fix #162 finish the algorithm of self-id-generator

pom.xml

@@ -10,6 +10,7 @@
         <module>sharding-jdbc-core</module>
         <module>sharding-jdbc-config-parent</module>
         <module>sharding-jdbc-transaction-parent</module>
+        <module>sharding-jdbc-id-generator-parent</module>
     </modules>
 
     <properties>

sharding-jdbc-core/src/main/java/com/dangdang/ddframe/rdb/sharding/id/generator/IdGenerator.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright 1999-2015 dangdang.com.
+ * <p>
+ * Licensed 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.
+ * </p>
+ */
+
+package com.dangdang.ddframe.rdb.sharding.id.generator;
+
+/**
+ * Id 生成接口.
+ * 
+ * @author gaohongtao
+ */
+public interface IdGenerator {
+
+    /**
+     * 初始化配置环境.
+     * 
+     * @param tableName 逻辑表名称
+     * @param columnName 需要生成的列名称
+     */
+    void initContext(String tableName, String columnName);
+
+    /**
+     * 生成Id.
+     * 
+     * @return 返回生成的Id,返回值应为@{@link Number}对象或者为@{@link String}对象
+     */
+    Object generateId();
+}

sharding-jdbc-core/src/test/java/com/dangdang/ddframe/rdb/sharding/id/generator/fixture/IncrementIdGenerator.java

@@ -0,0 +1,37 @@
+/*
+ * Copyright 1999-2015 dangdang.com.
+ * <p>
+ * Licensed 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.
+ * </p>
+ */
+
+package com.dangdang.ddframe.rdb.sharding.id.generator.fixture;
+
+import com.dangdang.ddframe.rdb.sharding.id.generator.IdGenerator;
+
+import java.util.concurrent.atomic.AtomicInteger;
+
+public class IncrementIdGenerator implements IdGenerator{
+
+    private final AtomicInteger i = new AtomicInteger();
+
+    @Override
+    public void initContext(final String tableName, final String columnName) {
+
+    }
+
+    @Override
+    public Object generateId() {
+        return i.incrementAndGet();
+    }
+}

sharding-jdbc-id-generator-parent/pom.xml

@@ -0,0 +1,64 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  ~ Copyright 1999-2015 dangdang.com.
+  ~ <p>
+  ~ Licensed 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.
+  ~ </p>
+  -->
+
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <artifactId>sharding-jdbc</artifactId>
+        <groupId>com.dangdang</groupId>
+        <version>1.4.0-SNAPSHOT</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>sharding-jdbc-id-generator-parent</artifactId>
+    <packaging>pom</packaging>
+    <modules>
+        <module>sharding-jdbc-self-id-generator</module>
+    </modules>
+
+
+    <dependencies>
+        <dependency>
+            <groupId>com.dangdang</groupId>
+            <artifactId>sharding-jdbc-core</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+        </dependency>
+    </dependencies>
+    <dependencyManagement>
+        <dependencies>
+            <dependency>
+                <groupId>com.dangdang</groupId>
+                <artifactId>sharding-jdbc</artifactId>
+                <version>${project.parent.version}</version>
+                <type>pom</type>
+                <scope>import</scope>
+            </dependency>
+            <dependency>
+                <groupId>com.github.stefanbirkner</groupId>
+                <artifactId>system-rules</artifactId>
+                <version>1.16.0</version>
+                <scope>test</scope>
+            </dependency>
+        </dependencies>
+    </dependencyManagement>
+</project>

sharding-jdbc-id-generator-parent/sharding-jdbc-self-id-generator/pom.xml

@@ -0,0 +1,51 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  ~ Copyright 1999-2015 dangdang.com.
+  ~ <p>
+  ~ Licensed 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.
+  ~ </p>
+  -->
+
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <artifactId>sharding-jdbc-id-generator-parent</artifactId>
+        <groupId>com.dangdang</groupId>
+        <version>1.4.0-SNAPSHOT</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>sharding-jdbc-self-id-generator</artifactId>
+
+    <dependencies>
+        <dependency>
+            <groupId>com.github.stefanbirkner</groupId>
+            <artifactId>system-rules</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.slf4j</groupId>
+            <artifactId>slf4j-api</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>ch.qos.logback</groupId>
+            <artifactId>logback-classic</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.slf4j</groupId>
+            <artifactId>jcl-over-slf4j</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+</project>

sharding-jdbc-id-generator-parent/sharding-jdbc-self-id-generator/src/main/java/com/dangdang/ddframe/rdb/sharding/id/generator/self/CommonSelfIdGenerator.java

@@ -0,0 +1,137 @@
+/*
+ * Copyright 1999-2015 dangdang.com.
+ * <p>
+ * Licensed 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.
+ * </p>
+ */
+
+package com.dangdang.ddframe.rdb.sharding.id.generator.self;
+
+import com.dangdang.ddframe.rdb.sharding.id.generator.IdGenerator;
+import com.dangdang.ddframe.rdb.sharding.id.generator.self.time.AbstractClock;
+import com.google.common.base.Preconditions;
+import com.google.common.base.Strings;
+import lombok.Getter;
+import lombok.Setter;
+
+/**
+ * 自生成Id生成器.
+ * 
+ * <p/>
+ * 长度为64bit,从高位到低位依次为
+ * <pre>
+ * 1bit   符号位 
+ * 41bits 时间偏移量从2016年11月1日零点到现在的毫秒数
+ * 10bits 工作进程Id
+ * 12bits 同一个毫秒内的自增量
+ * </pre>
+ * 
+ * <p/>
+ * 工作进程Id获取优先级: 系统变量{@code sjdbc.self.id.generator.worker.id} > 环境变量{@code SJDBC_SELF_ID_GENERATOR_WORKER_ID}
+ * ,另外可以调用@{@code CommonSelfIdGenerator.setWorkerId}进行设置
+ * 
+ * @author gaohongtao.
+ */
+@Getter
+public class CommonSelfIdGenerator implements IdGenerator {
+
+    public static final long SJDBC_EPOCH = 1477933200000L;
+
+    private static final long SEQUENCE_BITS = 12L;
+
+    private static final long WORKER_ID_BITS = 10L;
+
+    private static final long SEQUENCE_MASK = (1 << SEQUENCE_BITS) - 1;
+
+    private static final long WORKER_ID_LEFT_SHIFT_BITS = SEQUENCE_BITS;
+
+    private static final long TIMESTAMP_LEFT_SHIFT_BITS = WORKER_ID_LEFT_SHIFT_BITS + WORKER_ID_BITS;
+
+    private static final long WORKER_ID_MAX_VALUE = 1L << WORKER_ID_BITS;
+
+    @Setter
+    private static AbstractClock clock = AbstractClock.systemClock();
+
+    @Getter
+    private static long workerId;
+
+    static {
+        initWorkerId();
+    }
+
+    private long sequence;
+
+    private long lastTime;
+
+    private String tableName;
+
+    private String columnName;
+
+    static void initWorkerId() {
+        String workerId = System.getProperty("sjdbc.self.id.generator.worker.id");
+        if (!Strings.isNullOrEmpty(workerId)) {
+            setWorkerId(Long.valueOf(workerId));
+            return;
+        }
+        workerId = System.getenv("SJDBC_SELF_ID_GENERATOR_WORKER_ID");
+        if (Strings.isNullOrEmpty(workerId)) {
+            return;
+        }
+        setWorkerId(Long.valueOf(workerId));
+    }
+
+    public static void setWorkerId(final Long workerId) {
+        Preconditions.checkArgument(workerId >= 0L && workerId < WORKER_ID_MAX_VALUE);
+        CommonSelfIdGenerator.workerId = workerId;
+    }
+
+    /**
+     * 初始化环境.
+     * 
+     * @param tableName 逻辑表名称
+     * @param columnName 需要生成的列名称
+     */
+    @Override
+    public void initContext(final String tableName, final String columnName) {
+        this.tableName = tableName;
+        this.columnName = columnName;
+    }
+
+    /**
+     * 生成Id.
+     * 
+     * @return 返回@{@link Long}类型的Id
+     */
+    @Override
+    public synchronized Object generateId() {
+        long time = clock.millis();
+        Preconditions.checkState(lastTime <= time, "Clock is moving backwards, last time is %d milliseconds, current time is %d milliseconds", lastTime, time);
+        if (lastTime == time) {
+            if (0L == (++sequence & SEQUENCE_MASK)) {
+                time = waitUntilNextTime(time);
+            }
+        } else {
+            sequence = 0;
+        }
+        lastTime = time;
+        return ((time - SJDBC_EPOCH) << TIMESTAMP_LEFT_SHIFT_BITS) | (workerId << WORKER_ID_LEFT_SHIFT_BITS) | sequence;
+    }
+
+    private long waitUntilNextTime(final long lastTime) {
+        long time = clock.millis();
+        while (time <= lastTime) {
+            time = clock.millis();
+        }
+        return time;
+    }
+}

sharding-jdbc-id-generator-parent/sharding-jdbc-self-id-generator/src/main/java/com/dangdang/ddframe/rdb/sharding/id/generator/self/time/AbstractClock.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright 1999-2015 dangdang.com.
+ * <p>
+ * Licensed 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.
+ * </p>
+ */
+
+package com.dangdang.ddframe.rdb.sharding.id.generator.self.time;
+
+/**
+ * 时钟定义.
+ * 
+ * @author gaohongtao
+ */
+public abstract class AbstractClock {
+
+    /**
+     * 创建系统时钟.
+     * 
+     * @return 系统时钟
+     */
+    public static AbstractClock systemClock() {
+        return new SystemClock();
+    }
+
+    /**
+     * 返回从纪元开始的毫秒数.
+     * 
+     * @return 从纪元开始的毫秒数
+     */
+    public abstract long millis();
+
+    private static final class SystemClock extends AbstractClock {
+
+        @Override
+        public long millis() {
+            return System.currentTimeMillis();
+        }
+    }
+}