Class PartyUpdateService

Namespace

FishMMO.Database.Npgsql.Services

Assembly

FishMMO-DB.dll

Service for managing party update notifications in the database. Tracks when parties have been modified so clients can poll for changes. Implements execution strategies for automatic retry on transient database failures. Returns DatabaseResult for consistent, safe error handling.

public sealed class PartyUpdateService : BaseService<PartyUpdateEntity>, IPartyUpdateService

Inheritance

object

BaseService<PartyUpdateEntity>

PartyUpdateService

Implements

IPartyUpdateService

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.ReferenceEquals(object, object)

object.ToString()

Remarks

This service manages party update tracking including:

• Recording party updates with atomic UPSERT operations
• Fetching parties modified since a given timestamp
• Cleaning up update records for deleted parties

Database operations are executed via the BaseService execution wrappers for:

• Automatic transient failure retry
• Centralized exception handling and mapping
• Consistent DatabaseResult pattern

The update tracking pattern allows clients to efficiently poll for changes without needing to re-fetch all party data on each request.

Constructors

PartyUpdateService(INpgsqlDbContextFactory)

Initializes a new instance of PartyUpdateService.

public PartyUpdateService(INpgsqlDbContextFactory dbContextFactory)

Parameters

dbContextFactory INpgsqlDbContextFactory

DbContext factory for creating contexts.

Exceptions

ArgumentNullException

Thrown when dbContextFactory is null.

Methods

DeleteAsync(long, CancellationToken)

Deletes all update records for a party.

public Task<DatabaseResult<int>> DeleteAsync(long partyId, CancellationToken cancellationToken = default)

Parameters

partyId long

Party ID.

cancellationToken CancellationToken

Cancellation token.

Returns

Task<DatabaseResult<int>>

A DatabaseResult<T> containing the number of records deleted on success, or a DatabaseException on failure.

Remarks

This is an idempotent cleanup operation. Unlike entity delete methods, this method does NOT throw DatabaseEntityNotFoundException when no records exist. Instead, it returns 0 rows deleted. This design supports safe concurrent cleanup where multiple callers may attempt to delete the same records.

Uses a single-statement DELETE.

FetchAsync(List<long>, DateTime, CancellationToken)

Fetches party update records for specified parties updated since last fetch.

public Task<DatabaseResult<List<PartyUpdateData>>> FetchAsync(List<long> partyIds, DateTime lastFetch, CancellationToken cancellationToken = default)

Parameters

partyIds List<long>

List of party IDs to check.

lastFetch DateTime

Timestamp to compare against.

cancellationToken CancellationToken

Cancellation token.

Returns

Task<DatabaseResult<List<PartyUpdateData>>>

A DatabaseResult<T> containing the list of party update data on success, or a DatabaseException on failure.

Remarks

Filters by both timestamp and party ID list.

PersistAsync(long, CancellationToken)

Saves or updates the last update timestamp for a party using atomic UPSERT.

public Task<DatabaseResult> PersistAsync(long partyId, CancellationToken cancellationToken = default)

Parameters

partyId long

Party ID.

cancellationToken CancellationToken

Cancellation token.

Returns

Task<DatabaseResult>

A DatabaseResult indicating success or containing a DatabaseException on failure.

Remarks

Uses a single-statement PostgreSQL INSERT ... ON CONFLICT DO UPDATE with a conditional update to avoid regressing last_update.