hashCheck function

hashCheck

Check for Changes in List of Objects

hashCheck(..., file, .print. = TRUE, .names. = NULL)

Arguments

• ...: a list of objects including data frames, vectors, functions, and all other types of R objects that represent dependencies of a certain calculation
• file: name of file in which results are stored
• .print.: set to FALSE to suppress printing information messages about what has changed
• .names.: vector of names of original arguments if not calling hashCheck directly

Returns

a list with elements result (the computations), hash (the new hash), and changed which details what changed to make computations need to be run

Details

Given an RDS file name and a list of objects, does the following:

• makes a vector of hashes, one for each object. Function objects are run through deparse so that the environment of the function will not be considered.
• see if the file exists; if not, return a list with result=NULL, hash = new vector of hashes, changed='All'
• if the file exists, read the file and its hash attribute as prevhash
• if prevhash is not identical to hash: if .print.=TRUE (default), print to console a summary of what's changed return a list with result=NULL, hash = new hash vector, changed
• if prevhash = hash, return a list with result=file object, hash=new hash, changed=''

Set options(debughash=TRUE) to trace results in /tmp/debughash.txt

Author(s)

Frank Harrell