MINOR: stats: implement automatic metric generation from stat_col

This commit is a direct follow-up of the previous one which define a new
type "struct stat_col" to fully define a statistic entry.

Define a new function metric_generate(). For metrics statistics, it is
able to automatically calculate a stat value field for "offsets" from
"struct stat_col". Use it in stats_fill_*_stats() functions. Maintain a
fallback to previously used switch-case for old-style statistics.

This commit does not introduce functional change as currently no
statistic is defined as "struct stat_col". This will be the subject of a
future commit.

diff --git a/include/haproxy/stats.h b/include/haproxy/stats.h
index dab16dadf525256bc29ddbc37161de755392ab0c..e364824db903b0b1681f62d48dfdf5f9ee1a543c 100644 (file)
--- a/include/haproxy/stats.h
+++ b/include/haproxy/stats.h
@@ -72,6 +72,16 @@ int stats_emit_field_tags(struct buffer *out, const struct field *f,
                          char delim);
 
 
+static inline enum field_format stcol_format(const struct stat_col *col)
+{
+       return col->type & FF_MASK;
+}
+
+static inline enum field_nature stcol_nature(const struct stat_col *col)
+{
+       return col->type & FN_MASK;
+}
+
 static inline enum field_format field_format(const struct field *f, int e)
 {
        return f[e].type & FF_MASK;

diff --git a/src/stats.c b/src/stats.c
index 6080b194abe4231dac5c576b38260d760c031342..7dd18371ec897bc5df1df57c62ed332db803b395 100644 (file)
--- a/src/stats.c
+++ b/src/stats.c
@@ -90,6 +90,12 @@
     .cap = (cap_f),                                                           \
   }
 
+/* Returns true if <col> is fully defined, false if only used as name-desc. */
+static int stcol_is_generic(const struct stat_col *col)
+{
+       return !!(col->cap);
+}
+
 /* Convert stat_col <col> to old-style <name> as name_desc. */
 static void stcol2ndesc(struct name_desc *name, const struct stat_col *col)
 {
@@ -631,6 +637,50 @@ int stats_dump_one_line(const struct field *line, size_t stats_count,
        return ret;
 }
 
+/* Generate if possible a metric value from <col>. <cap> must be set to one of
+ * STATS_PX_CAP_* values to check if the metric is available for this object
+ * type. Metric value will be extracted from <counters>.
+ *
+ * Returns a field value or an empty one if cap not compatible.
+ */
+static struct field me_generate_field(const struct stat_col *col,
+                                      const void *counters, uint8_t cap)
+{
+       struct field value;
+       void *counter = NULL;
+
+       switch (cap) {
+       case STATS_PX_CAP_FE:
+       case STATS_PX_CAP_LI:
+               counter = (char *)counters + col->metric.offset[0];
+               break;
+
+       case STATS_PX_CAP_BE:
+       case STATS_PX_CAP_SRV:
+               counter = (char *)counters + col->metric.offset[1];
+               break;
+
+       default:
+               /* invalid cap requested */
+               ABORT_NOW();
+       }
+
+       /* Check if metric is defined for this side. */
+       if (!(col->cap & cap))
+               return (struct field){ .type = FF_EMPTY };
+
+       switch (stcol_format(col)) {
+       case FF_U64:
+               value = mkf_u64(stcol_nature(col), *(uint64_t *)counter);
+               break;
+       default:
+               /* only FF_U64 counters currently use generic metric calculation */
+               ABORT_NOW();
+       }
+
+       return value;
+}
+
 /* Fill <line> with the frontend statistics. <line> is preallocated array of
  * length <len>. If <index> is != NULL, only fill this one. The length
  * of the array must be at least ST_I_PX_MAX. If this length is less than
@@ -646,9 +696,14 @@ int stats_fill_fe_line(struct proxy *px, struct field *line, int len,
                return 0;
 
        for (; i < ST_I_PX_MAX; i++) {
+               const struct stat_col *col = &stat_cols_px[i];
                struct field field = { 0 };
 
-               switch (i) {
+               if (stcol_is_generic(col)) {
+                       field = me_generate_field(col, &px->fe_counters, STATS_PX_CAP_FE);
+               }
+               else {
+                       switch (i) {
                        case ST_I_PX_PXNAME:
                                field = mkf_str(FO_KEY|FN_NAME|FS_SERVICE, px->id);
                                break;
@@ -846,6 +901,7 @@ int stats_fill_fe_line(struct proxy *px, struct field *line, int len,
                                if (index)
                                        return 0;
                                continue;
+                       }
                }
                line[i] = field;
                if (index)
@@ -904,7 +960,7 @@ static int stats_dump_fe_line(struct stconn *sc, struct proxy *px)
 int stats_fill_li_line(struct proxy *px, struct listener *l, int flags,
                        struct field *line, int len, enum stat_idx_px *selected_field)
 {
-       enum stat_idx_px current_field = (selected_field != NULL ? *selected_field : 0);
+       enum stat_idx_px i = (selected_field != NULL ? *selected_field : 0);
        struct buffer *out = get_trash_chunk();
 
        if (len < ST_I_PX_MAX)
@@ -915,10 +971,15 @@ int stats_fill_li_line(struct proxy *px, struct listener *l, int flags,
 
        chunk_reset(out);
 
-       for (; current_field < ST_I_PX_MAX; current_field++) {
+       for (; i < ST_I_PX_MAX; i++) {
+               const struct stat_col *col = &stat_cols_px[i];
                struct field field = { 0 };
 
-               switch (current_field) {
+               if (stcol_is_generic(col)) {
+                       field = me_generate_field(col, l->counters, STATS_PX_CAP_LI);
+               }
+               else {
+                       switch (i) {
                        case ST_I_PX_PXNAME:
                                field = mkf_str(FO_KEY|FN_NAME|FS_SERVICE, px->id);
                                break;
@@ -1022,8 +1083,9 @@ int stats_fill_li_line(struct proxy *px, struct listener *l, int flags,
                                if (selected_field != NULL)
                                        return 0;
                                continue;
+                       }
                }
-               line[current_field] = field;
+               line[i] = field;
                if (selected_field != NULL)
                        break;
        }
@@ -1191,9 +1253,14 @@ int stats_fill_sv_line(struct proxy *px, struct server *sv, int flags,
        }
 
        for (; i < ST_I_PX_MAX; i++) {
+               const struct stat_col *col = &stat_cols_px[i];
                struct field field = { 0 };
 
-               switch (i) {
+               if (stcol_is_generic(col)) {
+                       field = me_generate_field(col, &sv->counters, STATS_PX_CAP_SRV);
+               }
+               else {
+                       switch (i) {
                        case ST_I_PX_PXNAME:
                                field = mkf_str(FO_KEY|FN_NAME|FS_SERVICE, px->id);
                                break;
@@ -1538,6 +1605,7 @@ int stats_fill_sv_line(struct proxy *px, struct server *sv, int flags,
                                if (index)
                                        return 0;
                                continue;
+                       }
                }
                line[i] = field;
                if (index)
@@ -1651,9 +1719,14 @@ int stats_fill_be_line(struct proxy *px, int flags, struct field *line, int len,
        }
 
        for (; i < ST_I_PX_MAX; i++) {
+               const struct stat_col *col = &stat_cols_px[i];
                struct field field = { 0 };
 
-               switch (i) {
+               if (stcol_is_generic(col)) {
+                       field = me_generate_field(col, &px->be_counters, STATS_PX_CAP_BE);
+               }
+               else {
+                       switch (i) {
                        case ST_I_PX_PXNAME:
                                field = mkf_str(FO_KEY|FN_NAME|FS_SERVICE, px->id);
                                break;
@@ -1870,6 +1943,7 @@ int stats_fill_be_line(struct proxy *px, int flags, struct field *line, int len,
                                if (index)
                                        return 0;
                                continue;
+                       }
                }
                line[i] = field;
                if (index)