/// <summary>
/// Used with deserialized channels, doesn't bind any event handlers
/// </summary>
/// <param name="log"></param>
/// <param name="hint"></param>
/// <param name="channel"></param>
/// <param name="eventCount"></param>
public ChannelLogger(FileLog log, FileLog.ChannelInfo hint, IChannel channel, int eventCount)
{
this.log = log;
this.hint = hint;
this.channel = channel;
this.eventCount = eventCount;
}
/// <summary>
/// Reads several consecutive events - more efficient than reading one by one using ReadEvent.
/// Note that all required events must already be written, this method doesn't check that.
/// </summary>
/// <param name="hint">channel info hint</param>
/// <param name="firstID">ID of the first required event</param>
/// <param name="count">number of consecutive events to return</param>
/// <returns></returns>
public IList <Event> ReadEvents(FileLog.ChannelInfo hint, int firstID, int count)
{
var ret = new List <Event>(count);
int off;
var table = getEventTableByIndex(hint.Hint + 2 * sizeof(long), firstID, out off);
lock (streamLock)
{
var initialPos = stream.Position;
while (count > 0)
{
while (count > 0 && off <= FileLog.EventsPerBlock)
{
stream.Position = table + off * sizeof(long);
ret.Add(readEventByPointer(binReader.ReadInt64()));
off++;
count--;
}
stream.Position = table;
// next table
table = binReader.ReadInt64();
off = 1; // 0 is a pointer to next table
}
stream.Position = initialPos;
}
return(ret);
}
/// <summary>
/// Normal constructor
/// </summary>
/// <param name="log"></param>
/// <param name="hint"></param>
/// <param name="channel"></param>
public ChannelLogger(FileLog log, FileLog.ChannelInfo hint, IChannel channel): this()
{
this.log = log;
this.hint = hint;
this.channel = channel;
generalHandler(EventType.ChannelCreated);
channel.BindAllEvents(handlers);
}
/// <summary>
/// Get channels event count
/// </summary>
/// <param name="hint">a pointer to correct channelInfo structure</param>
/// <returns>channel's event count</returns>
public int GetEventCount(FileLog.ChannelInfo hint)
{
lock (streamLock)
{
var initialPos = stream.Position;
// first (long) is a pointer to channel data
stream.Position = hint.Hint + sizeof(long);
var ret = binReader.ReadInt64();
stream.Position = initialPos;
return((int)ret);
}
}
/// <summary>
/// Reads Event from log
/// </summary>
/// <param name="hint">a pointer to channel info structure</param>
/// <param name="id">1-based Event ID</param>
/// <returns>Event</returns>
public Event ReadEvent(FileLog.ChannelInfo hint, int id)
{
lock (streamLock)
{
var initialPos = stream.Position;
int off;
// + 2*sizeof(long) to skip the pointer to channel data and event count
var table = getEventTableByIndex(hint.Hint + 2 * sizeof(long), id, out off);
stream.Position = table + off * sizeof(long);
var ret = readEventByPointer(binReader.ReadInt64());
stream.Position = initialPos;
return(ret);
}
}
