解决单个图片解码后内存占用超过内存缓存最大值，导致无法显示图片的问题

Signed-off-by: madixin <madixin@huawei.com>

library/src/main/ets/cache/MemoryLruCache.ets

@@ -46,6 +46,11 @@ export class MemoryLruCache implements IMemoryCache {
       throw new Error('key or value is invalid ');
     }
 
+    let size = this.getImageKnifeDataSize(value)
+    if (size <= 0 && size >= this.maxMemory) {
+      return
+    }
+
     // 如果size满了的话，需要按照LRU的方式删除第一个
     if (this.lruCache.length == this.maxSize && !this.lruCache.contains(key)) {
       this.remove(this.lruCache.keys()[0])
@@ -53,12 +58,9 @@ export class MemoryLruCache implements IMemoryCache {
       this.remove(key)
     }
 
-    let pre: ImageKnifeData = this.lruCache.put(key, value)
-    this.addMemorySize(value)
-    // if (pre !== undefined) {  // 当前返回不是key的之前value
-    //   this.removeMemorySize(pre)
-    // }
-    this.trimToSize();
+    this.lruCache.put(key, value)
+    this.currentMemory += size
+    this.trimToSize()
   }
 
   get(key: string): ImageKnifeData | undefined {
@@ -119,19 +121,21 @@ export class MemoryLruCache implements IMemoryCache {
     }
   }
 
-  private addMemorySize(value: ImageKnifeData): void {
+  private getImageKnifeDataSize(value: ImageKnifeData): number {
     if (value.source != undefined) {
       if (typeof value.source === 'string' && value.source != "") {
-        this.currentMemory += value.source.length
+        return value.source.length
       } else if (value.source == "") {
-        for (let index = 0;index < value.imageAnimator!.length;index++) {
+        let size: number = 0
+        for (let index = 0; index < value.imageAnimator!.length; index++) {
           let pixelMap = value.imageAnimator![index].src as PixelMap
-          this.currentMemory += pixelMap.getPixelBytesNumber()
+          size += pixelMap.getPixelBytesNumber()
         }
+        return size
       } else {
-        this.currentMemory += value.source.getPixelBytesNumber();
+        return value.source.getPixelBytesNumber();
       }
-      //LogUtil.log("MemoryCache addMemorySize: " + value.source.getPixelBytesNumber() + " currentMemory：" + this.currentMemory)
     }
+    return 0
   }
 }