Attribute file cache refactor

This is a big refactoring of the attribute file cache to be a bit
simpler which in turn makes it easier to enforce a lock around any
updates to the cache so that it can be used in a threaded env.
Tons of changes to the attributes and ignores code.

4 files changed, 106 insertions, 44 deletions

diff --git a/tests/threads/diff.c b/tests/threads/diff.c
index 5565c4bf1..562eec71c 100644
--- a/tests/threads/diff.c
+++ b/tests/threads/diff.c
@@ -1,59 +1,22 @@
 #include "clar_libgit2.h"
-#include "thread-utils.h"
+#include "thread_helpers.h"
 
 static git_repository *_repo;
 static git_tree *_a, *_b;
 static git_atomic _counts[4];
 static int _check_counts;
 
+#define THREADS 20
+
 void test_threads_diff__cleanup(void)
 {
 	cl_git_sandbox_cleanup();
 }
 
-static void run_in_parallel(
-	int repeats, int threads, void *(*func)(void *),
-	void (*before_test)(void), void (*after_test)(void))
-{
-	int r, t, *id = git__calloc(threads, sizeof(int));
-#ifdef GIT_THREADS
-	git_thread *th = git__calloc(threads, sizeof(git_thread));
-	cl_assert(th != NULL);
-#else
-	void *th = NULL;
-#endif
-
-	cl_assert(id != NULL);
-
-	for (r = 0; r < repeats; ++r) {
-		_repo = cl_git_sandbox_reopen(); /* reopen sandbox to flush caches */
-
-		if (before_test) before_test();
-
-		for (t = 0; t < threads; ++t) {
-			id[t] = t;
-#ifdef GIT_THREADS
-			cl_git_pass(git_thread_create(&th[t], NULL, func, &id[t]));
-#else
-			cl_assert(func(&id[t]) == &id[t]);
-#endif
-		}
-
-#ifdef GIT_THREADS
-		for (t = 0; t < threads; ++t)
-			cl_git_pass(git_thread_join(th[t], NULL));
-		memset(th, 0, threads * sizeof(git_thread));
-#endif
-
-		if (after_test) after_test();
-	}
-
-	git__free(id);
-	git__free(th);
-}
-
 static void setup_trees(void)
 {
+	_repo = cl_git_sandbox_reopen(); /* reopen sandbox to flush caches */
+
 	cl_git_pass(git_revparse_single(
 		(git_object **)&_a, _repo, "0017bd4ab1^{tree}"));
 	cl_git_pass(git_revparse_single(
@@ -62,8 +25,6 @@ static void setup_trees(void)
 	memset(_counts, 0, sizeof(_counts));
 }
 
-#define THREADS 20
-
 static void free_trees(void)
 {
 	git_tree_free(_a); _a = NULL;
diff --git a/tests/threads/iterator.c b/tests/threads/iterator.c
new file mode 100644
index 000000000..4dd251fa5
--- /dev/null
+++ b/tests/threads/iterator.c
@@ -0,0 +1,49 @@
+#include "clar_libgit2.h"
+#include "thread_helpers.h"
+#include "iterator.h"
+
+static git_repository *_repo;
+
+void test_threads_iterator__cleanup(void)
+{
+	cl_git_sandbox_cleanup();
+}
+
+static void *run_workdir_iterator(void *arg)
+{
+	int error = 0, thread = *(int *)arg;
+	git_iterator *iter;
+	const git_index_entry *entry = NULL;
+
+	cl_git_pass(git_iterator_for_workdir(
+		&iter, _repo, GIT_ITERATOR_DONT_AUTOEXPAND, NULL, NULL));
+
+	while (!error) {
+		if (entry && entry->mode == GIT_FILEMODE_TREE) {
+			error = git_iterator_advance_into(&entry, iter);
+
+			if (error == GIT_ENOTFOUND)
+				error = git_iterator_advance(&entry, iter);
+		} else {
+			error = git_iterator_advance(&entry, iter);
+		}
+
+		if (!error)
+			(void)git_iterator_current_is_ignored(iter);
+	}
+
+	cl_assert_equal_i(GIT_ITEROVER, error);
+
+	git_iterator_free(iter);
+
+	return arg;
+}
+
+
+void test_threads_iterator__workdir(void)
+{
+	_repo = cl_git_sandbox_init("status");
+
+	run_in_parallel(
+		1, 20, run_workdir_iterator, NULL, NULL);
+}
diff --git a/tests/threads/thread_helpers.c b/tests/threads/thread_helpers.c
new file mode 100644
index 000000000..25370dddb
--- /dev/null
+++ b/tests/threads/thread_helpers.c
@@ -0,0 +1,44 @@
+#include "clar_libgit2.h"
+#include "thread_helpers.h"
+
+void run_in_parallel(
+	int repeats,
+	int threads,
+	void *(*func)(void *),
+	void (*before_test)(void),
+	void (*after_test)(void))
+{
+	int r, t, *id = git__calloc(threads, sizeof(int));
+#ifdef GIT_THREADS
+	git_thread *th = git__calloc(threads, sizeof(git_thread));
+	cl_assert(th != NULL);
+#else
+	void *th = NULL;
+#endif
+
+	cl_assert(id != NULL);
+
+	for (r = 0; r < repeats; ++r) {
+		if (before_test) before_test();
+
+		for (t = 0; t < threads; ++t) {
+			id[t] = t;
+#ifdef GIT_THREADS
+			cl_git_pass(git_thread_create(&th[t], NULL, func, &id[t]));
+#else
+			cl_assert(func(&id[t]) == &id[t]);
+#endif
+		}
+
+#ifdef GIT_THREADS
+		for (t = 0; t < threads; ++t)
+			cl_git_pass(git_thread_join(th[t], NULL));
+		memset(th, 0, threads * sizeof(git_thread));
+#endif
+
+		if (after_test) after_test();
+	}
+
+	git__free(id);
+	git__free(th);
+}
diff --git a/tests/threads/thread_helpers.h b/tests/threads/thread_helpers.h
new file mode 100644
index 000000000..3c13cfb6b
--- /dev/null
+++ b/tests/threads/thread_helpers.h
@@ -0,0 +1,8 @@
+#include "thread-utils.h"
+
+void run_in_parallel(
+	int repeats,
+	int threads,
+	void *(*func)(void *),
+	void (*before_test)(void),
+	void (*after_test)(void));