private async Task TryLoadManifestAsync()
{
//Avoid unnecessary lock contention way after manifest is loaded by checking before lock
if (CacheManifest is null)
{
await ManifestLock.WaitAsync();
try
{
//Check that once we have lock (due to a race condition on the outer check) that we still need to load the manifest
if (CacheManifest is null)
{
if (File.Exists(ManifestPath))
{
CacheManifest = await DeserializeFileAsync<ConcurrentDictionary<string?, IManifestEntry>>(ManifestPath);
}
else
{
if (!Directory.Exists(DirectoryPath))
{
Directory.CreateDirectory(DirectoryPath);
}
CacheManifest = new ConcurrentDictionary<string?, IManifestEntry>();
await SerializeFileAsync(ManifestPath, CacheManifest);
}
}
}
finally
{
ManifestLock.Release();
}
}
}
/// <summary>
/// Saves the cache manifest to the file system.
/// </summary>
/// <returns></returns>
public async Task SaveManifestAsync()
{
await ManifestLock.WaitAsync();
try
{
if (!Directory.Exists(DirectoryPath))
{
Directory.CreateDirectory(DirectoryPath);
}
await SerializeFileAsync(ManifestPath, CacheManifest);
}
finally
{
ManifestLock.Release();
}
}
