1 file changed, 37 insertions, 3 deletions
diff --git a/source/ui-snapshot.h b/source/ui-snapshot.h
index a8deec36..9f1ec026 100644
--- a/source/ui-snapshot.h
+++ b/source/ui-snapshot.h
@@ -1,7 +1,41 @@
-#ifndef UI_SNAPSHOT_H
-#define UI_SNAPSHOT_H
+/*
+ * The snapshot page, which serves a commit as a downloadable archive. It owns
+ * the table of formats cgit knows how to write, so the config reader and the
+ * link builders both reach through here to ask which formats a repository
+ * offers. Each format has a bit in the per-repository snapshots mask, taken
+ * from its position in that table.
+ */
+
+#ifndef CGIT_UI_SNAPSHOT_H
+#define CGIT_UI_SNAPSHOT_H
+
+#include "cgit.h"
+
+typedef int (*write_archive_fn_t)(const char *hex, const char *prefix);
+
+struct cgit_snapshot_format {
+	const char *suffix;
+	const char *mimetype;
+	write_archive_fn_t write_func;
+};
+
+// Terminated by an entry with a NULL suffix.
+extern const struct cgit_snapshot_format cgit_snapshot_formats[];
+
+extern unsigned cgit_snapshot_format_bit(const struct cgit_snapshot_format *f);
+
+/*
+ * Turn a cgitrc snapshots value into a mask over cgit_snapshot_formats. A
+ * plain number is the legacy form meaning every format, as is the word all,
+ * otherwise the value is a space separated list of suffixes.
+ */
+extern int cgit_parse_snapshots_mask(const char *str);
+
+// The detached signature stored for this format under refs/notes, if any.
+extern const struct object_id *cgit_snapshot_get_sig(
+	const char *ref, const struct cgit_snapshot_format *f);
 
 extern void cgit_print_snapshot(const char *head, const char *hex,
 				const char *filename, int dwim);
 
-#endif /* UI_SNAPSHOT_H */
+#endif // CGIT_UI_SNAPSHOT_H