getVDigest | R Documentation |
The getVDigest
function extends digest
by allowing one to
set a function that returns hash summaries as a character vector of the same length as the input. It also provides a performance advantage
when repeated calls are necessary (e.g. applying a hash function repeatedly to an object). The returned function contains the same arguments as digest
with the exception of the raw
argument (see digest
for more details).
getVDigest(algo=c("md5", "sha1", "crc32", "sha256", "sha512", "xxhash32",
"xxhash64", "murmur32", "spookyhash", "blake3", "crc32c",
"xxh3_64", "xxh3_128"),
errormode=c("stop","warn","silent"))
algo |
The algorithms to be used; currently available choices are
|
errormode |
A character value denoting a choice for the behaviour in
the case of error: ‘stop’ aborts (and is the default value),
‘warn’ emits a warning and returns |
Note that since one hash summary will be returned for each element passed as input, care must be taken when determining whether or not to include the data structure as part of the object. For instance, to return the equivalent output of
digest(list("a"))
it would be necessary to wrap the list object itself
getVDigest()(list(list("a")))
The getVDigest
function returns a function for a given
algorithm and error-mode.
digest
, serialize
, md5sum
stretch_key <- function(d, n) {
md5 <- getVDigest()
for (i in seq_len(n))
d <- md5(d, serialize = FALSE)
d
}
stretch_key('abc123', 65e3)
sha1 <- getVDigest(algo = 'sha1')
sha1(letters)
md5Input <-
c("",
"a",
"abc",
"message digest",
"abcdefghijklmnopqrstuvwxyz",
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789",
paste("12345678901234567890123456789012345678901234567890123456789012",
"345678901234567890", sep=""))
md5Output <-
c("d41d8cd98f00b204e9800998ecf8427e",
"0cc175b9c0f1b6a831c399e269772661",
"900150983cd24fb0d6963f7d28e17f72",
"f96b697d7cb7938d525a2f31aaf161d0",
"c3fcd3d76192e4007dfb496cca67e13b",
"d174ab98d277d9f5a5611c2c9f419d9f",
"57edf4a22be3c955ac49da2e2107b67a")
md5 <- getVDigest()
stopifnot(identical(md5(md5Input, serialize = FALSE), md5Output))
stopifnot(identical(digest(list("abc")),
md5(list(list("abc")))))
sha512Input <-c(
"",
"The quick brown fox jumps over the lazy dog."
)
sha512Output <- c(
paste0("cf83e1357eefb8bdf1542850d66d8007d620e4050b5715dc83f4a921d36ce9ce",
"47d0d13c5d85f2b0ff8318d2877eec2f63b931bd47417a81a538327af927da3e"),
paste0("91ea1245f20d46ae9a037a989f54f1f790f0a47607eeb8a14d12890cea77a1bb",
"c6c7ed9cf205e67b7f2b8fd4c7dfd3a7a8617e45f3c463d481c7e586c39ac1ed")
)
sha512 <- getVDigest(algo = 'sha512')
stopifnot(identical(sha512(sha512Input, serialize = FALSE), sha512Output))
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