merge(third_party/git): Merge squashed git subtree at v2.23.0

Merge commit '1b593e1ea4' as 'third_party/git'

third_party/git/dir-iterator.c

@@ -0,0 +1,235 @@
+#include "cache.h"
+#include "dir.h"
+#include "iterator.h"
+#include "dir-iterator.h"
+
+struct dir_iterator_level {
+	DIR *dir;
+
+	/*
+	 * The length of the directory part of path at this level
+	 * (including a trailing '/'):
+	 */
+	size_t prefix_len;
+};
+
+/*
+ * The full data structure used to manage the internal directory
+ * iteration state. It includes members that are not part of the
+ * public interface.
+ */
+struct dir_iterator_int {
+	struct dir_iterator base;
+
+	/*
+	 * The number of levels currently on the stack. After the first
+	 * call to dir_iterator_begin(), if it succeeds to open the
+	 * first level's dir, this will always be at least 1. Then,
+	 * when it comes to zero the iteration is ended and this
+	 * struct is freed.
+	 */
+	size_t levels_nr;
+
+	/* The number of levels that have been allocated on the stack */
+	size_t levels_alloc;
+
+	/*
+	 * A stack of levels. levels[0] is the uppermost directory
+	 * that will be included in this iteration.
+	 */
+	struct dir_iterator_level *levels;
+
+	/* Combination of flags for this dir-iterator */
+	unsigned int flags;
+};
+
+/*
+ * Push a level in the iter stack and initialize it with information from
+ * the directory pointed by iter->base->path. It is assumed that this
+ * strbuf points to a valid directory path. Return 0 on success and -1
+ * otherwise, setting errno accordingly and leaving the stack unchanged.
+ */
+static int push_level(struct dir_iterator_int *iter)
+{
+	struct dir_iterator_level *level;
+
+	ALLOC_GROW(iter->levels, iter->levels_nr + 1, iter->levels_alloc);
+	level = &iter->levels[iter->levels_nr++];
+
+	if (!is_dir_sep(iter->base.path.buf[iter->base.path.len - 1]))
+		strbuf_addch(&iter->base.path, '/');
+	level->prefix_len = iter->base.path.len;
+
+	level->dir = opendir(iter->base.path.buf);
+	if (!level->dir) {
+		int saved_errno = errno;
+		if (errno != ENOENT) {
+			warning_errno("error opening directory '%s'",
+				      iter->base.path.buf);
+		}
+		iter->levels_nr--;
+		errno = saved_errno;
+		return -1;
+	}
+
+	return 0;
+}
+
+/*
+ * Pop the top level on the iter stack, releasing any resources associated
+ * with it. Return the new value of iter->levels_nr.
+ */
+static int pop_level(struct dir_iterator_int *iter)
+{
+	struct dir_iterator_level *level =
+		&iter->levels[iter->levels_nr - 1];
+
+	if (level->dir && closedir(level->dir))
+		warning_errno("error closing directory '%s'",
+			      iter->base.path.buf);
+	level->dir = NULL;
+
+	return --iter->levels_nr;
+}
+
+/*
+ * Populate iter->base with the necessary information on the next iteration
+ * entry, represented by the given dirent de. Return 0 on success and -1
+ * otherwise, setting errno accordingly.
+ */
+static int prepare_next_entry_data(struct dir_iterator_int *iter,
+				   struct dirent *de)
+{
+	int err, saved_errno;
+
+	strbuf_addstr(&iter->base.path, de->d_name);
+	/*
+	 * We have to reset these because the path strbuf might have
+	 * been realloc()ed at the previous strbuf_addstr().
+	 */
+	iter->base.relative_path = iter->base.path.buf +
+				   iter->levels[0].prefix_len;
+	iter->base.basename = iter->base.path.buf +
+			      iter->levels[iter->levels_nr - 1].prefix_len;
+
+	if (iter->flags & DIR_ITERATOR_FOLLOW_SYMLINKS)
+		err = stat(iter->base.path.buf, &iter->base.st);
+	else
+		err = lstat(iter->base.path.buf, &iter->base.st);
+
+	saved_errno = errno;
+	if (err && errno != ENOENT)
+		warning_errno("failed to stat '%s'", iter->base.path.buf);
+
+	errno = saved_errno;
+	return err;
+}
+
+int dir_iterator_advance(struct dir_iterator *dir_iterator)
+{
+	struct dir_iterator_int *iter =
+		(struct dir_iterator_int *)dir_iterator;
+
+	if (S_ISDIR(iter->base.st.st_mode) && push_level(iter)) {
+		if (errno != ENOENT && iter->flags & DIR_ITERATOR_PEDANTIC)
+			goto error_out;
+		if (iter->levels_nr == 0)
+			goto error_out;
+	}
+
+	/* Loop until we find an entry that we can give back to the caller. */
+	while (1) {
+		struct dirent *de;
+		struct dir_iterator_level *level =
+			&iter->levels[iter->levels_nr - 1];
+
+		strbuf_setlen(&iter->base.path, level->prefix_len);
+		errno = 0;
+		de = readdir(level->dir);
+
+		if (!de) {
+			if (errno) {
+				warning_errno("error reading directory '%s'",
+					      iter->base.path.buf);
+				if (iter->flags & DIR_ITERATOR_PEDANTIC)
+					goto error_out;
+			} else if (pop_level(iter) == 0) {
+				return dir_iterator_abort(dir_iterator);
+			}
+			continue;
+		}
+
+		if (is_dot_or_dotdot(de->d_name))
+			continue;
+
+		if (prepare_next_entry_data(iter, de)) {
+			if (errno != ENOENT && iter->flags & DIR_ITERATOR_PEDANTIC)
+				goto error_out;
+			continue;
+		}
+
+		return ITER_OK;
+	}
+
+error_out:
+	dir_iterator_abort(dir_iterator);
+	return ITER_ERROR;
+}
+
+int dir_iterator_abort(struct dir_iterator *dir_iterator)
+{
+	struct dir_iterator_int *iter = (struct dir_iterator_int *)dir_iterator;
+
+	for (; iter->levels_nr; iter->levels_nr--) {
+		struct dir_iterator_level *level =
+			&iter->levels[iter->levels_nr - 1];
+
+		if (level->dir && closedir(level->dir)) {
+			int saved_errno = errno;
+			strbuf_setlen(&iter->base.path, level->prefix_len);
+			errno = saved_errno;
+			warning_errno("error closing directory '%s'",
+				      iter->base.path.buf);
+		}
+	}
+
+	free(iter->levels);
+	strbuf_release(&iter->base.path);
+	free(iter);
+	return ITER_DONE;
+}
+
+struct dir_iterator *dir_iterator_begin(const char *path, unsigned int flags)
+{
+	struct dir_iterator_int *iter = xcalloc(1, sizeof(*iter));
+	struct dir_iterator *dir_iterator = &iter->base;
+	int saved_errno;
+
+	strbuf_init(&iter->base.path, PATH_MAX);
+	strbuf_addstr(&iter->base.path, path);
+
+	ALLOC_GROW(iter->levels, 10, iter->levels_alloc);
+	iter->levels_nr = 0;
+	iter->flags = flags;
+
+	/*
+	 * Note: stat already checks for NULL or empty strings and
+	 * inexistent paths.
+	 */
+	if (stat(iter->base.path.buf, &iter->base.st) < 0) {
+		saved_errno = errno;
+		goto error_out;
+	}
+
+	if (!S_ISDIR(iter->base.st.st_mode)) {
+		saved_errno = ENOTDIR;
+		goto error_out;
+	}
+
+	return dir_iterator;
+
+error_out:
+	dir_iterator_abort(dir_iterator);
+	errno = saved_errno;
+	return NULL;
+}