normalize_query.h

   1 /*-------------------------------------------------------------------------
   2  *
   3  * normalize_query.h
   4  *              Normalize query string.
   5  *
   6  * This header file is created from pg_stat_statements.c to implement
   7  * normalization of query string.
   8  *
   9  * Portions Copyright (c) 2008-2017, PostgreSQL Global Development Group
  10  */
  11 #ifndef NORMALIZE_QUERY_H
  12 #define NORMALIZE_QUERY_H
  13
  14 /*
  15  * Struct for tracking locations/lengths of constants during normalization
  16  */
  17 typedef struct pgssLocationLen
  18 {
  19         int                     location;               /* start offset in query text */
  20         int                     length;                 /* length in bytes, or -1 to ignore */
  21 } pgssLocationLen;
  22
  23 /*
  24  * Working state for computing a query jumble and producing a normalized
  25  * query string
  26  */
  27 typedef struct pgssJumbleState
  28 {
  29         /* Jumble of current query tree */
  30         unsigned char *jumble;
  31
  32         /* Number of bytes used in jumble[] */
  33         Size            jumble_len;
  34
  35         /* Array of locations of constants that should be removed */
  36         pgssLocationLen *clocations;
  37
  38         /* Allocated length of clocations array */
  39         int                     clocations_buf_size;
  40
  41         /* Current number of valid entries in clocations array */
  42         int                     clocations_count;
  43
  44         /* highest Param id we've seen, in order to start normalization correctly */
  45         int                     highest_extern_param_id;
  46 } pgssJumbleState;
  47
  48 static char *
  49 generate_normalized_query(pgssJumbleState *jstate, const char *query,
  50                                                   int query_loc, int *query_len_p, int encoding);
  51 static void JumbleQuery(pgssJumbleState *jstate, Query *query);
  52
  53 #define JUMBLE_SIZE             1024
  54
  55 #endif  /* NORMALIZE_QUERY_H */