WopiHost.FileSystemProvider 9.0.0

WopiHost.FileSystemProvider

Reference implementation of IWopiStorageProvider and IWopiWritableStorageProvider backed by a local directory tree. Identifiers are deterministic SHA-256 hashes of the canonical path, cached in-memory and mapped back to absolute paths.

Suitable for development, validator runs, and single-instance deployments. Storage only — token issuance and ACLs live in WopiHost.Core.

Install

dotnet add package WopiHost.FileSystemProvider

Configure

// appsettings.json
"Wopi": {
  "StorageProvider": {
    "RootPath": "./wopi-docs"   // absolute or relative to ContentRootPath
  }
}

RootPath is bound from the Wopi:StorageProvider section (WopiFileSystemProviderOptions.SectionName).

Register

builder.Services.AddFileSystemStorageProvider(builder.Configuration);
builder.Services.AddWopi(o =>
{
    o.ClientUrl = new Uri("https://your-office-online-server.com");
});

AddFileSystemStorageProvider registers WopiFileSystemProvider as both IWopiStorageProvider and IWopiWritableStorageProvider (one shared singleton instance) plus the singleton InMemoryFileIds map the provider uses for path↔id round-tripping. The runnable sample drives all of this through a sample-local Sample:StorageProvider discriminator — see sample/WopiHost/Program.cs.

How identifiers work

Identifiers are deterministic 64-character SHA-256 hex hashes of the canonical (case-folded) path, computed by InMemoryFileIds via WopiResourceId.FromCanonicalPath. Consumers treat them as opaque. Lookup is O(1) in both directions; the in-memory map is rebuilt at startup. (The WOPI validator's test.wopitest file is the one exception — it's given the fixed id WOPITEST.)

A consequence: because an id derives purely from the path, a file's id is stable across process restarts and across hosts pointing at the same tree, so long-lived WOPI URLs keep working without persisting a separate mapping. Renaming or moving a file changes its id (the path changed); the provider re-points the id on rename so an in-progress edit's URL doesn't break.

Customize

To layer behavior — versioning, audit, soft-delete — wrap the provider via composition. The concrete class' interface methods are non-virtual, so a decorator is the cleanest seam:

public class AuditingStorageProvider(IWopiWritableStorageProvider inner, IAuditLog audit)
    : IWopiWritableStorageProvider
{
    public async Task<bool> DeleteWopiFile(string id, CancellationToken ct = default)
    {
        var deleted = await inner.DeleteWopiFile(id, ct);
        if (deleted) audit.Log($"deleted file {id}");
        return deleted;
    }

    public async Task<bool> DeleteWopiContainer(string id, CancellationToken ct = default)
    {
        var deleted = await inner.DeleteWopiContainer(id, ct);
        if (deleted) audit.Log($"deleted container {id}");
        return deleted;
    }

    // Forward the rest of IWopiWritableStorageProvider to `inner`.
    public int FileNameMaxLength => inner.FileNameMaxLength;
    // ...
}

License

See the repo README.