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authorMichael Haggerty <mhagger@alum.mit.edu>2016-06-18 06:15:18 +0200
committerJunio C Hamano <gitster@pobox.com>2016-06-20 11:38:21 -0700
commit0fe5043dad74352c08447eb1913df0b6c3f2731c (patch)
tree7ed4e4f4b55b942da556e4c4914a379358c8de0e /dir-iterator.h
parentd24b21e9fcaa9ed4b7966275a8d82406f578577d (diff)
downloadgit-0fe5043dad74352c08447eb1913df0b6c3f2731c.tar.gz
dir_iterator: new API for iterating over a directory tree
The iterator interface is modeled on that for references, though no vtable is necessary because there is (so far?) only one type of dir_iterator. There are obviously a lot of features that could easily be added to this class: * Skip/include directory paths in the iteration * Shallow/deep iteration * Letting the caller decide which subdirectories to recurse into (e.g., via a dir_iterator_advance_into() function) * Option to iterate in sorted order * Option to iterate over directory paths before vs. after their contents But these are not needed for the current patch series, so I refrain. Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'dir-iterator.h')
-rw-r--r--dir-iterator.h87
1 files changed, 87 insertions, 0 deletions
diff --git a/dir-iterator.h b/dir-iterator.h
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+++ b/dir-iterator.h
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+#ifndef DIR_ITERATOR_H
+#define DIR_ITERATOR_H
+
+/*
+ * Iterate over a directory tree.
+ *
+ * Iterate over a directory tree, recursively, including paths of all
+ * types and hidden paths. Skip "." and ".." entries and don't follow
+ * symlinks except for the original path.
+ *
+ * Every time dir_iterator_advance() is called, update the members of
+ * the dir_iterator structure to reflect the next path in the
+ * iteration. The order that paths are iterated over within a
+ * directory is undefined, but directory paths are always iterated
+ * over before the subdirectory contents.
+ *
+ * A typical iteration looks like this:
+ *
+ * int ok;
+ * struct iterator *iter = dir_iterator_begin(path);
+ *
+ * while ((ok = dir_iterator_advance(iter)) == ITER_OK) {
+ * if (want_to_stop_iteration()) {
+ * ok = dir_iterator_abort(iter);
+ * break;
+ * }
+ *
+ * // Access information about the current path:
+ * if (S_ISDIR(iter->st.st_mode))
+ * printf("%s is a directory\n", iter->relative_path);
+ * }
+ *
+ * if (ok != ITER_DONE)
+ * handle_error();
+ *
+ * Callers are allowed to modify iter->path while they are working,
+ * but they must restore it to its original contents before calling
+ * dir_iterator_advance() again.
+ */
+
+struct dir_iterator {
+ /* The current path: */
+ struct strbuf path;
+
+ /*
+ * The current path relative to the starting path. This part
+ * of the path always uses "/" characters to separate path
+ * components:
+ */
+ const char *relative_path;
+
+ /* The current basename: */
+ const char *basename;
+
+ /* The result of calling lstat() on path: */
+ struct stat st;
+};
+
+/*
+ * Start a directory iteration over path. Return a dir_iterator that
+ * holds the internal state of the iteration.
+ *
+ * The iteration includes all paths under path, not including path
+ * itself and not including "." or ".." entries.
+ *
+ * path is the starting directory. An internal copy will be made.
+ */
+struct dir_iterator *dir_iterator_begin(const char *path);
+
+/*
+ * Advance the iterator to the first or next item and return ITER_OK.
+ * If the iteration is exhausted, free the dir_iterator and any
+ * resources associated with it and return ITER_DONE. On error, free
+ * dir_iterator and associated resources and return ITER_ERROR. It is
+ * a bug to use iterator or call this function again after it has
+ * returned ITER_DONE or ITER_ERROR.
+ */
+int dir_iterator_advance(struct dir_iterator *iterator);
+
+/*
+ * End the iteration before it has been exhausted. Free the
+ * dir_iterator and any associated resources and return ITER_DONE. On
+ * error, free the dir_iterator and return ITER_ERROR.
+ */
+int dir_iterator_abort(struct dir_iterator *iterator);
+
+#endif