2 * UCW Library -- Logging
4 * (c) 1997--2009 Martin Mares <mj@ucw.cz>
5 * (c) 2008 Tomas Gavenciak <gavento@ucw.cz>
7 * This software may be freely distributed and used according to the terms
8 * of the GNU Lesser General Public License.
14 #include "ucw/clists.h"
16 /* user de/allocated program/process name for use in the logsystem */
17 extern char *ls_title;
21 /* optional name, 0-term, de/allocated by constr./destr. or user */
23 /* number for use with msg parameter (from LS_SET_STRNUM()), -1 for closed log_stream */
25 /* arbitrary data for filter/handler */
28 /* severity levels to accept - bitmask of (1<<LEVEL) */
30 /* if filter returns nonzero, discard the message */
31 int (*filter)(struct log_stream* ls, const char *m, uns cat);
32 /* pass the message to these streams (simple-list of pointers) */
33 struct clist substreams;
34 /* what kind of string to format to pass to the handler (bitmask of LSFMT_xxx ) */
36 /* what to do to commit the message (ret 0 on success, nonzero on error)
37 * msg is 0-term string, with desired info, one line, ending with "\n\0". */
38 int (*handler)(struct log_stream* ls, const char *m, uns cat);
39 /* close the log_stream file/connection */
40 void (*close)(struct log_stream* ls);
43 /* the default logger */
44 extern const struct log_stream log_stream_default;
46 /* A message is processed as follows:
47 * 1. Discard if message level not in levels
48 * 2. Run filter (if any), discard if ret. nonzero
49 * 3. Pass the message to all log_streams in substreams
50 * 4. Format the message informaion acc. to msgfmt
54 /* log header verbosity specifying message passed to handler */
57 LSFMT_LEVEL=1, /* log severity level (one letter) */
58 LSFMT_TIME=2, /* log time (date-seconds) */
59 LSFMT_USEC=4, /* log also micro-seconds */
60 LSFMT_TITLE=8, /* log program title (global string) */
61 LSFMT_PID=16, /* log program PID */
62 LSFMT_LOGNAME=32, /* log log_stream name */
64 LSFMT_FULL=LSFMT_LEVEL+LSFMT_TIME+LSFMT_USEC+LSFMT_TITLE+LSFMT_PID+LSFMT_LOGNAME,
65 LSFMT_DEFAULT=LSFMT_LEVEL+LSFMT_TIME
68 /* Mask of containing all existing levels. */
69 #define LS_ALL_LEVELS 0xfff
71 // return the letter associated with the severity level
72 #define LS_LEVEL_LETTER(level) ("DIiWwEe!###"[( level )])
74 ///// Macros for extracting parts of the flags parameter
75 // The division of the flags parameter is decided only here
76 // The current division is (for 32 bit flags):
77 // MSB <5 bits: any internal log flags> <8 bits: "user" flags> <10 bits: stream number>
78 // <8 bits: severity level> LSB
91 LS_STRNUM_POS = LS_LEVEL_POS + LS_LEVEL_BITS,
92 LS_FLAGS_POS = LS_STRNUM_POS + LS_STRNUM_BITS,
93 LS_INTERNAL_POS = LS_FLAGS_POS + LS_FLAGS_BITS,
98 LS_LEVEL_MASK = (( 1 << LS_LEVEL_BITS ) - 1 ) << LS_LEVEL_POS,
99 LS_STRNUM_MASK = (( 1 << LS_STRNUM_BITS ) - 1 ) << LS_STRNUM_POS,
100 LS_FLAGS_MASK = (( 1 << LS_FLAGS_BITS ) - 1 ) << LS_FLAGS_POS,
101 LS_INTERNAL_MASK = (( 1 << LS_INTERNAL_BITS ) - 1 ) << LS_INTERNAL_POS,
104 // "Get" macros (break flags to parts)
105 #define LS_GET_LEVEL(flags) ((( flags ) & LS_LEVEL_MASK ) >> LS_LEVEL_POS )
106 #define LS_GET_STRNUM(flags) ((( flags ) & LS_STRNUM_MASK ) >> LS_STRNUM_POS )
107 #define LS_GET_FLAGS(flags) ((( flags ) & LS_FLAGS_MASK ) >> LS_FLAGS_POS )
108 #define LS_GET_INTERNAL(flags) ((( flags ) & LS_INTERNAL_MASK ) >> LS_INTERNAL_POS )
110 // "Set" macros (parts to flags)
111 #define LS_SET_LEVEL(level) (( level ) << LS_LEVEL_POS )
112 #define LS_SET_STRNUM(strnum) (( strnum ) << LS_STRNUM_POS )
113 #define LS_SET_FLAGS(flags) (( flags ) << LS_FLAGS_POS )
114 #define LS_SET_INTERNAL(intern) (( intern ) << LS_INTERNAL_POS )
116 // Internal flags of the logsystem
117 // Avoid operations that are unsafe in signal handlers
118 #define LSFLAG_SIGHANDLER LS_SET_INTERNAL(0x001)
120 // The module is initialized when a first stream is created.
121 // Before that only the default stream exists.
123 /* Return pointer a new (xmalloc()-ated) stream with no handler and an empty substream list. */
124 struct log_stream *log_new_stream(void);
126 /* Close and xfree() given log_stream */
127 /* Does not affect substreams */
128 void log_close_stream(struct log_stream *ls);
130 /* close all open streams, un-initialize the module, free all memory,
131 * use only ls_default_log */
132 void log_close_all(void);
134 /* add a new substream, xmalloc()-ate a new simp_node */
135 void log_add_substream(struct log_stream *where, struct log_stream *what);
137 /* remove all occurences of a substream, free() the simp_node */
138 /* return number of deleted entries */
139 int log_rm_substream(struct log_stream *where, struct log_stream *what);
141 /* get a stream by its number (regnum) */
142 /* returns NULL for free numbers */
143 /* defaults to ls_default_stream for 0 when stream number 0 not set */
144 struct log_stream *log_stream_by_flags(uns flags);
146 /* process a message (string) (INTERNAL) */
147 /* depth prevents undetected looping */
148 /* returns 1 in case of loop detection or other fatal error
150 int log_pass_msg(int depth, struct log_stream *ls, const char *stime, const char *sutime,
151 const char *msg, uns cat);
153 /* Define an array (growing buffer) for pointers to log_streams. */
154 #define GBUF_TYPE struct log_stream*
155 #define GBUF_PREFIX(x) lsbuf_##x
156 #include "ucw/gbuf.h"
158 extern struct lsbuf_t log_streams;
159 extern int log_streams_after;
161 /********* Individual handler types (constructors, handlers, destructors) */
163 /**** standard (filedes) files */
166 // under unix, for ordinary files open in append mode, the writes
167 // are atomic (unless you meet the quota or other bad things happen),
168 // so using a single log_stream is thread-safe and the file can be shared
169 // among multiple processes
171 /* assign log to a file descriptor */
172 /* initialize with the default formatting, does NOT close the descriptor */
173 struct log_stream *ls_fdfile_new(int fd);
175 /* open() a file (append mode) */
176 /* initialize with the default formatting */
177 struct log_stream *ls_file_new(const char *path);
183 // The syslog uses a bit different severity levels, for details, see
184 // ls_syslog_convert_level().
185 // syslog also prepends it's own time and severity info, so the default
186 // messaging passes only clean message
188 /* assign log to a syslog facility */
189 /* initialize with no formatting (syslog adds these inforamtion) */
190 /* name is optional prefix (NULL for none) */
191 struct log_stream *log_new_syslog(int facility, const char *name);