Question

我有一个很大的困难是一个星期。我得到一个包含许多对象的JSON，每个对象最多可以获得8张照片。我正在进行基于15,000个对象的测试，直到我收到错误"Malloc error “can't allocate region” failed with error code 3"

，我的内存消耗总是保持不变

我该如何解决这个问题？我试图重置我的核心对象日期的上下文，但也没有决定。

下面我提出了我的部分代码：

for item in products {
                i = i + 1
                print(i)

                let p = item as! NSDictionary
                let product = NSEntityDescription.insertNewObjectForEntityForName("PRODUCT", inManagedObjectContext: self.context) as! PRODUCT

                if tipo != "FULL"{
                    let chave = p["Chave"] as! String
                    if self.loadProductWithKey(chave).count > 0 {
                        self.deleteProductWithKey(chave)
                    }
                }

                product.chave = p["Chave"] as? String
                product.chaveFabricante = p["ChaveFabricante"] as? String
                product.chaveMarca = p["ChaveMarca"] as? String
                product.chaveUnidade = p["ChaveUnidade"] as? String
                product.chaveGrupo = p["ChaveGrupo"] as? String
                product.codigo = p["Codigo"] as? String
                product.codigoSegundario = p["CodigoSecundario"] as? String
                product.descricaoNF = p["DescricaoNf"] as? String
                product.descricaoDetalhada = p["DescricaoDetalhada"] as? String
                product.chaveLicenca = p["ChaveLicenca"] as? String


                var image = UIImage()
                var url = NSURL()
                var code = ""
                var chave = ""
                var fileName = ""

                let photo1Url = p["UrlFoto1"] as! String
                if photo1Url != ""{
                    url = NSURL(string: "\(_URLPREFIX)\(photo1Url)")!
                    if let foto = NSData(contentsOfURL: url) {
                        if foto.length > 0{
                            image = UIImage(data: foto)!
                            code = p["Codigo"] as! String
                            chave = p["Chave"] as! String
                            let documents = try! NSFileManager.defaultManager().URLForDirectory(.DocumentDirectory, inDomain: .UserDomainMask, appropriateForURL: nil, create: false)
                            fileName = "picture-\(chave)-\(code)-1.jpg"
                            let fileURL = documents.URLByAppendingPathComponent(fileName)
                            if let jpgImageData = UIImageJPEGRepresentation(image, 0.8) {
                                jpgImageData.writeToURL(fileURL, atomically: true)
                            }
                            product.urlFoto1 = fileName
                        }
                    }                    
                }

                let photo2Url = p["UrlFoto2"] as! String
                if photo2Url != ""{
                    url = NSURL(string: "\(_URLPREFIX)\(photo2Url)")!
                    if let foto = NSData(contentsOfURL: url) {
                        if foto.length > 0{
                            image = UIImage(data: foto)!
                            code = p["Codigo"] as! String
                            chave = p["Chave"] as! String
                            let documents = try! NSFileManager.defaultManager().URLForDirectory(.DocumentDirectory, inDomain: .UserDomainMask, appropriateForURL: nil, create: false)
                            fileName = "picture-\(chave)-\(code)-2.jpg"
                            let fileURL = documents.URLByAppendingPathComponent(fileName)
                            if let jpgImageData = UIImageJPEGRepresentation(image, 0.8) {
                                jpgImageData.writeToURL(fileURL, atomically: true)
                            }
                            product.urlFoto2 = fileName
                        }
                    }
                }

                let photo3Url = p["UrlFoto3"] as! String
                if photo3Url != ""{
                    url = NSURL(string: "\(_URLPREFIX)\(photo3Url)")!
                    if let foto = NSData(contentsOfURL: url) {
                        if foto.length > 0{
                            image = UIImage(data: foto)!
                            code = p["Codigo"] as! String
                            chave = p["Chave"] as! String
                            let documents = try! NSFileManager.defaultManager().URLForDirectory(.DocumentDirectory, inDomain: .UserDomainMask, appropriateForURL: nil, create: false)
                            fileName = "picture-\(chave)-\(code)-3.jpg"
                            let fileURL = documents.URLByAppendingPathComponent(fileName)
                            if let jpgImageData = UIImageJPEGRepresentation(image, 0.8) {
                                jpgImageData.writeToURL(fileURL, atomically: true)
                            }
                            product.urlFoto3 = fileName
                        }
                    }
                }

                let photo4Url = p["UrlFoto4"] as! String
                if photo4Url != ""{
                    url = NSURL(string: "\(_URLPREFIX)\(photo4Url)")!
                    if let foto = NSData(contentsOfURL: url) {
                        if foto.length > 0{
                            image = UIImage(data: foto)!
                            code = p["Codigo"] as! String
                            chave = p["Chave"] as! String
                            let documents = try! NSFileManager.defaultManager().URLForDirectory(.DocumentDirectory, inDomain: .UserDomainMask, appropriateForURL: nil, create: false)
                            fileName = "picture-\(chave)-\(code)-4.jpg"
                            let fileURL = documents.URLByAppendingPathComponent(fileName)
                            if let jpgImageData = UIImageJPEGRepresentation(image, 0.8) {
                                jpgImageData.writeToURL(fileURL, atomically: true)
                            }
                            product.urlFoto4 = fileName
                        }
                    }
                }

                let photo5Url = p["UrlFoto5"] as! String
                if photo5Url != ""{
                    url = NSURL(string: "\(_URLPREFIX)\(photo5Url)")!
                    if let foto = NSData(contentsOfURL: url) {
                        if foto.length > 0{
                            image = UIImage(data: foto)!
                            code = p["Codigo"] as! String
                            chave = p["Chave"] as! String
                            let documents = try! NSFileManager.defaultManager().URLForDirectory(.DocumentDirectory, inDomain: .UserDomainMask, appropriateForURL: nil, create: false)
                            fileName = "picture-\(chave)-\(code)-5.jpg"
                            let fileURL = documents.URLByAppendingPathComponent(fileName)
                            if let jpgImageData = UIImageJPEGRepresentation(image, 0.8) {
                                jpgImageData.writeToURL(fileURL, atomically: true)
                            }
                            product.urlFoto5 = fileName
                        }
                    }
                }

                do {
                    try self.context.save()
                } catch {
                    print("============ erro nos produtos")

                }
                self.context.refreshAllObjects()
            }

Answer 1

您的代码存在许多问题。

您不应使用NSData(contentsOfURL:)从远程站点加载数据。它冻结了主线程。而是使用NSURLSession。您可以创建一个下载任务，将您的图像数据直接下载到文件。它会异步执行，不会阻塞主线程。

您也不应该在循环中加载大量大对象而不采取措施以避免内存不足。将部件包含在循环内，在autoreleasepool块中加载大对象：

for (i, item) in products.enumerate() {
  autoreleasepool {
    //Put the body of your for loop here
  }
}

autoreleasepool{}块告诉编译器它应该释放每次退出大括号时在大括号内分配的临时（或自动释放）对象。（这被称为“耗尽自动释放池”）

通过在for循环中放置一个autoreleasepool{}块，可以释放代码在每次循环中创建的自动释放对象。

但是，如果您使用NSURLSession和下载任务，则无需担心。系统将下载文件并自动保存，并为您管理进程的内存。

减少日期核心

1 个答案: