started working on queueing #2

DESCRIPTION

@@ -10,7 +10,7 @@ License: MIT + file LICENSE
 URL: https://docs.ropensci.org/mutant, https://github.com/ropensci/mutant
 BugReports: https://github.com/ropensci/mutant/issues
 LazyData: true
-Roxygen: list(markdown = TRUE)
+Roxygen: list(markdown=TRUE)
 Encoding: UTF-8
 Imports:
     pkgapi,
@@ -20,6 +20,8 @@ Imports:
     astr,
     withr,
     R6,
-    pkgload
+    pkgload,
+    liteq,
+    rappdirs
 RoxygenNote: 7.1.0
 Remotes: r-lib/pkgapi, ropenscilabs/astr

R/queue.R

@@ -0,0 +1,55 @@
+#' mutant queue
+#' @importFrom liteq xxx
+#' @importFrom rappdirs user_cache_dir
+#' @param x x
+#' @param x x
+queue <- function(temporary = TRUE) {
+  assert(temporary, "logical")
+  if (temporary) db_path <- tempfile()
+  if (!temporary) {
+    db_path <- file.path(rappdirs::user_data_dir("R/mutant"),
+      basename(tempfile()))
+  }
+  q <- liteq::ensure_queue("jobs", db = db_path)
+
+}
+
+queue <- R6::R6Class(
+  'queue',
+  public = list(
+    q = NULL,
+    #' @description print method for `queue` objects
+    #' @param x self
+    #' @param ... ignored
+    print = function(x, ...) {
+      cat("<queue> ", sep = "\n")
+      for (i in seq_along(self$muts)) {
+        cat(paste0("  mutant name: ", self$muts[[i]]$name), sep = "\n")
+      }
+      invisible(self)
+    },
+
+    #' @description Create a new queue object
+    #' @return A new `queue` object
+    initialize = function(temporary = TRUE) {
+      assert(temporary, "logical")
+      if (temporary) db_path <- tempfile()
+      if (!temporary) {
+        db_path <- file.path(rappdirs::user_data_dir("R/mutant"),
+          basename(tempfile()))
+      }
+      self$q <- liteq::ensure_queue("jobs", db = db_path)
+      return(self)
+    },
+
+    publish = function(title, message) {
+      liteq::publish(self$q, title = title, message = message)
+    },
+
+    consume = function() {
+      liteq::try_consume(self$q)
+    }
+  ),
+  private = list()
+)
+