MEDIUM: stats: define an API to register stat modules

A stat module can be registered to quickly add new statistics on
haproxy. It must be attached to one of the available stats domain. The
register must be done using INITCALL on STG_REGISTER.

The stat module has a name which should be unique for each new module in
a domain. It also contains a statistics list with their name/desc and a
pointer to a function used to fill the stats from the module counters.

The module also provides the initial counters values used on
automatically allocated counters. The offset for these counters
are stored in the module structure.

diff --git a/include/haproxy/stats-t.h b/include/haproxy/stats-t.h
index d60cc24876866e50a0f704d41262353870861bfe..7d41b78f4bf1b08457c869fb6e13ae138d2a9a4e 100644 (file)
--- a/include/haproxy/stats-t.h
+++ b/include/haproxy/stats-t.h
@@ -453,6 +453,32 @@ struct field {
        } u;
 };
 
+enum counters_type {
+       COUNTERS_FE = 0,
+       COUNTERS_BE,
+       COUNTERS_SV,
+       COUNTERS_LI,
+
+       COUNTERS_OFF_END
+};
+
+/* Entity used to generate statistics on an HAProxy component */
+struct stats_module {
+       struct list list;
+       const char *name;
+
+       /* functor used to generate the stats module using counters provided through data parameter */
+       void (*fill_stats)(void *data, struct field *);
+
+       struct name_desc *stats; /* name/description of stats provided by the module */
+       void *counters;          /* initial values of allocated counters */
+       size_t counters_off[COUNTERS_OFF_END]; /* list of offsets of allocated counters in various objects */
+       size_t stats_count;      /* count of stats provided */
+       size_t counters_size;    /* sizeof counters */
+
+       uint32_t domain_flags;   /* stats application domain for this module */
+};
+
 /* stats_domain is used in a flag as a 1 byte field */
 enum stats_domain {
        STATS_DOMAIN_PROXY = 0,

diff --git a/include/haproxy/stats.h b/include/haproxy/stats.h
index e376b284f130789320e89502e0cafd6bf3df985a..272274610faee4238d71469f795305a7b2506d9c 100644 (file)
--- a/include/haproxy/stats.h
+++ b/include/haproxy/stats.h
@@ -123,6 +123,8 @@ static inline struct field mkf_flt(uint32_t type, double value)
 #define MK_STATS_PROXY_DOMAIN(px_cap) \
        ((px_cap) << STATS_PX_CAP | STATS_DOMAIN_PROXY)
 
+void stats_register_module(struct stats_module *m);
+
 #endif /* _HAPROXY_STATS_H */
 
 /*

diff --git a/src/stats.c b/src/stats.c
index ed0abc7b2991ce67f75903fd03789d8cb2328264..83c0e664532e156b6e0583ce6adaa09f385515c5 100644 (file)
--- a/src/stats.c
+++ b/src/stats.c
@@ -257,6 +257,11 @@ static THREAD_LOCAL struct field info[INF_TOTAL_FIELDS];
 /* one line of stats */
 static THREAD_LOCAL struct field stats[ST_F_TOTAL_FIELDS];
 
+/* list of all registered stats module */
+static struct list stats_module_list[STATS_DOMAIN_COUNT] = {
+       LIST_HEAD_INIT(stats_module_list[STATS_DOMAIN_PROXY]),
+};
+
 static inline uint8_t stats_get_domain(uint32_t domain)
 {
        return domain >> STATS_DOMAIN & STATS_DOMAIN_MASK;
@@ -4035,6 +4040,13 @@ static int cli_io_handler_dump_json_schema(struct appctx *appctx)
        return stats_dump_json_schema_to_buffer(appctx->owner);
 }
 
+void stats_register_module(struct stats_module *m)
+{
+       const uint8_t domain = stats_get_domain(m->domain_flags);
+
+       LIST_ADDQ(&stats_module_list[domain], &m->list);
+}
+
 /* register cli keywords */
 static struct cli_kw_list cli_kws = {{ },{
        { { "clear", "counters",  NULL }, "clear counters : clear max statistics counters (add 'all' for all counters)", cli_parse_clear_counters, NULL, NULL },