From 1b6c4d55037135271c66b43e81691c5131d9813b Mon Sep 17 00:00:00 2001
From: Sebastian Harl <sh@tokkee.org>
Date: Fri, 16 Jan 2015 23:45:23 +0100
Subject: [PATCH] client: Added sdb_client_rpc.

This function handles a full RPC call: it sends a message to the server and
waits for the reply. While doing so, it handles all asynchronous log messages.
That is, it'll return the actual result status of the command.
---
 src/client/sock.c            | 53 ++++++++++++++++++++++++++++++++++++
 src/include/client/sock.h    | 24 ++++++++++++++--
 src/include/frontend/proto.h | 12 ++++++++
 3 files changed, 87 insertions(+), 2 deletions(-)

diff --git a/src/client/sock.c b/src/client/sock.c
index cd9c8ce..6a1e49f 100644
--- a/src/client/sock.c
+++ b/src/client/sock.c
@@ -302,6 +302,59 @@ sdb_client_close(sdb_client_t *client)
 	client->eof = 1;
 } /* sdb_client_close */
 
+ssize_t
+sdb_client_rpc(sdb_client_t *client,
+		uint32_t cmd, uint32_t msg_len, const char *msg,
+		uint32_t *code, sdb_strbuf_t *buf)
+{
+	uint32_t rcode = 0;
+	ssize_t status;
+
+	if (! buf)
+		return -1;
+
+	if (sdb_client_send(client, cmd, msg_len, msg) < 0) {
+		char errbuf[1024];
+		sdb_strbuf_sprintf(buf, "Failed to send %s message to server: %s",
+				SDB_CONN_MSGTYPE_TO_STRING(cmd),
+				sdb_strerror(errno, errbuf, sizeof(errbuf)));
+		if (code)
+			*code = SDB_CONNECTION_ERROR;
+		return -1;
+	}
+
+	while (42) {
+		size_t offset = sdb_strbuf_len(buf);
+
+		status = sdb_client_recv(client, &rcode, buf);
+		if (status < 0) {
+			char errbuf[1024];
+			sdb_strbuf_sprintf(buf, "Failed to receive server response: %s",
+					sdb_strerror(errno, errbuf, sizeof(errbuf)));
+			if (code)
+				*code = SDB_CONNECTION_ERROR;
+			return status;
+		}
+
+		if (rcode == SDB_CONNECTION_LOG) {
+			uint32_t prio = 0;
+			if (sdb_proto_unmarshal_int32(SDB_STRBUF_STR(buf), &prio) < 0) {
+				sdb_log(SDB_LOG_WARNING, "Received a LOG message "
+						"with invalid or missing priority");
+				prio = (uint32_t)SDB_LOG_ERR;
+			}
+			sdb_log((int)prio, "%s", sdb_strbuf_string(buf) + offset);
+			sdb_strbuf_skip(buf, offset, sdb_strbuf_len(buf) - offset);
+			continue;
+		}
+		break;
+	}
+
+	if (code)
+		*code = rcode;
+	return status;
+} /* sdb_client_rpc */
+
 ssize_t
 sdb_client_send(sdb_client_t *client,
 		uint32_t cmd, uint32_t msg_len, const char *msg)
diff --git a/src/include/client/sock.h b/src/include/client/sock.h
index 638f862..9a7947b 100644
--- a/src/include/client/sock.h
+++ b/src/include/client/sock.h
@@ -97,10 +97,30 @@ sdb_client_shutdown(sdb_client_t *client, int how);
 void
 sdb_client_close(sdb_client_t *client);
 
+/*
+ * sdb_client_rpc:
+ * Send the specified message to the server and wait for the reply. All
+ * received data is written to the specified buffer. If specified, the
+ * returned status code is written to the memory location pointed to by
+ * 'code'. In case of an error or an incomplete command, the status code is
+ * set to UINT32_MAX. The returned data does not include the status code and
+ * message len as received from the remote side but only the data associated
+ * with the message. The function handles all asynchronous log messages by
+ * logging them at the right log level.
+ *
+ * Returns:
+ *  - the number of bytes read
+ *    (may be zero if the message did not include any data)
+ *  - a negative value on error
+ */
+ssize_t
+sdb_client_rpc(sdb_client_t *client,
+		uint32_t cmd, uint32_t msg_len, const char *msg,
+		uint32_t *code, sdb_strbuf_t *buf);
+
 /*
  * sdb_client_send:
- * Send the specified command and accompanying data to through the client
- * connection.
+ * Send the specified command and accompanying data to the server.
  *
  * Returns:
  *  - the number of bytes send
diff --git a/src/include/frontend/proto.h b/src/include/frontend/proto.h
index 52b50d1..833762d 100644
--- a/src/include/frontend/proto.h
+++ b/src/include/frontend/proto.h
@@ -300,6 +300,18 @@ typedef enum {
 	SDB_CONNECTION_EXPR,
 } sdb_conn_state_t;
 
+#define SDB_CONN_MSGTYPE_TO_STRING(t) \
+	(((t) == SDB_CONNECTION_IDLE) ? "IDLE" \
+		: ((t) == SDB_CONNECTION_PING) ? "PING" \
+		: ((t) == SDB_CONNECTION_STARTUP) ? "STARTUP" \
+		: ((t) == SDB_CONNECTION_QUERY) ? "QUERY" \
+		: ((t) == SDB_CONNECTION_FETCH) ? "FETCH" \
+		: ((t) == SDB_CONNECTION_LIST) ? "LIST" \
+		: ((t) == SDB_CONNECTION_LOOKUP) ? "LOOKUP" \
+		: ((t) == SDB_CONNECTION_TIMESERIES) ? "TIMESERIES" \
+		: ((t) == SDB_CONNECTION_STORE) ? "STORE" \
+		: "UNKNOWN")
+
 #ifdef __cplusplus
 } /* extern "C" */
 #endif
-- 
2.30.2