size_t header_cb()

in EMASCurl/EMASCurlProtocol.m [725:810]

• 72 lines of code
• 14 McCabe index (conditional complexity)

size_t header_cb(char *buffer, size_t size, size_t nitems, void *userdata) {
    EMASCurlProtocol *protocol = (__bridge EMASCurlProtocol *)userdata;

    size_t totalSize = size * nitems;
    NSData *data = [NSData dataWithBytes:buffer length:size * nitems];

    NSString *headerLine = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
    headerLine = [headerLine stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];

    if ([headerLine hasPrefix:@"HTTP/"]) {
        // 头部首行，标识新的头部开始
        [protocol.currentResponse reset];

        NSArray<NSString *> *components = [headerLine componentsSeparatedByString:@" "];
        if (components.count >= 3) {
            protocol.currentResponse.httpVersion = components[0];
            protocol.currentResponse.statusCode = [components[1] integerValue];
            protocol.currentResponse.reasonPhrase = [[components subarrayWithRange:NSMakeRange(2, components.count - 2)] componentsJoinedByString:@" "];
        } else if (components.count == 2) {
            protocol.currentResponse.httpVersion = components[0];
            protocol.currentResponse.statusCode = [components[1] integerValue];
            protocol.currentResponse.reasonPhrase = @"";
        }
    } else {
        NSRange delimiterRange = [headerLine rangeOfString:@": "];
        if (delimiterRange.location != NSNotFound) {
            NSString *key = [headerLine substringToIndex:delimiterRange.location];
            NSString *value = [headerLine substringFromIndex:delimiterRange.location + delimiterRange.length];

            // 设置cookie
            if ([key caseInsensitiveCompare:@"set-cookie"] == NSOrderedSame) {
                EMASCurlCookieStorage *cookieStorage = [EMASCurlCookieStorage sharedStorage];
                [cookieStorage setCookieWithString:value forURL:protocol.request.URL];
            }

            if (protocol.currentResponse.headers[key]) {
                NSString *existingValue = protocol.currentResponse.headers[key];
                NSString *combinedValue = [existingValue stringByAppendingFormat:@", %@", value];
                protocol.currentResponse.headers[key] = combinedValue;
            } else {
                protocol.currentResponse.headers[key] = value;
            }
        }
    }

    if ([headerLine length] == 0) {
        // 尾行，标识当前头部读取结束
        NSInteger statusCode = protocol.currentResponse.statusCode;
        NSString *reasonPhrase = protocol.currentResponse.reasonPhrase;

        NSHTTPURLResponse *httpResponse = [[NSHTTPURLResponse alloc] initWithURL:protocol.request.URL
                                                                      statusCode:protocol.currentResponse.statusCode
                                                                     HTTPVersion:protocol.currentResponse.httpVersion
                                                                    headerFields:protocol.currentResponse.headers];
        if (isRedirectionStatusCode(statusCode)) {
            if (!s_enableBuiltInRedirection) {
                // 关闭了重定向支持，则把重定向信息往外传递
                __block NSString *location = nil;
                [protocol.currentResponse.headers enumerateKeysAndObjectsUsingBlock:^(NSString * _Nonnull key, NSString * _Nonnull obj, BOOL * _Nonnull stop) {
                    if ([key caseInsensitiveCompare:@"Location"] == NSOrderedSame) {
                        location = obj;
                        *stop = YES;
                    }
                }];
                if (location) {
                    NSURL *locationURL = [NSURL URLWithString:location relativeToURL:protocol.request.URL];
                    NSMutableURLRequest *redirectedRequest = [protocol.request mutableCopy];
                    [redirectedRequest setURL:locationURL];
                    [protocol.client URLProtocol:protocol wasRedirectedToRequest:redirectedRequest redirectResponse:httpResponse];
                } else {

                }
            }
            [protocol.currentResponse reset];
        } else if (isInformationalStatusCode(statusCode)) {
            [protocol.currentResponse reset];
        } else if (isConnectEstablishedStatusCode(statusCode, reasonPhrase)) {
            [protocol.currentResponse reset];
        } else {
            [protocol.client URLProtocol:protocol didReceiveResponse:httpResponse cacheStoragePolicy:NSURLCacheStorageAllowed];
            protocol.currentResponse.isFinalResponse = YES;
        }
    }

    return totalSize;
}