BirthdayBot/BackgroundServices/DataRetention.cs
Noi 6f34fbe657 Modified all background services
-Removed a number of diagnostic messages
-Removed ConnectionStatus, connection scores, etc.
-Modified work intervals for certain background tasks
-Updated code style
2021-10-14 18:55:04 -07:00

113 lines
5.6 KiB
C#

using BirthdayBot.Data;
using NpgsqlTypes;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
namespace BirthdayBot.BackgroundServices;
/// <summary>
/// Automatically removes database information for guilds that have not been accessed in a long time.
/// </summary>
class DataRetention : BackgroundService {
private static readonly SemaphoreSlim _updateLock = new(ShardManager.MaxConcurrentOperations);
const int ProcessInterval = 3600 / ShardBackgroundWorker.Interval; // Process about once per hour
const int Stagger = 3; // How many ticks in between each group of guilds to stagger processing.
public DataRetention(ShardInstance instance) : base(instance) { }
public override async Task OnTick(int tickCount, CancellationToken token) {
// On each tick, run only a set group of guilds, each group still processed every ProcessInterval ticks.
if ((tickCount + ShardInstance.ShardId * Stagger) % ProcessInterval != 0) return;
try {
// A semaphore is used to restrict this work being done concurrently on other shards
// to avoid putting pressure on the SQL connection pool. Clearing old database information
// ultimately is a low priority among other tasks.
await _updateLock.WaitAsync(token).ConfigureAwait(false);
} catch (Exception ex) when (ex is OperationCanceledException or ObjectDisposedException) {
// Caller does not expect the exception that SemaphoreSlim throws...
throw new TaskCanceledException();
}
try {
// Build a list of all values to update
var updateList = new Dictionary<ulong, List<ulong>>();
foreach (var g in ShardInstance.DiscordClient.Guilds) {
// Get list of IDs for all users who exist in the database and currently exist in the guild
var userList = GuildUserConfiguration.LoadAllAsync(g.Id);
var guildUserIds = from gu in g.Users select gu.Id;
var savedUserIds = from cu in await userList.ConfigureAwait(false) select cu.UserId;
var existingCachedIds = savedUserIds.Intersect(guildUserIds);
updateList[g.Id] = existingCachedIds.ToList();
}
using var db = await Database.OpenConnectionAsync().ConfigureAwait(false);
// Statement for updating last_seen in guilds
var cUpdateGuild = db.CreateCommand();
cUpdateGuild.CommandText = $"update {GuildConfiguration.BackingTable} set last_seen = now() "
+ "where guild_id = @Gid";
var pUpdateG = cUpdateGuild.Parameters.Add("@Gid", NpgsqlDbType.Bigint);
cUpdateGuild.Prepare();
// Statement for updating last_seen in guild users
var cUpdateGuildUser = db.CreateCommand();
cUpdateGuildUser.CommandText = $"update {GuildUserConfiguration.BackingTable} set last_seen = now() "
+ "where guild_id = @Gid and user_id = @Uid";
var pUpdateGU_g = cUpdateGuildUser.Parameters.Add("@Gid", NpgsqlDbType.Bigint);
var pUpdateGU_u = cUpdateGuildUser.Parameters.Add("@Uid", NpgsqlDbType.Bigint);
cUpdateGuildUser.Prepare();
// Do actual updates
int updatedGuilds = 0;
int updatedUsers = 0;
foreach (var item in updateList) {
var guild = item.Key;
var userlist = item.Value;
pUpdateG.Value = (long)guild;
updatedGuilds += await cUpdateGuild.ExecuteNonQueryAsync(CancellationToken.None).ConfigureAwait(false);
pUpdateGU_g.Value = (long)guild;
foreach (var userid in userlist) {
pUpdateGU_u.Value = (long)userid;
updatedUsers += await cUpdateGuildUser.ExecuteNonQueryAsync(CancellationToken.None).ConfigureAwait(false);
}
}
var resultText = new StringBuilder();
resultText.Append($"Updated {updatedGuilds} guilds, {updatedUsers} users.");
// Delete all old values - expects referencing tables to have 'on delete cascade'
using var t = db.BeginTransaction();
int staleGuilds, staleUsers;
using (var c = db.CreateCommand()) {
// Delete data for guilds not seen in 4 weeks
c.CommandText = $"delete from {GuildConfiguration.BackingTable} where (now() - interval '28 days') > last_seen";
staleGuilds = await c.ExecuteNonQueryAsync(CancellationToken.None).ConfigureAwait(false);
}
using (var c = db.CreateCommand()) {
// Delete data for users not seen in 8 weeks
c.CommandText = $"delete from {GuildUserConfiguration.BackingTable} where (now() - interval '56 days') > last_seen";
staleUsers = await c.ExecuteNonQueryAsync(CancellationToken.None).ConfigureAwait(false);
}
if (staleGuilds != 0 || staleUsers != 0) {
resultText.Append(" Discarded ");
if (staleGuilds != 0) {
resultText.Append($"{staleGuilds} guilds");
if (staleUsers != 0) resultText.Append(", ");
}
if (staleUsers != 0) {
resultText.Append($"{staleUsers} standalone users");
}
resultText.Append('.');
}
t.Commit();
Log(resultText.ToString());
} finally {
_updateLock.Release();
}
}
}