1 files changed, 53 insertions, 0 deletions
diff --git a/database/engine/metadata_log/metadatalogprotocol.h b/database/engine/metadata_log/metadatalogprotocol.h
new file mode 100644
index 000000000..1017213ae
--- /dev/null
+++ b/database/engine/metadata_log/metadatalogprotocol.h
@@ -0,0 +1,53 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#ifndef NETDATA_METADATALOGPROTOCOL_H
+#define NETDATA_METADATALOGPROTOCOL_H
+
+#include "../rrddiskprotocol.h"
+
+#define RRDENG_METALOG_MAGIC "netdata-metadata-log"
+
+#define RRDENG_METALOG_VER (1)
+
+#define RRDENG_METALOG_SB_PADDING_SZ (RRDENG_BLOCK_SIZE - (RRDENG_MAGIC_SZ + sizeof(uint16_t)))
+/*
+ * Metadata log persistent super-block
+ */
+struct rrdeng_metalog_sb {
+    char magic_number[RRDENG_MAGIC_SZ];
+    uint16_t version;
+    uint8_t padding[RRDENG_METALOG_SB_PADDING_SZ];
+} __attribute__ ((packed));
+
+/*
+ * Metadata log record types
+ */
+#define METALOG_STORE_PADDING       (0)
+#define METALOG_CREATE_OBJECT       (1)
+#define METALOG_DELETE_OBJECT       (2)
+#define METALOG_OTHER               (3) /* reserved */
+
+/*
+ * Metadata log record header
+ */
+struct rrdeng_metalog_record_header {
+    /* when set to METALOG_STORE_PADDING jump to start of next block */
+    uint8_t type;
+
+    uint16_t header_length;
+    uint32_t payload_length;
+    /******************************************************
+     * No fields above this point can ever change.        *
+     ******************************************************
+     * All fields below this point are subject to change. *
+     ******************************************************/
+} __attribute__ ((packed));
+
+/*
+ * Metadata log record trailer
+ */
+struct rrdeng_metalog_record_trailer {
+    uint8_t checksum[CHECKSUM_SZ]; /* CRC32 */
+} __attribute__ ((packed));
+
+#endif /* NETDATA_METADATALOGPROTOCOL_H */