Next generation of AcoustID fingerprint index

Key changes from the first version

• Written in Zig instead of C++
• Supports updates and deletes
• HTTP API that can be used for managing multiple indexes
• Fast and concurrent write operations using WAL and in-memory segments
• Simplified internal file format, using msgpack for serialization wherever possible

Building

Building from source code:

zig build

Running tests:

zig build test --summary all

Running server:

zig build run -- --dir /tmp/fpindex --port 8080 --log-level debug

HTTP API

Index management

Check if index exists

Returns HTTP status 200 if the index exists.

HEAD /:indexname

Get index info

Returns information about an index.

GET /:indexname

Create index

Creates a new index.

PUT /:indexname

Delete index

Deletes an index.

DELETE /:indexname

Fingerprint management

Update

Performs multiple operations on an index.

POST /:indexname/_update

{
  "changes": [
    {"insert": {"id": 1, "hashes": [100, 200, 300]}},
    {"delete": {"id": 2}}
  ]
}

Search

Searches for a fingerprint in the index.

POST /:indexname/_search

{"query": [100, 200, 300], "timeout": 10}

Check if fingerprint exists

Returns HTTP status 200 if the fingerprint exists.

HEAD /:indexname/:fpid

Get fingerprint info

Gets information about a fingeprint.

There is no way to get back the original hashes, they are not stored in a way that makes it possible to retrieve them.

GET /:indexname/:fpid

Update single fingerprint

Updates a single fingerprint.

Prefer using /_update for bulk operations.

PUT /:indexname/:fpid

{"hashes": [100, 200, 300]}

Delete single fingerprint

Deletes a single fingerprint.

Prefer using /_update for bulk operations.

DELETE /:indexname/:fpid

System utilities

Healhcheck

GET /_health
GET /:indexname/_health

Prometheus metrics

GET /_metrics