GetPartialObject.cs

/*
 * MinIO .NET Library for Amazon S3 Compatible Cloud Storage, (C) 2017-2021 MinIO, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

using Minio.DataModel.Args;

namespace Minio.Examples.Cases;

internal static class GetPartialObject
{
    // Get object in a bucket for a particular offset range. Dotnet SDK currently
    // requires both start offset and end 
    public static async Task Run(IMinioClient minio,
        string bucketName = "my-bucket-name",
        string objectName = "my-object-name",
        string fileName = "my-file-name")
    {
        try
        {
            Console.WriteLine("Running example for API: GetObjectAsync");
            // Check whether the object exists using StatObjectAsync(). If the object is not found,
            // StatObjectAsync() will throw an exception.
            var statObjectArgs = new StatObjectArgs()
                .WithBucket(bucketName)
                .WithObject(objectName);
            _ = await minio.StatObjectAsync(statObjectArgs).ConfigureAwait(false);

            // Get object content starting at byte position 1024 and length of 4096
            var getObjectArgs = new GetObjectArgs()
                .WithBucket(bucketName)
                .WithObject(objectName)
                .WithOffsetAndLength(1024L, 4096L)
                .WithCallbackStream(async (stream, cancellationToken) =>
                {
                    var fileStream = File.Create(fileName);
                    await stream.CopyToAsync(fileStream, cancellationToken).ConfigureAwait(false);
                    await fileStream.DisposeAsync().ConfigureAwait(false);
                    var writtenInfo = new FileInfo(fileName);
                    var file_read_size = writtenInfo.Length;
                    // Uncomment to print the file on output console
                    // stream.CopyTo(Console.OpenStandardOutput());
                    Console.WriteLine(
                        $"Successfully downloaded object with requested offset and length {writtenInfo.Length} into file");
                    stream.Dispose();
                });
            _ = await minio.GetObjectAsync(getObjectArgs).ConfigureAwait(false);
            Console.WriteLine();
        }
        catch (Exception e)
        {
            Console.WriteLine($"[Bucket]  Exception: {e}");
        }
    }
}