// TODO: Currenly the last items are omitted with this variant. Use Listen() instead.
public async IAsyncEnumerable <(string, long, long)> ListenAsync_(int flushSize)
{
// Always start from beginning. Assume it is refilled or truncate works.
using (FasterLogScanIterator iter = logger.Scan(0, 1_000_000_000, name: "listen"))
{
int i = 0;
await foreach ((byte[] bytes, int length) in iter.GetAsyncEnumerable())
{
if (i >= flushSize)
{
nextAddress = iter.NextAddress;
break;
}
CancellationTokenSource cts = new CancellationTokenSource();
UTF8Encoding encoding = new UTF8Encoding();
i++;
// Probably shouldn't wait
// - https://microsoft.github.io/FASTER/docs/fasterlog#iteration
yield return(encoding.GetString(bytes), iter.CurrentAddress, iter.NextAddress);
}
}
}
public async IAsyncEnumerable <(string, long, long)> GetListAsync()
{
using (FasterLogScanIterator iter = logger.Scan(nextAddress, 100_000_000))
{
int i = 0;
await foreach ((byte[] bytes, int length) in iter.GetAsyncEnumerable())
{
if (i > 50)
{
nextAddress = iter.NextAddress;
break;
}
CancellationTokenSource cts = new CancellationTokenSource();
UTF8Encoding encoding = new UTF8Encoding();
try
{
await Task.WhenAny(WaitAsync(iter, cts.Token), SetTimeout(cts));
i++;
}
catch (Exception)
{
break;
}
yield return(encoding.GetString(bytes), iter.CurrentAddress, iter.NextAddress);
}
}
}
static async Task AsyncScan()
{
await foreach ((byte[] result, int length, long currentAddress) in iter.GetAsyncEnumerable())
{
if (Different(result, staticEntry))
{
throw new Exception("Invalid entry found");
}
log.TruncateUntilPageStart(iter.NextAddress);
}
}
static async Task AsyncScan()
{
using (iter = log.Scan(log.BeginAddress, long.MaxValue))
await foreach ((byte[] result, int length) in iter.GetAsyncEnumerable())
{
if (Different(result, staticEntry, out int location))
{
throw new Exception("Invalid entry found");
}
log.TruncateUntil(iter.NextAddress);
}
}
public async Task <List <(string, long, long)> > StartScan(string devicePath)
{
IDevice device = Devices.CreateLogDevice(devicePath);
FasterLog logger = new FasterLog(new FasterLogSettings {
LogDevice = device
});
long nextAddress = 0;
bool keepGoing = true;
int i = 0;
var result = new List <(string, long, long)>();
// using (FasterLogScanIterator iter = logger.Scan(logger.BeginAddress, 100_000_000, name: nameof(GetListAsync)))
using (FasterLogScanIterator iter = logger.Scan(nextAddress, 1_000_000_000))
{
while (keepGoing)
{
Console.WriteLine("Going");
LocalTime timeOfDay;
await foreach ((byte[] bytes, int length) in iter.GetAsyncEnumerable())
{
DateTimeZone tz = DateTimeZoneProviders.Tzdb.GetSystemDefault();
timeOfDay = SystemClock.Instance.GetCurrentInstant().InZone(tz).TimeOfDay;
nextAddress = iter.NextAddress;
Console.WriteLine("Time={1} NextAddress={0}, Count={2}", iter.NextAddress, timeOfDay, i++);
var cts = new CancellationTokenSource();
UTF8Encoding encoding = new UTF8Encoding();
try
{
await Task.WhenAny(WaitAsync(iter), SetTimeout(cts));
}
catch (Exception e)
{
Console.Error.WriteLine($"Error={e.GetType()}, Message={e.ToString()}");
break;
}
timeOfDay = SystemClock.Instance.GetCurrentInstant().InZone(tz).TimeOfDay;
Console.WriteLine("Time={2} ContentLength={0}", bytes.Length, iter.NextAddress, timeOfDay);
}
await Task.Delay(5000);
}
}
return(result);
}
