将Objective-C代码转换为Swift:可以省略释放调用吗？

Question

我们需要将以下代码从Objective-C转换为Swift.

题:

有一些函数调用来释放对象,例如CGImageRelease(newImage).是否可以安全地假设Swift版本不需要模拟,因为所有内存管理都是自动的,或者你是否需要在Swift中释放内存？

Objective-C代码:

CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(imageSampleBuffer);
CVPixelBufferLockBaseAddress(imageBuffer,0);
uint8_t *baseAddress = (uint8_t *)CVPixelBufferGetBaseAddress(imageBuffer);
size_t bytesPerRow = CVPixelBufferGetBytesPerRow(imageBuffer);
size_t width = CVPixelBufferGetWidth(imageBuffer);
size_t height = CVPixelBufferGetHeight(imageBuffer);
CVPixelBufferUnlockBaseAddress(imageBuffer,0);
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
CGContextRef newContext = CGBitmapContextCreate(baseAddress, width, height, 8, bytesPerRow, colorSpace, kCGBitmapByteOrder32Little | kCGImageAlphaPremultipliedFirst);
CGImageRef newImage = CGBitmapContextCreateImage(newContext); CGContextRelease(newContext);
CGColorSpaceRelease(colorSpace);
UIImage *image= [UIImage imageWithCGImage:newImage scale:1.0 orientation:orientation];
CGImageRelease(newImage);

到目前为止Swift版本:

private func turnBufferToPNGImage(imageSampleBuffer: CMSampleBufferRef, scale: CGFloat) -> UIImage {
    let imageBuffer = CMSampleBufferGetImageBuffer(imageSampleBuffer)

    // Lock base address
    CVPixelBufferLockBaseAddress(imageBuffer, 0)

    // Set properties for CGBitmapContext
    let pixelData = CVPixelBufferGetBaseAddress(imageBuffer)
    let width = CVPixelBufferGetWidth(imageBuffer)
    let height = CVPixelBufferGetHeight(imageBuffer)
    let bytesPerRow = CVPixelBufferGetBytesPerRow(imageBuffer)
    let colorSpace = CGColorSpaceCreateDeviceRGB()

    // Create CGBitmapContext
    let newContext = CGBitmapContextCreate(pixelData, width, height, 8, bytesPerRow, colorSpace, CGImageAlphaInfo.PremultipliedFirst.rawValue)

    // Create image from context
    let rawImage = CGBitmapContextCreateImage(newContext)!
    let newImage = UIImage(CGImage: rawImage, scale: scale, orientation: .Up)

    // Unlock base address
    CVPixelBufferUnlockBaseAddress(imageBuffer,0)

    // Return image
    return newImage
}

Answer 1

根据文档:

Core Foundation类型会自动导入为完整的Swift类.无论何处提供内存管理注释,Swift都会自动管理Core Foundation对象的内存,包括您自己实例化的Core Foundation对象

所以你可以省略这些电话.