[PATCH v4 1/2] reftable/stack: add env to disable autocompaction

["Justin Tobler via GitGitGadget" <gitgitgadget@gmail.com>]

From: Justin Tobler <jltobler@gmail.com>

In future tests it will be neccesary to create repositories with a set
number of tables. To make this easier, introduce the
`GIT_TEST_REFTABLE_AUTOCOMPACTION` environment variable that, when set
to false, disables autocompaction of reftables.

Signed-off-by: Justin Tobler <jltobler@gmail.com>
---
 reftable/stack.c           |  3 ++-
 reftable/system.h          |  1 +
 t/t0610-reftable-basics.sh | 21 +++++++++++++++++++++
 3 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/reftable/stack.c b/reftable/stack.c
index 1ecf1b9751c..4c373fb0ee2 100644
--- a/reftable/stack.c
+++ b/reftable/stack.c
@@ -681,7 +681,8 @@ int reftable_addition_commit(struct reftable_addition *add)
 	if (err)
 		goto done;
 
-	if (!add->stack->disable_auto_compact)
+	if (!add->stack->disable_auto_compact &&
+	    git_env_bool("GIT_TEST_REFTABLE_AUTOCOMPACTION", 1))
 		err = reftable_stack_auto_compact(add->stack);
 
 done:
diff --git a/reftable/system.h b/reftable/system.h
index 5d8b6dede50..05b7c8554af 100644
--- a/reftable/system.h
+++ b/reftable/system.h
@@ -17,6 +17,7 @@ license that can be found in the LICENSE file or at
 #include "tempfile.h"
 #include "hash-ll.h" /* hash ID, sizes.*/
 #include "dir.h" /* remove_dir_recursively, for tests.*/
+#include "parse.h"
 
 int hash_size(uint32_t id);
 
diff --git a/t/t0610-reftable-basics.sh b/t/t0610-reftable-basics.sh
index 686781192eb..444f7497907 100755
--- a/t/t0610-reftable-basics.sh
+++ b/t/t0610-reftable-basics.sh
@@ -299,6 +299,27 @@ test_expect_success 'ref transaction: writes cause auto-compaction' '
 	test_line_count = 1 repo/.git/reftable/tables.list
 '
 
+test_expect_success 'ref transaction: env var disables compaction' '
+	test_when_finished "rm -rf repo" &&
+
+	git init repo &&
+	test_commit -C repo A &&
+
+	start=$(wc -l <repo/.git/reftable/tables.list) &&
+	iterations=5 &&
+	expected=$((start + iterations)) &&
+
+	for i in $(test_seq $iterations)
+	do
+		GIT_TEST_REFTABLE_AUTOCOMPACTION=false \
+		git -C repo update-ref branch-$i HEAD || return 1
+	done &&
+	test_line_count = $expected repo/.git/reftable/tables.list &&
+
+	git -C repo update-ref foo HEAD &&
+	test_line_count -lt $expected repo/.git/reftable/tables.list
+'
+
 check_fsync_events () {
 	local trace="$1" &&
 	shift &&
-- 
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