接口

FireflySessionURLProtocol

注冊、解注冊過濾器

+(void)filter_register:(nonnull Class)filter;
+(void)filter_unregister:(nonnull Class)filter;
+(void)filter_unregisterAll;
+(void)filter_setlist:(nullable NSArray<Class> *)list;

獲取當前注冊的(de)過濾器

+(nullable NSArray<Class> *)filter_getlist;

FireflySessionURLCustomFilter（過濾器）

調用順序

 ->ff_canDoWithRequest
 ->initWithRequest
 ->ff_GetLocalData 如果處理成功 則到(dào)此結束
 ->didReceiveData
 ->didCompleteWithError

是(shì)否可以(yǐ)處理某個(gè)具體請求

對應NSURLProtocol::canonicalRequestForRequest

隻有結果爲(wéi / wèi)YES時(shí)，才會有（但不(bù)一(yī / yì ／yí)定有）後續的(de)處理過程

+(BOOL)ff_canDoWithRequest:(NSURLRequest *_Nonnull)inRequest canonicalRequest:(NSURLRequest *_Nonnull*_Nullable)outRequest outUserData:(NSObject *_Nullable*_Nonnull)outUserData;

初始化方法

-(id _Nonnull)initWithRequest:(NSURLRequest *_Nonnull)request userData:(NSObject *_Nullable)userData;

請求

@property (nonatomic,strong,readonly,nonnull) NSURLRequest * request;

參考initWithRequest的(de)request

用戶數據

@property (nonatomic,strong,readonly,nullable) NSObject *userData;

參考initWithRequest的(de)userData

接收網絡數據

-(void)ff_URLSession:(NSURLSession *_Nonnull)session dataTask:(NSURLSessionDataTask *_Nonnull)dataTask didReceiveData:(NSData *_Nonnull)data;

網絡請求完成

-(void)ff_URLSession:(NSURLSession *_Nonnull)session task:(NSURLSessionTask *_Nonnull)task didCompleteWithError:(NSError *_Nullable)error;

獲取本地(dì / de)數據

-(void)ff_GetLocalDataFrom:(in unsigned long)inOffset
                      size:(in unsigned long)inSize
                      data:(out NSData *_Nonnull*_Nullable)outData
                     total:(out unsigned long *_Nonnull)outTotal
                     error:(out NSError *_Nonnull*_Nullable)outErr;

如果本地(dì / de)數據處理成功，則不(bù)過發起網絡請求；這(zhè)個(gè)方法可能會被多次調用，直到(dào)數據讀取完畢。數據讀取完畢的(de)判斷條件是(shì)outTotal < inSize

本地(dì / de)文件路徑

-(NSString *_Nonnull)localFilePath;

如果确定過濾器可以(yǐ)處理請求，且本地(dì / de)有緩存文件，需要(yào / yāo)在(zài)這(zhè)個(gè)方法裏返回本地(dì / de)文件路徑。

清除本地(dì / de)文件

+(void)clearLocalFiles;

清除本地(dì / de)文件

+(void)clearLocalFiles;

獲取響應數據緩存

-(nullable NSURLResponse *)ff_GetLocalResponse;

FireflyWebImageCacheFilter(图片緩存)

是(shì)FireflySessionURLCustomFilter的(de)子(zǐ)類，重寫的(de)方法

+(BOOL)ff_canDoWithRequest:(NSURLRequest *)inRequest canonicalRequest:(NSURLRequest **)outRequest outUserData:(NSObject **)outUserData
{
    if (!inRequest  || !inRequest.URL)
        return NO;

    NSString *scheme = [inRequest.URL.scheme lowercaseString];
    if (![scheme isEqualToString:@"http"] && ![scheme isEqualToString:@"https"])
        return NO;

    NSString *userAgent = [inRequest valueForHTTPHeaderField:@"User-Agent"];
    if ([userAgent rangeOfString:@"AppleWebKit"].location == NSNotFound)
        return NO;

    NSString * ext = inRequest.URL.pathExtension.lowercaseString;
    static NSArray *extlist = nil;
    if (!extlist) extlist = @[@"jpg",@"jpeg",@"png",@"gif",@"tif",@"bmp",@"ico"];
    return [extlist indexOfObject:ext] != NSNotFound;
}

-(NSString *)localFilePath
{
    return @"具體文件的(de)本地(dì / de)路徑';
}

-(void)ff_GetLocalDataFrom:(in unsigned long)inOffset
                      size:(in unsigned long)inSize
                      data:(out NSData **)outData
                     total:(out unsigned long *)outTotal
                     error:(out NSError **)outErr
{
    NSString * path = [self localFilePath];
    if ([[NSFileManager defaultManager] fileExistsAtPath:path])
    {
        NSData *data = [NSData dataWithContentsOfFile:path];
        if (!data || data.length == 0)
        {//讀取文件錯誤或者空文件
            [[NSFileManager defaultManager] removeItemAtPath:path error:nil];
            return;
        }
        CGImageSourceRef source = CGImageSourceCreateWithData((CFDataRef)data, NULL);
        if (!source)
        {//图片初步解碼失敗
            [[NSFileManager defaultManager] removeItemAtPath:path error:nil];
            return;
        }

        CFRelease(source);
        *outData = data;
        *outTotal = data.length;
    }
}