Python File Reader

The Rogue FileReader class is a lightweight python class which can be used on its own with minimal dependencies. The file reader supports processing store data frame by frame and supports automatic extraction of configuration and status information which may exist in a specificed “config channel”. The passed file parameter can be a single file or a list of segemented data files.

The most current file can be downloaded from:

https://github.com/slaclab/rogue/blob/master/python/pyrogue/utilities/fileio/_FileReader.py

Below is an example of using the FileReader in a python script:

with FileReader(files="mydata.dat",configChan=1) as fd:

   # Loop through the file data
   for header,data in fd.records():

      # Look at record header data
      print(f"Processing record. Total={fd.totCount}, Current={fd.currCount}")
      print(f"Record size    = {header.size}")
      print(f"Record channel = {header.channel}")
      print(f"Record flags   = {header.flags:#x}")
      print(f"Record error   = {header.error:#x}")

      # Do something with the data here:
      for i in range(header.size):
         print(f" Byte {i} = {data[i]:#x}")

      # At any time you can access the current config and status state
      print(f"Data time = {fd.configValue['root.Time']}")

In some cases the data file contains frames that are “batched” using the BatcherV1 protocol:

with FileReader(files="mydata.dat",configChan=1,batched=True) as fd:

   # Loop through the file data
   for header,bHeader,data in fd.records():

      # Look at record header data
      print(f"Processing record. Total={fd.totCount}, Current={fd.currCount}")
      print(f"Record size    = {header.size}")
      print(f"Record channel = {header.channel}")
      print(f"Record flags   = {header.flags:#x}")
      print(f"Record error   = {header.error:#x}")
      print(f"Batcher size   = {bHeader.size}")
      print(f"Batcher tdest  = {bHeader.tdest:#x}")
      print(f"Batcher fUser  = {bHeader.fUser:#x}")
      print(f"Batcher lUser  = {bHeader.lUser:#x}")

      # Do something with the data here:
      for i in range(header.size):
         print(f" Byte {i} = {data[i]:#x}")

      # At any time you can access the current config and status state
      print(f"Data time = {fd.configValue['root.Time']}")

FileReader Description

The class description for the SimpleClient class is included below:

class pyrogue.utilities.fileio.FileReader(files, configChan=None, log=None, batched=False)

A lightweight file reader for Rogue.

Parameters:

• files (str or list) – Filename or list of filenams to read data from

• configChan (int) – Channel id of configuration/status stream in the data file. Set to None to disable processing configuration.

• log (obj) – Logging object to use. If set to None a new logger will be created with the name “pyrogue.FileReader”.

• batched (bool) – Flag to indicate if data file contains batched data

currCount

Number of data records processed from current file

Type:

int

totCount

Total number of data records processed from

Type:

int

configDig

Current configuration/status dictionary

Type:

obj

records()

Generator which returns (header, data) tuples

Returns:

• RogueHeader, bytearray – (header, data) tuple where header is a dictionary and data is a byte array, for batched = False.

• RogueHeader, BatchHeader, bytearray – (header, header, data) tuple where header are dictionaried and data is a byte array, for batched = True.

configValue(path)

Get a configuration or status value

Parameters:

path (str) – Path of the config/status value to return

Returns:

Requested configuration or status value

Return type:

obj

The header data record is described below:

class pyrogue.utilities.fileio.RogueHeader(size: int, flags: int, error: int, channel: int)