/// <summary>
/// Checkout out a <see cref="Guild"/>.
/// </summary>
/// <param name="guildId">An id representing a guild.</param>
/// <param name="recycleResult">A preallocated result that should be returned if passed in.</param>
/// <returns>The borrowed guild.</returns>
public async Task <GuildCheckoutResult> Checkout(Snowflake guildId, GuildCheckoutResult recycleResult = null)
{
var retVal = recycleResult ?? new GuildCheckoutResult();
try
{
string blobName = AzureBlobGuildRepository.GetBlobName(guildId);
var blobClient = this.blobContainerClient.GetBlockBlobClient(blobName);
// Aquire a lease on the blob
var blobLeaseClient = blobClient.GetBlobLeaseClient();
var leaseResult = await blobLeaseClient.AcquireAsync(AzureBlobGuildRepository.BlobLeaseDuration).ConfigureAwait(false);
var lease = leaseResult.Value;
Guild guild;
using (var sourceStream = await blobClient.OpenReadAsync())
using (var streamReader = new StreamReader(sourceStream))
using (var jsonReader = new JsonTextReader(streamReader))
{
guild = GuildConverter.FromJToken(guildId, await JObject.ReadFromAsync(jsonReader));
}
retVal.ToSuccess(new Borrowed <Guild>(
isntance: guild,
data: lease,
onReturn: this.ReturnGuild));
return(retVal);
}
catch (RequestFailedException e)
{
if (e.Status == AzureBlobGuildRepository.NotFoundStatus)
{
retVal.ToDoesNotExist();
return(retVal);
}
else if (e.Status == AzureBlobGuildRepository.ConflictStatus && "LeaseAlreadyPresent".Equals(e.ErrorCode, StringComparison.OrdinalIgnoreCase))
{
retVal.ToLocked();
return(retVal);
}
else
{
throw;
}
}
}
/// <summary>
/// The action invoked when a <see cref="Borrowed<T>"/> is being returned.
/// </summary>
/// <param name="guild">The guild that's being returned.</param>
/// <param name="data">
/// The object placed into the data field at the construction of the <see cref="Borrowed<T>"/>.
/// </param>
/// <param name="commit">
/// True if the user wanted to commit the changes, false if they wanted them discarded.
/// </param>
private void ReturnGuild(Guild guild, object data, bool commit)
{
string blobName = AzureBlobGuildRepository.GetBlobName(guild.Id);
var blobLease = (BlobLease)data;
var blobClient = this.blobContainerClient.GetBlockBlobClient(blobName);
// Get the lease client and populate the lease information in the request options
var blobLeaseClient = blobClient.GetBlobLeaseClient(blobLease.LeaseId);
var blobRequestConditions = new BlobRequestConditions()
{
LeaseId = blobLeaseClient.LeaseId
};
if (commit)
{
JsonSerializer serializer = new JsonSerializer();
#if DEBUG
serializer.Formatting = Formatting.Indented;
#else
serializer.Formatting = Formatting.None;
#endif
using (var stream = blobClient.OpenWrite(overwrite: true, new BlockBlobOpenWriteOptions()
{
OpenConditions = blobRequestConditions
}))
using (var streamWriter = new StreamWriter(stream))
using (var writer = new JsonTextWriter(streamWriter))
{
serializer.Serialize(writer, GuildConverter.ToJToken(guild));
}
}
// Release the lease on the blob
blobLeaseClient.Release();
}