R/db_replicate.r

In ropensci/sofa: Connector to 'CouchDB'

#' Upload (replicate) a local database to a remote database server,
#' e.g., Cloudant, Iriscouch
#'
#' @export
#' @template return
#' @param from Couch to replicate from. An object of class [Cushion].
#' Required.
#' @param to Remote couch to replicate to. An object of class [Cushion].
#' Required.
#' @param dbname (character) Database name. Required.
#' @param createdb If `TRUE`, the function creates the db on the remote
#' server before uploading. The db has to exist before uploading, so either
#' you do it separately or this fxn can do it for you. Default: `FALSE`
#' @param as (character) One of list (default) or json
#' @param ... Curl args passed on to [crul::HttpClient]
#' @examples \dontrun{
#' if (interactive()) {
#'   ## create a connection
#'   user <- Sys.getenv("COUCHDB_TEST_USER")
#'   pwd <- Sys.getenv("COUCHDB_TEST_PWD")
#'   (x <- Cushion$new(user = user, pwd = pwd))
#'
#'   # Create a database locally
#'   db_list(x)
#'   if ("hello_earth" %in% db_list(x)) {
#'     invisible(db_delete(x, dbname = "hello_earth"))
#'   }
#'   db_create(x, "hello_earth")
#'
#'   ## replicate to a remote server
#'   z <- Cushion$new(
#'     host = "ropensci.cloudant.com", transport = "https",
#'     port = NULL, user = "ropensci", pwd = Sys.getenv("CLOUDANT_PWD")
#'   )
#'
#'   ## do the replication
#'   db_replicate(x, z, dbname = "hello_earth")
#'
#'   ## check changes on the remote
#'   db_list(z)
#'   db_changes(z, dbname = "hello_earth")
#'
#'   ## make some changes on the remote
#'   doc_create(z,
#'     dbname = "hello_earth",
#'     '{"language":"python","library":"requests"}', "stuff"
#'   )
#'   changes(z, dbname = "hello_earth")
#'
#'   ## create another document, and try to get it
#'   doc_create(z,
#'     dbname = "hello_earth", doc = '{"language":"R"}',
#'     docid = "R_rules"
#'   )
#'   doc_get(z, dbname = "hello_earth", docid = "R_rules")
#'
#'   ## cleanup - delete the database
#'   db_delete(z, "hello_earth")
#' }
#' }
db_replicate <- function(from, to, dbname, createdb = FALSE, as = "list", ...) {
  check_cushion(to)
  check_cushion(from)
  if (createdb) db_create(to, dbname)
  fromurl <- file.path(from$make_url(), "_replicate")
  tourl <- file.path(to$make_url(), dbname)
  args <- list(source = unbox(dbname), target = unbox(cloudant_url(to, dbname)))
  message("Uploading ...")
  sofa_POST(fromurl, as,
    body = args, encode = "json",
    from$get_headers(), from$get_auth(), ...
  )
}