/// <summary>
/// Allocates a session from the pool if possible, or creates a new Spanner Session.
/// </summary>
/// <param name="spannerClient">The client to associate with the session. Must not be null.</param>
/// <param name="project">The project of the session. Must not be null.</param>
/// <param name="spannerInstance">The instance of the session. Must not be null.</param>
/// <param name="spannerDatabase">The database of the session. Must not be null.</param>
/// <param name="options">The transaction options for the session. Must not be null.</param>
/// <param name="cancellationToken">A cancellation token for the asynchronous operation.</param>
/// <returns>A task which, when completed, will return the session.</returns>
public async Task <Session> CreateSessionFromPoolAsync(
SpannerClient spannerClient,
string project,
string spannerInstance,
string spannerDatabase,
TransactionOptions options,
CancellationToken cancellationToken)
{
GaxPreconditions.CheckNotNull(spannerClient, nameof(spannerClient));
GaxPreconditions.CheckNotNull(project, nameof(project));
GaxPreconditions.CheckNotNull(spannerInstance, nameof(spannerInstance));
GaxPreconditions.CheckNotNull(spannerDatabase, nameof(spannerDatabase));
GaxPreconditions.CheckNotNull(options, nameof(options));
await StartSessionCreatingAsync(cancellationToken).ConfigureAwait(false);
Session sessionResult = null;
SessionPoolKey sessionPoolKey = default;
try
{
sessionPoolKey = new SessionPoolKey(spannerClient, project, spannerInstance, spannerDatabase);
SessionPoolImpl targetPool = _poolByClientAndDatabase.GetOrAdd(sessionPoolKey, key => new SessionPoolImpl(key, Options));
sessionResult = await targetPool.AcquireSessionAsync(options, cancellationToken).ConfigureAwait(false);
// Refresh the MRU list which tells us what sessions need to be trimmed from the pool when we want
// to add another poolEntry.
return(sessionResult);
}
finally
{
EndSessionCreating(sessionResult, sessionPoolKey);
}
}
// Only present for testing.
internal int GetPoolSize(SpannerClient spannerClient, string project, string spannerInstance, string spannerDatabase)
{
GaxPreconditions.CheckNotNull(spannerClient, nameof(spannerClient));
GaxPreconditions.CheckNotNull(project, nameof(project));
GaxPreconditions.CheckNotNull(spannerInstance, nameof(spannerInstance));
GaxPreconditions.CheckNotNull(spannerDatabase, nameof(spannerDatabase));
var sessionPoolKey = new SessionPoolKey(spannerClient, project, spannerInstance, spannerDatabase);
SessionPoolImpl targetPool = _poolByClientAndDatabase.GetOrAdd(sessionPoolKey, key => new SessionPoolImpl(key, Options));
return(targetPool.GetPoolSize());
}
private void EndSessionCreating(Session sessionResult, SessionPoolKey sessionPoolKey)
{
lock (_waitSync)
{
if (sessionResult != null)
{
_sessionsInUse.AddOrUpdate(sessionResult,
x => sessionPoolKey,
(x, y) => sessionPoolKey);
}
_sessionsCreating--;
LogSessionsInUse();
//signal more queue entries (in fair order) if we still have room.
SignalAnyWaitingRequests();
}
}
internal int GetPoolSize(
SpannerClient spannerClient,
string project,
string spannerInstance,
string spannerDatabase)
{
project.ThrowIfNullOrEmpty(nameof(project));
spannerInstance.ThrowIfNullOrEmpty(nameof(spannerInstance));
spannerDatabase.ThrowIfNullOrEmpty(nameof(spannerDatabase));
var sessionPoolKey = new SessionPoolKey(spannerClient,
project,
spannerInstance,
spannerDatabase);
SessionPoolImpl targetPool = _poolByClientAndDatabase.GetOrAdd(sessionPoolKey,
key => new SessionPoolImpl(key, Options));
return(targetPool.GetPoolSize());
}
/// <summary>
/// Allocates a session from the pool if possible, or creates a new Spanner Session.
/// </summary>
/// <param name="spannerClient"></param>
/// <param name="project"></param>
/// <param name="spannerInstance"></param>
/// <param name="spannerDatabase"></param>
/// <param name="options"></param>
/// <param name="cancellationToken"></param>
/// <returns></returns>
public static async Task <Session> CreateSessionFromPoolAsync(
this SpannerClient spannerClient,
string project,
string spannerInstance,
string spannerDatabase,
TransactionOptions options,
CancellationToken cancellationToken)
{
project.ThrowIfNullOrEmpty(nameof(project));
spannerInstance.ThrowIfNullOrEmpty(nameof(spannerInstance));
spannerDatabase.ThrowIfNullOrEmpty(nameof(spannerDatabase));
await StartSessionCreatingAsync(cancellationToken).ConfigureAwait(false);
Session sessionResult = null;
SessionPoolKey sessionPoolKey = default(SessionPoolKey);
try
{
sessionPoolKey = new SessionPoolKey(spannerClient,
project,
spannerInstance,
spannerDatabase);
SessionPoolImpl targetPool = s_poolByClientAndDatabase.GetOrAdd(sessionPoolKey,
key => new SessionPoolImpl(key));
sessionResult = await targetPool.AcquireSessionAsync(options, cancellationToken).ConfigureAwait(false);
//refresh the mru list which tells us what sessions need to be trimmed from the pool when we want
// to add another poolEntry.
ReSortMru(targetPool);
return(sessionResult);
} finally
{
EndSessionCreating(sessionResult, sessionPoolKey);
}
}
internal SessionPoolImpl(SessionPoolKey key)
{
Key = key;
}
internal SessionPoolImpl(SessionPoolKey key, SessionPoolOptions options)
{
_options = GaxPreconditions.CheckNotNull(options, nameof(options));
_sessionCreateThrottle = new SemaphoreSlim(_options.MaximumConcurrentSessionCreates, _options.MaximumConcurrentSessionCreates);
Key = key;
}
