tar_unblock_process()

ropensci · Nov 14, 2024 · 90ebe9a · 90ebe9a
1 parent 085639e
commit 90ebe9a
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Showing 24 changed files with 118 additions and 19 deletions.
diff --git a/NAMESPACE b/NAMESPACE
@@ -535,6 +535,7 @@ export(tar_timestamp)
 export(tar_timestamp_raw)
 export(tar_toggle)
 export(tar_traceback)
+export(tar_unblock_process)
 export(tar_unscript)
 export(tar_unversion)
 export(tar_validate)

diff --git a/NEWS.md b/NEWS.md
@@ -20,6 +20,7 @@
 * Compress branches into references when `retrieval` is `"worker"` and the whole pattern is part of the subpipeline.
 * Avoid duplicated branch aggregation: just send the branches over the network.
 * Back-compatibly switch `format = "qs"` from `qs` to `qs2` (#1373).
+* Add `tar_unblock_process()`.
 
 # targets 1.8.0
 

diff --git a/R/class_process.R b/R/class_process.R
@@ -81,9 +81,15 @@ process_class <- R6::R6Class(
             pid,
             "is really a {targets} pipeline and not a false positive,",
             "then terminate it manually. In case of a false positive,",
-            "remove the file",
+            "run",
+            sprintf(
+              "targets::tar_unblock_process(store = \"%s\")",
+              dirname(dirname(self$database$path))
+            ),
+            "(or manually remove",
             shQuote(self$database$path),
-            "and try again. False positives may happen if you run",
+            ") and try again.",
+            "False positives may happen if you run",
             "different calls to tar_make() in quick succession",
             "or if you run tar_make(callr_function = NULL) in a",
             "different R process and keep that process running."

diff --git a/R/tar_unblock_process.R b/R/tar_unblock_process.R
@@ -0,0 +1,20 @@
+#' @title Unblock the pipeline process
+#' @export
+#' @family utilities
+#' @description `targets` tries to avoid running two concurrent instances
+#'   of [tar_make()] on the same pipeline writing to the same data store.
+#'   Sometimes it generates false positives (meaning [tar_make()] throws
+#'   this error even though there is only one instance of the pipeline
+#'   running.) If there is a false positive, [tar_unblock_process()]
+#'   gets the pipeline unstuck by removing the `_targets/meta/process` file.
+#'   This allows the next call to [tar_make()] to resume.
+#' @return `NULL` (invisibly). Called for its side effects.
+#' @param store Character string, path to the data store
+#'   (usually `"_targets"`).
+tar_unblock_process <- function(store = targets::tar_config_get("store")) {
+  tar_assert_allow_meta("tar_meta", store)
+  tar_assert_scalar(store)
+  tar_assert_chr(store)
+  tar_assert_nzchar(store)
+  unlink(path_process(store), force = TRUE)
+}
diff --git a/_pkgdown.yml b/_pkgdown.yml
@@ -173,6 +173,7 @@ reference:
   - 'tar_path_store'
   - 'tar_path_target'
   - 'tar_source'
+  - 'tar_unblock_store'
 - title: Extending targets
   contents:
   - 'tar_assert'

diff --git a/man/tar_active.Rd b/man/tar_active.Rd
diff --git a/man/tar_backoff.Rd b/man/tar_backoff.Rd
diff --git a/man/tar_call.Rd b/man/tar_call.Rd
diff --git a/man/tar_cancel.Rd b/man/tar_cancel.Rd
diff --git a/man/tar_definition.Rd b/man/tar_definition.Rd
diff --git a/man/tar_described_as.Rd b/man/tar_described_as.Rd
diff --git a/man/tar_envir.Rd b/man/tar_envir.Rd
diff --git a/man/tar_format_get.Rd b/man/tar_format_get.Rd
diff --git a/man/tar_group.Rd b/man/tar_group.Rd
diff --git a/man/tar_name.Rd b/man/tar_name.Rd
diff --git a/man/tar_path.Rd b/man/tar_path.Rd
diff --git a/man/tar_path_script.Rd b/man/tar_path_script.Rd
diff --git a/man/tar_path_script_support.Rd b/man/tar_path_script_support.Rd
diff --git a/man/tar_path_store.Rd b/man/tar_path_store.Rd
diff --git a/man/tar_path_target.Rd b/man/tar_path_target.Rd
diff --git a/man/tar_source.Rd b/man/tar_source.Rd
diff --git a/man/tar_store.Rd b/man/tar_store.Rd
diff --git a/man/tar_unblock_process.Rd b/man/tar_unblock_process.Rd
diff --git a/tests/testthat/test-tar_unblock_process.R b/tests/testthat/test-tar_unblock_process.R
@@ -0,0 +1,8 @@
+targets::tar_test("tar_unblock_process()", {
+  skip_cran()
+  tar_script(tar_target(x, 1))
+  tar_make(callr_function = NULL)
+  expect_true(file.exists(path_process(path_store_default())))
+  tar_unblock_process()
+  expect_false(file.exists(path_process(path_store_default())))
+})