CultLib/src/GameCult.Networking/CultNetDatabaseSubscriptionServer.cs
2026-08-19 13:55:03 +02:00

629 lines
29 KiB
C#

using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Runtime.CompilerServices;
using System.Net;
using System.Threading.Tasks;
using GameCult.Caching;
using R3;
namespace GameCult.Networking
{
/// <summary>
/// Publishes live database changes through any schema-v0 server transport.
/// Optional record projection runs after authorization and owns both initial
/// snapshot and live-update delivery for a peer.
/// </summary>
public sealed class CultNetDatabaseSubscriptionServer : IDisposable
{
private readonly ICultNetSchemaServer _server;
private readonly CultNetDatabase _database;
private readonly Func<CultNetDatabaseSubscribeMessage, ICultNetSchemaServerPeer, Task> _subscribe;
private readonly Func<CultNetDatabaseUnsubscribeMessage, ICultNetSchemaServerPeer, Task> _unsubscribe;
private readonly Func<CultNetDatabaseSubscribeMessage, ICultNetSchemaServerPeer, bool>? _authorizeRequest;
private readonly Func<CultNetDatabaseSubscribeMessage, ICultNetSchemaServerPeer, string, string, bool>? _authorizeRecord;
private readonly Func<CultNetDatabaseSubscribeMessage, ICultNetSchemaServerPeer, CultNetRawDocumentRecord, CultNetRawDocumentRecord?>? _projectRecord;
private readonly ICultNetSchemaServerPeerLifecycle? _peerLifecycle;
private readonly ConcurrentDictionary<SubscriptionKey, IDisposable> _subscriptions =
new ConcurrentDictionary<SubscriptionKey, IDisposable>(SubscriptionKeyComparer.Instance);
private readonly ConcurrentDictionary<SubscriptionKey, CultNetDatabaseSubscribeMessage> _requests =
new ConcurrentDictionary<SubscriptionKey, CultNetDatabaseSubscribeMessage>(SubscriptionKeyComparer.Instance);
private readonly ConcurrentDictionary<SubscriptionKey, SubscriptionProjectionState> _projections =
new ConcurrentDictionary<SubscriptionKey, SubscriptionProjectionState>(SubscriptionKeyComparer.Instance);
private readonly object _lifecycleGate = new();
private bool _disposed;
/// <summary>Attaches live database subscription handlers to a schema server.</summary>
public CultNetDatabaseSubscriptionServer(
ICultNetSchemaServer server,
CultNetDatabase database,
Func<CultNetDatabaseSubscribeMessage, ICultNetSchemaServerPeer, bool>? authorizeRequest = null,
Func<CultNetDatabaseSubscribeMessage, ICultNetSchemaServerPeer, string, string, bool>? authorizeRecord = null,
Func<CultNetDatabaseSubscribeMessage, ICultNetSchemaServerPeer, CultNetRawDocumentRecord, CultNetRawDocumentRecord?>? projectRecord = null)
{
_server = server ?? throw new ArgumentNullException(nameof(server));
_database = database ?? throw new ArgumentNullException(nameof(database));
_authorizeRequest = authorizeRequest;
_authorizeRecord = authorizeRecord;
_projectRecord = projectRecord;
_subscribe = HandleSubscribeAsync;
_unsubscribe = HandleUnsubscribeAsync;
_server.OnCultNet(_subscribe);
_server.OnCultNet(_unsubscribe);
_peerLifecycle = server as ICultNetSchemaServerPeerLifecycle;
if (_peerLifecycle != null)
_peerLifecycle.PeerDisconnected += HandlePeerDisconnected;
}
/// <summary>
/// Raised when an exact subscription is activated or withdrawn. Providers can use
/// the requested records and schemas to materialize reactive state only while a
/// consumer needs it; body publishers additionally use the negotiated body route.
/// </summary>
public event Action<CultNetDatabaseSubscriptionDemand>? DemandChanged;
/// <summary>
/// Re-evaluates every live peer projection against current authorization and source state.
/// Records that lost visibility are explicitly removed and body demand is withdrawn while
/// the request is unauthorized. The subscription intent remains available for a later
/// authorized generation on the same established peer.
/// </summary>
public void Reconcile()
{
lock (_lifecycleGate)
{
if (_disposed) return;
foreach (var entry in _requests.ToArray())
Reconcile(entry.Key, entry.Value);
}
}
/// <summary>Detaches handlers and releases all active watches.</summary>
public void Dispose()
{
lock (_lifecycleGate)
{
if (_disposed) return;
_disposed = true;
_server.RemoveCultNetMessageListener<CultNetDatabaseSubscribeMessage>(_subscribe);
_server.RemoveCultNetMessageListener<CultNetDatabaseUnsubscribeMessage>(_unsubscribe);
if (_peerLifecycle != null)
_peerLifecycle.PeerDisconnected -= HandlePeerDisconnected;
foreach (var entry in _subscriptions.ToArray())
Withdraw(entry.Key, sendRemovals: false, forgetRequest: true);
_subscriptions.Clear();
_requests.Clear();
_projections.Clear();
}
}
private void HandlePeerDisconnected(ICultNetSchemaServerPeer peer)
{
lock (_lifecycleGate)
{
foreach (var key in _subscriptions.Keys.Where(candidate =>
SubscriptionKeyComparer.SamePeer(candidate.Peer, peer)).ToArray())
Withdraw(key, sendRemovals: false, forgetRequest: true);
}
}
private Task HandleSubscribeAsync(CultNetDatabaseSubscribeMessage request, ICultNetSchemaServerPeer peer)
{
var subscriptionId = string.IsNullOrWhiteSpace(request.SubscriptionId)
? request.MessageId
: request.SubscriptionId;
if (string.IsNullOrWhiteSpace(subscriptionId))
{
peer.SendCultNet(new CultNetErrorMessage { Error = "Database subscription requires a subscriptionId or messageId." });
return Task.CompletedTask;
}
if (_authorizeRequest?.Invoke(request, peer) == false)
{
peer.SendCultNet(new CultNetErrorMessage { Error = "Database subscription is not authorized for this peer." });
return Task.CompletedTask;
}
lock (_lifecycleGate)
{
var key = new SubscriptionKey(peer, subscriptionId);
Withdraw(key, sendRemovals: true, forgetRequest: true);
var projection = new SubscriptionProjectionState();
_projections[key] = projection;
_requests[key] = request;
try
{
_subscriptions[key] = Watch(request, subscriptionId, peer, key);
if (request.IncludeSnapshot)
{
var snapshot = CreateProjectedSnapshot(request, peer);
foreach (var entry in snapshot.BySourceRecordKey)
projection.DeliveredBySourceRecordKey[entry.Key] = entry.Value;
peer.SendCultNet(new CultNetSnapshotResponseRawMessage
{
MessageId = request.MessageId,
Documents = snapshot.Documents
});
}
else
{
peer.SendCultNet(new CultNetSnapshotResponseRawMessage
{
MessageId = request.MessageId,
Documents = Array.Empty<CultNetRawDocumentRecord>()
});
}
PublishDemand(request, key, active: true);
projection.DemandActive = true;
}
catch
{
Withdraw(key, sendRemovals: false, forgetRequest: true);
throw;
}
}
return Task.CompletedTask;
}
private Task HandleUnsubscribeAsync(CultNetDatabaseUnsubscribeMessage request, ICultNetSchemaServerPeer peer)
{
var subscriptionId = string.IsNullOrWhiteSpace(request.SubscriptionId)
? request.MessageId
: request.SubscriptionId;
if (!string.IsNullOrWhiteSpace(subscriptionId))
{
var key = new SubscriptionKey(peer, subscriptionId);
lock (_lifecycleGate)
Withdraw(key, sendRemovals: false, forgetRequest: true);
}
return Task.CompletedTask;
}
private void PublishDemand(
CultNetDatabaseSubscribeMessage request,
SubscriptionKey key,
bool active)
{
DemandChanged?.Invoke(new CultNetDatabaseSubscriptionDemand(
string.IsNullOrWhiteSpace(request.ConsumerRuntimeId) ? key.Id : request.ConsumerRuntimeId!,
key.Id,
(request.RecordKeys ?? Array.Empty<string>())
.Where(value => !string.IsNullOrWhiteSpace(value))
.Distinct(StringComparer.Ordinal)
.ToArray(),
(request.SchemaIds ?? Array.Empty<string>())
.Where(value => !string.IsNullOrWhiteSpace(value))
.Distinct(StringComparer.Ordinal)
.ToArray(),
(request.BodyIds ?? Array.Empty<string>())
.Where(value => !string.IsNullOrWhiteSpace(value))
.Distinct(StringComparer.Ordinal)
.ToArray(),
(request.SupportedBodyTransports ?? Array.Empty<string>())
.Where(value => !string.IsNullOrWhiteSpace(value))
.Distinct(StringComparer.OrdinalIgnoreCase)
.ToArray(),
IsSameMachine(key.Peer),
active));
}
private static bool IsSameMachine(ICultNetSchemaServerPeer peer)
{
if (peer is ICultNetSchemaServerPeerLocation located && located.RemoteEndPoint is IPEndPoint ip)
return IPAddress.IsLoopback(ip.Address);
return false;
}
private IDisposable Watch(
CultNetDatabaseSubscribeMessage request,
string subscriptionId,
ICultNetSchemaServerPeer peer,
SubscriptionKey key)
{
return _database.WatchAllChanges().Subscribe(change =>
{
lock (_lifecycleGate)
{
if (_disposed || !_requests.ContainsKey(key) || !_projections.TryGetValue(key, out var projection))
return;
if (_authorizeRequest?.Invoke(request, peer) == false)
{
Reconcile(key, request);
return;
}
var sourceRecordKey = ResolveChangeRecordKey(change);
var message = CreateAuthorizedChange(change, request, subscriptionId, peer);
var projected = message?.Document;
if (projected != null && _projectRecord != null)
projected = _projectRecord(request, peer, projected);
ApplyProjectedChange(
projection,
sourceRecordKey,
projected,
peer,
subscriptionId);
}
});
}
private void Reconcile(SubscriptionKey key, CultNetDatabaseSubscribeMessage request)
{
if (!_projections.TryGetValue(key, out var projection)) return;
var authorized = _authorizeRequest?.Invoke(request, key.Peer) != false;
var next = authorized
? CreateProjectedSnapshot(request, key.Peer)
: ProjectedSnapshot.Empty;
foreach (var previous in projection.DeliveredBySourceRecordKey.ToArray())
{
if (!next.BySourceRecordKey.TryGetValue(previous.Key, out var current))
{
SendRemoval(key.Peer, key.Id, previous.Value);
continue;
}
if (!string.Equals(previous.Value.RecordKey, current.RecordKey, StringComparison.Ordinal) ||
!string.Equals(previous.Value.SchemaId, current.SchemaId, StringComparison.Ordinal))
{
SendRemoval(key.Peer, key.Id, previous.Value);
SendUpsert(key.Peer, key.Id, current, added: true);
}
else if (!Equivalent(previous.Value, current))
{
SendUpsert(key.Peer, key.Id, current, added: false);
}
}
foreach (var current in next.BySourceRecordKey)
{
if (!projection.DeliveredBySourceRecordKey.ContainsKey(current.Key))
SendUpsert(key.Peer, key.Id, current.Value, added: true);
}
projection.DeliveredBySourceRecordKey.Clear();
foreach (var current in next.BySourceRecordKey)
projection.DeliveredBySourceRecordKey[current.Key] = current.Value;
if (projection.DemandActive != authorized)
{
projection.DemandActive = authorized;
PublishDemand(request, key, authorized);
}
}
private ProjectedSnapshot CreateProjectedSnapshot(
CultNetDatabaseSubscribeMessage request,
ICultNetSchemaServerPeer peer)
{
var snapshot = _database.Documents.CreateRawSnapshotResponse(
_database.Cache,
request.MessageId,
new CultNetSnapshotRequestMessage
{
MessageId = request.MessageId,
SchemaIds = request.SchemaIds,
RecordKeys = request.RecordKeys
});
var bySourceRecordKey = new Dictionary<string, CultNetRawDocumentRecord>(StringComparer.Ordinal);
var projectedRecordKeys = new HashSet<string>(StringComparer.Ordinal);
foreach (var source in snapshot.Documents)
{
var sourceRecordKey = source.RecordKey;
if (_authorizeRecord?.Invoke(request, peer, sourceRecordKey, source.SchemaId) == false)
continue;
var projected = _projectRecord == null ? source : _projectRecord(request, peer, source);
if (projected == null) continue;
if (!projectedRecordKeys.Add(projected.RecordKey))
throw new InvalidOperationException(
$"Database subscription projection produced duplicate record key '{projected.RecordKey}'.");
bySourceRecordKey[sourceRecordKey] = projected;
}
return new ProjectedSnapshot(bySourceRecordKey);
}
private void ApplyProjectedChange(
SubscriptionProjectionState projection,
string sourceRecordKey,
CultNetRawDocumentRecord? current,
ICultNetSchemaServerPeer peer,
string subscriptionId)
{
projection.DeliveredBySourceRecordKey.TryGetValue(sourceRecordKey, out var previous);
if (current == null)
{
if (previous != null)
{
projection.DeliveredBySourceRecordKey.Remove(sourceRecordKey);
SendRemoval(peer, subscriptionId, previous);
}
return;
}
if (previous == null)
{
projection.DeliveredBySourceRecordKey[sourceRecordKey] = current;
SendUpsert(peer, subscriptionId, current, added: true);
return;
}
if (!string.Equals(previous.RecordKey, current.RecordKey, StringComparison.Ordinal) ||
!string.Equals(previous.SchemaId, current.SchemaId, StringComparison.Ordinal))
{
SendRemoval(peer, subscriptionId, previous);
projection.DeliveredBySourceRecordKey[sourceRecordKey] = current;
SendUpsert(peer, subscriptionId, current, added: true);
return;
}
if (!Equivalent(previous, current))
{
projection.DeliveredBySourceRecordKey[sourceRecordKey] = current;
SendUpsert(peer, subscriptionId, current, added: false);
}
}
private static string ResolveChangeRecordKey(object change)
{
var value = change.GetType().GetProperty("Key")?.GetValue(change);
return value is CultRecordKey key ? key.Value : string.Empty;
}
private static bool Equivalent(CultNetRawDocumentRecord left, CultNetRawDocumentRecord right) =>
string.Equals(left.SchemaId, right.SchemaId, StringComparison.Ordinal) &&
string.Equals(left.SchemaName, right.SchemaName, StringComparison.Ordinal) &&
string.Equals(left.SchemaVersion, right.SchemaVersion, StringComparison.Ordinal) &&
string.Equals(left.SchemaContentHash, right.SchemaContentHash, StringComparison.Ordinal) &&
string.Equals(left.RecordKey, right.RecordKey, StringComparison.Ordinal) &&
string.Equals(left.PayloadEncoding, right.PayloadEncoding, StringComparison.Ordinal) &&
left.Payload.SequenceEqual(right.Payload) &&
string.Equals(left.SourceRuntimeId, right.SourceRuntimeId, StringComparison.Ordinal) &&
string.Equals(left.SourceAgentId, right.SourceAgentId, StringComparison.Ordinal) &&
string.Equals(left.SourceRole, right.SourceRole, StringComparison.Ordinal);
private static void SendUpsert(
ICultNetSchemaServerPeer peer,
string subscriptionId,
CultNetRawDocumentRecord document,
bool added) =>
peer.SendCultNet(new CultNetDatabaseChangeRawMessage
{
MessageId = Guid.NewGuid().ToString("N"),
SubscriptionId = subscriptionId,
ChangeKind = added ? "added" : "updated",
Document = document
});
private static void SendRemoval(
ICultNetSchemaServerPeer peer,
string subscriptionId,
CultNetRawDocumentRecord document) =>
peer.SendCultNet(new CultNetDatabaseChangeRawMessage
{
MessageId = Guid.NewGuid().ToString("N"),
SubscriptionId = subscriptionId,
ChangeKind = "removed",
RecordKey = document.RecordKey,
SchemaId = document.SchemaId
});
private void Withdraw(SubscriptionKey key, bool sendRemovals, bool forgetRequest)
{
if (_subscriptions.TryRemove(key, out var subscription))
subscription.Dispose();
if (_projections.TryRemove(key, out var projection))
{
if (sendRemovals)
{
foreach (var delivered in projection.DeliveredBySourceRecordKey.Values)
SendRemoval(key.Peer, key.Id, delivered);
}
if (projection.DemandActive && _requests.TryGetValue(key, out var activeRequest))
PublishDemand(activeRequest, key, active: false);
}
if (forgetRequest)
_requests.TryRemove(key, out _);
}
private CultNetDatabaseChangeRawMessage? CreateAuthorizedChange(
object change,
CultNetDatabaseSubscribeMessage request,
string subscriptionId,
ICultNetSchemaServerPeer peer)
{
return CreateChangeCore(change, request, subscriptionId, (recordKey, schemaId) =>
_authorizeRecord?.Invoke(request, peer, recordKey, schemaId) != false);
}
private CultNetDatabaseChangeRawMessage? CreateChange(
object change,
CultNetDatabaseSubscribeMessage request,
string subscriptionId)
{
return CreateChangeCore(change, request, subscriptionId, (_, _) => true);
}
private CultNetDatabaseChangeRawMessage? CreateChangeCore(
object change,
CultNetDatabaseSubscribeMessage request,
string subscriptionId,
Func<string, string, bool> authorizeRecord)
{
var changeType = change.GetType();
var key = (CultRecordKey)(changeType.GetProperty("Key")?.GetValue(change) ?? new CultRecordKey(""));
if (request.RecordKeys is { Length: > 0 } && !request.RecordKeys.Contains(key.Value, StringComparer.Ordinal))
return null;
var kind = (CultNetDatabaseChangeKind)(changeType.GetProperty("Kind")?.GetValue(change) ?? CultNetDatabaseChangeKind.Updated);
var document = changeType.GetProperty("Document")?.GetValue(change);
if (kind == CultNetDatabaseChangeKind.Removed || document == null)
{
var previous = changeType.GetProperty("PreviousDocument")?.GetValue(change);
var schemaId = ResolveWireSchemaId(previous, (string?)changeType.GetProperty("SchemaId")?.GetValue(change) ?? "");
if (!MatchesRequestedSchema(request.SchemaIds, previous, schemaId))
return null;
if (!authorizeRecord(key.Value, schemaId))
return null;
return new CultNetDatabaseChangeRawMessage
{
MessageId = Guid.NewGuid().ToString("N"),
SubscriptionId = subscriptionId,
ChangeKind = "removed",
RecordKey = key.Value,
SchemaId = schemaId
};
}
var raw = CreateRawRecord(key, document);
if (!MatchesRequestedSchema(request.SchemaIds, document, raw.SchemaId))
return null;
if (!authorizeRecord(key.Value, raw.SchemaId))
return null;
return new CultNetDatabaseChangeRawMessage
{
MessageId = Guid.NewGuid().ToString("N"),
SubscriptionId = subscriptionId,
ChangeKind = kind == CultNetDatabaseChangeKind.Added ? "added" : "updated",
Document = raw
};
}
private string ResolveWireSchemaId(object? document, string fallback)
{
if (document == null) return fallback;
return _database.Documents.GetByDocumentType(document.GetType())?.SchemaId ?? fallback;
}
private bool MatchesRequestedSchema(string[]? requestedSchemaIds, object? document, string wireSchemaId)
{
if (requestedSchemaIds is not { Length: > 0 }) return true;
if (requestedSchemaIds.Contains(wireSchemaId, StringComparer.Ordinal)) return true;
return document != null && CultNetSchemaAliasMatching.MatchesAny(
requestedSchemaIds,
_database.Cache.Registry.GetRequired(document.GetType()));
}
private CultNetRawDocumentRecord CreateRawRecord(CultRecordKey key, object document)
{
var method = typeof(CultNetDocumentRegistry)
.GetMethods(BindingFlags.Public | BindingFlags.Instance)
.Single(candidate => candidate.Name == nameof(CultNetDocumentRegistry.CreateRawDocumentPutMessage) &&
candidate.IsGenericMethodDefinition);
var documentType = document.GetType();
var handle = Activator.CreateInstance(
typeof(CultRecordHandle<>).MakeGenericType(documentType),
new object[] { key });
var put = method.MakeGenericMethod(documentType)
.Invoke(_database.Documents, new[] { Guid.NewGuid().ToString("N"), handle, document, null });
return ((CultNetDocumentPutRawMessage)put!).Document;
}
private sealed class SubscriptionProjectionState
{
public Dictionary<string, CultNetRawDocumentRecord> DeliveredBySourceRecordKey { get; } =
new(StringComparer.Ordinal);
public bool DemandActive { get; set; }
}
private sealed class ProjectedSnapshot
{
public ProjectedSnapshot(Dictionary<string, CultNetRawDocumentRecord> bySourceRecordKey)
{
BySourceRecordKey = bySourceRecordKey;
Documents = bySourceRecordKey.Values.ToArray();
}
public static ProjectedSnapshot Empty { get; } =
new(new Dictionary<string, CultNetRawDocumentRecord>(StringComparer.Ordinal));
public Dictionary<string, CultNetRawDocumentRecord> BySourceRecordKey { get; }
public CultNetRawDocumentRecord[] Documents { get; }
}
private sealed class SubscriptionKey
{
public SubscriptionKey(ICultNetSchemaServerPeer peer, string id)
{
Peer = peer;
Id = id;
}
public ICultNetSchemaServerPeer Peer { get; }
public string Id { get; }
}
private sealed class SubscriptionKeyComparer : IEqualityComparer<SubscriptionKey>
{
public static SubscriptionKeyComparer Instance { get; } = new SubscriptionKeyComparer();
public bool Equals(SubscriptionKey? x, SubscriptionKey? y) =>
x != null && y != null && SamePeer(x.Peer, y.Peer) && string.Equals(x.Id, y.Id, StringComparison.Ordinal);
public int GetHashCode(SubscriptionKey value) =>
(PeerHash(value.Peer) * 397) ^ StringComparer.Ordinal.GetHashCode(value.Id);
internal static bool SamePeer(ICultNetSchemaServerPeer left, ICultNetSchemaServerPeer right)
{
if (ReferenceEquals(left, right)) return true;
if (left is RudpCultNetSchemaServerPeer leftRudp && right is RudpCultNetSchemaServerPeer rightRudp)
return ReferenceEquals(leftRudp.TransportPeer, rightRudp.TransportPeer);
if (left is CultNetServerPeer leftLite && right is CultNetServerPeer rightLite)
return ReferenceEquals(leftLite.Peer, rightLite.Peer);
return false;
}
private static int PeerHash(ICultNetSchemaServerPeer peer)
{
if (peer is RudpCultNetSchemaServerPeer rudp)
return RuntimeHelpers.GetHashCode(rudp.TransportPeer);
if (peer is CultNetServerPeer lite)
return RuntimeHelpers.GetHashCode(lite.Peer);
return RuntimeHelpers.GetHashCode(peer);
}
}
}
/// <summary>One active or withdrawn exact state subscription and its optional hot-body route.</summary>
public sealed class CultNetDatabaseSubscriptionDemand
{
public CultNetDatabaseSubscriptionDemand(
string consumerRuntimeId,
string subscriptionId,
IReadOnlyList<string> bodyIds,
IReadOnlyList<string> supportedBodyTransports,
bool sameMachine,
bool active)
: this(
consumerRuntimeId,
subscriptionId,
Array.Empty<string>(),
Array.Empty<string>(),
bodyIds,
supportedBodyTransports,
sameMachine,
active)
{
}
public CultNetDatabaseSubscriptionDemand(
string consumerRuntimeId,
string subscriptionId,
IReadOnlyList<string> recordKeys,
IReadOnlyList<string> schemaIds,
IReadOnlyList<string> bodyIds,
IReadOnlyList<string> supportedBodyTransports,
bool sameMachine,
bool active)
{
ConsumerRuntimeId = consumerRuntimeId;
SubscriptionId = subscriptionId;
RecordKeys = recordKeys;
SchemaIds = schemaIds;
BodyIds = bodyIds;
SupportedBodyTransports = supportedBodyTransports;
SameMachine = sameMachine;
Active = active;
}
public string ConsumerRuntimeId { get; }
public string SubscriptionId { get; }
public IReadOnlyList<string> RecordKeys { get; }
public IReadOnlyList<string> SchemaIds { get; }
public IReadOnlyList<string> BodyIds { get; }
public IReadOnlyList<string> SupportedBodyTransports { get; }
public bool SameMachine { get; }
public bool Active { get; }
}
}