1 files changed, 38 insertions, 0 deletions
diff --git a/src/libdisfluid/disfluid-cache-entry.h b/src/libdisfluid/disfluid-cache-entry.h
index ca4f743..1c06537 100644
--- a/src/libdisfluid/disfluid-cache-entry.h
+++ b/src/libdisfluid/disfluid-cache-entry.h
@@ -26,6 +26,9 @@ ao_cache_entry_push (int fd, size_t *offset,
 		     const string_desc_t response_header,
 		     const string_desc_t response_body);
 
+MAYBE_UNUSED static int
+ao_cache_entry_invalidate (int fd, size_t offset, size_t *invalidated_offset);
+
 # include "disfluid-append-only-file.h"
 # include "safe-alloc.h"
 
@@ -355,4 +358,39 @@ ao_cache_entry_push (int fd, size_t *offset,
     }
   return 0;
 }
+
+static int
+ao_cache_entry_invalidate (int fd, size_t offset, size_t *invalidated_offset)
+{
+  struct cache_entry_header header;
+  uint8_t header_bytes[12 * 2 + 16 * 3 + 1 + 7] = { 0 };
+  string_desc_t data = {._nbytes = sizeof (header_bytes),._data = header_bytes
+  };
+  *invalidated_offset = offset;
+  if (ao_file_read (fd, offset, data) < 0)
+    {
+      return -1;
+    }
+  if (ao_cache_entry_from_bytes (header_bytes, &header) < 0)
+    {
+      return -1;
+    }
+  if (header.invalidated)
+    {
+      return 0;
+    }
+  header.invalidated = true;
+  /* Push just the header, reuse the memory for key, response header
+     and body. */
+  if (ao_cache_entry_to_bytes (&header, header_bytes) < 0)
+    {
+      return -1;
+    }
+  if (ao_file_push_data (fd, data, invalidated_offset) < 0)
+    {
+      return -1;
+    }
+  return 0;
+}
+
 #endif /* DISFLUID_DISFLUID_CACHE_ENTRY_INCLUDED */