LCOV - code coverage report
Current view: top level - disco/metrics - fd_prometheus.c (source / functions) Hit Total Coverage
Test: cov.lcov Lines: 84 146 57.5 %
Date: 2026-07-01 06:01:22 Functions: 7 11 63.6 %

          Line data    Source code
       1             : #include "fd_prometheus.h"
       2             : 
       3             : #include "fd_metrics.h"
       4             : 
       5             : #include "../topo/fd_topo.h"
       6             : #include "../../waltz/http/fd_http_server.h"
       7             : 
       8             : struct fd_prom_render {
       9             :   fd_http_server_t * http;
      10             :   ulong              last_name_hash;
      11             : };
      12             : 
      13             : typedef struct fd_prom_render fd_prom_render_t;
      14             : 
      15             : fd_prom_render_t
      16           3 : fd_prom_render_create( fd_http_server_t * http ) {
      17           3 :   return (fd_prom_render_t) {
      18           3 :     .http           = http,
      19           3 :     .last_name_hash = 0UL
      20           3 :   };
      21           3 : }
      22             : 
      23             : /* Counters are exported with a "_total" suffix per Prometheus naming
      24             :    conventions.  Gauges and histograms keep their bare name (histograms
      25             :    additionally emit the standard _bucket/_sum/_count series). */
      26             : 
      27             : static char const *
      28             : metric_export_name( fd_metrics_meta_t const * metric,
      29             :                     char *                    buf,
      30         432 :                     ulong                     buf_sz ) {
      31         432 :   if( metric->type==FD_METRICS_TYPE_COUNTER ) {
      32         387 :     FD_TEST( fd_cstr_printf_check( buf, buf_sz, NULL, "%s_total", metric->name ) );
      33         387 :     return buf;
      34         387 :   }
      35          45 :   return metric->name;
      36         432 : }
      37             : 
      38             : static void
      39             : render_header( fd_prom_render_t *        r,
      40         294 :                fd_metrics_meta_t const * metric ) {
      41             :   /* Only render header once per metric name */
      42         294 :   ulong hash = fd_cstr_hash( metric->name );
      43         294 :   if( r->last_name_hash != hash ) {
      44         144 :     if( r->last_name_hash ) {
      45         141 :       fd_http_server_printf( r->http, "\n" );
      46         141 :     }
      47         144 :     char name_buf[ 256 ];
      48         144 :     char const * name = metric_export_name( metric, name_buf, sizeof(name_buf) );
      49         144 :     fd_http_server_printf( r->http, "# HELP %s %s\n# TYPE %s %s\n", name, metric->desc, name, fd_metrics_meta_type_str( metric ) );
      50         144 :     r->last_name_hash = hash;
      51         144 :   }
      52         294 : }
      53             : 
      54             : static void
      55             : render_link( fd_prom_render_t *        r,
      56             :              fd_metrics_meta_t const * metric,
      57             :              fd_topo_tile_t const *    tile,
      58             :              fd_topo_link_t const *    link,
      59           0 :              ulong                     value ) {
      60           0 :   render_header( r, metric );
      61           0 :   switch( metric->converter ) {
      62           0 :   case FD_METRICS_CONVERTER_NANOSECONDS:
      63           0 :     value = fd_metrics_convert_ticks_to_nanoseconds( value );
      64           0 :     break;
      65           0 :   case FD_METRICS_CONVERTER_NONE:
      66           0 :     break;
      67           0 :   default:
      68           0 :     FD_LOG_ERR(( "unknown converter %i", metric->converter ));
      69           0 :   }
      70           0 :   char name_buf[ 256 ];
      71           0 :   char const * name = metric_export_name( metric, name_buf, sizeof(name_buf) );
      72           0 :   fd_http_server_printf( r->http, "%s{kind=\"%s\",kind_id=\"%lu\",link_kind=\"%s\",link_kind_id=\"%lu\"} %lu\n", name, tile->name, tile->kind_id, link->name, link->kind_id, value );
      73           0 : }
      74             : 
      75             : static void
      76             : render_histogram( fd_prom_render_t *        r,
      77             :                   fd_metrics_meta_t const * metric,
      78           6 :                   fd_topo_tile_t const *    tile ) {
      79           6 :   render_header( r, metric );
      80             : 
      81           6 :   fd_histf_t hist[1];
      82           6 :   if( FD_LIKELY( metric->converter==FD_METRICS_CONVERTER_SECONDS ) )
      83           6 :     FD_TEST( fd_histf_new( hist, fd_metrics_convert_seconds_to_ticks( metric->histogram.seconds.min ), fd_metrics_convert_seconds_to_ticks ( metric->histogram.seconds.max ) ) );
      84           0 :   else if( FD_LIKELY( metric->converter==FD_METRICS_CONVERTER_NONE ) )
      85           0 :     FD_TEST( fd_histf_new( hist, metric->histogram.none.min, metric->histogram.none.max ) );
      86           0 :   else FD_LOG_ERR(( "unknown converter %i", metric->converter ));
      87             : 
      88           6 :   ulong value = 0;
      89           6 :   char value_str[ 64 ];
      90         102 :   for( ulong k=0; k<FD_HISTF_BUCKET_CNT; k++ ) {
      91          96 :     value += *(fd_metrics_tile( tile->metrics ) + metric->offset + k);
      92             : 
      93          96 :     char * le; /* le here means "less then or equal" not "left edge" */
      94          96 :     char le_str[ 64 ];
      95          96 :     if( FD_UNLIKELY( k==FD_HISTF_BUCKET_CNT-1UL ) ) le = "+Inf";
      96          90 :     else {
      97          90 :       ulong edge = fd_histf_right( hist, k );
      98          90 :       if( FD_LIKELY( metric->converter==FD_METRICS_CONVERTER_SECONDS ) ) {
      99          90 :         double edgef = fd_metrics_convert_ticks_to_seconds( edge-1 );
     100          90 :         FD_TEST( fd_cstr_printf_check( le_str, sizeof( le_str ), NULL, "%.17g", edgef ) );
     101          90 :       } else {
     102           0 :         FD_TEST( fd_cstr_printf_check( le_str, sizeof( le_str ), NULL, "%lu", edge-1 ) );
     103           0 :       }
     104          90 :       le = le_str;
     105          90 :     }
     106             : 
     107          96 :     FD_TEST( fd_cstr_printf_check( value_str, sizeof( value_str ), NULL, "%lu", value ));
     108          96 :     fd_http_server_printf( r->http, "%s_bucket{kind=\"%s\",kind_id=\"%lu\",le=\"%s\"} %s\n", metric->name, tile->name, tile->kind_id, le, value_str );
     109          96 :   }
     110             : 
     111           6 :   char sum_str[ 64 ];
     112           6 :   if( FD_LIKELY( metric->converter==FD_METRICS_CONVERTER_SECONDS ) ) {
     113           6 :     double sumf = fd_metrics_convert_ticks_to_seconds( *(fd_metrics_tile( tile->metrics ) + metric->offset + FD_HISTF_BUCKET_CNT) );
     114           6 :     FD_TEST( fd_cstr_printf_check( sum_str, sizeof( sum_str ), NULL, "%.17g", sumf ) );
     115           6 :   } else {
     116           0 :     FD_TEST( fd_cstr_printf_check( sum_str, sizeof( sum_str ), NULL, "%lu", *(fd_metrics_tile( tile->metrics ) + metric->offset + FD_HISTF_BUCKET_CNT) ));
     117           0 :   }
     118             : 
     119           6 :   fd_http_server_printf( r->http, "%s_sum{kind=\"%s\",kind_id=\"%lu\"} %s\n", metric->name, tile->name, tile->kind_id, sum_str );
     120           6 :   fd_http_server_printf( r->http, "%s_count{kind=\"%s\",kind_id=\"%lu\"} %s\n", metric->name, tile->name, tile->kind_id, value_str );
     121           6 : }
     122             : 
     123             : static void
     124             : render_counter( fd_prom_render_t *        r,
     125             :                 fd_metrics_meta_t const * metric,
     126         288 :                 fd_topo_tile_t const *    tile ) {
     127         288 :   render_header( r, metric );
     128         288 :   ulong raw_value = *(fd_metrics_tile( tile->metrics ) + metric->offset);
     129             : 
     130         288 :   char name_buf[ 256 ];
     131         288 :   char const * name = metric_export_name( metric, name_buf, sizeof(name_buf) );
     132         288 :   fd_http_server_printf( r->http, "%s{kind=\"%s\",kind_id=\"%lu\"", name, tile->name, tile->kind_id );
     133         288 :   if( metric->enum_name ) {
     134         180 :     fd_http_server_printf( r->http, ",%s=\"%s\"", metric->enum_name, metric->enum_variant );
     135         180 :   }
     136         288 :   switch( metric->converter ) {
     137           0 :   case FD_METRICS_CONVERTER_NANOSECONDS:
     138           0 :     fd_http_server_printf( r->http, "} %lu\n", fd_metrics_convert_ticks_to_nanoseconds( raw_value ) );
     139           0 :     break;
     140           0 :   case FD_METRICS_CONVERTER_SECONDS:
     141           0 :     fd_http_server_printf( r->http, "} %e\n", fd_metrics_convert_ticks_to_seconds( raw_value ) );
     142           0 :     break;
     143         288 :   case FD_METRICS_CONVERTER_NONE:
     144         288 :     fd_http_server_printf( r->http, "} %lu\n", raw_value );
     145         288 :     break;
     146           0 :   default:
     147           0 :     FD_LOG_ERR(( "unknown converter %i", metric->converter ));
     148         288 :   }
     149         288 : }
     150             : 
     151             : static void
     152             : render_links_in( fd_prom_render_t *        r,
     153             :                  fd_topo_t const *         topo,
     154             :                  ulong                     metrics_cnt,
     155           0 :                  fd_metrics_meta_t const * metrics ) {
     156           0 :   for( ulong i=0UL; i<metrics_cnt; i++ ) {
     157           0 :     fd_metrics_meta_t const * metric = &metrics[ i ];
     158           0 :     for( ulong j=0UL; j<topo->tile_cnt; j++ ) {
     159           0 :       fd_topo_tile_t const * tile = &topo->tiles[ j ];
     160           0 :       ulong polled_in_idx = 0UL;
     161           0 :       for( ulong k=0UL; k<tile->in_cnt; k++ ) {
     162           0 :         if( FD_UNLIKELY( !tile->in_link_poll[ k ] ) ) continue;
     163           0 :         fd_topo_link_t const * link = &topo->links[ tile->in_link_id[ k ] ];
     164           0 :         ulong value = *(fd_metrics_link_in( tile->metrics, polled_in_idx ) + metric->offset );
     165           0 :         render_link( r, metric, tile, link, value );
     166           0 :         polled_in_idx++;
     167           0 :       }
     168           0 :     }
     169           0 :   }
     170           0 : }
     171             : 
     172             : static void
     173             : render_tile_metric( fd_prom_render_t *        r,
     174             :                     fd_topo_tile_t const *    tile,
     175         294 :                     fd_metrics_meta_t const * metric ) {
     176         294 :   if( FD_LIKELY( metric->type==FD_METRICS_TYPE_COUNTER || metric->type==FD_METRICS_TYPE_GAUGE ) ) {
     177         288 :     render_counter( r, metric, tile );
     178         288 :   } else if( FD_LIKELY( metric->type==FD_METRICS_TYPE_HISTOGRAM ) ) {
     179           6 :     render_histogram( r, metric, tile );
     180           6 :   }
     181         294 : }
     182             : 
     183             : static void
     184             : render_tile( fd_prom_render_t *        r,
     185             :              fd_topo_t const *         topo,
     186             :              char const *              tile_name,
     187             :              ulong                     metrics_cnt,
     188           0 :              fd_metrics_meta_t const * metrics ) {
     189           0 :   for( ulong i=0UL; i<metrics_cnt; i++ ) {
     190           0 :     for( ulong j=0UL; j<topo->tile_cnt; j++ ) {
     191             :       /* FIXME: This is O(n^2) rather than O(n). */
     192           0 :       if( FD_LIKELY( tile_name!=NULL && 0!=strcmp( topo->tiles[ j ].name, tile_name ) ) ) continue;
     193           0 :       render_tile_metric( r, topo->tiles+j, metrics+i );
     194           0 :     }
     195           0 :   }
     196           0 : }
     197             : 
     198             : void
     199             : fd_prometheus_render_tile( fd_http_server_t *        http,
     200             :                            fd_topo_tile_t const *    tile,
     201             :                            fd_metrics_meta_t const * metrics,
     202           3 :                            ulong                     metrics_cnt ) {
     203           3 :   fd_prom_render_t r = fd_prom_render_create( http );
     204         297 :   for( ulong i=0UL; i<metrics_cnt; i++ ) {
     205         294 :     render_tile_metric( &r, tile, metrics+i );
     206         294 :   }
     207           3 : }
     208             : 
     209             : void
     210             : fd_prometheus_render_all( fd_topo_t const *  topo,
     211           0 :                           fd_http_server_t * http ) {
     212           0 :   fd_prom_render_t r = fd_prom_render_create( http );
     213           0 :   render_tile( &r, topo, NULL, FD_METRICS_ALL_TOTAL, FD_METRICS_ALL );
     214           0 :   render_links_in( &r, topo, FD_METRICS_ALL_LINK_IN_TOTAL, FD_METRICS_ALL_LINK_IN );
     215           0 :   for( ulong i=0UL; i<FD_METRICS_TILE_KIND_CNT; i++ ) {
     216           0 :     render_tile( &r, topo, FD_METRICS_TILE_KIND_NAMES[ i ], FD_METRICS_TILE_KIND_SIZES[ i ], FD_METRICS_TILE_KIND_METRICS[ i ] );
     217           0 :   }
     218           0 : }

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