AFNetworking2.0源码解析<二>
2014-9-3
本篇我们继续来看看AFNetworking的下一个模块 — AFURLRequestSerialization。
AFURLRequestSerialization用于帮助构建NSURLRequest，主要做了两个事情：
1.构建普通请求：格式化请求参数，生成HTTP Header。
2.构建multipart请求。
分别看看它在这两点具体做了什么，怎么做的。
1.构建普通请求
A.格式化请求参数
一般我们请求都会按key=value的方式带上各种参数，GET方法参数直接加在URL上，POST方法放在body上，NSURLRequest没有封装好这个参数的解析，只能我们自己拼好字符串。AFNetworking提供了接口，让参数可以是NSDictionary, NSArray, NSSet这些类型，再由内部解析成字符串后赋给NSURLRequest。
转化过程大致是这样的：
@{
@"name" : @"bang",
@"phone": @{@"mobile": @"xx", @"home": @"xx"},
@"families": @[@"father", @"mother"],
@"nums": [NSSet setWithObjects:@"1", @"2", nil]
}
->
@[
field: @"name", value: @"bang",
field: @"phone[mobile]", value: @"xx",
field: @"phone[home]", value: @"xx",
field: @"families[]", value: @"father",
field: @"families[]", value: @"mother",
field: @"nums", value: @"1",
field: @"nums", value: @"2",
]
->
name=bang&phone[mobile]=xx&phone[home]=xx&families[]=father&families[]=mother&nums=1&num=2
第一部分是用户传进来的数据，支持包含NSArray,NSDictionary,NSSet这三种数据结构。
第二部分是转换成AFNetworking内自己的数据结构，每一个key-value对都用一个对象AFQueryStringPair表示，作用是最后可以根据不同的字符串编码生成各自的key=value字符串。主要函数是AFQueryStringPairsFromKeyAndValue，详见源码注释。
第三部分是最后生成NSURLRequest可用的字符串数据，并且对参数进行url编码，在AFQueryStringFromParametersWithEncoding这个函数里。
最后在把数据赋给NSURLRequest时根据不同的HTTP方法分别处理，对于GET/HEAD/DELETE方法，把参数加到URL后面，对于其他如POST/PUT方法，把数据加到body上，并设好HTTP头，告诉服务端字符串的编码。
B.HTTP Header
AFNetworking帮你组装好了一些HTTP请求头，包括语言Accept-Language，根据[NSLocale preferredLanguages]方法读取本地语言，告诉服务端自己能接受的语言。还有构建User-Agent，以及提供Basic Auth认证接口，帮你把用户名密码做base64编码后放入HTTP请求头。详见源码注释。
C.其他格式化方式
HTTP请求参数不一定是要key=value形式，可以是任何形式的数据，可以是json格式，苹果的plist格式，二进制protobuf格式等，AFNetworking提供了方法可以很容易扩展支持这些格式，默认就实现了json和plist格式。详见源码的类AFJSONRequestSerializer和AFPropertyListRequestSerializer。
2.构建multipart请求
构建Multipart请求是占篇幅很大的一个功能，AFURLRequestSerialization里2/3的代码都是在做这个事。
A.Multipart协议介绍
Multipart是HTTP协议为web表单新增的上传文件的协议，协议文档是rfc1867，它基于HTTP的POST方法，数据同样是放在body上，跟普通POST方法的区别是数据不是key=value形式，key=value形式难以表示文件实体，为此Multipart协议添加了分隔符，有自己的格式结构，大致如下：
—AaB03x
content-disposition: form-data; name=“name"
bang
–AaB03x
content-disposition: form-data; name=”pic”; filename=“content.txt”
Content-Type: text/plain
… contents of bang.txt …
–AaB03x–
以上表示数据name=bang以及一个文件，content.txt是文件名，… contents of bang.txt …是文件实体内容。分隔符—AaB03x是可以自定义的，写在HTTP头部里：
Content-type: multipart/form-data, boundary=AaB03x
每一个部分都有自己的头部，表明这部分的数据类型以及其他一些参数，例如文件名，普通字段的key。最后一个分隔符会多加两横，表示数据已经结束：—AaB03x—。
B.实现
接下来说说怎样构造Multipart里的数据，最简单的方式就是直接拼数据，要发送一个文件，就直接把文件所有内容读取出来，再按上述协议加上头部和分隔符，拼接好数据后扔给NSURLRequest的body就可以发送了，很简单。但这样做是不可用的，因为文件可能很大，这样拼数据把整个文件读进内存，很可能把内存撑爆了。
第二种方法是不把文件读出来，不在内存拼，而是新建一个临时文件，在这个文件上拼接数据，再把文件地址扔给NSURLRequest的bodyStream，这样上传的时候是分片读取这个文件，不会撑爆内存，但这样每次上传都需要新建个临时文件，对这个临时文件的管理也挺麻烦的。
第三种方法是构建自己的数据结构，只保存要上传的文件地址，边上传边拼数据，上传是分片的，拼数据也是分片的，拼到文件实体部分时直接从原来的文件分片读取。这方法没上述两种的问题，只是实现起来也没上述两种简单，AFNetworking就是实现这第三种方法，而且还更进一步，除了文件，还可以添加多个其他不同类型的数据，包括NSData，和InputStream。
AFNetworking里multipart请求的使用方式是这样：
AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
NSDictionary *parameters = @{@"foo": @"bar"};
NSURL *filePath = [NSURL fileURLWithPath:@"file://path/to/image.png"];
[manager POST:@"http://example.com/resources.json" parameters:parameters constructingBodyWithBlock:^(id formData) {
[formData appendPartWithFileURL:filePath name:@"image" error:nil];
} success:^(AFHTTPRequestOperation *operation, id responseObject) {
NSLog(@"Success: %@", responseObject);
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
NSLog(@"Error: %@", error);
}];
这里通过constructingBodyWithBlock向使用者提供了一个AFStreamingMultipartFormData对象，调这个对象的几种append方法就可以添加不同类型的数据，包括FileURL/NSData/NSInputStream，AFStreamingMultipartFormData内部把这些append的数据转成不同类型的AFHTTPBodyPart，添加到自定义的AFMultipartBodyStream里。最后把AFMultipartBodyStream赋给原来NSMutableURLRequest的bodyStream。NSURLConnection发送请求时会读取这个bodyStream，在读取数据时会调用这个bodyStream的-read:maxLength:方法，AFMultipartBodyStream重写了这个方法，不断读取之前append进来的AFHTTPBodyPart数据直到读完。
AFHTTPBodyPart封装了各部分数据的组装和读取，一个AFHTTPBodyPart就是一个数据块。实际上三种类型(FileURL/NSData/NSInputStream)的数据在AFHTTPBodyPart都转成NSInputStream，读取数据时只需读这个inputStream。inputStream只保存了数据的实体，没有包括分隔符和头部，AFHTTPBodyPart是边读取变拼接数据，用一个状态机确定现在数据读取到哪一部份，以及保存这个状态下已被读取的字节数，以此定位要读的数据位置，详见AFHTTPBodyPart的-read:maxLength:方法。
AFMultipartBodyStream封装了整个multipart数据的读取，主要是根据读取的位置确定现在要读哪一个AFHTTPBodyPart。AFStreamingMultipartFormData对外提供友好的append接口，并把构造好的AFMultipartBodyStream赋回给NSMutableURLRequest，关系大致如下图：
C.NSInputStream子类
NSURLRequest的setHTTPBodyStream接受的是一个NSInputStream*参数，那我们要自定义inputStream的话，创建一个NSInputStream的子类传给它是不是就可以了？实际上不行，这样做后用NSURLRequest发出请求会导致crash，提示[xx _scheduleInCFRunLoop:forMode:]: unrecognized selector。
这是因为NSURLRequest实际上接受的不是NSInputStream对象，而是CoreFoundation的CFReadStreamRef对象，因为CFReadStreamRef和NSInputStream是toll-free bridged，可以自由转换，但CFReadStreamRef会用到CFStreamScheduleWithRunLoop这个方法，当它调用到这个方法时，object-c的toll-free bridging机制会调用object-c对象NSInputStream的相应函数，这里就调用到了_scheduleInCFRunLoop:forMode:，若不实现这个方法就会crash。详见这篇文章。
3.源码注释
// AFSerialization.h
//
// Copyright (c) 2013-2014 AFNetworking (http://afnetworking.com)
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
#import "AFURLRequestSerialization.h"
//兼容Mac和iOS引入不同的库
#if __IPHONE_OS_VERSION_MIN_REQUIRED
#import <MobileCoreServices/MobileCoreServices.h>
#else
#import <CoreServices/CoreServices.h>
#endif
NSString * const AFURLRequestSerializationErrorDomain = @"com.alamofire.error.serialization.request";
NSString * const AFNetworkingOperationFailingURLRequestErrorKey = @"com.alamofire.serialization.request.error.response";
typedef NSString * (^AFQueryStringSerializationBlock)(NSURLRequest *request, NSDictionary *parameters, NSError *__autoreleasing *error);
//base64编码实现，用于Basic Auth
static NSString * AFBase64EncodedStringFromString(NSString *string) {
NSData *data = [NSData dataWithBytes:[string UTF8String] length:[string lengthOfBytesUsingEncoding:NSUTF8StringEncoding]];
NSUInteger length = [data length];
NSMutableData *mutableData = [NSMutableData dataWithLength:((length + 2) / 3) * 4];
uint8_t *input = (uint8_t *)[data bytes];
uint8_t *output = (uint8_t *)[mutableData mutableBytes];
for (NSUInteger i = 0; i < length; i += 3) {
NSUInteger value = 0;
for (NSUInteger j = i; j < (i + 3); j++) {
value <<= 8;
if (j < length) { value |= (0xFF & input[j]); } } static uint8_t const kAFBase64EncodingTable[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; NSUInteger idx = (i / 3) * 4; output[idx + 0] = kAFBase64EncodingTable[(value >> 18) & 0x3F];
output[idx + 1] = kAFBase64EncodingTable[(value >> 12) & 0x3F];
output[idx + 2] = (i + 1) < length ? kAFBase64EncodingTable[(value >> 6) & 0x3F] : '=';
output[idx + 3] = (i + 2) < length ? kAFBase64EncodingTable[(value >> 0) & 0x3F] : '=';
}
return [[NSString alloc] initWithData:mutableData encoding:NSASCIIStringEncoding];
}
//参数编码相关工具方法
static NSString * const kAFCharactersToBeEscapedInQueryString = @":/?&=;+!@#$()',*";
static NSString * AFPercentEscapedQueryStringKeyFromStringWithEncoding(NSString *string, NSStringEncoding encoding) {
static NSString * const kAFCharactersToLeaveUnescapedInQueryStringPairKey = @"[].";
return (__bridge_transfer NSString *)CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault, (__bridge CFStringRef)string, (__bridge CFStringRef)kAFCharactersToLeaveUnescapedInQueryStringPairKey, (__bridge CFStringRef)kAFCharactersToBeEscapedInQueryString, CFStringConvertNSStringEncodingToEncoding(encoding));
}
static NSString * AFPercentEscapedQueryStringValueFromStringWithEncoding(NSString *string, NSStringEncoding encoding) {
return (__bridge_transfer NSString *)CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault, (__bridge CFStringRef)string, NULL, (__bridge CFStringRef)kAFCharactersToBeEscapedInQueryString, CFStringConvertNSStringEncodingToEncoding(encoding));
}
#pragma mark -
//参数转化中间数据对象
@interface AFQueryStringPair : NSObject
@property (readwrite, nonatomic, strong) id field;
@property (readwrite, nonatomic, strong) id value;
- (id)initWithField:(id)field value:(id)value;
- (NSString *)URLEncodedStringValueWithEncoding:(NSStringEncoding)stringEncoding;
@end
@implementation AFQueryStringPair
- (id)initWithField:(id)field value:(id)value {
self = [super init];
if (!self) {
return nil;
}
self.field = field;
self.value = value;
return self;
}
- (NSString *)URLEncodedStringValueWithEncoding:(NSStringEncoding)stringEncoding {
if (!self.value || [self.value isEqual:[NSNull null]]) {
return AFPercentEscapedQueryStringKeyFromStringWithEncoding([self.field description], stringEncoding);
} else {
return [NSString stringWithFormat:@"%@=%@", AFPercentEscapedQueryStringKeyFromStringWithEncoding([self.field description], stringEncoding), AFPercentEscapedQueryStringValueFromStringWithEncoding([self.value description], stringEncoding)];
}
}
@end
#pragma mark -
//转化参数相关方法
extern NSArray * AFQueryStringPairsFromDictionary(NSDictionary *dictionary);
extern NSArray * AFQueryStringPairsFromKeyAndValue(NSString *key, id value);
static NSString * AFQueryStringFromParametersWithEncoding(NSDictionary *parameters, NSStringEncoding stringEncoding) {
NSMutableArray *mutablePairs = [NSMutableArray array];
for (AFQueryStringPair *pair in AFQueryStringPairsFromDictionary(parameters)) {
[mutablePairs addObject:[pair URLEncodedStringValueWithEncoding:stringEncoding]];
}
return [mutablePairs componentsJoinedByString:@"&"];
}
NSArray * AFQueryStringPairsFromDictionary(NSDictionary *dictionary) {
return AFQueryStringPairsFromKeyAndValue(nil, dictionary);
}
NSArray * AFQueryStringPairsFromKeyAndValue(NSString *key, id value) {
/*
转换效果：
@{
@"name" : @"bang",
@"phone": @{@"mobile": @"xx", @"home": @"xx"},
@"families": @[@"father", @"mother"],
@"nums": [NSSet setWithObjects:@"1", @"2", nil]
}
->
@[
field: @"name", value: @"bang",
field: @"phone[mobile]", value: @"xx",
field: @"phone[home]", value: @"xx",
field: @"families[]", value: @"father",
field: @"families[]", value: @"mother",
field: @"nums", value: @"1",
field: @"nums", value: @"2",
]
*/
NSMutableArray *mutableQueryStringComponents = [NSMutableArray array];
//用NSSortDescriptor排序
//http://nshipster.com/nssortdescriptor/
NSSortDescriptor *sortDescriptor = [NSSortDescriptor sortDescriptorWithKey:@"description" ascending:YES selector:@selector(compare:)];
if ([value isKindOfClass:[NSDictionary class]]) {
//对应上述例子的 @"phone": @{@"mobile": @"xx", @"home": @"xx"}
NSDictionary *dictionary = value;
// Sort dictionary keys to ensure consistent ordering in query string, which is important when deserializing potentially ambiguous sequences, such as an array of dictionaries
for (id nestedKey in [dictionary.allKeys sortedArrayUsingDescriptors:@[ sortDescriptor ]]) {
id nestedValue = [dictionary objectForKey:nestedKey];
if (nestedValue) {
[mutableQueryStringComponents addObjectsFromArray:AFQueryStringPairsFromKeyAndValue((key ? [NSString stringWithFormat:@"%@[%@]", key, nestedKey] : nestedKey), nestedValue)];
}
}
} else if ([value isKindOfClass:[NSArray class]]) {
//对应上述例子的 @"families": @[@"father", @"mother"]
NSArray *array = value;
for (id nestedValue in array) {
[mutableQueryStringComponents addObjectsFromArray:AFQueryStringPairsFromKeyAndValue([NSString stringWithFormat:@"%@[]", key], nestedValue)];
}
} else if ([value isKindOfClass:[NSSet class]]) {
//对应上述例子的 @"nums": [NSSet setWithObjects:@"1", @"2", nil]
NSSet *set = value;
for (id obj in [set sortedArrayUsingDescriptors:@[ sortDescriptor ]]) {
[mutableQueryStringComponents addObjectsFromArray:AFQueryStringPairsFromKeyAndValue(key, obj)];
}
} else {
//其他类型，对应上述例子@"name" : @"bang"
//key和value都可以不是NSString类型，转成字符串时会调用这个对象的description方法
[mutableQueryStringComponents addObject:[[AFQueryStringPair alloc] initWithField:key value:value]];
}
return mutableQueryStringComponents;
}
#pragma mark -
@interface AFStreamingMultipartFormData : NSObject
- (instancetype)initWithURLRequest:(NSMutableURLRequest *)urlRequest
stringEncoding:(NSStringEncoding)encoding;
- (NSMutableURLRequest *)requestByFinalizingMultipartFormData;
@end
#pragma mark -
@interface AFHTTPRequestSerializer ()
@property (readwrite, nonatomic, strong) NSMutableDictionary *mutableHTTPRequestHeaders;
@property (readwrite, nonatomic, assign) AFHTTPRequestQueryStringSerializationStyle queryStringSerializationStyle;
@property (readwrite, nonatomic, copy) AFQueryStringSerializationBlock queryStringSerialization;
@end
@implementation AFHTTPRequestSerializer
+ (instancetype)serializer {
return [[self alloc] init];
}
- (instancetype)init {
self = [super init];
if (!self) {
return nil;
}
self.stringEncoding = NSUTF8StringEncoding;
self.allowsCellularAccess = YES;
self.cachePolicy = NSURLRequestUseProtocolCachePolicy;
self.HTTPShouldHandleCookies = YES;
self.HTTPShouldUsePipelining = NO;
self.networkServiceType = NSURLNetworkServiceTypeDefault;
self.timeoutInterval = 60;
self.mutableHTTPRequestHeaders = [NSMutableDictionary dictionary];
// Accept-Language HTTP Header; see http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.4
NSMutableArray *acceptLanguagesComponents = [NSMutableArray array];
[[NSLocale preferredLanguages] enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
float q = 1.0f - (idx * 0.1f);
[acceptLanguagesComponents addObject:[NSString stringWithFormat:@"%@;q=%0.1g", obj, q]];
*stop = q <= 0.5f;
}];
[self setValue:[acceptLanguagesComponents componentsJoinedByString:@", "] forHTTPHeaderField:@"Accept-Language"];
//分别为iOS Mac构建userAgent
//iOS的构建结果是
//AFNetworking iOS ProjectName/1.0.0 (iPhone 4; iOS 7.0.3; Scale/2.00)
NSString *userAgent = nil;
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wgnu"
#if defined(__IPHONE_OS_VERSION_MIN_REQUIRED)
// User-Agent Header; see http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.43
userAgent = [NSString stringWithFormat:@"%@/%@ (%@; iOS %@; Scale/%0.2f)", [[[NSBundle mainBundle] infoDictionary] objectForKey:(__bridge NSString *)kCFBundleExecutableKey] ?: [[[NSBundle mainBundle] infoDictionary] objectForKey:(__bridge NSString *)kCFBundleIdentifierKey], (__bridge id)CFBundleGetValueForInfoDictionaryKey(CFBundleGetMainBundle(), kCFBundleVersionKey) ?: [[[NSBundle mainBundle] infoDictionary] objectForKey:(__bridge NSString *)kCFBundleVersionKey], [[UIDevice currentDevice] model], [[UIDevice currentDevice] systemVersion], [[UIScreen mainScreen] scale]];
#elif defined(__MAC_OS_X_VERSION_MIN_REQUIRED)
userAgent = [NSString stringWithFormat:@"%@/%@ (Mac OS X %@)", [[[NSBundle mainBundle] infoDictionary] objectForKey:(__bridge NSString *)kCFBundleExecutableKey] ?: [[[NSBundle mainBundle] infoDictionary] objectForKey:(__bridge NSString *)kCFBundleIdentifierKey], [[[NSBundle mainBundle] infoDictionary] objectForKey:@"CFBundleShortVersionString"] ?: [[[NSBundle mainBundle] infoDictionary] objectForKey:(__bridge NSString *)kCFBundleVersionKey], [[NSProcessInfo processInfo] operatingSystemVersionString]];
#endif
#pragma clang diagnostic pop
if (userAgent) {
if (![userAgent canBeConvertedToEncoding:NSASCIIStringEncoding]) {
NSMutableString *mutableUserAgent = [userAgent mutableCopy];
if (CFStringTransform((__bridge CFMutableStringRef)(mutableUserAgent), NULL, (__bridge CFStringRef)@"Any-Latin; Latin-ASCII; [:^ASCII:] Remove", false)) {
userAgent = mutableUserAgent;
}
}
[self setValue:userAgent forHTTPHeaderField:@"User-Agent"];
}
// HTTP Method Definitions; see http://www.w3.org/Protocols/rfc2616/rfc2616-sec9.html
//需要把参数写在URL上的HTTP方法
self.HTTPMethodsEncodingParametersInURI = [NSSet setWithObjects:@"GET", @"HEAD", @"DELETE", nil];
return self;
}
#pragma mark -
- (NSDictionary *)HTTPRequestHeaders {
return [NSDictionary dictionaryWithDictionary:self.mutableHTTPRequestHeaders];
}
- (void)setValue:(NSString *)value forHTTPHeaderField:(NSString *)field {
[self.mutableHTTPRequestHeaders setValue:value forKey:field];
}
- (void)setAuthorizationHeaderFieldWithUsername:(NSString *)username password:(NSString *)password {
//加basic认证HTTP头
NSString *basicAuthCredentials = [NSString stringWithFormat:@"%@:%@", username, password];
[self setValue:[NSString stringWithFormat:@"Basic %@", AFBase64EncodedStringFromString(basicAuthCredentials)] forHTTPHeaderField:@"Authorization"];
}
- (void)setAuthorizationHeaderFieldWithToken:(NSString *)token {
[self setValue:[NSString stringWithFormat:@"Token token=\"%@\"", token] forHTTPHeaderField:@"Authorization"];
}
- (void)clearAuthorizationHeader {
[self.mutableHTTPRequestHeaders removeObjectForKey:@"Authorization"];
}
#pragma mark -
- (void)setQueryStringSerializationWithStyle:(AFHTTPRequestQueryStringSerializationStyle)style {
self.queryStringSerializationStyle = style;
self.queryStringSerialization = nil;
}
- (void)setQueryStringSerializationWithBlock:(NSString *(^)(NSURLRequest *, NSDictionary *, NSError *__autoreleasing *))block {
//让用户可以通过block自己组装请求参数
self.queryStringSerialization = block;
}
#pragma mark -
- (NSMutableURLRequest *)requestWithMethod:(NSString *)method
URLString:(NSString *)URLString
parameters:(id)parameters
{
return [self requestWithMethod:method URLString:URLString parameters:parameters error:nil];
}
- (NSMutableURLRequest *)requestWithMethod:(NSString *)method
URLString:(NSString *)URLString
parameters:(id)parameters
error:(NSError *__autoreleasing *)error
{
NSParameterAssert(method);
NSParameterAssert(URLString);
NSURL *url = [NSURL URLWithString:URLString];
NSParameterAssert(url);
NSMutableURLRequest *mutableRequest = [[NSMutableURLRequest alloc] initWithURL:url];
mutableRequest.HTTPMethod = method;
mutableRequest.allowsCellularAccess = self.allowsCellularAccess;
mutableRequest.cachePolicy = self.cachePolicy;
mutableRequest.HTTPShouldHandleCookies = self.HTTPShouldHandleCookies;
mutableRequest.HTTPShouldUsePipelining = self.HTTPShouldUsePipelining;
mutableRequest.networkServiceType = self.networkServiceType;
mutableRequest.timeoutInterval = self.timeoutInterval;
mutableRequest = [[self requestBySerializingRequest:mutableRequest withParameters:parameters error:error] mutableCopy];
return mutableRequest;
}
- (NSMutableURLRequest *)multipartFormRequestWithMethod:(NSString *)method
URLString:(NSString *)URLString
parameters:(NSDictionary *)parameters
constructingBodyWithBlock:(void (^)(id formData))block
{
return [self multipartFormRequestWithMethod:method URLString:URLString parameters:parameters constructingBodyWithBlock:block error:nil];
}
- (NSMutableURLRequest *)multipartFormRequestWithMethod:(NSString *)method
URLString:(NSString *)URLString
parameters:(NSDictionary *)parameters
constructingBodyWithBlock:(void (^)(id formData))block
error:(NSError *__autoreleasing *)error
{
NSParameterAssert(method);
//GET和HEAD方法不能用multipart传数据，一般都是POST方法
NSParameterAssert(![method isEqualToString:@"GET"] && ![method isEqualToString:@"HEAD"]);
NSMutableURLRequest *mutableRequest = [self requestWithMethod:method URLString:URLString parameters:nil error:error];
__block AFStreamingMultipartFormData *formData = [[AFStreamingMultipartFormData alloc] initWithURLRequest:mutableRequest stringEncoding:NSUTF8StringEncoding];
if (parameters) {
//把请求参数也放到multipart里
for (AFQueryStringPair *pair in AFQueryStringPairsFromDictionary(parameters)) {
NSData *data = nil;
if ([pair.value isKindOfClass:[NSData class]]) {
data = pair.value;
} else if ([pair.value isEqual:[NSNull null]]) {
data = [NSData data];
} else {
data = [[pair.value description] dataUsingEncoding:self.stringEncoding];
}
if (data) {
[formData appendPartWithFormData:data name:[pair.field description]];
}
}
}
//执行对外暴露的block接口，用户在这里append文件等数据
if (block) {
block(formData);
}
return [formData requestByFinalizingMultipartFormData];
}
//额外提供的一个方法，把request里的bodyStream写到文件
//即可以把multipart发送的内容先生成好保存到文件
- (NSMutableURLRequest *)requestWithMultipartFormRequest:(NSURLRequest *)request
writingStreamContentsToFile:(NSURL *)fileURL
completionHandler:(void (^)(NSError *error))handler
{
if (!request.HTTPBodyStream) {
return [request mutableCopy];
}
NSParameterAssert([fileURL isFileURL]);
NSInputStream *inputStream = request.HTTPBodyStream;
NSOutputStream *outputStream = [[NSOutputStream alloc] initWithURL:fileURL append:NO];
__block NSError *error = nil;
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
//新开一条线程做这个事，stream的read和write是阻塞的
[inputStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
[outputStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
[inputStream open];
[outputStream open];
while ([inputStream hasBytesAvailable] && [outputStream hasSpaceAvailable]) {
uint8_t buffer[1024];
NSInteger bytesRead = [inputStream read:buffer maxLength:1024];
if (inputStream.streamError || bytesRead < 0) {
error = inputStream.streamError;
break;
}
NSInteger bytesWritten = [outputStream write:buffer maxLength:(NSUInteger)bytesRead];
if (if (outputStream.streamError || bytesWritten < 0) {
error = outputStream.streamError;
break;
}
if (bytesRead == 0 && bytesWritten == 0) {
break;
}
}
[outputStream close];
[inputStream close];
if (handler) {
dispatch_async(dispatch_get_main_queue(), ^{
handler(error);
});
}
});
NSMutableURLRequest *mutableRequest = [request mutableCopy];
mutableRequest.HTTPBodyStream = nil;
return mutableRequest;
}
#pragma mark - AFURLRequestSerialization
- (NSURLRequest *)requestBySerializingRequest:(NSURLRequest *)request
withParameters:(id)parameters
error:(NSError *__autoreleasing *)error
{
NSParameterAssert(request);
NSMutableURLRequest *mutableRequest = [request mutableCopy];
[self.HTTPRequestHeaders enumerateKeysAndObjectsUsingBlock:^(id field, id value, BOOL * __unused stop) {
//设好HTTP header，不覆盖原有的header
if (![request valueForHTTPHeaderField:field]) {
[mutableRequest setValue:value forHTTPHeaderField:field];
}
}];
if (parameters) {
NSString *query = nil;
if (self.queryStringSerialization) {
//用传进来的自定义block格式化请求参数
query = self.queryStringSerialization(request, parameters, error);
} else {
switch (self.queryStringSerializationStyle) {
case AFHTTPRequestQueryStringDefaultStyle:
//默认的格式化方式
query = AFQueryStringFromParametersWithEncoding(parameters, self.stringEncoding);
break;
}
}
if ([self.HTTPMethodsEncodingParametersInURI containsObject:[[request HTTPMethod] uppercaseString]]) {
//参数加在URL上的HTTP方法，包括GET HEAD DELETE
mutableRequest.URL = [NSURL URLWithString:[[mutableRequest.URL absoluteString] stringByAppendingFormat:mutableRequest.URL.query ? @"&%@" : @"?%@", query]];
} else {
//参数带在body上，大多是POST PUT
if (![mutableRequest valueForHTTPHeaderField:@"Content-Type"]) {
//设置Content-Type HTTP头，告诉服务端body的参数编码类型
NSString *charset = (__bridge NSString *)CFStringConvertEncodingToIANACharSetName(CFStringConvertNSStringEncodingToEncoding(self.stringEncoding));
[mutableRequest setValue:[NSString stringWithFormat:@"application/x-www-form-urlencoded; charset=%@", charset] forHTTPHeaderField:@"Content-Type"];
}
[mutableRequest setHTTPBody:[query dataUsingEncoding:self.stringEncoding]];
}
}
return mutableRequest;
}
#pragma mark - NSecureCoding
+ (BOOL)supportsSecureCoding {
return YES;
}
- (id)initWithCoder:(NSCoder *)decoder {
self = [self init];
if (!self) {
return nil;
}
self.mutableHTTPRequestHeaders = [[decoder decodeObjectOfClass:[NSDictionary class] forKey:NSStringFromSelector(@selector(mutableHTTPRequestHeaders))] mutableCopy];
self.queryStringSerializationStyle = [[decoder decodeObjectOfClass:[NSNumber class] forKey:NSStringFromSelector(@selector(queryStringSerializationStyle))] unsignedIntegerValue];
return self;
}
- (void)encodeWithCoder:(NSCoder *)coder {
[coder encodeObject:self.mutableHTTPRequestHeaders forKey:NSStringFromSelector(@selector(mutableHTTPRequestHeaders))];
[coder encodeInteger:self.queryStringSerializationStyle forKey:NSStringFromSelector(@selector(queryStringSerializationStyle))];
}
#pragma mark - NSCopying
- (id)copyWithZone:(NSZone *)zone {
AFHTTPRequestSerializer *serializer = [[[self class] allocWithZone:zone] init];
serializer.mutableHTTPRequestHeaders = [self.mutableHTTPRequestHeaders mutableCopyWithZone:zone];
serializer.queryStringSerializationStyle = self.queryStringSerializationStyle;
serializer.queryStringSerialization = self.queryStringSerialization;
return serializer;
}
@end
#pragma mark -
/************* Multipart相关 ************/
static NSString * AFCreateMultipartFormBoundary() {
//生成分隔符
return [NSString stringWithFormat:@"Boundary+%08X%08X", arc4random(), arc4random()];
}
static NSString * const kAFMultipartFormCRLF = @"\r\n";
static inline NSString * AFMultipartFormInitialBoundary(NSString *boundary) {
//第一部分数据的分隔符
return [NSString stringWithFormat:@"--%@%@", boundary, kAFMultipartFormCRLF];
}
static inline NSString * AFMultipartFormEncapsulationBoundary(NSString *boundary) {
//中间部分数据的分隔符，前面要换行
return [NSString stringWithFormat:@"%@--%@%@", kAFMultipartFormCRLF, boundary, kAFMultipartFormCRLF];
}
static inline NSString * AFMultipartFormFinalBoundary(NSString *boundary) {
//最后一个分隔符，加--表示结束
return [NSString stringWithFormat:@"%@--%@--%@", kAFMultipartFormCRLF, boundary, kAFMultipartFormCRLF];
}
static inline NSString * AFContentTypeForPathExtension(NSString *extension) {
//通过系统CoreService库的方法根据文件后缀拿到mime类型
#ifdef __UTTYPE__
NSString *UTI = (__bridge_transfer NSString *)UTTypeCreatePreferredIdentifierForTag(kUTTagClassFilenameExtension, (__bridge CFStringRef)extension, NULL);
NSString *contentType = (__bridge_transfer NSString *)UTTypeCopyPreferredTagWithClass((__bridge CFStringRef)UTI, kUTTagClassMIMEType);
if (!contentType) {
return @"application/octet-stream";
} else {
return contentType;
}
#else
#pragma unused (extension)
return @"application/octet-stream";
#endif
}
//multipart上传时，3G网络建议的每个包的大小和读取延时
NSUInteger const kAFUploadStream3GSuggestedPacketSize = 1024 * 16;
NSTimeInterval const kAFUploadStream3GSuggestedDelay = 0.2;
@interface AFHTTPBodyPart : NSObject
@property (nonatomic, assign) NSStringEncoding stringEncoding;
@property (nonatomic, strong) NSDictionary *headers;
@property (nonatomic, copy) NSString *boundary;
@property (nonatomic, strong) id body;
@property (nonatomic, assign) unsigned long long bodyContentLength;
@property (nonatomic, strong) NSInputStream *inputStream;
@property (nonatomic, assign) BOOL hasInitialBoundary;
@property (nonatomic, assign) BOOL hasFinalBoundary;
@property (readonly, nonatomic, assign, getter = hasBytesAvailable) BOOL bytesAvailable;
@property (readonly, nonatomic, assign) unsigned long long contentLength;
- (NSInteger)read:(uint8_t *)buffer
maxLength:(NSUInteger)length;
@end
@interface AFMultipartBodyStream : NSInputStream <NSStreamDelegate>
@property (nonatomic, assign) NSUInteger numberOfBytesInPacket;
@property (nonatomic, assign) NSTimeInterval delay;
@property (nonatomic, strong) NSInputStream *inputStream;
@property (readonly, nonatomic, assign) unsigned long long contentLength;
@property (readonly, nonatomic, assign, getter = isEmpty) BOOL empty;
- (id)initWithStringEncoding:(NSStringEncoding)encoding;
- (void)setInitialAndFinalBoundaries;
- (void)appendHTTPBodyPart:(AFHTTPBodyPart *)bodyPart;
@end
#pragma mark -
//桥梁，对外提供接口，组装bodyStream给NSMutableURLRequest
@interface AFStreamingMultipartFormData ()
@property (readwrite, nonatomic, copy) NSMutableURLRequest *request;
@property (readwrite, nonatomic, assign) NSStringEncoding stringEncoding;
@property (readwrite, nonatomic, copy) NSString *boundary;
@property (readwrite, nonatomic, strong) AFMultipartBodyStream *bodyStream;
@end
@implementation AFStreamingMultipartFormData
- (id)initWithURLRequest:(NSMutableURLRequest *)urlRequest
stringEncoding:(NSStringEncoding)encoding
{
self = [super init];
if (!self) {
return nil;
}
self.request = urlRequest;
self.stringEncoding = encoding;
self.boundary = AFCreateMultipartFormBoundary();
self.bodyStream = [[AFMultipartBodyStream alloc] initWithStringEncoding:encoding];
return self;
}
- (BOOL)appendPartWithFileURL:(NSURL *)fileURL
name:(NSString *)name
error:(NSError * __autoreleasing *)error
{
NSParameterAssert(fileURL);
NSParameterAssert(name);
//便捷接口，自动判断mimetype
NSString *fileName = [fileURL lastPathComponent];
NSString *mimeType = AFContentTypeForPathExtension([fileURL pathExtension]);
return [self appendPartWithFileURL:fileURL name:name fileName:fileName mimeType:mimeType error:error];
}
- (BOOL)appendPartWithFileURL:(NSURL *)fileURL
name:(NSString *)name
fileName:(NSString *)fileName
mimeType:(NSString *)mimeType
error:(NSError * __autoreleasing *)error
{
NSParameterAssert(fileURL);
NSParameterAssert(name);
NSParameterAssert(fileName);
NSParameterAssert(mimeType);
//确保是能读到的文件路径
if (![fileURL isFileURL]) {
NSDictionary *userInfo = @{NSLocalizedFailureReasonErrorKey: NSLocalizedStringFromTable(@"Expected URL to be a file URL", @"AFNetworking", nil)};
if (error) {
*error = [[NSError alloc] initWithDomain:AFURLRequestSerializationErrorDomain code:NSURLErrorBadURL userInfo:userInfo];
}
return NO;
} else if ([fileURL checkResourceIsReachableAndReturnError:error] == NO) {
NSDictionary *userInfo = @{NSLocalizedFailureReasonErrorKey: NSLocalizedStringFromTable(@"File URL not reachable.", @"AFNetworking", nil)};
if (error) {
*error = [[NSError alloc] initWithDomain:AFURLRequestSerializationErrorDomain code:NSURLErrorBadURL userInfo:userInfo];
}
return NO;
}
NSDictionary *fileAttributes = [[NSFileManager defaultManager] attributesOfItemAtPath:[fileURL path] error:error];
if (!fileAttributes) {
//文件属性拿不到就不知道文件大小，不给添加
return NO;
}
NSMutableDictionary *mutableHeaders = [NSMutableDictionary dictionary];
[mutableHeaders setValue:[NSString stringWithFormat:@"form-data; name=\"%@\"; filename=\"%@\"", name, fileName] forKey:@"Content-Disposition"];
[mutableHeaders setValue:mimeType forKey:@"Content-Type"];
AFHTTPBodyPart *bodyPart = [[AFHTTPBodyPart alloc] init];
bodyPart.stringEncoding = self.stringEncoding;
bodyPart.headers = mutableHeaders;
bodyPart.boundary = self.boundary;
//AFHTTPBodyPart会根据body的isKindOfClass:判断数据类型
bodyPart.body = fileURL;
bodyPart.bodyContentLength = [[fileAttributes objectForKey:NSFileSize] unsignedLongLongValue];
[self.bodyStream appendHTTPBodyPart:bodyPart];
return YES;
}
- (void)appendPartWithInputStream:(NSInputStream *)inputStream
name:(NSString *)name
fileName:(NSString *)fileName
length:(int64_t)length
mimeType:(NSString *)mimeType
{
NSParameterAssert(name);
NSParameterAssert(fileName);
NSParameterAssert(mimeType);
NSMutableDictionary *mutableHeaders = [NSMutableDictionary dictionary];
[mutableHeaders setValue:[NSString stringWithFormat:@"form-data; name=\"%@\"; filename=\"%@\"", name, fileName] forKey:@"Content-Disposition"];
[mutableHeaders setValue:mimeType forKey:@"Content-Type"];
AFHTTPBodyPart *bodyPart = [[AFHTTPBodyPart alloc] init];
bodyPart.stringEncoding = self.stringEncoding;
bodyPart.headers = mutableHeaders;
bodyPart.boundary = self.boundary;
bodyPart.body = inputStream;
bodyPart.bodyContentLength = (unsigned long long)length;
[self.bodyStream appendHTTPBodyPart:bodyPart];
}
- (void)appendPartWithFileData:(NSData *)data
name:(NSString *)name
fileName:(NSString *)fileName
mimeType:(NSString *)mimeType
{
NSParameterAssert(name);
NSParameterAssert(fileName);
NSParameterAssert(mimeType);
NSMutableDictionary *mutableHeaders = [NSMutableDictionary dictionary];
[mutableHeaders setValue:[NSString stringWithFormat:@"form-data; name=\"%@\"; filename=\"%@\"", name, fileName] forKey:@"Content-Disposition"];
[mutableHeaders setValue:mimeType forKey:@"Content-Type"];
[self appendPartWithHeaders:mutableHeaders body:data];
}
- (void)appendPartWithFormData:(NSData *)data
name:(NSString *)name
{
NSParameterAssert(name);
NSMutableDictionary *mutableHeaders = [NSMutableDictionary dictionary];
[mutableHeaders setValue:[NSString stringWithFormat:@"form-data; name=\"%@\"", name] forKey:@"Content-Disposition"];
[self appendPartWithHeaders:mutableHeaders body:data];
}
- (void)appendPartWithHeaders:(NSDictionary *)headers
body:(NSData *)body
{
NSParameterAssert(body);
AFHTTPBodyPart *bodyPart = [[AFHTTPBodyPart alloc] init];
bodyPart.stringEncoding = self.stringEncoding;
bodyPart.headers = headers;
bodyPart.boundary = self.boundary;
bodyPart.bodyContentLength = [body length];
bodyPart.body = body;
[self.bodyStream appendHTTPBodyPart:bodyPart];
}
- (void)throttleBandwidthWithPacketSize:(NSUInteger)numberOfBytes
delay:(NSTimeInterval)delay
{
self.bodyStream.numberOfBytesInPacket = numberOfBytes;
self.bodyStream.delay = delay;
}
- (NSMutableURLRequest *)requestByFinalizingMultipartFormData {
//bodyStream构造完成，数据都准备好了，把它赋给request
if ([self.bodyStream isEmpty]) {
return self.request;
}
// Reset the initial and final boundaries to ensure correct Content-Length
//下面会调用[self.bodyStream contentLength]，这里需要先设好每个bodyPart的位置类型，才能正确算出整个bodyStream的长度
[self.bodyStream setInitialAndFinalBoundaries];
[self.request setHTTPBodyStream:self.bodyStream];
[self.request setValue:[NSString stringWithFormat:@"multipart/form-data; boundary=%@", self.boundary] forHTTPHeaderField:@"Content-Type"];
[self.request setValue:[NSString stringWithFormat:@"%llu", [self.bodyStream contentLength]] forHTTPHeaderField:@"Content-Length"];
return self.request;
}
@end
#pragma mark -
@interface NSStream ()
@property (readwrite) NSStreamStatus streamStatus;
@property (readwrite, copy) NSError *streamError;
@end
@interface AFMultipartBodyStream () <NSCopying>
@property (readwrite, nonatomic, assign) NSStringEncoding stringEncoding;
@property (readwrite, nonatomic, strong) NSMutableArray *HTTPBodyParts;
@property (readwrite, nonatomic, strong) NSEnumerator *HTTPBodyPartEnumerator;
@property (readwrite, nonatomic, strong) AFHTTPBodyPart *currentHTTPBodyPart;
@property (readwrite, nonatomic, strong) NSOutputStream *outputStream;
@property (readwrite, nonatomic, strong) NSMutableData *buffer;
@end
@implementation AFMultipartBodyStream
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wimplicit-atomic-properties"
@synthesize streamStatus;
@synthesize streamError;
#pragma clang diagnostic pop
- (id)initWithStringEncoding:(NSStringEncoding)encoding {
self = [super init];
if (!self) {
return nil;
}
self.stringEncoding = encoding;
self.HTTPBodyParts = [NSMutableArray array];
self.numberOfBytesInPacket = NSIntegerMax;
return self;
}
- (void)setInitialAndFinalBoundaries {
if ([self.HTTPBodyParts count] > 0) {
for (AFHTTPBodyPart *bodyPart in self.HTTPBodyParts) {
bodyPart.hasInitialBoundary = NO;
bodyPart.hasFinalBoundary = NO;
}
//标识第一个和最后一个bodyPart，因为需要添加的分隔符不一样
[[self.HTTPBodyParts objectAtIndex:0] setHasInitialBoundary:YES];
[[self.HTTPBodyParts lastObject] setHasFinalBoundary:YES];
}
}
- (void)appendHTTPBodyPart:(AFHTTPBodyPart *)bodyPart {
[self.HTTPBodyParts addObject:bodyPart];
}
- (BOOL)isEmpty {
return [self.HTTPBodyParts count] == 0;
}
#pragma mark - NSInputStream
- (NSInteger)read:(uint8_t *)buffer
maxLength:(NSUInteger)length
{
if ([self streamStatus] == NSStreamStatusClosed) {
return 0;
}
NSInteger totalNumberOfBytesRead = 0;
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wgnu"
//一次读取的数据不超过系统指定的maxLength和用户指定的numberOfBytesInPacket中的最小值
//self.numberOfBytesInPacket用于3G网络请求优化，指定每次读取的数据包大小，有个建议值kAFUploadStream3GSuggestedPacketSize
while ((NSUInteger)totalNumberOfBytesRead < MIN(length, self.numberOfBytesInPacket)) {
//通过self.currentHTTPBodyPart和各个AFHTTPBodyPart里的游标决定读取数据的位置
if (!self.currentHTTPBodyPart || ![self.currentHTTPBodyPart hasBytesAvailable]) {
//self.currentHTTPBodyPart已读完，看看还有没有下一个
if (!(self.currentHTTPBodyPart = [self.HTTPBodyPartEnumerator nextObject])) {
//没有的话数据读取结束
//问题：NSURLRequest怎么知道数据读完了？
//应该是这个函数返回0时外部就知道stream已经读完，调用它的close方法。
//上面的-requestWithMultipartFormRequest:writingStreamContentsToFile:completionHandler:就是这样用的
break;
}
} else {
//这里maxLength是进入AFHTTPBodyPart读取的maxLength
//这里应该有bug，应该是
//NSUInteger maxLength = MIN(length, self.numberOfBytesInPacket) - (NSUInteger)totalNumberOfBytesRead
NSUInteger maxLength = length - (NSUInteger)totalNumberOfBytesRead;
//从bodyPart里读数据到buffer
NSInteger numberOfBytesRead = [self.currentHTTPBodyPart read:&buffer[totalNumberOfBytesRead] maxLength:maxLength];
if (numberOfBytesRead == -1) {
self.streamError = self.currentHTTPBodyPart.inputStream.streamError;
break;
} else {
totalNumberOfBytesRead += numberOfBytesRead;
//self.delay用于3G网络请求优化，读取数据时延时，有个建议值kAFUploadStream3GSuggestedDelay
if (self.delay > 0.0f) {
[NSThread sleepForTimeInterval:self.delay];
}
}
}
}
#pragma clang diagnostic pop
return totalNumberOfBytesRead;
}
- (BOOL)getBuffer:(__unused uint8_t **)buffer
length:(__unused NSUInteger *)len
{
return NO;
}
- (BOOL)hasBytesAvailable {
//这里估计是难以准确判断数据是否读完，简单做成只要是open状态就是有数据
//外面通过-read:maxLength读不到数据再close stream
return [self streamStatus] == NSStreamStatusOpen;
}
#pragma mark - NSStream
- (void)open {
if (self.streamStatus == NSStreamStatusOpen) {
return;
}
self.streamStatus = NSStreamStatusOpen;
[self setInitialAndFinalBoundaries];
self.HTTPBodyPartEnumerator = [self.HTTPBodyParts objectEnumerator];
}
- (void)close {
self.streamStatus = NSStreamStatusClosed;
}
- (id)propertyForKey:(__unused NSString *)key {
return nil;
}
- (BOOL)setProperty:(__unused id)property
forKey:(__unused NSString *)key
{
return NO;
}
//scheduleInRunLoop是为了delegate可以接收到stream状态改变的回调，估计是NSURLRequest没有用到delegate处理状态改变，这里简单置空了
- (void)scheduleInRunLoop:(__unused NSRunLoop *)aRunLoop
forMode:(__unused NSString *)mode
{}
- (void)removeFromRunLoop:(__unused NSRunLoop *)aRunLoop
forMode:(__unused NSString *)mode
{}
- (unsigned long long)contentLength {
unsigned long long length = 0;
//bodyStream的文件长度等于所有bodyPart长度相加
//[bodyPart contentLength]已包含分隔符等数据的长度
for (AFHTTPBodyPart *bodyPart in self.HTTPBodyParts) {
length += [bodyPart contentLength];
}
return length;
}
#pragma mark - Undocumented CFReadStream Bridged Methods
//NSURLRequest会调下面这三个方法，不定义会crash "unrecognized selector"
//http://blog.octiplex.com/2011/06/how-to-implement-a-corefoundation-toll-free-bridged-nsinputstream-subclass/
- (void)_scheduleInCFRunLoop:(__unused CFRunLoopRef)aRunLoop
forMode:(__unused CFStringRef)aMode
{}
- (void)_unscheduleFromCFRunLoop:(__unused CFRunLoopRef)aRunLoop
forMode:(__unused CFStringRef)aMode
{}
- (BOOL)_setCFClientFlags:(__unused CFOptionFlags)inFlags
callback:(__unused CFReadStreamClientCallBack)inCallback
context:(__unused CFStreamClientContext *)inContext {
return NO;
}
#pragma mark - NSCopying
-(id)copyWithZone:(NSZone *)zone {
AFMultipartBodyStream *bodyStreamCopy = [[[self class] allocWithZone:zone] initWithStringEncoding:self.stringEncoding];
for (AFHTTPBodyPart *bodyPart in self.HTTPBodyParts) {
[bodyStreamCopy appendHTTPBodyPart:[bodyPart copy]];
}
[bodyStreamCopy setInitialAndFinalBoundaries];
return bodyStreamCopy;
}
@end
#pragma mark -
typedef enum {
AFEncapsulationBoundaryPhase = 1,
AFHeaderPhase = 2,
AFBodyPhase = 3,
AFFinalBoundaryPhase = 4,
} AFHTTPBodyPartReadPhase;
@interface AFHTTPBodyPart () {
AFHTTPBodyPartReadPhase _phase;
NSInputStream *_inputStream;
unsigned long long _phaseReadOffset;
}
- (BOOL)transitionToNextPhase;
- (NSInteger)readData:(NSData *)data
intoBuffer:(uint8_t *)buffer
maxLength:(NSUInteger)length;
@end
@implementation AFHTTPBodyPart
- (id)init {
self = [super init];
if (!self) {
return nil;
}
//进入AFEncapsulationBoundaryPhase状态
[self transitionToNextPhase];
return self;
}
- (void)dealloc {
if (_inputStream) {
[_inputStream close];
_inputStream = nil;
}
}
- (NSInputStream *)inputStream {
//数据源NSData/FileURL/NSInputStream都统一成NSInputStream
if (!_inputStream) {
if ([self.body isKindOfClass:[NSData class]]) {
_inputStream = [NSInputStream inputStreamWithData:self.body];
} else if ([self.body isKindOfClass:[NSURL class]]) {
_inputStream = [NSInputStream inputStreamWithURL:self.body];
} else if ([self.body isKindOfClass:[NSInputStream class]]) {
_inputStream = self.body;
}
}
return _inputStream;
}
- (NSString *)stringForHeaders {
//组装这一部分数据的头部
NSMutableString *headerString = [NSMutableString string];
for (NSString *field in [self.headers allKeys]) {
[headerString appendString:[NSString stringWithFormat:@"%@: %@%@", field, [self.headers valueForKey:field], kAFMultipartFormCRLF]];
}
[headerString appendString:kAFMultipartFormCRLF];
return [NSString stringWithString:headerString];
}
- (unsigned long long)contentLength {
unsigned long long length = 0;
//若是第一个part，加上开头分隔符（区别是前面没有换行），否则加上中间部分分隔符
NSData *encapsulationBoundaryData = [([self hasInitialBoundary] ? AFMultipartFormInitialBoundary(self.boundary) : AFMultipartFormEncapsulationBoundary(self.boundary)) dataUsingEncoding:self.stringEncoding];
length += [encapsulationBoundaryData length];
//算上这部分header数据的长度
NSData *headersData = [[self stringForHeaders] dataUsingEncoding:self.stringEncoding];
length += [headersData length];
//在构造AFHTTPBodyPart的时候已经算好_bodyContentLength
length += _bodyContentLength;
//若是最后一个part，要加上结尾分隔符
NSData *closingBoundaryData = ([self hasFinalBoundary] ? [AFMultipartFormFinalBoundary(self.boundary) dataUsingEncoding:self.stringEncoding] : [NSData data]);
length += [closingBoundaryData length];
return length;
}
- (BOOL)hasBytesAvailable {
// Allows `read:maxLength:` to be called again if `AFMultipartFormFinalBoundary` doesn't fit into the available buffer
if (_phase == AFFinalBoundaryPhase) {
return YES;
}
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wcovered-switch-default"
switch (self.inputStream.streamStatus) {
case NSStreamStatusNotOpen:
case NSStreamStatusOpening:
case NSStreamStatusOpen:
case NSStreamStatusReading:
case NSStreamStatusWriting:
return YES;
case NSStreamStatusAtEnd:
case NSStreamStatusClosed:
case NSStreamStatusError:
default:
return NO;
}
#pragma clang diagnostic pop
}
- (NSInteger)read:(uint8_t *)buffer
maxLength:(NSUInteger)length
{
//因为有可能跨几个阶段读取数据，需要一个变量记录总共被读取的数据长度
NSInteger totalNumberOfBytesRead = 0;
if (_phase == AFEncapsulationBoundaryPhase) {
//读取分隔符
NSData *encapsulationBoundaryData = [([self hasInitialBoundary] ? AFMultipartFormInitialBoundary(self.boundary) : AFMultipartFormEncapsulationBoundary(self.boundary)) dataUsingEncoding:self.stringEncoding];
totalNumberOfBytesRead += [self readData:encapsulationBoundaryData intoBuffer:&buffer[totalNumberOfBytesRead] maxLength:(length - (NSUInteger)totalNumberOfBytesRead)];
}
if (_phase == AFHeaderPhase) {
//读取header
NSData *headersData = [[self stringForHeaders] dataUsingEncoding:self.stringEncoding];
totalNumberOfBytesRead += [self readData:headersData intoBuffer:&buffer[totalNumberOfBytesRead] maxLength:(length - (NSUInteger)totalNumberOfBytesRead)];
}
if (_phase == AFBodyPhase) {
//读取body
NSInteger numberOfBytesRead = 0;
numberOfBytesRead = [self.inputStream read:&buffer[totalNumberOfBytesRead] maxLength:(length - (NSUInteger)totalNumberOfBytesRead)];
if (numberOfBytesRead == -1) {
return -1;
} else {
totalNumberOfBytesRead += numberOfBytesRead;
if ([self.inputStream streamStatus] >= NSStreamStatusAtEnd) {
[self transitionToNextPhase];
}
}
}
if (_phase == AFFinalBoundaryPhase) {
//若是最后一个部分，读取最后的分隔符
NSData *closingBoundaryData = ([self hasFinalBoundary] ? [AFMultipartFormFinalBoundary(self.boundary) dataUsingEncoding:self.stringEncoding] : [NSData data]);
totalNumberOfBytesRead += [self readData:closingBoundaryData intoBuffer:&buffer[totalNumberOfBytesRead] maxLength:(length - (NSUInteger)totalNumberOfBytesRead)];
}
return totalNumberOfBytesRead;
}
- (NSInteger)readData:(NSData *)data
intoBuffer:(uint8_t *)buffer
maxLength:(NSUInteger)length
{
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wgnu"
//根据阶段和当前阶段已读取的字节数_phaseReadOffset，得到要读的数据范围，写入buffer
NSRange range = NSMakeRange((NSUInteger)_phaseReadOffset, MIN([data length] - ((NSUInteger)_phaseReadOffset), length));
[data getBytes:buffer range:range];
#pragma clang diagnostic pop
//记录当前阶段已被读取的字节数
_phaseReadOffset += range.length;
if (((NSUInteger)_phaseReadOffset) >= [data length]) {
//当前阶段的数据读完了，进入下一阶段
[self transitionToNextPhase];
}
return (NSInteger)range.length;
}
- (BOOL)transitionToNextPhase {
if (![[NSThread currentThread] isMainThread]) {
[self performSelectorOnMainThread:@selector(transitionToNextPhase) withObject:nil waitUntilDone:YES];
return YES;
}
//状态机，切换到下一个阶段
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wcovered-switch-default"
switch (_phase) {
case AFEncapsulationBoundaryPhase:
//进入读取Header阶段
_phase = AFHeaderPhase;
break;
case AFHeaderPhase:
//进入读取body阶段，内容源inputStream要打开了
[self.inputStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSRunLoopCommonModes];
[self.inputStream open];
_phase = AFBodyPhase;
break;
case AFBodyPhase:
//读取结尾阶段，只有最后一个part有结尾
[self.inputStream close];
_phase = AFFinalBoundaryPhase;
break;
case AFFinalBoundaryPhase:
default:
//第一次进来时走这里，_phase的初始化在这里……，解析读取分隔符阶段
_phase = AFEncapsulationBoundaryPhase;
break;
}
//_phaseReadOffset记录当前状态已被读取的字节数，进入下一个阶段要清零
_phaseReadOffset = 0;
#pragma clang diagnostic pop
return YES;
}
#pragma mark - NSCopying
- (id)copyWithZone:(NSZone *)zone {
AFHTTPBodyPart *bodyPart = [[[self class] allocWithZone:zone] init];
bodyPart.stringEncoding = self.stringEncoding;
bodyPart.headers = self.headers;
bodyPart.bodyContentLength = self.bodyContentLength;
bodyPart.body = self.body;
bodyPart.boundary = self.boundary;
return bodyPart;
}
@end
#pragma mark -
@implementation AFJSONRequestSerializer
+ (instancetype)serializer {
return [self serializerWithWritingOptions:0];
}
+ (instancetype)serializerWithWritingOptions:(NSJSONWritingOptions)writingOptions
{
AFJSONRequestSerializer *serializer = [[self alloc] init];
serializer.writingOptions = writingOptions;
return serializer;
}
#pragma mark - AFURLRequestSerialization
- (NSURLRequest *)requestBySerializingRequest:(NSURLRequest *)request
withParameters:(id)parameters
error:(NSError *__autoreleasing *)error
{
NSParameterAssert(request);
//参数带在URL的请求方法不处理，json只能放在body里
if ([self.HTTPMethodsEncodingParametersInURI containsObject:[[request HTTPMethod] uppercaseString]]) {
return [super requestBySerializingRequest:request withParameters:parameters error:error];
}
NSMutableURLRequest *mutableRequest = [request mutableCopy];
[self.HTTPRequestHeaders enumerateKeysAndObjectsUsingBlock:^(id field, id value, BOOL * __unused stop) {
if (![request valueForHTTPHeaderField:field]) {
[mutableRequest setValue:value forHTTPHeaderField:field];
}
}];
if (parameters) {
if (![mutableRequest valueForHTTPHeaderField:@"Content-Type"]) {
NSString *charset = (__bridge NSString *)CFStringConvertEncodingToIANACharSetName(CFStringConvertNSStringEncodingToEncoding(NSUTF8StringEncoding));
[mutableRequest setValue:[NSString stringWithFormat:@"application/json; charset=%@", charset] forHTTPHeaderField:@"Content-Type"];
}
[mutableRequest setHTTPBody:[NSJSONSerialization dataWithJSONObject:parameters options:self.writingOptions error:error]];
}
return mutableRequest;
}
#pragma mark - NSecureCoding
- (id)initWithCoder:(NSCoder *)decoder {
self = [super initWithCoder:decoder];
if (!self) {
return nil;
}
self.writingOptions = [[decoder decodeObjectOfClass:[NSNumber class] forKey:NSStringFromSelector(@selector(writingOptions))] unsignedIntegerValue];
return self;
}
- (void)encodeWithCoder:(NSCoder *)coder {
[super encodeWithCoder:coder];
[coder encodeInteger:self.writingOptions forKey:NSStringFromSelector(@selector(writingOptions))];
}
#pragma mark - NSCopying
- (id)copyWithZone:(NSZone *)zone {
AFJSONRequestSerializer *serializer = [super copyWithZone:zone];
serializer.writingOptions = self.writingOptions;
return serializer;
}
@end
#pragma mark -
@implementation AFPropertyListRequestSerializer
+ (instancetype)serializer {
return [self serializerWithFormat:NSPropertyListXMLFormat_v1_0 writeOptions:0];
}
+ (instancetype)serializerWithFormat:(NSPropertyListFormat)format
writeOptions:(NSPropertyListWriteOptions)writeOptions
{
AFPropertyListRequestSerializer *serializer = [[self alloc] init];
serializer.format = format;
serializer.writeOptions = writeOptions;
return serializer;
}
#pragma mark - AFURLRequestSerializer
- (NSURLRequest *)requestBySerializingRequest:(NSURLRequest *)request
withParameters:(id)parameters
error:(NSError *__autoreleasing *)error
{
NSParameterAssert(request);
if ([self.HTTPMethodsEncodingParametersInURI containsObject:[[request HTTPMethod] uppercaseString]]) {
return [super requestBySerializingRequest:request withParameters:parameters error:error];
}
NSMutableURLRequest *mutableRequest = [request mutableCopy];
[self.HTTPRequestHeaders enumerateKeysAndObjectsUsingBlock:^(id field, id value, BOOL * __unused stop) {
if (![request valueForHTTPHeaderField:field]) {
[mutableRequest setValue:value forHTTPHeaderField:field];
}
}];
if (parameters) {
if (![mutableRequest valueForHTTPHeaderField:@"Content-Type"]) {
NSString *charset = (__bridge NSString *)CFStringConvertEncodingToIANACharSetName(CFStringConvertNSStringEncodingToEncoding(NSUTF8StringEncoding));
[mutableRequest setValue:[NSString stringWithFormat:@"application/x-plist; charset=%@", charset] forHTTPHeaderField:@"Content-Type"];
}
[mutableRequest setHTTPBody:[NSPropertyListSerialization dataWithPropertyList:parameters format:self.format options:self.writeOptions error:error]];
}
return mutableRequest;
}
#pragma mark - NSecureCoding
- (id)initWithCoder:(NSCoder *)decoder {
self = [super initWithCoder:decoder];
if (!self) {
return nil;
}
self.format = [[decoder decodeObjectOfClass:[NSNumber class] forKey:NSStringFromSelector(@selector(format))] unsignedIntegerValue];
self.writeOptions = [[decoder decodeObjectOfClass:[NSNumber class] forKey:NSStringFromSelector(@selector(writeOptions))] unsignedIntegerValue];
return self;
}
- (void)encodeWithCoder:(NSCoder *)coder {
[super encodeWithCoder:coder];
[coder encodeInteger:self.format forKey:NSStringFromSelector(@selector(format))];
[coder encodeObject:@(self.writeOptions) forKey:NSStringFromSelector(@selector(writeOptions))];
}
#pragma mark - NSCopying
- (id)copyWithZone:(NSZone *)zone {
AFPropertyListRequestSerializer *serializer = [super copyWithZone:zone];
serializer.format = self.format;
serializer.writeOptions = self.writeOptions;
return serializer;
}
@end
这一系列的几篇正解了我的燃眉之急。多谢多谢！
PS：B.HTTP Header 第二行，“高速”——》“告诉”。