Data and IO

ssdaq.core

class ssdaq.core.io.BaseFileWriter(file_prefix: str, writer, file_ext: str, folder: str = '', file_enumerator: str = None, filesize_lim: int = None)

A data file writer wrapper class that handles filename enumerators and size limits.

Filename enumerators can be date-time or order starting at 000. A new file is started if the preceeding file exceeds the filesize limit or if the method data_cond() returns true. This method may be overidden by inheriting classes

close()

Closes the file writer

data_cond(data)

A callback method which starts a new file when True is returned

Parameters:() (data) – received data Returns:if true a new file will be started Return type:bool

write(data)

Write data to file

Parameters:data (TYPE) – The data to be written to file

class ssdaq.core.io.RawObjectReaderBase(filename: str)

This class

read() → bytes

Reads one object at the position of the file pointer.

Returns:Bytes that represent the object Return type:bytes

read_at(ind: int) → bytes

Reads one object at the index indicated by ind

Parameters:ind (int) – the index of the object to be read Returns:that represent the object Return type:bytes Raises:IndexError – if index out of range

reload()

Reload the index table. Useful if the file is being written too when read

resetfp()

Resets file pointer to the first object in file

class ssdaq.core.io.RawObjectWriterBase(filename: str, protocol=1, compressor='bz2', **kwargs)

Acts as a file object for writing chunks of serialized data to file. Prepends each chunk with: chunk length in bytes (4 bytes) and a crc32 hash (4 bytes)

write(data: bytes)

Writes a stream of bytes to file

Parameters:data (bytes) – bytes to be writen to file

class ssdaq.core.io.RawObjectWriterV0(filename: str, header: int = 0)

Acts as a file object for writing chunks of serialized data to file. Prepends each chunk with: chunk length in bytes (4 bytes) and a crc32 hash (4 bytes)

The file header is 24 bytes long and has the following layout

bytes: field: 0-7 Custom field for file format specifications (set by the header parameter) 8-11 Protocol version 12-15 Not used 16-19 Not used 20-23 Not used

General file structure:

File Header

Chunk Header

Data

Chunk Header

Data

write(data: bytes)

Writes a stream of bytes to file

Parameters:data (bytes) – bytes to be writen to file

class ssdaq.core.io.RawObjectWriterV1(filename: str, header_ext: bytes = None, marker_ext: str = '', compressor=None, bunchsize: int = 1000000)

Acts as a file object for writing chunks of serialized data to file. Prepends each chunk with: chunk length in bytes (4 bytes) and a crc32 hash (4 bytes)

The file header is 24 bytes long and has the following layout

bytes: field: 0-7 Custom field for file format specifications (set by the header parameter) 8-11 Protocol version 12-15 Not used 16-19 Not used 20-23 Not used

General file structure:

File Header

Chunk Header

Data

Chunk Header

Data

write(data: bytes)

Writes a stream of bytes to file

Parameters:data (bytes) – bytes to be writen to file

ssdaq.data.io

class ssdaq.data.io.SSDataWriter(filename: str, attrs: dict = None, filters: tables.filters.Filters = None, buffer: int = 1000, tel_table=True)

A writer for Slow Signal data

close_file()

Closes file handle

class ssdaq.data.io.SSDataReader(filename, mapping='ssl2asic_ch')

A reader for Slow Signal data

close_file()

Closes file handle

load_all_data(tm, calib=None, mapping=None)

Loads all rows of data for a particular target moduel into memory (in the future a selection of modules)

Parameters:tm (int) – The slot number of the target module

Kwargs:

calib (arraylike): an array with calibration coefficient that should be applied to the data mapping (str or arraylike): a string to select a mapping or an array with the mapping

[‘ssl2colrow’,’ssl2asic_ch’,’raw’]

read(start=None, stop=None, step=None)

A data file iterator for reading data rows.

Parameters:

• start (int) – starting row number
• stop (int) – stopping row number
• step (int) – size of the step at each iteration

class ssdaq.data.io.DataReader(filename: str)

read()

Reads one object at the position of the file pointer.

Returns:Bytes that represent the object Return type:bytes

read_at(ind: int)

Reads one object at the index indicated by ind

Parameters:ind (int) – the index of the object to be read Returns:that represent the object Return type:bytes Raises:IndexError – if index out of range

reload()

Reload the index table. Useful if the file is being written too when read

resetfp()

Resets file pointer to the first object in file