pgsp_explain.c

   1 /*-------------------------------------------------------------------------
   2  *
   3  * pgsp_explain.c: extracted code from explain.c for explain of triggers.
   4  *
   5  * Copyright (c) 2008-2019, PostgreSQL Global Development Group
   6  * Copyright (c) 2012-2019, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
   7  *
   8  * IDENTIFICATION
   9  *        pg_store_plan/pgsp_explain.c
  10  *
  11  *-------------------------------------------------------------------------
  12  */
  13
  14 #include "postgres.h"
  15 #include "commands/explain.h"
  16 #include "utils/rel.h"
  17 #include "utils/lsyscache.h"
  18 #include "utils/json.h"
  19 #include "pgsp_explain.h"
  20
  21 static void pgspExplainOpenGroup(const char *objtype, const char *labelname,
  22                                           bool labeled, ExplainState *es);
  23 static void pgspExplainCloseGroup(const char *objtype, const char *labelname,
  24                                            bool labeled, ExplainState *es);
  25 static void report_triggers(ResultRelInfo *rInfo, bool show_relname,
  26                                          ExplainState *es);
  27 static void pgspExplainPropertyText(const char *qlabel, const char *value, ExplainState *es);
  28 static void pgspExplainPropertyFloat(const char *qlabel, double value, int ndigits,
  29                                                   ExplainState *es);
  30 static void pgspExplainProperty(const char *qlabel, const char *value, bool numeric,
  31                                                         ExplainState *es);
  32 static void pgspExplainJSONLineEnding(ExplainState *es);
  33
  34 /*
  35  * ExplainState is modified at 9.4.1 and 9.3.6. But the change is for
  36  * internal use and to avoid binary-incompatibility not changing the
  37  * size of ExplainState. So we can use ExplainState->extra as if it
  38  * were grouping_stack safely and should do so. Using ->extra as List*
  39  * discards the memory for ExplainStateExtra but it is not a problem
  40  * since it is allocated by palloc.
  41  */
  42 #if (PG_VERSION_NUM >= 90401 && PG_VERSION_NUM < 90500) || \
  43         (PG_VERSION_NUM >= 90306 && PG_VERSION_NUM < 90400)
  44 #define GROUPING_STACK(es) (*((List **)(&(es)->extra)))
  45 #else
  46 #define GROUPING_STACK(es) ((es)->grouping_stack)
  47 #endif
  48
  49 /* ExplainInitState() is replaced with NewExlainState() in 9.5 */
  50 #if PG_VERSION_NUM < 90500
  51 ExplainState *
  52 NewExplainState(void)
  53 {
  54   ExplainState *es = (ExplainState *)palloc0(sizeof(ExplainState));
  55
  56   ExplainInitState(es);
  57   es->costs = true;
  58   return es;
  59 }
  60 #endif
  61
  62 void
  63 pgspExplainTriggers(ExplainState *es, QueryDesc *queryDesc)
  64 {
  65         if (es->analyze)
  66         {
  67                 ResultRelInfo *rInfo;
  68                 bool            show_relname;
  69                 int                     numrels = queryDesc->estate->es_num_result_relations;
  70                 List       *targrels = queryDesc->estate->es_trig_target_relations;
  71                 int                     nr;
  72                 ListCell   *l;
  73
  74                 pgspExplainOpenGroup("Triggers", "Triggers", false, es);
  75
  76                 show_relname = (numrels > 1 || targrels != NIL);
  77                 rInfo = queryDesc->estate->es_result_relations;
  78                 for (nr = 0; nr < numrels; rInfo++, nr++)
  79                         report_triggers(rInfo, show_relname, es);
  80
  81                 foreach(l, targrels)
  82                 {
  83                         rInfo = (ResultRelInfo *) lfirst(l);
  84                         report_triggers(rInfo, show_relname, es);
  85                 }
  86
  87                 pgspExplainCloseGroup("Triggers", "Triggers", false, es);
  88         }
  89 }
  90
  91 static void
  92 pgspExplainOpenGroup(const char *objtype, const char *labelname,
  93                                  bool labeled, ExplainState *es)
  94 {
  95         pgspExplainJSONLineEnding(es);
  96         appendStringInfoSpaces(es->str, 2 * es->indent);
  97         if (labelname)
  98         {
  99                 escape_json(es->str, labelname);
 100                 appendStringInfoString(es->str, ": ");
 101         }
 102         appendStringInfoChar(es->str, labeled ? '{' : '[');
 103
 104         GROUPING_STACK(es) = lcons_int(0, GROUPING_STACK(es));
 105         es->indent++;
 106 }
 107
 108 static void
 109 pgspExplainCloseGroup(const char *objtype, const char *labelname,
 110                                   bool labeled, ExplainState *es)
 111 {
 112         es->indent--;
 113         appendStringInfoChar(es->str, '\n');
 114         appendStringInfoSpaces(es->str, 2 * es->indent);
 115         appendStringInfoChar(es->str, labeled ? '}' : ']');
 116         GROUPING_STACK(es) = list_delete_first(GROUPING_STACK(es));
 117 }
 118
 119 static void
 120 report_triggers(ResultRelInfo *rInfo, bool show_relname, ExplainState *es)
 121 {
 122         int                     nt;
 123
 124         if (!rInfo->ri_TrigDesc || !rInfo->ri_TrigInstrument)
 125                 return;
 126         for (nt = 0; nt < rInfo->ri_TrigDesc->numtriggers; nt++)
 127         {
 128                 Trigger    *trig = rInfo->ri_TrigDesc->triggers + nt;
 129                 Instrumentation *instr = rInfo->ri_TrigInstrument + nt;
 130                 char       *relname;
 131                 char       *conname = NULL;
 132
 133                 /* Must clean up instrumentation state */
 134                 InstrEndLoop(instr);
 135
 136                 /*
 137                  * We ignore triggers that were never invoked; they likely aren't
 138                  * relevant to the current query type.
 139                  */
 140                 if (instr->ntuples == 0)
 141                         continue;
 142
 143                 pgspExplainOpenGroup("Trigger", NULL, true, es);
 144
 145                 relname = RelationGetRelationName(rInfo->ri_RelationDesc);
 146                 if (OidIsValid(trig->tgconstraint))
 147                         conname = get_constraint_name(trig->tgconstraint);
 148
 149                 pgspExplainPropertyText("Trigger Name", trig->tgname, es);
 150                 if (conname)
 151                         pgspExplainPropertyText("Constraint Name", conname, es);
 152                 pgspExplainPropertyText("Relation", relname, es);
 153                 pgspExplainPropertyFloat("Time", 1000.0 * instr->total, 3, es);
 154                 pgspExplainPropertyFloat("Calls", instr->ntuples, 0, es);
 155
 156                 if (conname)
 157                         pfree(conname);
 158
 159                 pgspExplainCloseGroup("Trigger", NULL, true, es);
 160         }
 161 }
 162
 163 static void
 164 pgspExplainPropertyText(const char *qlabel, const char *value, ExplainState *es)
 165 {
 166         pgspExplainProperty(qlabel, value, false, es);
 167 }
 168
 169 static void
 170 pgspExplainPropertyFloat(const char *qlabel, double value, int ndigits,
 171                                          ExplainState *es)
 172 {
 173         char            buf[256];
 174
 175         snprintf(buf, sizeof(buf), "%.*f", ndigits, value);
 176         pgspExplainProperty(qlabel, buf, true, es);
 177 }
 178
 179
 180 static void
 181 pgspExplainProperty(const char *qlabel, const char *value, bool numeric,
 182                                 ExplainState *es)
 183 {
 184         pgspExplainJSONLineEnding(es);
 185         appendStringInfoSpaces(es->str, es->indent * 2);
 186         escape_json(es->str, qlabel);
 187         appendStringInfoString(es->str, ": ");
 188         if (numeric)
 189                 appendStringInfoString(es->str, value);
 190         else
 191                 escape_json(es->str, value);
 192 }
 193
 194 static void
 195 pgspExplainJSONLineEnding(ExplainState *es)
 196 {
 197         Assert(es->format == EXPLAIN_FORMAT_JSON);
 198         if (linitial_int(GROUPING_STACK(es)) != 0)
 199                 appendStringInfoChar(es->str, ',');
 200         else
 201                 linitial_int(GROUPING_STACK(es)) = 1;
 202         appendStringInfoChar(es->str, '\n');
 203 }
 204