Remove ZipHelper.ReadBytes wrapper methods and use Stream.ReadAtLeast directly

[Copilot]

This PR removes the unnecessary ZipHelper.ReadBytes and ZipHelper.ReadBytesAsync wrapper methods and replaces all call sites with direct calls to Stream.ReadAtLeast and Stream.ReadAtLeastAsync.

Changes Made

Before:

internal static int ReadBytes(Stream stream, Span<byte> buffer, int bytesToRead)
{
    return stream.ReadAtLeast(buffer, bytesToRead, throwOnEndOfStream: true);
}

internal static async Task<int> ReadBytesAsync(Stream stream, Memory<byte> buffer, int bytesToRead, CancellationToken cancellationToken)
{
    cancellationToken.ThrowIfCancellationRequested();
    return await stream.ReadAtLeastAsync(buffer, bytesToRead, throwOnEndOfStream: true, cancellationToken).ConfigureAwait(false);
}

// Usage:
ZipHelper.ReadBytes(_archive.ArchiveStream, _compressedBytes[i], maxSingleBufferSize);

After:

// Direct usage:
_archive.ArchiveStream.ReadAtLeast(_compressedBytes[i], maxSingleBufferSize, throwOnEndOfStream: true);

Benefits

1. Reduced Code Maintenance: Eliminates unnecessary wrapper methods that provide no additional functionality
2. Better Performance: Avoids extra async state machine overhead for the async version when operations need to pend
3. Cleaner API: Direct use of the standard Stream.ReadAtLeast methods is more straightforward
4. Consistency: Aligns with conventional usage of Stream.ReadAtLeast throughout the codebase

Backward Compatibility

The change maintains functional compatibility because the behavior is identical - all call sites now use Stream.ReadAtLeast with throwOnEndOfStream: true, which is exactly what the wrapper methods were doing.

All existing tests (1329) continue to pass, confirming no behavioral changes.

Addresses feedback from @stephentoub in #111679.

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[Copilot]

Pull Request Overview

This PR simplifies the ZipHelper.ReadBytes and ZipHelper.ReadBytesAsync methods by leveraging the built-in EOF handling of Stream.ReadAtLeast instead of manually checking for end-of-stream conditions and throwing exceptions.

Key changes:

• Removes manual EOF checking and exception throwing logic
• Uses throwOnEndOfStream: true parameter to let ReadAtLeast handle EOF scenarios automatically
• Changes exception type from IOException to EndOfStreamException for EOF conditions

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
ZipHelper.cs	Simplified ReadBytes method by removing manual EOF check and using built-in ReadAtLeast exception handling
ZipHelper.Async.cs	Simplified ReadBytesAsync method with the same approach as the synchronous version

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[stephentoub]

@copilot, please address my feedback.

[rokonec]

I'd like to mention that it might be a breaking change. We throw different type of exception than before. Probability of breaking someone is small here, but still...

[stephentoub]

We throw different type of exception than before.

It used to throw IOException and now it'll throw EndOfStreamException... which is an IOException. While it can affect someone who's doing an exact type test, we generally don't consider throwing a more derived type to be "breaking".
https://github.com/dotnet/runtime/blob/main/docs/coding-guidelines/breaking-change-rules.md#exceptions

[Copilot]

@copilot, please address my feedback.

Feedback addressed. Both ZipHelper.ReadBytes and ZipHelper.ReadBytesAsync wrapper methods have been removed and all call sites now use Stream.ReadAtLeast/ReadAtLeastAsync directly. All 1329 tests continue to pass. Commit 0199b1c