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#' Check for BDB support
#'
#' Detect whether Berkeley Database for disk-based storage of RDF graphs
#' is available. Disk-based storage requires redland package
#' to be installed from source with support for the Berkeley DB
#' (libdb-dev on Ubuntu, berkeley-db on homebrew), otherwise `rdf()` will
#' fall back to in-memory storage with a warning.
#'
#' @return TRUE if BDB support is detected, false otherwise
#' @export
#' @examples
#' rdf_has_bdb()
rdf_has_bdb <- function(){
rdf_storage("BDB", new_db = TRUE, check_only = TRUE)
}
rdf_has_virtuoso <- function(user="dba",
password="dba",
dsn="Local Virtuoso"){
# has_driver <- rdf_storage("virtuoso",
# user = user,
# password = password,
# dsn = dsn,
# check_only=TRUE)
r <- tryCatch(rdf("virtuoso", user = user,
password = password, dsn = dsn, fallback = FALSE),
error = function(e) FALSE)
if(is.logical(r)){
has_connection <- r
} else {
rdf_add(r, "", "dc:name", "bob")
if(length(r) >= 1){
has_connection <- TRUE
} else {
has_connection <- FALSE
}
rdf_free(r)
}
has_connection
}
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