Age Owner Branch data TLA Line data Source code
1 : : /*-------------------------------------------------------------------------
2 : : *
3 : : * explain_state.c
4 : : * Code for initializing and accessing ExplainState objects
5 : : *
6 : : * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
7 : : * Portions Copyright (c) 1994-5, Regents of the University of California
8 : : *
9 : : * In-core options have hard-coded fields inside ExplainState; e.g. if
10 : : * the user writes EXPLAIN (BUFFERS) then ExplainState's "buffers" member
11 : : * will be set to true. Extensions can also register options using
12 : : * RegisterExtensionExplainOption; so that e.g. EXPLAIN (BICYCLE 'red')
13 : : * will invoke a designated handler that knows what the legal values are
14 : : * for the BICYCLE option. However, it's not enough for an extension to be
15 : : * able to parse new options: it also needs a place to store the results
16 : : * of that parsing, and an ExplainState has no 'bicycle' field.
17 : : *
18 : : * To solve this problem, an ExplainState can contain an array of opaque
19 : : * pointers, one per extension. An extension can use GetExplainExtensionId
20 : : * to acquire an integer ID to acquire an offset into this array that is
21 : : * reserved for its exclusive use, and then use GetExplainExtensionState
22 : : * and SetExplainExtensionState to read and write its own private state
23 : : * within an ExplainState.
24 : : *
25 : : * Note that there is no requirement that the name of the option match
26 : : * the name of the extension; e.g. a pg_explain_conveyance extension could
27 : : * implement options for BICYCLE, MONORAIL, etc.
28 : : *
29 : : * IDENTIFICATION
30 : : * src/backend/commands/explain_state.c
31 : : *
32 : : *-------------------------------------------------------------------------
33 : : */
34 : : #include "postgres.h"
35 : :
36 : : #include "commands/defrem.h"
37 : : #include "commands/explain.h"
38 : : #include "commands/explain_state.h"
39 : :
40 : : /* Hook to perform additional EXPLAIN options validation */
41 : : explain_validate_options_hook_type explain_validate_options_hook = NULL;
42 : :
43 : : typedef struct
44 : : {
45 : : const char *option_name;
46 : : ExplainOptionHandler option_handler;
47 : : } ExplainExtensionOption;
48 : :
49 : : static const char **ExplainExtensionNameArray = NULL;
50 : : static int ExplainExtensionNamesAssigned = 0;
51 : : static int ExplainExtensionNamesAllocated = 0;
52 : :
53 : : static ExplainExtensionOption *ExplainExtensionOptionArray = NULL;
54 : : static int ExplainExtensionOptionsAssigned = 0;
55 : : static int ExplainExtensionOptionsAllocated = 0;
56 : :
57 : : /*
58 : : * Create a new ExplainState struct initialized with default options.
59 : : */
60 : : ExplainState *
172 rhaas@postgresql.org 61 :CBC 12041 : NewExplainState(void)
62 : : {
63 : 12041 : ExplainState *es = (ExplainState *) palloc0(sizeof(ExplainState));
64 : :
65 : : /* Set default options (most fields can be left as zeroes). */
66 : 12041 : es->costs = true;
67 : : /* Prepare output buffer. */
68 : 12041 : es->str = makeStringInfo();
69 : :
70 : 12041 : return es;
71 : : }
72 : :
73 : : /*
74 : : * Parse a list of EXPLAIN options and update an ExplainState accordingly.
75 : : */
76 : : void
77 : 12031 : ParseExplainOptionList(ExplainState *es, List *options, ParseState *pstate)
78 : : {
79 : : ListCell *lc;
80 : 12031 : bool timing_set = false;
81 : 12031 : bool buffers_set = false;
82 : 12031 : bool summary_set = false;
83 : :
84 : : /* Parse options list. */
85 [ + + + + : 23444 : foreach(lc, options)
+ + ]
86 : : {
87 : 11417 : DefElem *opt = (DefElem *) lfirst(lc);
88 : :
89 [ + + ]: 11417 : if (strcmp(opt->defname, "analyze") == 0)
90 : 1743 : es->analyze = defGetBoolean(opt);
91 [ + + ]: 9674 : else if (strcmp(opt->defname, "verbose") == 0)
92 : 1253 : es->verbose = defGetBoolean(opt);
93 [ + + ]: 8421 : else if (strcmp(opt->defname, "costs") == 0)
94 : 6826 : es->costs = defGetBoolean(opt);
95 [ + + ]: 1595 : else if (strcmp(opt->defname, "buffers") == 0)
96 : : {
97 : 489 : buffers_set = true;
98 : 489 : es->buffers = defGetBoolean(opt);
99 : : }
100 [ - + ]: 1106 : else if (strcmp(opt->defname, "wal") == 0)
172 rhaas@postgresql.org 101 :UBC 0 : es->wal = defGetBoolean(opt);
172 rhaas@postgresql.org 102 [ + + ]:CBC 1106 : else if (strcmp(opt->defname, "settings") == 0)
103 : 6 : es->settings = defGetBoolean(opt);
104 [ + + ]: 1100 : else if (strcmp(opt->defname, "generic_plan") == 0)
105 : 9 : es->generic = defGetBoolean(opt);
106 [ + + ]: 1091 : else if (strcmp(opt->defname, "timing") == 0)
107 : : {
108 : 451 : timing_set = true;
109 : 451 : es->timing = defGetBoolean(opt);
110 : : }
111 [ + + ]: 640 : else if (strcmp(opt->defname, "summary") == 0)
112 : : {
113 : 439 : summary_set = true;
114 : 439 : es->summary = defGetBoolean(opt);
115 : : }
116 [ + + ]: 201 : else if (strcmp(opt->defname, "memory") == 0)
117 : 15 : es->memory = defGetBoolean(opt);
118 [ + + ]: 186 : else if (strcmp(opt->defname, "serialize") == 0)
119 : : {
120 [ + + ]: 15 : if (opt->arg)
121 : : {
122 : 6 : char *p = defGetString(opt);
123 : :
124 [ + - - + ]: 6 : if (strcmp(p, "off") == 0 || strcmp(p, "none") == 0)
172 rhaas@postgresql.org 125 :UBC 0 : es->serialize = EXPLAIN_SERIALIZE_NONE;
172 rhaas@postgresql.org 126 [ + + ]:CBC 6 : else if (strcmp(p, "text") == 0)
127 : 3 : es->serialize = EXPLAIN_SERIALIZE_TEXT;
128 [ + - ]: 3 : else if (strcmp(p, "binary") == 0)
129 : 3 : es->serialize = EXPLAIN_SERIALIZE_BINARY;
130 : : else
172 rhaas@postgresql.org 131 [ # # ]:UBC 0 : ereport(ERROR,
132 : : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
133 : : errmsg("unrecognized value for EXPLAIN option \"%s\": \"%s\"",
134 : : opt->defname, p),
135 : : parser_errposition(pstate, opt->location)));
136 : : }
137 : : else
138 : : {
139 : : /* SERIALIZE without an argument is taken as 'text' */
172 rhaas@postgresql.org 140 :CBC 9 : es->serialize = EXPLAIN_SERIALIZE_TEXT;
141 : : }
142 : : }
143 [ + + ]: 171 : else if (strcmp(opt->defname, "format") == 0)
144 : : {
145 : 156 : char *p = defGetString(opt);
146 : :
147 [ + + ]: 156 : if (strcmp(p, "text") == 0)
148 : 6 : es->format = EXPLAIN_FORMAT_TEXT;
149 [ + + ]: 150 : else if (strcmp(p, "xml") == 0)
150 : 4 : es->format = EXPLAIN_FORMAT_XML;
151 [ + + ]: 146 : else if (strcmp(p, "json") == 0)
152 : 140 : es->format = EXPLAIN_FORMAT_JSON;
153 [ + - ]: 6 : else if (strcmp(p, "yaml") == 0)
154 : 6 : es->format = EXPLAIN_FORMAT_YAML;
155 : : else
172 rhaas@postgresql.org 156 [ # # ]:UBC 0 : ereport(ERROR,
157 : : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
158 : : errmsg("unrecognized value for EXPLAIN option \"%s\": \"%s\"",
159 : : opt->defname, p),
160 : : parser_errposition(pstate, opt->location)));
161 : : }
172 rhaas@postgresql.org 162 [ + + ]:CBC 15 : else if (!ApplyExtensionExplainOption(es, opt, pstate))
163 [ + - ]: 4 : ereport(ERROR,
164 : : (errcode(ERRCODE_SYNTAX_ERROR),
165 : : errmsg("unrecognized EXPLAIN option \"%s\"",
166 : : opt->defname),
167 : : parser_errposition(pstate, opt->location)));
168 : : }
169 : :
170 : : /* check that WAL is used with EXPLAIN ANALYZE */
171 [ - + - - ]: 12027 : if (es->wal && !es->analyze)
172 rhaas@postgresql.org 172 [ # # ]:UBC 0 : ereport(ERROR,
173 : : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
174 : : errmsg("EXPLAIN option %s requires ANALYZE", "WAL")));
175 : :
176 : : /* if the timing was not set explicitly, set default value */
172 rhaas@postgresql.org 177 [ + + ]:CBC 12027 : es->timing = (timing_set) ? es->timing : es->analyze;
178 : :
179 : : /* if the buffers was not set explicitly, set default value */
180 [ + + ]: 12027 : es->buffers = (buffers_set) ? es->buffers : es->analyze;
181 : :
182 : : /* check that timing is used with EXPLAIN ANALYZE */
183 [ + + - + ]: 12027 : if (es->timing && !es->analyze)
172 rhaas@postgresql.org 184 [ # # ]:UBC 0 : ereport(ERROR,
185 : : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
186 : : errmsg("EXPLAIN option %s requires ANALYZE", "TIMING")));
187 : :
188 : : /* check that serialize is used with EXPLAIN ANALYZE */
172 rhaas@postgresql.org 189 [ + + - + ]:CBC 12027 : if (es->serialize != EXPLAIN_SERIALIZE_NONE && !es->analyze)
172 rhaas@postgresql.org 190 [ # # ]:UBC 0 : ereport(ERROR,
191 : : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
192 : : errmsg("EXPLAIN option %s requires ANALYZE", "SERIALIZE")));
193 : :
194 : : /* check that GENERIC_PLAN is not used with EXPLAIN ANALYZE */
172 rhaas@postgresql.org 195 [ + + + + ]:CBC 12027 : if (es->generic && es->analyze)
196 [ + - ]: 3 : ereport(ERROR,
197 : : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
198 : : errmsg("EXPLAIN options ANALYZE and GENERIC_PLAN cannot be used together")));
199 : :
200 : : /* if the summary was not set explicitly, set default value */
201 [ + + ]: 12024 : es->summary = (summary_set) ? es->summary : es->analyze;
202 : :
203 : : /* plugin specific option validation */
170 204 [ - + ]: 12024 : if (explain_validate_options_hook)
170 rhaas@postgresql.org 205 :UBC 0 : (*explain_validate_options_hook) (es, options, pstate);
172 rhaas@postgresql.org 206 :CBC 12024 : }
207 : :
208 : : /*
209 : : * Map the name of an EXPLAIN extension to an integer ID.
210 : : *
211 : : * Within the lifetime of a particular backend, the same name will be mapped
212 : : * to the same ID every time. IDs are not stable across backends. Use the ID
213 : : * that you get from this function to call GetExplainExtensionState and
214 : : * SetExplainExtensionState.
215 : : *
216 : : * extension_name is assumed to be a constant string or allocated in storage
217 : : * that will never be freed.
218 : : */
219 : : int
220 : 1 : GetExplainExtensionId(const char *extension_name)
221 : : {
222 : : /* Search for an existing extension by this name; if found, return ID. */
223 [ - + ]: 1 : for (int i = 0; i < ExplainExtensionNamesAssigned; ++i)
172 rhaas@postgresql.org 224 [ # # ]:UBC 0 : if (strcmp(ExplainExtensionNameArray[i], extension_name) == 0)
225 : 0 : return i;
226 : :
227 : : /* If there is no array yet, create one. */
172 rhaas@postgresql.org 228 [ + - ]:CBC 1 : if (ExplainExtensionNameArray == NULL)
229 : : {
230 : 1 : ExplainExtensionNamesAllocated = 16;
231 : 1 : ExplainExtensionNameArray = (const char **)
232 : 1 : MemoryContextAlloc(TopMemoryContext,
233 : : ExplainExtensionNamesAllocated
234 : : * sizeof(char *));
235 : : }
236 : :
237 : : /* If there's an array but it's currently full, expand it. */
238 [ - + ]: 1 : if (ExplainExtensionNamesAssigned >= ExplainExtensionNamesAllocated)
239 : : {
172 rhaas@postgresql.org 240 :UBC 0 : int i = pg_nextpower2_32(ExplainExtensionNamesAssigned + 1);
241 : :
242 : 0 : ExplainExtensionNameArray = (const char **)
243 : 0 : repalloc(ExplainExtensionNameArray, i * sizeof(char *));
244 : 0 : ExplainExtensionNamesAllocated = i;
245 : : }
246 : :
247 : : /* Assign and return new ID. */
172 rhaas@postgresql.org 248 :CBC 1 : ExplainExtensionNameArray[ExplainExtensionNamesAssigned] = extension_name;
249 : 1 : return ExplainExtensionNamesAssigned++;
250 : : }
251 : :
252 : : /*
253 : : * Get extension-specific state from an ExplainState.
254 : : *
255 : : * See comments for SetExplainExtensionState, below.
256 : : */
257 : : void *
258 : 50 : GetExplainExtensionState(ExplainState *es, int extension_id)
259 : : {
260 [ - + ]: 50 : Assert(extension_id >= 0);
261 : :
262 [ + + ]: 50 : if (extension_id >= es->extension_state_allocated)
263 : 9 : return NULL;
264 : :
265 : 41 : return es->extension_state[extension_id];
266 : : }
267 : :
268 : : /*
269 : : * Store extension-specific state into an ExplainState.
270 : : *
271 : : * To use this function, first obtain an integer extension_id using
272 : : * GetExplainExtensionId. Then use this function to store an opaque pointer
273 : : * in the ExplainState. Later, you can retrieve the opaque pointer using
274 : : * GetExplainExtensionState.
275 : : */
276 : : void
277 : 9 : SetExplainExtensionState(ExplainState *es, int extension_id, void *opaque)
278 : : {
279 [ - + ]: 9 : Assert(extension_id >= 0);
280 : :
281 : : /* If there is no array yet, create one. */
282 [ + - ]: 9 : if (es->extension_state == NULL)
283 : : {
284 : 9 : es->extension_state_allocated = 16;
285 : 9 : es->extension_state =
286 : 9 : palloc0(es->extension_state_allocated * sizeof(void *));
287 : : }
288 : :
289 : : /* If there's an array but it's currently full, expand it. */
290 [ - + ]: 9 : if (extension_id >= es->extension_state_allocated)
291 : : {
292 : : int i;
293 : :
172 rhaas@postgresql.org 294 :UBC 0 : i = pg_nextpower2_32(es->extension_state_allocated + 1);
295 : 0 : es->extension_state = (void **)
296 : 0 : repalloc0(es->extension_state,
297 : 0 : es->extension_state_allocated * sizeof(void *),
298 : : i * sizeof(void *));
299 : 0 : es->extension_state_allocated = i;
300 : : }
301 : :
172 rhaas@postgresql.org 302 :CBC 9 : es->extension_state[extension_id] = opaque;
303 : 9 : }
304 : :
305 : : /*
306 : : * Register a new EXPLAIN option.
307 : : *
308 : : * When option_name is used as an EXPLAIN option, handler will be called and
309 : : * should update the ExplainState passed to it. See comments at top of file
310 : : * for a more detailed explanation.
311 : : *
312 : : * option_name is assumed to be a constant string or allocated in storage
313 : : * that will never be freed.
314 : : */
315 : : void
316 : 2 : RegisterExtensionExplainOption(const char *option_name,
317 : : ExplainOptionHandler handler)
318 : : {
319 : : ExplainExtensionOption *exopt;
320 : :
321 : : /* Search for an existing option by this name; if found, update handler. */
322 [ + + ]: 3 : for (int i = 0; i < ExplainExtensionOptionsAssigned; ++i)
323 : : {
324 [ - + ]: 1 : if (strcmp(ExplainExtensionOptionArray[i].option_name,
325 : : option_name) == 0)
326 : : {
172 rhaas@postgresql.org 327 :UBC 0 : ExplainExtensionOptionArray[i].option_handler = handler;
328 : 0 : return;
329 : : }
330 : : }
331 : :
332 : : /* If there is no array yet, create one. */
172 rhaas@postgresql.org 333 [ + + ]:CBC 2 : if (ExplainExtensionOptionArray == NULL)
334 : : {
335 : 1 : ExplainExtensionOptionsAllocated = 16;
336 : 1 : ExplainExtensionOptionArray = (ExplainExtensionOption *)
337 : 1 : MemoryContextAlloc(TopMemoryContext,
338 : : ExplainExtensionOptionsAllocated
339 : : * sizeof(char *));
340 : : }
341 : :
342 : : /* If there's an array but it's currently full, expand it. */
343 [ - + ]: 2 : if (ExplainExtensionOptionsAssigned >= ExplainExtensionOptionsAllocated)
344 : : {
172 rhaas@postgresql.org 345 :UBC 0 : int i = pg_nextpower2_32(ExplainExtensionOptionsAssigned + 1);
346 : :
347 : 0 : ExplainExtensionOptionArray = (ExplainExtensionOption *)
348 : 0 : repalloc(ExplainExtensionOptionArray, i * sizeof(char *));
349 : 0 : ExplainExtensionOptionsAllocated = i;
350 : : }
351 : :
352 : : /* Assign and return new ID. */
172 rhaas@postgresql.org 353 :CBC 2 : exopt = &ExplainExtensionOptionArray[ExplainExtensionOptionsAssigned++];
354 : 2 : exopt->option_name = option_name;
355 : 2 : exopt->option_handler = handler;
356 : : }
357 : :
358 : : /*
359 : : * Apply an EXPLAIN option registered by an extension.
360 : : *
361 : : * If no extension has registered the named option, returns false. Otherwise,
362 : : * calls the appropriate handler function and then returns true.
363 : : */
364 : : bool
365 : 15 : ApplyExtensionExplainOption(ExplainState *es, DefElem *opt, ParseState *pstate)
366 : : {
367 [ + + ]: 22 : for (int i = 0; i < ExplainExtensionOptionsAssigned; ++i)
368 : : {
369 : 18 : if (strcmp(ExplainExtensionOptionArray[i].option_name,
370 [ + + ]: 18 : opt->defname) == 0)
371 : : {
372 : 11 : ExplainExtensionOptionArray[i].option_handler(es, opt, pstate);
373 : 11 : return true;
374 : : }
375 : : }
376 : :
377 : 4 : return false;
378 : : }
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