R/RocksetConnection.R

In rockset/RRockset: R Package Client for REST API

#' @include QueryRequestSql.R QueryRequest.R QueriesApi.R RocksetResult.R

#' S4 implementation of \code{DBIConnection} for Rockset
#'
#' @keywords internal
#' @export
setClass('RocksetConnection',
         contains='DBIConnection',
         slots=c(
           'apiclient'='ANY'
         )
)

#' @rdname RocksetConnection-class
#' @export
setMethod('show',
          'RocksetConnection',
          function(object) {
            cat(
              '<RocksetConnection: ', object@apiclient$basePath, '>\n',
              'ApiKey: ', object@apiclient$apikey, '\n',
              sep=''
            )
          }
)

#' @param conn A \code{\linkS4class{RocksetConnection}} object
#' @return [dbDisconnect] A \code{\link{logical}} value indicating success
#' @export
#' @rdname RocksetConnection-class
setMethod('dbDisconnect',
          'RocksetConnection',
          function(conn) {
            return(TRUE)
          }
)

#' @rdname RocksetConnection-class
#' @export
setMethod('dbSendQuery', c('RocksetConnection', 'character'), function(conn, statement, params = NULL) {
  dbSend(conn, statement, params)
})

dbSend <- function(conn, statement, params = NULL) {
  statement <- enc2utf8(statement)

  parameter <- list()
  if (!is.null(params)) {
    for (l in params) {
      queryParameter <- 
        QueryParameter$new(name=l$name, type=l$type, value=l$value)
      parameter <- append(parameter, queryParameter)
    }
  }
  
  query <- QueriesApi$new()
  query$initialize(apiClient=conn@apiclient)
  
  cursor <- RocksetCursor$new(query, statement, parameter)
  rr <- new('RocksetResult',
            connection=conn,
            cursor=cursor)
  return(rr)
}

#' @rdname RocksetConnection-class
#' @export
setMethod('dbGetQuery', c('RocksetConnection', 'character'), function(conn, statement, params = NULL) {
  res <- dbSendQuery(conn, statement, params)
  on.exit(dbClearResult(res))
  return(dbFetch(res))
})