2 * UCW Library -- Logging: Management of Log Streams
4 * (c) 2008 Tomas Gavenciak <gavento@ucw.cz>
5 * (c) 2009 Martin Mares <mj@ucw.cz>
7 * This software may be freely distributed and used according to the terms
8 * of the GNU Lesser General Public License.
13 #include "ucw/log-internal.h"
14 #include "ucw/simple-lists.h"
18 /* Initial number of streams to allocate (must be >=2) */
19 #define LS_INIT_STREAMS 8
21 /* Flag indicating initialization of the module */
22 static int log_initialized = 0;
24 /* The head of the list of freed log_streams indexes in log_streams.ptr (~0U if none free).
25 * Freed positions in log_streams.ptr are connected into a linked list in the following way:
26 * log_streams.ptr[log_streams_free].levels is the index of next freed position (or ~0U) */
27 static uns log_streams_free = ~0U;
29 /* Initialize the logstream module.
30 * It is not neccessary to call this explicitely as it is called by
31 * the first log_new_stream() (for backward compatibility and ease of use). */
38 /* Create the growing array */
39 lsbuf_init(&log_streams);
40 lsbuf_set_size(&log_streams, LS_INIT_STREAMS);
42 bzero(log_streams.ptr, sizeof(struct log_stream*) * (log_streams.len));
43 log_streams_free = ~0U;
47 /* init the default stream (0) as forwarder to fd2 */
48 struct log_stream *ls = log_new_stream(sizeof(*ls));
49 ASSERT(ls == log_streams.ptr[0]);
50 ASSERT(ls->regnum == 0);
52 log_add_substream(ls, &log_stream_default);
55 /* Close all open streams, un-initialize the module, free all memory,
56 * and fall back to using only log_stream_default. */
64 for (int i=0; i < log_streams_after; i++)
66 if (log_streams.ptr[i]->regnum >= 0)
67 log_close_stream(log_streams.ptr[i]);
68 xfree(log_streams.ptr[i]);
71 /* Back to the default state */
72 lsbuf_done(&log_streams);
73 log_streams_after = 0;
74 log_streams_free = ~0U;
78 /* Add a new substream. The parent stream takes a reference on the substream,
79 * preventing it from being closed as long as it is linked. */
81 log_add_substream(struct log_stream *where, struct log_stream *what)
86 simp_node *n = xmalloc(sizeof(simp_node));
87 n->p = log_ref_stream(what);
88 clist_add_tail(&where->substreams, &n->n);
91 /* Remove all occurrences of a substream together with the references they
92 * keep. If a substream becomes unreferenced, it is closed. If what is NULL,
93 * all substreams are removed. Returns the number of deleted entries. */
95 log_rm_substream(struct log_stream *where, struct log_stream *what)
101 CLIST_FOR_EACH_DELSAFE(simp_node *, i, where->substreams, tmp)
102 if (i->p == what || !what)
105 log_close_stream(i->p);
112 /* Return a pointer to a new stream with no handler and an empty substream list. */
114 log_new_stream(size_t size)
116 struct log_stream *l;
119 /* Initialize the data structures if needed */
122 /* Get a free stream, possibly recycling a closed one */
123 if (log_streams_free == ~0U)
125 lsbuf_grow(&log_streams, log_streams_after+1);
126 index = log_streams_after++;
127 l = log_streams.ptr[index] = xmalloc(size);
131 index = log_streams_free;
132 l = xrealloc(log_streams.ptr[index], size);
133 log_streams.ptr[index] = l;
134 log_streams_free = l->levels;
137 /* Initialize the stream */
138 bzero(l, sizeof(*l));
140 l->regnum = LS_SET_STRNUM(index);
141 clist_init(&l->substreams);
142 return log_ref_stream(l);
145 /* Remove a reference on a stream and close it if it was the last reference.
146 * Closing automatically unlinks all substreams and closes them if they are
147 * no longer referenced. Returns 1 if the stream has been really closed. */
149 log_close_stream(struct log_stream *ls)
152 ASSERT(ls->use_count);
156 /* Unlink all subtreams */
157 log_rm_substream(ls, NULL);
159 /* Close the stream and add it to the free-list */
162 ls->levels = log_streams_free;
163 log_streams_free = LS_GET_STRNUM(ls->regnum);
169 log_set_format(struct log_stream *ls, uns mask, uns data)
171 ls->msgfmt = (ls->msgfmt & mask) | data;
172 CLIST_FOR_EACH(simp_node *, i, ls->substreams)
173 log_set_format(i->p, mask, data);