Shared C-core helpers

Thin access to the compiled core that ships in rmoriebricklayer. rmoriedata links that core via LinkingTo: rmoriebricklayer, so these functions call the exact same kernels that package exports – no duplicated C code. They back fast data-integrity hashing and summaries for the bundled datasets.

Usage

mdsha(x)

mdmean(x)

Arguments

x

For mdsha(), a length-1 character vector or a raw vector. For mdmean(), a numeric vector (coerced with as.numeric()); NA/NaN propagate.

Value

mdsha() returns a 64-character lowercase hex digest. mdmean() returns a length-1 numeric.

Examples

## ---- mdsha(): 64-char lowercase hex digest --------------
mdsha("abc") # hash a character scalar
#> [1] "ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad"
mdsha("") # the empty string still hashes
#> [1] "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"
mdsha(charToRaw("abc")) # identical digest from raw bytes
#> [1] "ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad"

# character input and its raw-byte equivalent agree:
identical(mdsha("abc"), mdsha(charToRaw("abc")))
#> [1] TRUE

# Data-integrity pin: verify a value is byte-for-byte what you expect.
expected <- mdsha("record-42")
stopifnot(mdsha("record-42") == expected)

# Fingerprint a whole object by hashing its serialization.
mdsha(serialize(list(a = 1, b = "x"), NULL))
#> [1] "0868b672eeb21ba79d0478942b4a667d55460e855144c49ff948eb80d09dede5"

## ---- mdmean(): fast length-1 mean --------------------------
mdmean(1:10) # 5.5
#> [1] 5.5
mdmean(c(2, 4, 6)) # 4
#> [1] 4
mdmean(c(-1, 0, 1)) # 0
#> [1] 0
mdmean(c(1, 2, NA)) # NA propagates (no na.rm)
#> [1] NA
mdmean(complaint_sample$year) # mean over a bundled column
#> [1] 2020