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Write a value

Source: R/data.R
mdbx_put.Rd

Stores value under key, replacing any existing value unless overwrite is FALSE.

Usage

mdbx_put(txn, key, value, overwrite = TRUE, db = NULL)

Arguments

txn

An mdbx_txn object from mdbx_txn_begin(), opened with write = TRUE.

key

A raw vector, or a single string, which is stored as its UTF-8 bytes.

value

A raw vector, or a single string, which is stored as its UTF-8 bytes. Use serialize(x, NULL) for an arbitrary R object.

overwrite

If FALSE, leave an existing value alone and return FALSE instead of replacing it.

db

An mdbx_dbi object from mdbx_dbi_open() naming a database to address instead of the unnamed main one, or NULL for the main database.

Value

TRUE if the value was stored, FALSE if overwrite = FALSE and the key already existed. Returned invisibly.

See also

mdbx_get(), mdbx_del()

Examples

path <- tempfile(fileext = ".mdbx")
env <- mdbx_env_open(path)

mdbx_with_write(env, function(txn) {
  mdbx_put(txn, "k", "first")

  # Refuses to replace, and says so.
  mdbx_put(txn, "k", "second", overwrite = FALSE)
})

mdbx_env_close(env)
unlink(c(path, paste0(path, "-lck")))