我有一个
protobuf v2 in Swift,我试图附加到另一个原型.这是我正在尝试的：
let attachment = getAttachment(id: 987) //From cloud database
var protosData = NSMutableData(data: attachment)
items.forEach { //Some struct array of values
guard let proto = try? MyProtoBuf.Builder()
.setEpochMillis($0.date.epochMilliseconds)
.setValue($0.value)
.build() else { return }
protosData.appendData(proto.data())
}
saveAttachment(protosData) //Store to cloud
看来我正在破坏数据,因为我读回来时会收到这个错误：
malloc: *** mach_vm_map(size=2749415424) Failed (error code=3) *** error: can't allocate region *** set a breakpoint in malloc_error_break to debug
也许是我的回读值是不正确的,这是我正在做的从存储读取附加数据：
extension GeneratedMessageProtocol {
static func getStreamData(data: NSData) -> [Self] {
var messages = [Self]()
do {
let inStream = NSInputStream(data:data)
inStream.open()
defer { inStream.close() }
while inStream.hasBytesAvailable {
var sizeBuffer: [UInt8] = [0,0]
inStream.read(&sizeBuffer,maxLength: sizeBuffer.count)
let data = NSData(bytes: sizeBuffer,length: sizeBuffer.count)
let messageSize = data.uint32.littleEndian
var buffer = Array<UInt8>(count: Int(messageSize),repeatedValue: 0)
inStream.read(&buffer,maxLength: Int(messageSize))
let messageData = NSData(bytes: buffer,length:Int(messageSize))
messages.append(try self.parseFromData(messageData))
}
}
catch {
}
return messages
}
}
extension NSData {
var uint32: UInt32 {
get {
var number: UInt32 = 0
self.getBytes(&number,length: sizeof(UInt32))
return number
}
}
}
这里是我的protobuf信息：
Syntax = "proto2";
message MyProtoBuf {
optional uint64 epochMillis = 1;
optional uint32 value = 2;
}
将数据附加到现有protobuf的正确方法是什么,而不是逐个解析数组项,附加原型,然后将整个数组转换回字节？
你的阅读部分没问题.在链接原始对象时,您将缺少分隔符.首先计算并添加分隔符到流,然后再添加原始对象.然后为每个原型对象做.
let attachment = getAttachment(id: 987) //From cloud database
var arr: [UInt32] = [UInt32(attachment.length)] //Assuming attachment is NSData type
let delimiter = NSData(bytes: arr,length: arr.count * sizeof(UInt32))
let protosData = NSMutableData(data: delimiter)
protosData.appendData(attachment)
items.forEach { //Some struct array of values
guard let proto = try? MyProtoBuf.Builder()
.setEpochMillis($0.date.epochMilliseconds)
.setValue($0.value)
.build() else { return }
var array: [UInt32] = [UInt32(proto.data().length)]
let delimit = NSData(bytes: array,length: arr.count * sizeof(UInt32))
protosData.appendData(delimit)
protosData.appendData(proto.data())
}
saveAttachment(protosData) //Store to cloud