fastdigest {fastdigest} | R Documentation |
Fast, memory constant hashing of R objects
fastdigest(obj, ref_serializer = NULL)
obj |
The object to generate a hash digest for |
ref_serializer |
(optional) A serializer for reference-style
objects, see |
obj
will be hashed using R's internal serialization logic
with a custom target which applies applying Jenkins' SpookyHash (v2) in a
streaming fashion. This avoids (ever) copying the data out of the R object
itself, providing both speed and memory constancy.
It also guarantees that the "representation" of the R object being hashed is the same as the serialized version would be, if created.
Gabriel Becker
Jenkins, B. (2012). SpookyHash: a 128-bit noncryptographic hash. http://burtleburtle.net/bob/hash/spooky.html.
x = rnorm(100) h = fastdigest(x) y = x ## force dup y[100] = 1 h2 = fastdigest(y) identical(h, h2) #FALSE y[100] = x[100] h3 = fastdigest(y) identical(h, h3) # TRUE