supports JDK8 (#70)

* implement support for jdk8

* update docs

* update ci

* remove pid feature

* fix unit tests fail

Author: tuhuynh27

.github/workflows/build.yml

@@ -13,10 +13,10 @@ jobs:
       - uses: actions/checkout@v2
         with:
           fetch-depth: 0  # Shallow clones should be disabled for a better relevancy of analysis
-      - name: Set up JDK 11
+      - name: Set up JDK 8
         uses: actions/setup-java@v1
         with:
-          java-version: 11
+          java-version: 8
       - name: Cache SonarCloud packages
         uses: actions/cache@v1
         with:

config/src/main/java/com/keva/config/ConfigLoader.java

@@ -15,7 +15,7 @@ public final class ConfigLoader {
     public static final String DEFAULT_FILE_PATH = Paths.get(".", "keva.properties").toString();
 
     public static <T> T loadConfig(String[] args, Class<T> clazz) throws IOException {
-        var returnConf = ConfigLoaderUtil.fromProperties(new Properties(), clazz);
+        T returnConf = ConfigLoaderUtil.fromProperties(new Properties(), clazz);
         val config = ArgsParser.parse(args);
         val overrider = ConfigLoaderUtil.fromArgs(config, clazz);
 

config/src/test/java/com/keva/config/ArgsParserTest.java

@@ -6,6 +6,8 @@
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNull;
 
+import lombok.var;
+
 class ArgsParserTest {
 
     @Test

core/src/main/java/dev/keva/core/command/impl/key/Del.java

@@ -10,6 +10,8 @@
 import dev.keva.protocol.resp.reply.IntegerReply;
 import dev.keva.store.KevaDatabase;
 
+import lombok.var;
+
 import static dev.keva.core.command.annotation.ParamLength.Type.AT_LEAST;
 
 @Component

core/src/main/java/dev/keva/core/command/impl/key/Exists.java

@@ -9,6 +9,8 @@
 import dev.keva.protocol.resp.reply.Reply;
 import dev.keva.store.KevaDatabase;
 
+import lombok.var;
+
 import static dev.keva.core.command.annotation.ParamLength.Type.AT_LEAST;
 
 @Component

core/src/main/java/dev/keva/core/command/impl/key/Expire.java

@@ -10,6 +10,8 @@
 
 import java.nio.charset.StandardCharsets;
 
+import lombok.val;
+
 @Component
 @CommandImpl("expire")
 @ParamLength(2)
@@ -24,7 +26,7 @@ public Expire(ExpirationManager expirationManager) {
     @Execute
     public IntegerReply execute(byte[] key, byte[] after) {
         try {
-            var afterInMillis = Long.parseLong(new String(after, StandardCharsets.UTF_8));
+            val afterInMillis = Long.parseLong(new String(after, StandardCharsets.UTF_8));
             expirationManager.expireAfter(key, afterInMillis);
             return new IntegerReply(1);
         } catch (Exception ignore) {

core/src/main/java/dev/keva/core/command/impl/key/ExpireAt.java

@@ -10,6 +10,8 @@
 
 import java.nio.charset.StandardCharsets;
 
+import lombok.val;
+
 @Component
 @CommandImpl("expireat")
 @ParamLength(2)
@@ -24,7 +26,7 @@ public ExpireAt(ExpirationManager expirationManager) {
     @Execute
     public IntegerReply execute(byte[] key, byte[] at) {
         try {
-            var atInMillis = Long.parseLong(new String(at, StandardCharsets.UTF_8));
+            val atInMillis = Long.parseLong(new String(at, StandardCharsets.UTF_8));
             expirationManager.expireAt(key, atInMillis);
             return new IntegerReply(1);
         } catch (Exception ignore) {

core/src/main/java/dev/keva/core/command/impl/key/Incrby.java

@@ -12,6 +12,8 @@
 
 import java.nio.charset.StandardCharsets;
 
+import lombok.var;
+
 import static dev.keva.core.command.annotation.ParamLength.Type.EXACT;
 
 @Component

core/src/main/java/dev/keva/core/command/impl/pubsub/Publish.java

@@ -12,6 +12,7 @@
 import dev.keva.protocol.resp.reply.Reply;
 import io.netty.channel.Channel;
 import lombok.val;
+import lombok.var;
 
 import java.util.Set;
 

core/src/main/java/dev/keva/core/command/impl/pubsub/Subscribe.java

@@ -13,6 +13,7 @@
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelHandlerContext;
 import lombok.val;
+import lombok.var;
 
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;

core/src/main/java/dev/keva/core/command/impl/pubsub/Unsubscribe.java

@@ -12,6 +12,7 @@
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelHandlerContext;
 import lombok.val;
+import lombok.var;
 
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;

core/src/main/java/dev/keva/core/command/impl/transaction/Discard.java

@@ -9,6 +9,8 @@
 import dev.keva.protocol.resp.reply.StatusReply;
 import io.netty.channel.ChannelHandlerContext;
 
+import lombok.val;
+
 @Component
 @CommandImpl("discard")
 @ParamLength(0)
@@ -22,7 +24,7 @@ public Discard(TransactionManager manager) {
 
     @Execute
     public StatusReply execute(ChannelHandlerContext ctx) {
-        var txContext = manager.getTransactions().get(ctx.channel());
+        val txContext = manager.getTransactions().get(ctx.channel());
         if (txContext != null) {
             txContext.discard();
         }

core/src/main/java/dev/keva/core/command/impl/transaction/Exec.java

@@ -10,6 +10,8 @@
 import dev.keva.store.KevaDatabase;
 import io.netty.channel.ChannelHandlerContext;
 
+import lombok.val;
+
 import static dev.keva.protocol.resp.reply.BulkReply.NIL_REPLY;
 
 @Component
@@ -27,7 +29,7 @@ public Exec(TransactionManager manager, KevaDatabase database) {
 
     @Execute
     public Reply<?> execute(ChannelHandlerContext ctx) throws InterruptedException {
-        var txContext = manager.getTransactions().get(ctx.channel());
+        val txContext = manager.getTransactions().get(ctx.channel());
         if (txContext == null) {
             return NIL_REPLY;
         }

core/src/main/java/dev/keva/core/command/impl/transaction/Multi.java

@@ -12,6 +12,8 @@
 import dev.keva.store.KevaDatabase;
 import io.netty.channel.ChannelHandlerContext;
 
+import lombok.var;
+
 @Component
 @CommandImpl("multi")
 @ParamLength(0)

core/src/main/java/dev/keva/core/command/impl/transaction/Unwatch.java

@@ -22,7 +22,7 @@ public Unwatch(TransactionManager manager) {
 
     @Execute
     public StatusReply execute(ChannelHandlerContext ctx, byte[]... keys) {
-        var txContext = manager.getTransactions().get(ctx.channel());
+        val txContext = manager.getTransactions().get(ctx.channel());
         if (txContext != null) {
             if (keys.length == 0) {
                 txContext.getWatchMap().clear();

core/src/main/java/dev/keva/core/command/impl/transaction/Watch.java

@@ -14,6 +14,7 @@
 import dev.keva.store.KevaDatabase;
 import io.netty.channel.ChannelHandlerContext;
 import lombok.val;
+import lombok.var;
 
 import static dev.keva.core.command.annotation.ParamLength.Type.AT_LEAST;
 

core/src/main/java/dev/keva/core/command/impl/transaction/manager/TransactionContext.java

@@ -10,6 +10,7 @@
 import io.netty.channel.ChannelHandlerContext;
 import lombok.Getter;
 import lombok.val;
+import lombok.var;
 
 import java.util.*;
 import java.util.concurrent.locks.Lock;

core/src/main/java/dev/keva/core/server/KevaServer.java

@@ -103,10 +103,9 @@ public void run() {
             aofManager.init();
 
             val sync = server.bind(config.getPort()).sync();
-            log.info("{} server started at {}:{}, PID: {}, in {} ms",
+            log.info("{} server started at {}:{}, in {} ms",
                     KEVA_BANNER,
                     config.getHostname(), config.getPort(),
-                    ProcessHandle.current().pid(),
                     stopwatch.elapsed(TimeUnit.MILLISECONDS));
             log.info("Ready to accept connections");
 

core/src/test/java/dev/keva/core/server/AbstractServerTest.java

@@ -8,9 +8,12 @@
 import redis.clients.jedis.exceptions.JedisDataException;
 
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ExecutionException;
 
+import lombok.var;
+
 import static org.junit.jupiter.api.Assertions.*;
 
 public abstract class AbstractServerTest {
@@ -245,7 +248,7 @@ void setAfterExpireAt() {
     void getSetLongString() {
         try {
             final int aKB = 1024;
-            String testStr = "a".repeat(Math.max(0, aKB));
+            String testStr = String.join("", Collections.nCopies(aKB, "a"));
             String setAbc = jedis.set("abc", testStr);
             String getAbc = jedis.get("abc");
             assertEquals("OK", setAbc);
@@ -260,7 +263,7 @@ void getSetLongString() {
     void getSetLongKeyString() {
         try {
             final int aKB = 1026;
-            final String testStr = "a".repeat(Math.max(0, aKB));
+            final String testStr = String.join("", Collections.nCopies(aKB, "a"));
             final String setAbc = jedis.set(testStr, "123");
             final String getAbc = jedis.get(testStr);
             assertEquals("OK", setAbc);

docs/src/guide/developer-guide.md

@@ -2,7 +2,7 @@
 
 ## Build requirements
 
-- [OpenJDK 11](https://openjdk.java.net/projects/jdk/11/)
+- [JDK 8](https://openjdk.java.net/install/)
 - Consider using [Jabba](https://github.com/shyiko/jabba) for convenient installation of JDK.
 
 ## How to build

docs/src/guide/overview/install.md

@@ -3,7 +3,7 @@
 ## Requirements
 
 - Linux/macOS environment
-- Java 11 (JDK/JRE 11) or higher
+- Java 8 (JDK/JRE 8) or higher
 
 ## Download
 

store/src/main/java/dev/keva/store/impl/OffHeapDatabaseImpl.java

@@ -8,6 +8,7 @@
 import lombok.Getter;
 import lombok.extern.slf4j.Slf4j;
 import lombok.val;
+import lombok.var;
 import net.openhft.chronicle.map.ChronicleMap;
 import net.openhft.chronicle.map.ChronicleMapBuilder;
 import org.apache.commons.lang3.SerializationUtils;

store/src/main/java/dev/keva/store/impl/OnHeapDatabaseImpl.java

@@ -6,6 +6,7 @@
 import dev.keva.store.lock.SpinLock;
 import lombok.Getter;
 import lombok.val;
+import lombok.var;
 import org.apache.commons.lang3.SerializationUtils;
 
 import java.nio.charset.StandardCharsets;