TLA  Line data    Source code

       1                 : /*-------------------------------------------------------------------------
       2                 :  *
       3                 :  * queryjumble.h
       4                 :  *    Query normalization and fingerprinting.
       5                 :  *
       6                 :  * Portions Copyright (c) 1996-2023, 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 QUERYJUBLE_H
      15                 : #define QUERYJUBLE_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, const char *querytext);
      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 ECB             :  */
      76                 : static inline bool
      77 CBC      640143 : IsQueryIdEnabled(void)
      78 EUB             : {
      79 CBC      640143 :     if (compute_query_id == COMPUTE_QUERY_ID_OFF)
      80 LBC           0 :         return false;
      81 CBC      640143 :     if (compute_query_id == COMPUTE_QUERY_ID_ON)
      82 GIC          20 :         return true;
      83          640123 :     return query_id_enabled;
      84                 : }
      85                 : 
      86                 : #endif                          /* QUERYJUMBLE_H */