Indiko.Blocks.Storage.Abstractions 4.0.0

Indiko.Blocks.Storage.Abstractions

Storage contracts and option models for pluggable file storage providers.

Overview

This package defines the core storage abstractions used by concrete providers (local file system, Azure Blob, S3).

Key Components

• IFileProvider
• IStorageBlock
• StorageOptions
• StorageOptionsExtensions (shared extension and size validation)
• StoragePath (key building and file-name validation)
• SizeLimitedReadStream (size enforcement while streaming)

IFileProvider Responsibilities

The provider interface includes operations for:

• saving content and stream/file uploads,
• loading file bytes or opening a stream (OpenReadAsync),
• deleting, copying, moving files,
• reading file lists and metadata,
• producing a time-limited URL (GetPresignedUrlAsync).

OpenReadAsync and GetPresignedUrlAsync carry default implementations, so an existing implementation of the interface keeps compiling: the former falls back to GetFileAsync and buffers, the latter throws NotSupportedException. Providers that can do better override them.

Configuration

StorageOptions:

• Enabled
• MaxFileSize (in megabytes)
• AllowedFileTypes

AllowedFileTypes is compared case-insensitively and independently of a leading dot, so "png" and ".PNG" are equivalent. An empty or unset list rejects every upload.

Shared Helpers

Both rules every provider has to enforce -- allowed extension, maximum size -- live in StorageOptionsExtensions rather than being re-implemented per backend:

options.EnsureFileTypeAllowed(fileExtension, logger);
options.EnsureSizeWithinLimit(content.Length, logger);
var maximum = options.GetMaxFileSizeInBytes();

StoragePath turns a caller-supplied name into a key or path and rejects anything that would escape the configured root (.., a rooted path, a drive letter). CombineKey drops an empty prefix instead of producing a leading slash.

SizeLimitedReadStream wraps a forward-only stream and fails once the limit is passed, so a provider can stream an upload without buffering it to measure its length first.

Runtime Notes

• This package contains contracts and shared helpers; no backend is implemented here.
• Providers are expected to enforce size/type validation and throw the exceptions from Indiko.Blocks.Common.Abstractions.Exceptions.
• Only one storage provider can be active per application: they all register IFileProvider under the same contract.

Minimal Usage

public sealed class MyProvider : IFileProvider
{
    // implement required methods
}

Target Framework

• .NET 10

Related Packages

• Indiko.Blocks.Storage.Local
• Indiko.Blocks.Storage.AzureBlobStorage
• Indiko.Blocks.Storage.S3