Line data    Source code

       1             : /*-------------------------------------------------------------------------
       2             :  *
       3             :  * queryjumble.h
       4             :  *    Query normalization and fingerprinting.
       5             :  *
       6             :  * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
       7             :  * Portions Copyright (c) 1994, Regents of the University of California
       8             :  *
       9             :  * IDENTIFICATION
      10             :  *    src/include/nodes/queryjumble.h
      11             :  *
      12             :  *-------------------------------------------------------------------------
      13             :  */
      14             : #ifndef QUERYJUMBLE_H
      15             : #define QUERYJUMBLE_H
      16             : 
      17             : #include "nodes/parsenodes.h"
      18             : 
      19             : /*
      20             :  * Struct for tracking locations/lengths of constants during normalization
      21             :  */
      22             : typedef struct LocationLen
      23             : {
      24             :     int         location;       /* start offset in query text */
      25             :     int         length;         /* length in bytes, or -1 to ignore */
      26             : } LocationLen;
      27             : 
      28             : /*
      29             :  * Working state for computing a query jumble and producing a normalized
      30             :  * query string
      31             :  */
      32             : typedef struct JumbleState
      33             : {
      34             :     /* Jumble of current query tree */
      35             :     unsigned char *jumble;
      36             : 
      37             :     /* Number of bytes used in jumble[] */
      38             :     Size        jumble_len;
      39             : 
      40             :     /* Array of locations of constants that should be removed */
      41             :     LocationLen *clocations;
      42             : 
      43             :     /* Allocated length of clocations array */
      44             :     int         clocations_buf_size;
      45             : 
      46             :     /* Current number of valid entries in clocations array */
      47             :     int         clocations_count;
      48             : 
      49             :     /* highest Param id we've seen, in order to start normalization correctly */
      50             :     int         highest_extern_param_id;
      51             : } JumbleState;
      52             : 
      53             : /* Values for the compute_query_id GUC */
      54             : enum ComputeQueryIdType
      55             : {
      56             :     COMPUTE_QUERY_ID_OFF,
      57             :     COMPUTE_QUERY_ID_ON,
      58             :     COMPUTE_QUERY_ID_AUTO,
      59             :     COMPUTE_QUERY_ID_REGRESS,
      60             : };
      61             : 
      62             : /* GUC parameters */
      63             : extern PGDLLIMPORT int compute_query_id;
      64             : 
      65             : 
      66             : extern const char *CleanQuerytext(const char *query, int *location, int *len);
      67             : extern JumbleState *JumbleQuery(Query *query);
      68             : extern void EnableQueryId(void);
      69             : 
      70             : extern PGDLLIMPORT bool query_id_enabled;
      71             : 
      72             : /*
      73             :  * Returns whether query identifier computation has been enabled, either
      74             :  * directly in the GUC or by a module when the setting is 'auto'.
      75             :  */
      76             : static inline bool
      77      798326 : IsQueryIdEnabled(void)
      78             : {
      79      798326 :     if (compute_query_id == COMPUTE_QUERY_ID_OFF)
      80           0 :         return false;
      81      798326 :     if (compute_query_id == COMPUTE_QUERY_ID_ON)
      82         258 :         return true;
      83      798068 :     return query_id_enabled;
      84             : }
      85             : 
      86             : #endif                          /* QUERYJUMBLE_H */