Object store item size fix

[darkwatchuk]

ObjectStore ObjectMetaData.Size is currently an int and causes a JSON deserialization crash when pointing to an object store with large files.

Changing to a ulong fixes this issue.

e.g. someone has uploaded large files to this object store on demo.nats.io

   [Fact]
   public async Task LargeDemoTest()
   {
       var cts = new CancellationTokenSource(TimeSpan.FromSeconds(10));
       var cancellationToken = cts.Token;

       await using var nats = new NatsConnection(new NatsOpts { Url = "nats://demo.nats.io" });
       var js = new NatsJSContext(nats);
       var ob = new NatsObjContext(js);

       var objStore = await ob.GetObjectStoreAsync("omarchy-3_0_1", cancellationToken);

       await foreach (var thing in objStore.ListAsync(cancellationToken: cancellationToken))
       {
           Console.WriteLine($"{thing.Name} : {thing.Size}");
       }
   }

[Copilot]

Pull Request Overview

This PR fixes a JSON deserialization crash that occurs when ObjectStore points to objects with large files by changing the Size property from int to ulong in ObjectMetadata.

• Changed ObjectMetadata.Size property from int to ulong to handle large file sizes
• Updated all related code to use ulong for size calculations and comparisons
• Modified test assertions to use decimal literals for consistency with the new data type

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.

File	Description
src/NATS.Client.ObjectStore/Models/ObjectMetadata.cs	Changed Size property from int to ulong
src/NATS.Client.ObjectStore/NatsObjStore.cs	Updated size variables and calculations to use ulong
tests/NATS.Client.ObjectStore.Tests/ObjectStoreTest.cs	Updated test assertions to use decimal literals and ulong casts
tests/NATS.Client.ObjectStore.Tests/WatcherTest.cs	Changed count variable from int to ulong

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[mtmk]

Aligning with ADR-20:

https://github.com/nats-io/nats-architecture-and-design/blob/main/adr/ADR-20.md#objectinfo

type ObjectInfo struct {
    ObjectMeta
    Bucket  string    `json:"bucket"`
    NUID    string    `json:"nuid"`

    // the total object size in bytes
    Size    uint64    `json:"size"`    // <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

    ModTime time.Time `json:"mtime"`

    // the total number of chunks
    Chunks  uint32    `json:"chunks"` // <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

    // as in http, <digest-algorithm>=<digest-value>
    Digest  string    `json:"digest,omitempty"`
    Deleted bool      `json:"deleted,omitempty"`
}

[mtmk]

since using large files won't be possible I just check the type here.

[mtmk]

turns out this one is not align with the spec either (ADR-20)

[scottf]

I have long (int 64) in both java and .net v1. ADR has uint32 so I think this is fine.

[mtmk]

LGTM thanks @darkwatchuk

(I shall ask for one more review since I added a change too)

[darkwatchuk]

LGTM thanks @darkwatchuk

(I shall ask for one more review since I added a change too)

Thank you!

[mtmk]

sorry for the delay @darkwatchuk we should get this merged soon then I'm hoping to get it released some time this week.

[scottf]

LGTM

[scottf]

I have long (int 64) in both java and .net v1. ADR has uint32 so I think this is fine.