proto: Let unmarshal functions return the number of bytes processed.

[sysdb.git] / src / include / utils / proto.h

diff --git a/src/include/utils/proto.h b/src/include/utils/proto.h
index 8ab2e1ee7b3a22adb1481fb7cfecb09daaef77c7..a872dd51b309c6a05a659d9ea4e70a70933fdf35 100644 (file)
--- a/src/include/utils/proto.h
+++ b/src/include/utils/proto.h
@@ -28,6 +28,8 @@
 #ifndef SDB_UTILS_PROTO_H
 #define SDB_UTILS_PROTO_H 1
 
+#include "core/data.h"
+
 #include <stdint.h>
 #include <unistd.h>
 
@@ -35,13 +37,120 @@
 extern "C" {
 #endif
 
-ssize_t
-sdb_proto_send(int fd, size_t msg_len, const char *msg);
+/*
+ * sdb_proto_host, sdb_proto_service, sdb_proto_metric:
+ * Protocol-specific representations of the basic information of stored
+ * objects.
+ */
+typedef struct {
+       sdb_time_t last_update;
+       const char *name;
+} sdb_proto_host_t;
+
+typedef struct {
+       sdb_time_t last_update;
+       const char *hostname;
+       const char *name;
+} sdb_proto_service_t;
 
+typedef struct {
+       sdb_time_t last_update;
+       const char *hostname;
+       const char *name;
+       const char *store_type; /* optional */
+       const char *store_id;   /* optional */
+} sdb_proto_metric_t;
+
+typedef struct {
+       sdb_time_t last_update;
+       int parent_type;
+       const char *hostname; /* optional */
+       const char *parent;
+       const char *key;
+       const sdb_data_t *value;
+} sdb_proto_attribute_t;
+
+/*
+ * sdb_proto_marshal:
+ * Encode the message into the wire format by adding an appropriate header.
+ * The encoded message is written to buf which has to be large enough to store
+ * the header (64 bits) and the entire message.
+ *
+ * Returns:
+ *  - The number of bytes of the full encoded message on success. The function
+ *    does not write more than 'buf_len' bytes. If the output was truncated
+ *    then the return value is the number of bytes which would have been
+ *    written if enough space had been available.
+ *  - a negative value on error
+ */
 ssize_t
-sdb_proto_send_msg(int fd, uint32_t code,
+sdb_proto_marshal(char *buf, size_t buf_len, uint32_t code,
                uint32_t msg_len, const char *msg);
 
+/*
+ * sdb_proto_marshal_data:
+ * Encode a datum into the wire format and write it to buf.
+ *
+ * Returns:
+ *  - The number of bytes of the full encoded datum on success. The function
+ *    does not write more than 'buf_len' bytes. If the output was truncated
+ *    then the return value is the number of bytes which would have been
+ *    written if enough space had been available.
+ *  - a negative value else
+ */
+ssize_t
+sdb_proto_marshal_data(char *buf, size_t buf_len, const sdb_data_t *datum);
+
+/*
+ * sdb_proto_marshal_host, sdb_proto_marshal_service,
+ * sdb_proto_marshal_metric, sdb_proto_marshal_attribute:
+ * Encode the basic information of a stored object into the wire format and
+ * write it to buf. These functions are similar to the sdb_store_<type>
+ * functions. See their documentation for details about the arguments.
+ *
+ * Returns:
+ *  - The number of bytes of the full encoded datum on success. The function
+ *    does not write more than 'buf_len' bytes. If the output was truncated
+ *    then the return value is the number of bytes which would have been
+ *    written if enough space had been available.
+ *  - a negative value else
+ */
+ssize_t
+sdb_proto_marshal_host(char *buf, size_t buf_len,
+               const sdb_proto_host_t *host);
+ssize_t
+sdb_proto_marshal_service(char *buf, size_t buf_len,
+               const sdb_proto_service_t *svc);
+ssize_t
+sdb_proto_marshal_metric(char *buf, size_t buf_len,
+               const sdb_proto_metric_t *metric);
+ssize_t
+sdb_proto_marshal_attribute(char *buf, size_t buf_len,
+               const sdb_proto_attribute_t *attr);
+
+/*
+ * sdb_proto_unmarshal_header:
+ * Read and decode a message header from the specified string.
+ *
+ * Returns:
+ *  - the number of bytes read on success
+ *  - a negative value else
+ */
+ssize_t
+sdb_proto_unmarshal_header(const char *buf, size_t buf_len,
+               uint32_t *code, uint32_t *msg_len);
+
+/*
+ * sdb_proto_unmarshal_int32:
+ * Read and decode a 32-bit integer from the specified string.
+ *
+ * Returns:
+ *  - the number of bytes read on success
+ *  - a negative value else
+ */
+ssize_t
+sdb_proto_unmarshal_int32(const char *buf, size_t buf_len, uint32_t *v);
+
 #ifdef __cplusplus
 } /* extern "C" */
 #endif