joelverhagen / Delta

Find the difference between two sequences of things. Implemented for Azure Blob Storage, Table Storage, and Azure Search.

Delta

Find the difference between two sequences of things. Currently, I've implemented logic for:

• Azure Blob Storage - Knapcode.BlobDelta
• Azure Table Storage - Knapcode.TableDelta
• Azure Search Service - Knapcode.SearchDelta

Each of these is a different package.

Example

Here's an example where I use the Blob delta logic to compare my "staging" blob container for my blog to my "production" container. It uses the Content-MD5 header to compare the blobs so it's pretty fast, albeit serial.

var containerLeft = GetContainer("staging", "$web");
var containerRight = GetContainer("prod", "$web");

var enumerableLeft = new BlobEnumerable(containerLeft);
var enumerableRight = new BlobEnumerable(containerRight);

Console.WriteLine($"Left  | {containerLeft.Uri}");
Console.WriteLine($"Right | {containerRight.Uri}");

var blobPairEnumerable = new BlobComparisonEnumerable(
    enumerableLeft,
    enumerableRight);

Console.WriteLine("Finding delta...");
var enumerator = blobPairEnumerable.GetEnumerator();
while (await enumerator.MoveNextAsync())
{
    var paddedType = enumerator.Current.Type.ToString().PadRight(MaxTypeWidth);
    var blobName = enumerator.Current.Left?.Blob.Name ?? enumerator.Current.Right?.Blob.Name;
    Console.WriteLine($"{paddedType} | {blobName}");
}

The output looks like this (truncated):

Left  | https://staging.blob.core.windows.net/$web
Right | https://prod.blob.core.windows.net/$web
Finding delta...
...
Same                | attachments/blog/2020/11/dynamically-activate-objects-net/ActivatePerf-data.zip
DifferentContent    | attachments/blog/2020/11/dynamically-activate-objects-net/diagram-1.png
Same                | attachments/blog/2020/11/dynamicly-activate-types-net/ActivatePerf-data.zip
Same                | attachments/blog/2020/11/dynamicly-activate-types-net/diagram-1.png
Same                | attachments/blog/2020/12/fastest-net-csv-parsers/BenchmarkDotNet.Artifacts.zip
Same                | attachments/blog/2020/12/fastest-net-csv-parsers/diagram-1.png
Same                | attachments/resume.pdf
DifferentContent    | blog/2009/09/flickr-tree/index.html
DifferentContent    | blog/2010/01/set-v0-5/index.html
DifferentContent    | blog/2010/11/convert-an-int-to-a-string-and-vice-versa-in-c/index.html
...
Same                | img/twitter.png
DifferentContent    | index.html
Same                | keybase.txt
MissingFromLeft     | robots.txt
Same                | sandbox/tests/.htaccess
Same                | sandbox/tests/10MB.zip
...