我正在尝试将一些字符串和图像数据从python脚本发送到在OSX上运行的目标C应用程序。
我正在使用GCDAsyncSocket收集传输的数据，并将其附加到NSMutableData，直到服务器断开连接。然后我处理NSData并将其拆分为原始部分。
传输的数据包括以下内容：
ID字符串，填写为16个字节。
图像编号字符串，填写为16个字节。
原始图像数据。
终止字符串，填写为16个字节。
问题是我没有接收/获取最后一块数据，我最终错过了JPEG图像的结尾，导致图像损坏（尽管显示最多），以及缺少终止字符串。
以下是我使用GCDAsyncSocket获取数据并处理数据的代码：
套接字连接：
- (void)socket:(GCDAsyncSocket *)sock didAcceptNewSocket:(GCDAsyncSocket *)newSocket
{
// This method is executed on the socketQueue (not the main thread)
@synchronized(connectedSockets)
{
[connectedSockets addObject:newSocket];
}
NSString *host = [newSocket connectedHost];
UInt16 port = [newSocket connectedPort];
dispatch_async(dispatch_get_main_queue(), ^{
@autoreleasepool {
[self logInfo:FORMAT(@"Accepted client %@:%hu", host, port)];
}
});
[newSocket readDataToData:[GCDAsyncSocket CRLFData] withTimeout:-1 tag:0];
}
收到套接字数据
- (void)socket:(GCDAsyncSocket *)sock didReadData:(NSData *)data withTag:(long)tag
{
// This method is executed on the socketQueue (not the main thread)
dispatch_async(dispatch_get_main_queue(), ^{
@autoreleasepool {
NSLog(@"Thread Data Length is %lu", (unsigned long)[data length]);
if (!imageBuffer){
imageBuffer = [[NSMutableData alloc]init];
}
[imageBuffer appendData:[data subdataWithRange:NSMakeRange(0, [data length])]];
NSLog(@"Total Data Length is %lu", (unsigned long)[imageBuffer length]);
}
});
// Echo message back to client
[sock writeData:data withTimeout:-1 tag:ECHO_MSG];
[sock readDataToData:[GCDAsyncSocket CRLFData] withTimeout:-1 tag:0];
}
套接字已断开
- (void)socketDidDisconnect:(GCDAsyncSocket *)sock withError:(NSError *)err
{
if (sock != listenSocket)
{
dispatch_async(dispatch_get_main_queue(), ^{
@autoreleasepool {
[self logInfo:FORMAT(@"Client Disconnected")];
NSData *cameraNumberData;
NSData *imageNumberData;
NSData *imageData;
NSData *endCommandData;
//if ([data length] > 40){
cameraNumberData = [imageBuffer subdataWithRange:NSMakeRange(0, 16)];
imageNumberData = [imageBuffer subdataWithRange:NSMakeRange(16, 16)];
imageData = [imageBuffer subdataWithRange:NSMakeRange(32, [imageBuffer length]-34)];
endCommandData = [imageBuffer subdataWithRange:NSMakeRange([imageBuffer length]-16, 16)];
//}
NSString *cameraNumberString = [[NSString alloc] initWithData:cameraNumberData encoding:NSUTF8StringEncoding];
NSString *imageNumberString = [[NSString alloc] initWithData:imageNumberData encoding:NSUTF8StringEncoding];
NSString *endCommandString = [[NSString alloc] initWithData:endCommandData encoding:NSUTF8StringEncoding];
NSImage* image = [[NSImage alloc]initWithData:imageData];
if (cameraNumberString)
{
NSLog(@"Image recieved from Camera no %@", cameraNumberString);
[self logMessage:cameraNumberString];
}
else
{
[self logError:@"Error converting received data into UTF-8 String"];
}
if (imageNumberString)
{
NSLog(@"Image is number %@", imageNumberString);
[self logMessage:imageNumberString];
}
else
{
[self logError:@"Error converting received data into UTF-8 String"];
}
if (image)
{
NSLog(@"We have an image");
[self.imageView setImage:image];
}
else
{
[self logError:@"Error converting received data into image"];
}
if (endCommandString)
{
NSLog(@"Command String is %@", endCommandString);
[self logMessage:endCommandString];
}
else
{
[self logError:@"No command string"];
}
//self.imageBuffer = nil;
}
});
@synchronized(connectedSockets)
{
[connectedSockets removeObject:sock];
}
}
}
我使用过wireshark，数据正在传输，它只是没有通过GCDAsynSocket。
所以，我显然遗漏了一些东西。对这样的数据进行套接字编程和编码/解码对我来说相对较新，所以我可能是个白痴。
非常感谢！
由于
加雷
答案 0 :(得分：2)
好的，所以我终于有了这个工作。它涉及修改Python中的传输代码，以在数据末尾发送完成字符串，并观察它。最大的好处是每次socket读取一些数据时我都需要重新调用readDataToData：方法，否则它只会坐在那里等待，而发送套接字也只是坐在那里。
我还必须实现使用标记重新调用第二个接收，这样我就可以将接收到的数据存储在NSMutableArray中的正确NSMutableData对象中，否则我无法知道在第一次接收后哪个传输套接字数据是因为ID只出现在第一条消息的开头。
这是didReadData代码：
- (void)socket:(GCDAsyncSocket *)sock didReadData:(NSData *)data withTag:(long)tag
{
dispatch_async(dispatch_get_main_queue(), ^{
@autoreleasepool {
NSInteger cameraNumberNumber = 0;
NSString *cameraNumberString = [[NSString alloc]init];
if (tag > 10){
cameraNumberNumber = tag-11;
DDLogVerbose(@"Second data loop, tag is %ld", tag);
} else {
NSData *cameraNumberData;
//if ([data length] > 40){
cameraNumberData = [data subdataWithRange:NSMakeRange(0, 16)];
NSString *cameraNumberString = [[NSString alloc] initWithData:cameraNumberData encoding:NSUTF8StringEncoding];
cameraNumberString = [cameraNumberString stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
cameraNumberNumber = [cameraNumberString intValue]-1;
}
if (cameraNumberNumber+1 <= self.images.count){
if ([self.images objectAtIndex:cameraNumberNumber] == [NSNull null]){
image* cameraImage = [[image alloc]init];
[self.images replaceObjectAtIndex: cameraNumberNumber withObject:cameraImage];
}
image* cameraImage = [self.images objectAtIndex:cameraNumberNumber];
[cameraImage.imageData appendData:[data subdataWithRange:NSMakeRange(0, [data length])]];
cameraImage.cameraNumber = cameraNumberString;
if (!imageBuffer){
imageBuffer = [[NSMutableData alloc]init];
}
[imageBuffer appendData:[data subdataWithRange:NSMakeRange(0, [data length])]];
DDLogVerbose(@"Total Data Length is %lu", (unsigned long)[imageBuffer length]);
} else {
DDLogInfo(@"Wrong camera quantity!");
NSAlert *testAlert = [NSAlert alertWithMessageText:@"Wrong camera quantity!"
defaultButton:@"Ok"
alternateButton:nil
otherButton:nil
informativeTextWithFormat:@"We have recieved more images than cameras, please set No.Cameras correctly!"];
[testAlert beginSheetModalForWindow:[self window]
modalDelegate:self
didEndSelector:@selector(stop)
contextInfo:nil];
}
[sock readDataToData:[@"end" dataUsingEncoding:NSUTF8StringEncoding] withTimeout:-1 tag:cameraNumberNumber + 11];
}
});
}
这里是socketDidDisconnect代码，这里有很多东西在上下文之外没有意义，但是它显示了我如何处理接收到的数据。
- (void)socketDidDisconnect:(GCDAsyncSocket *)sock withError:(NSError *)err
{
if (sock != listenSocket)
{
dispatch_async(dispatch_get_main_queue(), ^{
@autoreleasepool {
totalCamerasFetched = [NSNumber numberWithInt:1+[totalCamerasFetched intValue]];
if ([totalCamerasFetched integerValue] >= [numberOfCameras integerValue]){
for (image* cameraImage in self.images){
NSData *cameraNumberData;
NSData *imageNumberData;
NSData *imageData;
NSData *endCommandData;
NSInteger cameraNumberNumber = 0;
cameraNumberData = [cameraImage.imageData subdataWithRange:NSMakeRange(0, 16)];
imageNumberData = [cameraImage.imageData subdataWithRange:NSMakeRange(16, 16)];
imageData = [cameraImage.imageData subdataWithRange:NSMakeRange(32, [cameraImage.imageData length]-32)];
endCommandData = [cameraImage.imageData subdataWithRange:NSMakeRange([cameraImage.imageData length]-16, 16)];
NSString *cameraNumberString = [[NSString alloc] initWithData:cameraNumberData encoding:NSUTF8StringEncoding];
cameraNumberString = [cameraNumberString stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
NSString *imageNumberString = [[NSString alloc] initWithData:imageNumberData encoding:NSUTF8StringEncoding];
imageNumberString = [imageNumberString stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
NSString *endCommandString = [[NSString alloc] initWithData:endCommandData encoding:NSUTF8StringEncoding];
NSImage* image = [[NSImage alloc]initWithData:imageData];
cameraNumberNumber = [cameraNumberString intValue]-1;
if (cameraNumberString)
{
DDLogInfo(@"Image recieved from Camera no %@", cameraNumberString);
}
else
{
DDLogError(@"No Camera number in data");
}
if (imageNumberString)
{
DDLogInfo(@"Image is number %@", imageNumberString);
}
else
{
DDLogError(@"No Image number in data");
}
if (image)
{
DDLogVerbose(@"We have an image");
NSString* dataPath = [[NSString alloc]initWithFormat:@"%@/image%@/",self.exportLocation, imageNumberString];
if (![[NSFileManager defaultManager] fileExistsAtPath:dataPath]){
NSError* error;
[[NSFileManager defaultManager] createDirectoryAtPath:dataPath withIntermediateDirectories:NO attributes:nil error:&error];
if (error)
{
DDLogError(@"[%@] ERROR: attempting to write directory for images", [self class]);
NSAssert( FALSE, @"Failed to create directory maybe out of disk space?");
}
}
NSString* dataPathVideo = [[NSString alloc]initWithFormat:@"%@/video%@/",self.exportLocation, imageNumberString];
if (![[NSFileManager defaultManager] fileExistsAtPath:dataPathVideo]){
NSError* error;
[[NSFileManager defaultManager] createDirectoryAtPath:dataPathVideo withIntermediateDirectories:NO attributes:nil error:&error];
if (error)
{
DDLogError(@"[%@] ERROR: attempting to write directory for images", [self class]);
NSAssert( FALSE, @"Failed to create directory maybe out of disk space?");
}
}
NSString * exportLocationFull = [[NSString alloc]initWithFormat:@"%@/image%@/camera_%@.jpg",self.exportLocation, imageNumberString, cameraNumberString];
DDLogInfo(@"Full export URL = %@", exportLocationFull);
[imageData writeToFile:exportLocationFull atomically:YES];
self.currentSet = [NSNumber numberWithInt:[imageNumberString intValue]];
NSImage* imageToStore = [[NSImage alloc]initWithData:imageData];
[self.imagesToMakeVideo replaceObjectAtIndex: cameraNumberNumber withObject:imageToStore];
} else {
DDLogError(@"No image loacted in data");
}
if (endCommandString)
{
DDLogVerbose(@"Command String is %@", endCommandString);
//[self logMessage:endCommandString];
}
else
{
//[self logError:@"No command string"];
}
self.imageBuffer = nil;
}
self.totalCamerasFetched = [NSNumber numberWithInt:0];
[self loadandDisplayLatestImages];
[self createVideowithImages:imagesToMakeVideo toLocation:[[NSString alloc]initWithFormat:@"%@/video%@/image_sequence_%@.mov",self.exportLocation, self.currentSet, self.currentSet]];
processing = false;
}//end of for loop
}
});
@synchronized(connectedSockets)
{
[connectedSockets removeObject:sock];
}
}
}
这里也是我如何修改Python代码以添加额外的“结束”标记。
def send_media_to(self, ip, port, media_name, media_number, media_dir):
camera_number = self.camera.current_mode['option'].number
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.connect((ip, port))
try:
sock.send(bytes(str(camera_number).ljust(16), 'utf-8'))
sock.send(bytes(str(media_number).ljust(16), 'utf-8'))
with open(media_dir + media_name, 'rb') as media:
sock.sendall(media.read())
finally:
sock.send(bytes(str("end").ljust(16), 'utf-8'))
sock.close()
希望这有助于其他人陷入同样的境地！