Add API to precompile all diff driversrb/test-builtin-drivers

3 files changed, 51 insertions, 4 deletions

diff --git a/include/git2/sys/diff.h b/include/git2/sys/diff.h
index 034d5c478..f54bd2e77 100644
--- a/include/git2/sys/diff.h
+++ b/include/git2/sys/diff.h
@@ -89,6 +89,18 @@ GIT_EXTERN(int) git_diff_get_perfdata(
 GIT_EXTERN(int) git_status_list_get_perfdata(
 	git_diff_perfdata *out, const git_status_list *status);
 
+/**
+ * Compile all builtin diff drivers.
+ *
+ * Normally builtin diff drivers are only compiled on-demand when they are
+ * used.  This function loops through the internal table and compiles and
+ * caches all of the builtin diff drivers.  This can be done for testing
+ * purposes or to control when the driver compilation costs are paid.
+ *
+ * @return 0 for success, <0 for error
+ */
+GIT_EXTERN(int) git_diff_driver_compile_builtins(git_repository *repo);
+
 /** @} */
 GIT_END_DECL
 #endif
diff --git a/src/diff_driver.c b/src/diff_driver.c
index c3c5f365b..9ae72ac6c 100644
--- a/src/diff_driver.c
+++ b/src/diff_driver.c
@@ -203,11 +203,11 @@ static int git_diff_driver_builtin(
 		error = 0;
 
 done:
-	if (error && drv)
+	if (error && drv) {
 		git_diff_driver_free(drv);
-	else
-		*out = drv;
-
+		drv = NULL;
+	}
+	*out = drv;
 	return error;
 }
 
@@ -335,6 +335,32 @@ done:
 	return error;
 }
 
+int git_diff_driver_compile_builtins(git_repository *repo)
+{
+	int error = 0;
+	git_diff_driver_registry *reg;
+	git_diff_driver *drv;
+	size_t i;
+
+	assert(repo);
+
+	if ((reg = git_repository_driver_registry(repo)) == NULL)
+		return -1;
+
+	for (i = 0; i < ARRAY_SIZE(builtin_defs); ++i) {
+		const char *name = builtin_defs[i].name;
+		khiter_t pos = git_strmap_lookup_index(reg->drivers, name);
+
+		if (!git_strmap_valid_index(reg->drivers, pos) &&
+			(error = git_diff_driver_builtin(&drv, reg, name)) < 0)
+			break;
+
+		fprintf(stderr, "compiled diff driver '%s'\n", name);
+	}
+
+	return error;
+}
+
 int git_diff_driver_lookup(
 	git_diff_driver **out, git_repository *repo, const char *path)
 {
diff --git a/tests/diff/drivers.c b/tests/diff/drivers.c
index 8b12368ea..6a54e1428 100644
--- a/tests/diff/drivers.c
+++ b/tests/diff/drivers.c
@@ -250,3 +250,12 @@ void test_diff_drivers__builtins(void)
 	git_buf_free(&expected);
 	git_vector_free(&files);
 }
+
+#include "git2/sys/diff.h"
+
+void test_diff_drivers__check_builtins(void)
+{
+	g_repo = cl_git_sandbox_init("empty_standard_repo");
+	cl_git_pass(git_diff_driver_compile_builtins(g_repo));
+}
+