FileEventStreamSearch

java.lang.Object
- edu.stanford.slac.archiverappliance.PB.search.FileEventStreamSearch

```
public class FileEventStreamSearch
extends Object
```
This is a variant of binary search that searches for an event in a event stream file. We assume a time-sorted PB file separated by unix newlines as outlined in the archiver appliance design doc. We pass in file channel and a function that compares an event line (most likely a PB) to the desired time t1. The fileChannels position is moved to a spot where this constraint is satisfied s1 ≤ t1 < s2 That is
1. Search the file for a time t1
2. Do a LineByteStream.seekToFirstNewLine
3. LineByteStream.readLine's after this should give events that satisfy getData's requirements.
4. Remember to terminate appropriately
Author:

mshankar

Constructor Summary

Constructors
Constructor Description

FileEventStreamSearch(Path path, long startPosn)

Method Summary

Modifier and Type	Method	Description
`long`	`getFoundPosition()`
`boolean`	`seekToTime(CompareEventLine comparefunction)`	This should only be used by the unit tests.
`boolean`	`seekToTime(ArchDBRTypes dbrtype, int secondsIntoYear)`	Set the fileChannels position to a point that best satisfies the requirements for getData(t1,...).

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - FileEventStreamSearch
```
public FileEventStreamSearch(Path path,
                             long startPosn)
```
    Parameters:
    
    path - Path
    
    startPosn - a starting position of search PB files
- Method Detail
  - getFoundPosition
```
public long getFoundPosition()
```
  - seekToTime
```
public boolean seekToTime(ArchDBRTypes dbrtype,
                          int secondsIntoYear)
                   throws IOException
```
    Set the fileChannels position to a point that best satisfies the requirements for getData(t1,...). If found (return value is true), the file's position is set such that LineByteStream lis = new LineByteStream(fchannel); lis.seekToFirstNewLine(); byte[] line = lis.readLine(); starts returning events that satisfy getData's requirements
    
    Parameters:
    
    dbrtype - ArchDBRType the enumeration type
    
    secondsIntoYear - Search seconds into year
    
    Returns:
    
    true or false
    
    Throws:
    
    IOException -
    
    See Also:
    
    ComparePBEvent
  - seekToTime
```
public boolean seekToTime(CompareEventLine comparefunction)
                   throws IOException
```
    This should only be used by the unit tests.
    
    Parameters:
    
    comparefunction - CompareEventLine
    
    Returns:
    
    true or false
    
    Throws:
    
    IOException - when parsing the absolute path