[arrow-nanoarrow] branch main updated: fix(r): Release streams when calling `as.vector()` or `as.data.frame()` (#202)

[pa...@apache.org]

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paleolimbot pushed a commit to branch main
in repository https://gitbox.apache.org/repos/asf/arrow-nanoarrow.git


The following commit(s) were added to refs/heads/main by this push:
     new 8090475  fix(r): Release streams when calling `as.vector()` or `as.data.frame()` (#202)
8090475 is described below

commit 80904754895c7709ef4bee6c5e6f7d11ecdfc6cf
Author: Dewey Dunnington <de...@dunnington.ca>
AuthorDate: Wed May 24 13:17:50 2023 -0400

    fix(r): Release streams when calling `as.vector()` or `as.data.frame()` (#202)
    
    In https://github.com/apache/arrow-adbc/pull/706 , the added
    `read_adbc()` releases a stream whose statement (and possibly
    connection) will be released when the stream itself is released. When
    the user is definitely consuming the entire stream, it is helpful to
    release it at a guaranteed time so that subsequent operations (e.g.,
    closing a connection, deleting a file on Windows) don't confusingly
    fail.
---
 r/R/array-stream.R                   | 6 ++++++
 r/tests/testthat/test-array-stream.R | 2 ++
 2 files changed, 8 insertions(+)

diff --git a/r/R/array-stream.R b/r/R/array-stream.R
index 4c3ca65..54863a4 100644
--- a/r/R/array-stream.R
+++ b/r/R/array-stream.R
@@ -161,6 +161,11 @@ infer_nanoarrow_schema.nanoarrow_array_stream <- function(x, ...) {
 
 #' @export
 as.data.frame.nanoarrow_array_stream <- function(x, ...) {
+  # Always release the input: we are always consuming the entire stream.
+  # For more fine-grained behaviour on error, one can use
+  # convert_array_stream()
+  on.exit(x$release())
+
   to <- infer_nanoarrow_ptype(x$get_schema())
   if (!inherits(to, "data.frame")) {
     stop("Can't convert non-struct array stream to data.frame")
@@ -171,6 +176,7 @@ as.data.frame.nanoarrow_array_stream <- function(x, ...) {
 
 #' @export
 as.vector.nanoarrow_array_stream <- function(x, mode) {
+  on.exit(x$release())
   convert_array_stream(x)
 }
 
diff --git a/r/tests/testthat/test-array-stream.R b/r/tests/testthat/test-array-stream.R
index a6020ca..195c31c 100644
--- a/r/tests/testthat/test-array-stream.R
+++ b/r/tests/testthat/test-array-stream.R
@@ -110,6 +110,7 @@ test_that("as.data.frame() is implemented for streams", {
     as.data.frame(stream),
     data.frame(x = 1:5)
   )
+  expect_false(nanoarrow_pointer_is_valid(stream))
 })
 
 test_that("as.vector() is implemented for streams", {
@@ -118,6 +119,7 @@ test_that("as.vector() is implemented for streams", {
     as.vector(stream),
     data.frame(x = 1:5)
   )
+  expect_false(nanoarrow_pointer_is_valid(stream))
 })
 
 test_that("nanoarrow_array_stream list interface works", {