From 66baca51d777aa583ae2a20494b036ce9cc1a9e3 Mon Sep 17 00:00:00 2001
From: Redkale <22250530@qq.com>
Date: Thu, 25 Jan 2018 14:24:28 +0800
Subject: [PATCH] =?UTF-8?q?CacheSource=E5=A2=9E=E5=8A=A0getIfAbsent?=
 =?UTF-8?q?=E7=B3=BB=E5=88=97=E6=96=B9=E6=B3=95?=
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---
 src/org/redkale/source/CacheSource.java | 45 +++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/src/org/redkale/source/CacheSource.java b/src/org/redkale/source/CacheSource.java
index 7833e394a..3ec8aaaf9 100644
--- a/src/org/redkale/source/CacheSource.java
+++ b/src/org/redkale/source/CacheSource.java
@@ -8,6 +8,7 @@ package org.redkale.source;
 import java.lang.reflect.Type;
 import java.util.*;
 import java.util.concurrent.*;
+import java.util.function.Function;
 import org.redkale.convert.ConvertColumn;
 import org.redkale.convert.json.JsonFactory;
 import org.redkale.util.ConstructorParameters;
@@ -36,8 +37,26 @@ public interface CacheSource<V extends Object> {
 
     public V get(final String key);
 
+    default V getIfAbsent(final String key, Function<String, ? extends V> mappingFunction) {
+        V rs = get(key);
+        if (rs == null) {
+            rs = mappingFunction.apply(key);
+            if (rs != null) set(key, rs);
+        }
+        return rs;
+    }
+
     public V getAndRefresh(final String key, final int expireSeconds);
 
+    default V getAndRefreshIfAbsent(final String key, final int expireSeconds, Function<String, ? extends V> mappingFunction) {
+        V rs = getAndRefresh(key, expireSeconds);
+        if (rs == null) {
+            rs = mappingFunction.apply(key);
+            if (rs != null) set(expireSeconds, key, rs);
+        }
+        return rs;
+    }
+
     public void refresh(final String key, final int expireSeconds);
 
     public void set(final String key, final V value);
@@ -127,8 +146,34 @@ public interface CacheSource<V extends Object> {
 
     public CompletableFuture<V> getAsync(final String key);
 
+    default CompletableFuture<V> getIfAbsentAsync(final String key, Function<String, ? extends V> mappingFunction) {
+        return getAsync(key).thenCompose((V rs) -> {
+            if (rs == null) {
+                rs = mappingFunction.apply(key);
+                if (rs != null) {
+                    final V v = rs;
+                    return setAsync(key, rs).thenApply((k) -> v);
+                }
+            }
+            return CompletableFuture.completedFuture(rs);
+        });
+    }
+
     public CompletableFuture<V> getAndRefreshAsync(final String key, final int expireSeconds);
 
+    default CompletableFuture<V> getAndRefreshIfAbsentAsync(final String key, final int expireSeconds, Function<String, ? extends V> mappingFunction) {
+        return getAndRefreshAsync(key, expireSeconds).thenCompose((V rs) -> {
+            if (rs == null) {
+                rs = mappingFunction.apply(key);
+                if (rs != null) {
+                    final V v = rs;
+                    return setAsync(expireSeconds, key, rs).thenApply((k) -> v);
+                }
+            }
+            return CompletableFuture.completedFuture(rs);
+        });
+    }
+
     public CompletableFuture<Void> refreshAsync(final String key, final int expireSeconds);
 
     public CompletableFuture<Void> setAsync(final String key, final V value);