1 /*
2 * SysDB - src/include/frontend/connection.h
3 * Copyright (C) 2013 Sebastian 'tokkee' Harl <sh@tokkee.org>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
17 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
18 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR
19 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
20 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
28 #ifndef SDB_FRONTEND_CONNECTION_H
29 #define SDB_FRONTEND_CONNECTION_H 1
31 #include "frontend/proto.h"
32 #include "core/store.h"
33 #include "utils/llist.h"
34 #include "utils/strbuf.h"
35 #include "utils/proto.h"
37 #include <inttypes.h>
39 #ifdef __cplusplus
40 extern "C" {
41 #endif
43 /*
44 * sdb_conn_t represents an open connection from a client. It inherits from
45 * sdb_object_t and may safely be cast to a generic object.
46 */
47 typedef struct sdb_conn sdb_conn_t;
49 /*
50 * sdb_conn_node_t represents an interface for the result of parsing a command
51 * string. The first field of an actual implementation of the interface is a
52 * sdb_conn_state_t in order to fascilitate casting to and from the interface
53 * type to the implementation type.
54 */
55 typedef struct {
56 sdb_object_t super;
57 sdb_conn_state_t cmd;
58 } sdb_conn_node_t;
59 #define SDB_CONN_NODE(obj) ((sdb_conn_node_t *)(obj))
61 /*
62 * sdb_conn_setup_cb is a callback function used to setup a connection. For
63 * example, it may be used to initialize session information.
64 */
65 typedef int (*sdb_conn_setup_cb)(sdb_conn_t *, void *);
67 /*
68 * sdb_connection_enable_logging:
69 * Enable logging of connection-related messages to the current client
70 * connection. After this function has been called all log messages
71 * originating from the thread handling the current client connection will
72 * also be sent to the client.
73 *
74 * Returns:
75 * - 0 on success
76 * - a negative value else
77 */
78 int
79 sdb_connection_enable_logging(void);
81 /*
82 * sdb_connection_accpet:
83 * Accept a new connection on the specified file-descriptor 'fd' and return a
84 * newly allocated connection object. If specified, the setup callback is used
85 * to setup the newly created connection. It will receive the connection
86 * object and the specified user data as its arguments.
87 *
88 * Returns:
89 * - 0 on success
90 * - a negative value else
91 */
92 sdb_conn_t *
93 sdb_connection_accept(int fd, sdb_conn_setup_cb setup, void *user_data);
95 /*
96 * sdb_connection_close:
97 * Close an open connection. Any subsequent reads from the connection will
98 * fail. Use sdb_object_deref to free the memory used by the object.
99 */
100 void
101 sdb_connection_close(sdb_conn_t *conn);
103 /*
104 * sdb_connection_handle:
105 * Read from an open connection until reading would block and handle all
106 * incoming commands.
107 *
108 * Returns:
109 * - the number of bytes read (0 on EOF)
110 * - a negative value on error
111 */
112 ssize_t
113 sdb_connection_handle(sdb_conn_t *conn);
115 /*
116 * sdb_connection_send:
117 * Send to an open connection.
118 *
119 * Returns:
120 * - the number of bytes written
121 * - a negative value on error
122 */
123 ssize_t
124 sdb_connection_send(sdb_conn_t *conn, uint32_t code,
125 uint32_t msg_len, const char *msg);
127 /*
128 * sdb_connection_ping:
129 * Send back a backend status indicator to the connected client.
130 *
131 * Returns:
132 * - 0 on success
133 * - a negative value else
134 */
135 int
136 sdb_connection_ping(sdb_conn_t *conn);
138 /*
139 * sdb_connection_server_version:
140 * Send back the backend server version to the connected client.
141 *
142 * Returns:
143 * - 0 on success
144 * - a negative value else
145 */
146 int
147 sdb_connection_server_version(sdb_conn_t *conn);
149 /*
150 * sdb_fe_parse:
151 * Parse the query text specified in 'query' of length 'len' and return a list
152 * of parse trees (for each command). The list has to be freed by the caller.
153 * If 'len' is less than zero, parse the whole (nul-terminated) string. If
154 * specified, errbuf will be used to record parse errors.
155 *
156 * Returns:
157 * - an sdb_llist_t object of sdb_conn_node_t on success
158 * - NULL in case of an error
159 */
160 sdb_llist_t *
161 sdb_fe_parse(const char *query, int len, sdb_strbuf_t *errbuf);
163 /*
164 * session handling
165 */
167 /*
168 * sdb_fe_session_start:
169 * Start a new user session on the specified connection.
170 *
171 * Returns:
172 * - 0 on success
173 * - a negative value else
174 */
175 int
176 sdb_fe_session_start(sdb_conn_t *conn);
178 /*
179 * store access
180 */
182 /*
183 * sdb_fe_query, sdb_fe_fetch, sdb_fe_list, sdb_fe_lookup, sdb_fe_store:
184 * Handle the SDB_CONNECTION_QUERY, SDB_CONNECTION_FETCH, SDB_CONNECTION_LIST,
185 * SDB_CONNECTION_LOOKUP, and SDB_CONNECTION_STORE commands respectively. It
186 * is expected that the current command has been initialized already.
187 *
188 * Returns:
189 * - 0 on success
190 * - a negative value else
191 */
192 int
193 sdb_fe_query(sdb_conn_t *conn);
194 int
195 sdb_fe_fetch(sdb_conn_t *conn);
196 int
197 sdb_fe_list(sdb_conn_t *conn);
198 int
199 sdb_fe_lookup(sdb_conn_t *conn);
200 int
201 sdb_fe_store(sdb_conn_t *conn);
203 /*
204 * sdb_fe_store_host, sdb_fe_store_service, sdb_fe_store_metric,
205 * sdb_fe_store_attribute:
206 * Execute the 'STORE' command for the respective object type.
207 *
208 * Returns:
209 * - 0 on success
210 * - a negative value else
211 */
212 int
213 sdb_fe_store_host(sdb_conn_t *conn, const sdb_proto_host_t *host);
214 int
215 sdb_fe_store_service(sdb_conn_t *conn, const sdb_proto_service_t *svc);
216 int
217 sdb_fe_store_metric(sdb_conn_t *conn, const sdb_proto_metric_t *metric);
218 int
219 sdb_fe_store_attribute(sdb_conn_t *conn, const sdb_proto_attribute_t *attr);
221 #ifdef __cplusplus
222 } /* extern "C" */
223 #endif
225 #endif /* ! SDB_FRONTEND_CONNECTION_H */
227 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */