实现缓存功能

src/api/repository.ts

@@ -5,7 +5,12 @@ export async function search (keyword:string, page:number) {
   url.searchParams.append('q', keyword)
   url.searchParams.append('page', page.toString())
   const response = await fetch(url.toString(), { method: 'get' })
+
   const result = await response.json()
 
+  if (response.status >= 400) {
+    throw new Error(result.message)
+  }
+
   return result as RepositorySearchResultList
 }

src/components/RepositoryList.tsx

@@ -3,6 +3,7 @@ import { search as SearchRepository } from '../api/repository'
 import RepopositoryItem from './RepositoryItem'
 import { RepositorySearchResultItem } from '../api/api'
 import classes from './style/RepositoryList.module.css'
+import { RepositorySearchCache } from '../utils/cache/RepositorySearch'
 
 interface RepositoryListProps {
 
@@ -20,6 +21,8 @@ interface RepositoryListProps {
 const DEFAULT_PER_PAGE = 30
 
 export default function RepositoryList (props:RepositoryListProps) {
+  const cache = RepositorySearchCache(props.keyword, props.max_cache_page)
+
   /** 当前页 */
   const [current_page, setCurrentPage] = useState(1)
 
@@ -37,27 +40,53 @@ export default function RepositoryList (props:RepositoryListProps) {
 
   const [list, setList] = useState<RepositorySearchResultItem[]>([])
 
-  async function search (page:number) {
+  /**
+   * 调用搜索接口
+   * @param {number} page 页码
+   * @returns {Promise<void>}
+   */
+  async function search (page:number):Promise<void> {
     setLoading(true)
-    try {
-      /* eslint-disable */
-      var result = await SearchRepository(props.keyword, page)
-    } catch (err) {
-      setLoading(false)
-      return
+
+    const cache_list = cache.read(page)
+
+    let _total_page = 0
+
+    // 有缓存
+    if (cache_list) {
+      setList(cache_list)
+      _total_page = cache.getTotalPage()
+    } else {
+      // 没有缓存，调用接口
+      try {
+        /* eslint-disable */
+        var result = await SearchRepository(props.keyword, page)
+        
+      } catch (err) {
+        console.log('fetch',err);
+        alert(err.message)
+        setLoading(false)
+        return
+      }
+      
+      _total_page = Math.ceil(result.total_count / DEFAULT_PER_PAGE)
+  
+      setList(result.items)
+
+      cache.add(page,result.items)
+      cache.updateTotalPage(_total_page)
     }
 
-    const _total_page = Math.ceil(result.total_count / DEFAULT_PER_PAGE)
+    setPrevButtonEnable(page>1)
+
+    setNextButtonEnable(page<_total_page)
+
     setTotalPage(_total_page)
   
     setCurrentPage(page)
 
-    setList(result.items)
-
-    setPrevButtonEnable(page>1)
-    setNextButtonEnable(page<_total_page)
-
     setLoading(false)
+
   }
 
   useEffect(() => {

src/utils/cache/RepositorySearch.ts

@@ -0,0 +1,88 @@
+import { RepositorySearchResultItem } from '../../api/api'
+
+interface CacheWrapper<T> {
+  [keyword:string]:Caches<T>
+}
+
+interface Caches<T> {
+  total_page:number
+  list:{[page:number]:T[]}
+}
+
+const cache:CacheWrapper<RepositorySearchResultItem> = {}
+
+export function RepositorySearchCache (keyword:string, max_cache_count:number) {
+  if (!cache[keyword]) {
+    cache[keyword] = {
+      list: [],
+      total_page: 0
+    }
+  }
+
+  const _cache = cache[keyword]
+  const _cache_list = _cache.list
+
+  return {
+
+    /**
+     * 读取指定页码的缓存
+     * @param {number} page 页码
+     * @returns {RepositorySearchResultItem[]|undefined}
+     */
+    read (page:number):RepositorySearchResultItem[]|undefined {
+      return _cache_list[page]
+    },
+
+    /**
+     * 添加指定页码的缓存
+     * @param {number} page 页码
+     * @param {RepositorySearchResultItem[]} data 缓存数据
+     * @returns {this}
+     */
+    add (page:number, data:RepositorySearchResultItem[]) {
+      if (!_cache_list[page] && this.getCount() >= max_cache_count) {
+        this.remove(
+          parseInt(Object.keys(_cache_list).shift()!, 10)
+        )
+      }
+      _cache_list[page] = data
+      return this
+    },
+
+    /**
+     * 移除指定页码的缓存
+     * @param {number} page 页码
+     * @returns {this}
+     */
+    remove (page:number) {
+      delete _cache_list[page]
+      return this
+    },
+
+    /**
+     * 更新页码总数的缓存
+     * @param {number} total 页码总数
+     * @returns {this}
+     */
+    updateTotalPage (total:number) {
+      _cache.total_page = total
+      return this
+    },
+
+    /**
+     * 获取页码总数缓存
+     * @returns {number}
+     */
+    getTotalPage ():number {
+      return _cache.total_page
+    },
+
+    /**
+     * 获取当前缓存总数
+     * @returns {number}
+     */
+    getCount ():number {
+      return Object.keys(_cache_list).length
+    }
+  }
+}