Memoize performance tests

memoize.R

library(profvis)
library(microbenchmark)
library(memoise)
library(digest)

# Bare function
f <- function(a, b) {
  a + b
}

# With memoise
g <- memoise(f)

# Manually memoized version
h <- local({
  cache <- new.env(parent = emptyenv())
  function(a, b) {
    hash <- digest(list(a, b), algo = "xxhash64")
    if (is.null(cache[[hash]])) {
      res <- f(a, b)
      cache[[hash]] <- res
    }
    cache[[hash]]
  }
})



microbenchmark(
  f(1, 100),
  g(1, 100),
  h(1, 100),
  times = 1000
)

profvis({
  for (i in 1:5000) {
    f(1, 100)
  }
  for (i in 1:5000) {
    g(1, 100)
  }
  for (i in 1:5000) {
    h(1, 100)
  }
})