<< Click to Display Table of Contents >> Navigation:  Nodes > Tasks > File Management > Checksum

 

Purpose

 

Given an input file this node calculates its CRC using the specified algorithm, and it creates a checksum sidecar file with it. A checksum sidecar file is a file in the same folder and with the same name but with a second CRC type extension added at the end, indicating the type of checksum algorithm (.md4 .md5 or .sha1).

 

A checksum file contains a key value (CRC) that is dependent of the file content (for example the sum of all its bytes).  So if the file changes its checksum will also change. It is typically used to check the integrity of a file after copying or sending it to other places, or just to check if a particular version of the file is the same as another one.

 

You can use this node in two modes, depending on the Validate input property:

 

Validate input = Off:-  Creates the checksum file. If it already exists it will overwrite it. The checksum type extension is added at the end, as a second extension.

 

Example:

 

Original File: test.mxf

Checksum File: test.mxf.md5  (if md5 was selected as CRC Type )

 

Validate input = On:  If it finds the checksum file ( .md4 .md5 or .sha1 in the same path as the input) then it will be used to validate its content against the CRC of the given file.

Then the status of the node will depend on the result, stopping the workflow if the checksum file didn't exist or if it exists but it does not match the calculation (reporting the corresponding error and sending the offending files to the FailedUps node), or continuing the workflow otherwise.  

 

Note: If they exist, the checksum files are considered sidecar files, so when they are manipulated with Mistika Workflows they will always travel together (copied, moved, uploaded, deleted...). Yo do not need to manage checksum files independently.

 

Inputs

 

File: Input file to calculate the checksum

 

Outputs

 

Files: The input file with the sidecar checksum file.

 

 

Standard properties

Object Name

Color

Bypass

Lock

 

Node specific properties

 

CRC type: Type of CRC to generate or validate.

 

Validate input: Check this box to ensure that the file is going to be validated with the checksum file. If this box is not checked, the node will generate the CRC checksum file.

 

 

 

Developer reference (API Rest - node/Checksum/property/[Property ID])