protected override async Task ExecuteAsync(CancellationToken stoppingToken)
{
while (!stoppingToken.IsCancellationRequested)
{
try
{
if (!Enabled)
{
goto sleep;
}
await using (await _locker.EnterAsync($"scrape:{Type}", stoppingToken))
{
_logger.LogDebug($"Begin {Type} scrape.");
await TestAsync(stoppingToken);
using (_scrapingTime.Labels(Type.ToString()).Measure())
await RunAsync(stoppingToken);
_logger.LogDebug($"End {Type} scrape.");
}
}
catch (Exception e)
{
_scrapeErrors.Labels(Type.ToString()).Inc();
_logger.LogWarning(e, $"Exception while scraping {Type}.");
}
sleep:
await Task.Delay(_options.CurrentValue.Interval, stoppingToken);
}
}
public async Task IndexAsync(DbBook[] books, CancellationToken cancellationToken = default)
{
books = DryMerge(books);
// must prevent concurrent book indexing because unique books are created in bulk
await using (await _locker.EnterAsync("index:book", cancellationToken))
{
// refresh immediately to speed up indexing
using (_client.UseIndexingOptions(new IndexingOptions {
Refresh = Refresh.True
}))
await CreateAsync(await MergeAsync(books, cancellationToken), cancellationToken);
}
}
protected sealed override async Task ExecuteAsync(CancellationToken stoppingToken)
{
while (!stoppingToken.IsCancellationRequested)
{
try
{
if (!Enabled)
{
goto sleep;
}
await using (await _writeControl.EnterAsync(stoppingToken))
await using (await _locker.EnterAsync($"scrape:{Type}", stoppingToken))
{
_logger.LogDebug($"Begin {Type} scrape.");
// run tests before scrape
await TestAsync(stoppingToken);
// load last state from storage
var state = await _storage.ReadObjectAsync <TState>($"scrapers/{Type}/state", stoppingToken) ?? new TState();
// execute scraper
using (ScraperMetrics.ScrapingTime.Labels(Type.ToString()).Measure())
await RunAsync(state, stoppingToken);
// save state
await _storage.WriteObjectAsync($"scrapers/{Type}/state", state, stoppingToken);
if (_logger.IsEnabled(LogLevel.Debug))
{
_logger.LogDebug($"Saved scraper state {Type}: {JsonConvert.SerializeObject(state)}");
}
_logger.LogDebug($"End {Type} scrape.");
}
}
catch (Exception e)
{
SentrySdk.CaptureException(e);
ScraperMetrics.ScrapeErrors.Labels(Type.ToString()).Inc();
_logger.LogWarning(e, $"Exception while scraping {Type}.");
}
sleep:
await Task.Delay(_options.CurrentValue.Interval, stoppingToken);
}
}
public async Task <DbUser> GetOrCreateUserAsync(DiscordOAuthUser user, CancellationToken cancellationToken = default)
{
await using (await _locker.EnterAsync($"oauth:discord:{user.Id}", cancellationToken))
{
var entry = await GetByIdAsync(user.Id, cancellationToken);
// if user already exists, update their info
if (entry != null)
{
do
{
user.ApplyOn(entry.Value);
}while (!await entry.TryUpdateAsync(cancellationToken));
}
// otherwise create new user
else
{
entry = _client.Entry(_users.MakeUserObject());
user.ApplyOn(entry.Value);
await entry.CreateAsync(cancellationToken);
await _snapshots.CreateAsync(entry.Value, new SnapshotArgs
{
Source = SnapshotSource.User,
Committer = entry.Value,
Event = SnapshotEvent.AfterCreation,
Reason = $"Registered via Discord OAuth2 '{user.Username}'."
}, cancellationToken);
}
return(entry.Value);
}
}
public async Task RunAsync(CancellationToken cancellationToken = default)
{
// block database writes
await _writeControl.BlockAsync(cancellationToken);
await using (await _locker.EnterAsync("maintenance:migrations", cancellationToken))
{
var options = _options.CurrentValue;
var indexes = await _elastic.RequestAsync(c => c.Cat.IndicesAsync(cc => cc.Index($"{options.IndexPrefix}*"), cancellationToken));
var count = 0;
// not all indexes get migrated every migration, so use the max
var lastMigrationId = indexes.Records.Select(r => TryParseIndexName(r.Index, out _, out var migrationId) ? migrationId : 0).Max();
foreach (var nextMigrationId in MigrationTypes.Keys.OrderBy(x => x))
{
if (nextMigrationId <= lastMigrationId)
{
continue;
}
var migration = (MigrationBase)ActivatorUtilities.CreateInstance(_services, MigrationTypes[nextMigrationId]);
_logger.LogWarning($"Applying migration {migration.Id}.");
try
{
using var measure = new MeasureContext();
await migration.RunAsync(cancellationToken);
_logger.LogInformation($"Successfully migrated {migration.Id} in {measure}.");
}
catch (Exception e)
{
_logger.LogError(e, $"Could not apply migration {migration.Id}.");
foreach (var index in migration.IndexesCreated)
{
try
{
await _elastic.RequestAsync(c => c.Indices.DeleteAsync(index, null, cancellationToken));
_logger.LogInformation($"Deleted incomplete index '{index}'.");
}
catch (Exception ee)
{
_logger.LogWarning(ee, $"Could not delete incomplete index '{index}'.");
}
}
break;
}
count++;
}
_logger.LogInformation($"All {count} migration(s) applied.");
}
}
