = value11,value12 & key2 = value21 & key2 != value22 => key3 = value3 & key4 = value41,vlaue42 & key5 !=value51
* </code>。
* <code>=></code>之前的称为When条件，是KV对；之后是Then条件，是KV对。KV的Value可以有多个值。<br><br>
*
* 值对象，线程安全。
*
* @author william.liangf
* @author ding.lid
*/
public class RouteRule {
public static class MatchPair {
Set<String> matches = new HashSet<String>();
Set<String> unmatches = new HashSet<String>();
public MatchPair() {
}
public MatchPair(Set<String> matches, Set<String> unmatches) {
if(matches == null || unmatches == null) {
throw new IllegalArgumentException("argument of MatchPair is null!");
}
this.matches = matches;
this.unmatches = unmatches;
}
public Set<String> getMatches() {
return matches;
}
public Set<String> getUnmatches() {
return unmatches;
}
public MatchPair copy() {
MatchPair ret = new MatchPair();
ret.matches.addAll(matches);
ret.unmatches.addAll(unmatches);
return ret;
}
private volatile boolean freezed = false;
void freeze() {
if(freezed) return;
synchronized (this) {
if(freezed) return;
matches = Collections.unmodifiableSet(matches);
unmatches = Collections.unmodifiableSet(unmatches);
}
}
public boolean containeValue(String value) {
return matches.contains(value) || unmatches.contains(value);
}
/**
* 给定的值是否通过该{@link MatchPair}匹配。<p>
* 返回{@code false}，如果
* <ol>
* <li>value在unmatches列表中
* <li>matches列表有值，但value不在matches列表中。
* </ol>
* otherwise返回<code>true</code>。
*/
public boolean pass(String sample) {
if(unmatches.contains(sample)) return false;
if(matches.isEmpty()) return true;
return matches.contains(sample);
}
@Override
public String toString() {
return String.format("{matches=%s,unmatches=%s}", matches.toString(), unmatches.toString());
}
// 用Eclipse自动生成
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + ((matches == null) ? 0 : matches.hashCode());
result = prime * result + ((unmatches == null) ? 0 : unmatches.hashCode());
return result;
}
// 用Eclipse自动生成
@Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
MatchPair other = (MatchPair) obj;
if (matches == null) {
if (other.matches != null)
return false;
} else if (!matches.equals(other.matches))
return false;
if (unmatches == null) {
if (other.unmatches != null)
return false;
} else if (!unmatches.equals(other.unmatches))
return false;
return true;
}
}
final Map<String, MatchPair> whenCondition;
final Map<String, MatchPair> thenCondition;
private static Pattern ROUTE_PATTERN = Pattern.compile("([&!=,]*)\\s*([^&!=,\\s]+)");
private static Pattern CONDITION_SEPERATOR = Pattern.compile("(.*)=>(.*)");
public static Map<String, MatchPair> parseRule(String rule)
throws ParseException {
Map<String, MatchPair> condition = new HashMap<String, RouteRule.MatchPair>();
if(StringUtils.isBlank(rule)) {
return condition;
}
// 匹配或不匹配Key-Value对
MatchPair pair = null;
// 多个Value值
Set<String> values = null;
final Matcher matcher = ROUTE_PATTERN.matcher(rule);
while (matcher.find()) { // 逐个匹配
String separator = matcher.group(1);
String content = matcher.group(2);
// 表达式开始
if (separator == null || separator.length() == 0) {
pair = new MatchPair();
condition.put(content, pair);
}
// KV开始
else if ("&".equals(separator)) {
if (condition.get(content) == null) {
pair = new MatchPair();
condition.put(content, pair);
} else {
condition.put(content, pair);
}
}
// KV的Value部分开始
else if ("=".equals(separator)) {
if (pair == null)
throw new ParseException("Illegal route rule \""
+ rule + "\", The error char '" + separator
+ "' at index " + matcher.start() + " before \""
+ content + "\".", matcher.start());
values = pair.matches;
values.add(content);
}
// KV的Value部分开始
else if ("!=".equals(separator)) {
if (pair == null)
throw new ParseException("Illegal route rule \""
+ rule + "\", The error char '" + separator
+ "' at index " + matcher.start() + " before \""
+ content + "\".", matcher.start());
values = pair.unmatches;
values.add(content);
}
// KV的Value部分的多个条目
else if (",".equals(separator)) { // 如果为逗号表示
if (values == null || values.size() == 0)
throw new ParseException("Illegal route rule \""
+ rule + "\", The error char '" + separator
+ "' at index " + matcher.start() + " before \""
+ content + "\".", matcher.start());
values.add(content);
} else {
throw new ParseException("Illegal route rule \"" + rule
+ "\", The error char '" + separator + "' at index "
+ matcher.start() + " before \"" + content + "\".", matcher.start());
}
}
return condition;
}
// FIXME 集合都要加上unmodified的Wrapper，避免构造后的对象被修改
private RouteRule(Map<String, MatchPair> when, Map<String, MatchPair> then) {
for(Map.Entry<String, MatchPair> entry : when.entrySet()) {
entry.getValue().freeze();
}
for(Map.Entry<String, MatchPair> entry : then.entrySet()) {
entry.getValue().freeze();
}
// NOTE: When条件是允许为空的，外部业务来保证类似的约束条件
this.whenCondition = when;
this.thenCondition = then;
}
@SuppressWarnings("unchecked")
static RouteRule EMPTY = new RouteRule(Collections.EMPTY_MAP, Collections.EMPTY_MAP);
/**
* 把字符串形式的RouteRule的解析成对象。
*
* @throws ParseException RouteRule字符串格式不对了。以下输入的情况，RouteRule都是非法的。
* <ul> <li> 输入是<code>null</code>。
* <li> 输入是空串，或是空白串。
* <li> 输入的Rule，没有When条件
* <li> 输入的Rule，没有Then条件
* </ul>
*/
public static RouteRule parse(Route route) throws ParseException {
if(route == null)
throw new ParseException("null route!", 0);
if(route.getMatchRule() == null && route.getFilterRule() == null) {
return parse(route.getRule());
}
return parse(route == null ? null : route.getMatchRule(), route == null ? null : route.getFilterRule());
}
public static RouteRule parse(String whenRule, String thenRule) throws ParseException {
/*if (whenRule == null || whenRule.trim().length() == 0) {
throw new ParseException("Illegal route rule without when express", 0);
}*/
if (thenRule == null || thenRule.trim().length() == 0) {
throw new ParseException("Illegal route rule without then express", 0);
}
Map<String, MatchPair> when = parseRule(whenRule.trim());
Map<String, MatchPair> then = parseRule(thenRule.trim());
return new RouteRule(when, then);
}
public static RouteRule parse(String rule) throws ParseException {
if(StringUtils.isBlank(rule)) {
throw new ParseException("Illegal blank route rule", 0);
}
final Matcher matcher = CONDITION_SEPERATOR.matcher(rule);
if(!matcher.matches()) throw new ParseException("condition seperator => not found!", 0);
return parse(matcher.group(1), matcher.group(2));
}
/**
* @see #parse(String)
* @throws RuntimeException 解析出错时，Wrap了{@link #parse(String)}方法的抛出的{@link ParseException}的异常。
*/
public static RouteRule parseQuitely(Route route) {
try {
return parse(route);
} catch (ParseException e) {
throw new RuntimeException(e);
}
}
private static Pattern VALUE_LIST_SEPARATOR = Pattern.compile("\\s*,\\s*");
static Map<String, MatchPair> parseNameAndValueListString2Condition(Map<String, String> params, Map<String, String> notParams) {
Map<String, MatchPair> condition = new HashMap<String, RouteRule.MatchPair>();
for(Entry<String, String> entry : params.entrySet()) {
String valueListString = entry.getValue();
if(StringUtils.isBlank(valueListString)) {
continue;
}
String[] list = VALUE_LIST_SEPARATOR.split(valueListString);
Set<String> set = new HashSet<String>();
for(String item : list) {
if(StringUtils.isBlank(item)) {
continue;
}
set.add(item.trim());
}
if(set.isEmpty()) {
continue;
}
String key = entry.getKey();
MatchPair matchPair = condition.get(key);
if(null == matchPair) {
matchPair = new MatchPair();
condition.put(key, matchPair);
}
matchPair.matches = set;
}
for(Entry<String, String> entry : notParams.entrySet()) {
String valueListString = entry.getValue();
if(StringUtils.isBlank(valueListString)) {
continue;
}
String[] list = VALUE_LIST_SEPARATOR.split(valueListString);
Set<String> set = new HashSet<String>();
for(String item : list) {
if(StringUtils.isBlank(item)) {
continue;
}
set.add(item.trim());
}
if(set.isEmpty()) {
continue;
}
String key = entry.getKey();
MatchPair matchPair = condition.get(key);
if(null == matchPair) {
matchPair = new MatchPair();
condition.put(key, matchPair);
}
matchPair.unmatches = set;
}
return condition;
}
public static RouteRule createFromNameAndValueListString(Map<String, String> whenParams, Map<String, String> notWhenParams,
Map<String, String> thenParams, Map<String, String> notThenParams) {
Map<String, MatchPair> when = parseNameAndValueListString2Condition(whenParams, notWhenParams);
Map<String, MatchPair> then = parseNameAndValueListString2Condition(thenParams, notThenParams);
return new RouteRule(when, then);
}
public static RouteRule createFromCondition(Map<String, MatchPair> whenCondition, Map<String, MatchPair> thenCondition) {
return new RouteRule(whenCondition, thenCondition);
}
public static RouteRule copyWithRemove(RouteRule copy, Set<String> whenParams, Set<String> thenParams) {
Map<String, MatchPair> when = new HashMap<String, RouteRule.MatchPair>();
for(Entry<String, MatchPair> entry : copy.getWhenCondition().entrySet()) {
if(whenParams == null || !whenParams.contains(entry.getKey())) {
when.put(entry.getKey(), entry.getValue());
}
}
Map<String, MatchPair> then = new HashMap<String, RouteRule.MatchPair>();
for(Entry<String, MatchPair> entry : copy.getThenCondition().entrySet()) {
if(thenParams ==null || !thenParams.contains(entry.getKey())) {
then.put(entry.getKey(), entry.getValue());
}
}
return new RouteRule(when, then);
}
/**
* 使用新的条件值来替换。
*
* @param copy 替换的Base
* @param whenCondition 要替换的whenCondition，如果Base没有项目，则直接插入。
* @param thenCondition 要替换的thenCondition，如果Base没有项目，则直接插入。
* @return 替换后的RouteRule
*/
public static RouteRule copyWithReplace(RouteRule copy, Map<String, MatchPair> whenCondition, Map<String, MatchPair> thenCondition) {
if(null == copy) {
throw new NullPointerException("Argument copy is null!");
}
Map<String, MatchPair> when = new HashMap<String, RouteRule.MatchPair>();
when.putAll(copy.getWhenCondition());
if(whenCondition != null) {
when.putAll(whenCondition);
}
Map<String, MatchPair> then = new HashMap<String, RouteRule.MatchPair>();
then.putAll(copy.getThenCondition());
if(thenCondition != null) {
then.putAll(thenCondition);
}
return new RouteRule(when, then);
}
// TODO 目前ToString出来的列表是乱序的，是否要排序？
static void join(StringBuilder sb, Set<String> valueSet) {
boolean isFirst = true;
for(String s : valueSet) {
if(isFirst) {
isFirst = false;
}
else {
sb.append(",");
}
sb.append(s);
}
}
/**
* 样本是否通过条件。
* <p>
* 如果样本的KV中，存在Key有对应的MatchPair，且Value不通过MatchPair里，返回{@code false}；
* 否则返回{@code true}。
*
* @see MatchPair#pass(String)
*/
public static boolean matchCondition(Map<String, String> sample,
Map<String, MatchPair> condition) {
for (Map.Entry<String, String> entry : sample.entrySet()) {
String key = entry.getKey();
MatchPair pair = condition.get(key);
if (pair != null && !pair.pass(entry.getValue())) {
return false;
}
}
return true;
}
// FIXME 去掉这样的方法调用
public static String join(Set<String> valueSet) {
StringBuilder sb = new StringBuilder(128);
join(sb, valueSet);
return sb.toString();
}
// TODO 目前Condition的多个Key是乱序的，是否要排序？
public static void contidionToString(StringBuilder sb, Map<String, MatchPair> condition) {
boolean isFirst = true;
for(Entry<String, MatchPair> entry: condition.entrySet()) {
String keyName = entry.getKey();
MatchPair p = entry.getValue();
@SuppressWarnings("unchecked")
Set<String>[] setArray = new Set[]{p.matches, p.unmatches};
String[] opArray = {" = ", " != "};
for(int i = 0; i < setArray.length; ++i) {
if(setArray[i].isEmpty()) {
continue;
}
if(isFirst) {
isFirst = false;
}
else {
sb.append(" & ");
}
sb.append(keyName);
sb.append(opArray[i]);
join(sb, setArray[i]);
}
}
}
public boolean isWhenContainValue(String key, String value) {
MatchPair matchPair = whenCondition.get(key);
if(null == matchPair) {
return false;
}
return matchPair.containeValue(value);
}
public boolean isThenContainValue(String key, String value) {
MatchPair matchPair = thenCondition.get(key);
if(null == matchPair) {
return false;
}
return matchPair.containeValue(value);
}
public boolean isContainValue(String key, String value) {
return isWhenContainValue(key, value) || isThenContainValue(key, value);
}
public Map<String, MatchPair> getWhenCondition() {
return whenCondition;
}
public Map<String, MatchPair> getThenCondition() {
return thenCondition;
}
public String getWhenConditionString() {
StringBuilder sb = new StringBuilder(512);
contidionToString(sb, whenCondition);
return sb.toString();
}
public String getThenConditionString() {
StringBuilder sb = new StringBuilder(512);
contidionToString(sb, thenCondition);
return sb.toString();
}
private volatile String tostring = null;
@Override
public String toString() {
if(tostring != null)
return tostring;
StringBuilder sb = new StringBuilder(512);
contidionToString(sb, whenCondition);
sb.append(" => ");
contidionToString(sb, thenCondition);
return tostring = sb.toString();
}
// 用Eclipse自动生成
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + ((thenCondition == null) ? 0 : thenCondition.hashCode());
result = prime * result + ((whenCondition == null) ? 0 : whenCondition.hashCode());
return result;
}
// 用Eclipse自动生成
@Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
RouteRule other = (RouteRule) obj;
if (thenCondition == null) {
if (other.thenCondition != null)
return false;
} else if (!thenCondition.equals(other.thenCondition))
return false;
if (whenCondition == null) {
if (other.whenCondition != null)
return false;
} else if (!whenCondition.equals(other.whenCondition))
return false;
return true;
}
}