Amazon.EC2.Import.DiskImageImporter.ConstructImportPartsList C# (CSharp) Метод

        Import ConstructImportPartsList(long? volumeSize, DateTime urlExpiration)
        {
            var imageFilename = Path.GetFileName(ImageFilePath);
            var imageFileinfo = new FileInfo(ImageFilePath);
            var diskImageSize = imageFileinfo.Length;

            var partCount = (int)Math.Ceiling((double)diskImageSize / DefaultPartSize);

            var parts = new ImageFileParts { Count = partCount };
            var partKeyPrefix = string.Format(CultureInfo.InvariantCulture,
                                              "{0}/{1}.",
                                              ArtifactsKeyPrefix,
                                              imageFilename);

            long partStartOffset = 0;
            for (var i = 0; i < partCount; i++)
            {
                var partEndOffset = partStartOffset + DefaultPartSize - 1;
                if (partEndOffset >= diskImageSize)
                    partEndOffset = diskImageSize - 1;

                var partKey = string.Concat(partKeyPrefix, PartSuffix, i);
                var part = new ImageFilePart
                {
                    Index = i,
                    ByteRange = new ImageFilePartByteRange { Start = partStartOffset, End = partEndOffset },
                    Key = partKey,


                    HeadUrl = S3Client.GeneratePreSignedURL(
                        BucketName, 
                        partKey, 
                        urlExpiration,
                        new Dictionary<string, object> { { "Verb", "HEAD" } }),

                    GetUrl = S3Client.GeneratePreSignedURL(
                        BucketName,
                        partKey,
                        urlExpiration,
                        new Dictionary<string, object> { { "Verb", "GET" } }),

                    DeleteUrl = S3Client.GeneratePreSignedURL(
                        BucketName,
                        partKey,
                        urlExpiration,
                        new Dictionary<string, object> { { "Verb", "DELETE" } })
                };
                parts.PartInstances.Add(part);

                partStartOffset += DefaultPartSize;
            }

            return new Import
            {
                Size = diskImageSize,
                VolumeSize = VolumeSizeFor(diskImageSize, volumeSize),
                PartsList = parts
            };
        }