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https://git.postgresql.org/git/postgresql.git
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3a0e4d36eb
Commit 3855968f32
added syntax, pg_dump,
psql support, and documentation, but the triggers didn't actually fire.
With this commit, they now do. This is still a pretty basic facility
overall because event triggers do not get a whole lot of information
about what the user is trying to do unless you write them in C; and
there's still no option to fire them anywhere except at the very
beginning of the execution sequence, but it's better than nothing,
and a good building block for future work.
Along the way, add a regression test for ALTER LARGE OBJECT, since
testing of event triggers reveals that we haven't got one.
Dimitri Fontaine and Robert Haas
2123 lines
58 KiB
C
2123 lines
58 KiB
C
/*-------------------------------------------------------------------------
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*
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* pg_stat_statements.c
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* Track statement execution times across a whole database cluster.
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*
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* Execution costs are totalled for each distinct source query, and kept in
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* a shared hashtable. (We track only as many distinct queries as will fit
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* in the designated amount of shared memory.)
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*
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* As of Postgres 9.2, this module normalizes query entries. Normalization
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* is a process whereby similar queries, typically differing only in their
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* constants (though the exact rules are somewhat more subtle than that) are
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* recognized as equivalent, and are tracked as a single entry. This is
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* particularly useful for non-prepared queries.
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*
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* Normalization is implemented by fingerprinting queries, selectively
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* serializing those fields of each query tree's nodes that are judged to be
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* essential to the query. This is referred to as a query jumble. This is
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* distinct from a regular serialization in that various extraneous
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* information is ignored as irrelevant or not essential to the query, such
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* as the collations of Vars and, most notably, the values of constants.
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*
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* This jumble is acquired at the end of parse analysis of each query, and
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* a 32-bit hash of it is stored into the query's Query.queryId field.
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* The server then copies this value around, making it available in plan
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* tree(s) generated from the query. The executor can then use this value
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* to blame query costs on the proper queryId.
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*
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* Note about locking issues: to create or delete an entry in the shared
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* hashtable, one must hold pgss->lock exclusively. Modifying any field
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* in an entry except the counters requires the same. To look up an entry,
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* one must hold the lock shared. To read or update the counters within
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* an entry, one must hold the lock shared or exclusive (so the entry doesn't
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* disappear!) and also take the entry's mutex spinlock.
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*
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*
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* Copyright (c) 2008-2012, PostgreSQL Global Development Group
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*
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* IDENTIFICATION
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* contrib/pg_stat_statements/pg_stat_statements.c
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*
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*-------------------------------------------------------------------------
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*/
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#include "postgres.h"
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#include <unistd.h>
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#include "access/hash.h"
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#include "executor/instrument.h"
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#include "funcapi.h"
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#include "mb/pg_wchar.h"
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#include "miscadmin.h"
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#include "parser/analyze.h"
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#include "parser/parsetree.h"
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#include "parser/scanner.h"
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#include "pgstat.h"
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#include "storage/fd.h"
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#include "storage/ipc.h"
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#include "storage/spin.h"
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#include "tcop/utility.h"
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#include "utils/builtins.h"
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PG_MODULE_MAGIC;
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/* Location of stats file */
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#define PGSS_DUMP_FILE "global/pg_stat_statements.stat"
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/* This constant defines the magic number in the stats file header */
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static const uint32 PGSS_FILE_HEADER = 0x20120328;
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/* XXX: Should USAGE_EXEC reflect execution time and/or buffer usage? */
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#define USAGE_EXEC(duration) (1.0)
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#define USAGE_INIT (1.0) /* including initial planning */
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#define ASSUMED_MEDIAN_INIT (10.0) /* initial assumed median usage */
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#define USAGE_DECREASE_FACTOR (0.99) /* decreased every entry_dealloc */
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#define STICKY_DECREASE_FACTOR (0.50) /* factor for sticky entries */
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#define USAGE_DEALLOC_PERCENT 5 /* free this % of entries at once */
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#define JUMBLE_SIZE 1024 /* query serialization buffer size */
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/*
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* Hashtable key that defines the identity of a hashtable entry. We separate
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* queries by user and by database even if they are otherwise identical.
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*
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* Presently, the query encoding is fully determined by the source database
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* and so we don't really need it to be in the key. But that might not always
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* be true. Anyway it's notationally convenient to pass it as part of the key.
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*/
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typedef struct pgssHashKey
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{
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Oid userid; /* user OID */
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Oid dbid; /* database OID */
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int encoding; /* query encoding */
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uint32 queryid; /* query identifier */
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} pgssHashKey;
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/*
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* The actual stats counters kept within pgssEntry.
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*/
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typedef struct Counters
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{
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int64 calls; /* # of times executed */
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double total_time; /* total execution time, in msec */
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int64 rows; /* total # of retrieved or affected rows */
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int64 shared_blks_hit; /* # of shared buffer hits */
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int64 shared_blks_read; /* # of shared disk blocks read */
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int64 shared_blks_dirtied; /* # of shared disk blocks dirtied */
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int64 shared_blks_written; /* # of shared disk blocks written */
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int64 local_blks_hit; /* # of local buffer hits */
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int64 local_blks_read; /* # of local disk blocks read */
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int64 local_blks_dirtied; /* # of local disk blocks dirtied */
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int64 local_blks_written; /* # of local disk blocks written */
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int64 temp_blks_read; /* # of temp blocks read */
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int64 temp_blks_written; /* # of temp blocks written */
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double blk_read_time; /* time spent reading, in msec */
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double blk_write_time; /* time spent writing, in msec */
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double usage; /* usage factor */
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} Counters;
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/*
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* Statistics per statement
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*
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* NB: see the file read/write code before changing field order here.
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*/
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typedef struct pgssEntry
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{
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pgssHashKey key; /* hash key of entry - MUST BE FIRST */
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Counters counters; /* the statistics for this query */
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int query_len; /* # of valid bytes in query string */
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slock_t mutex; /* protects the counters only */
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char query[1]; /* VARIABLE LENGTH ARRAY - MUST BE LAST */
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/* Note: the allocated length of query[] is actually pgss->query_size */
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} pgssEntry;
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/*
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* Global shared state
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*/
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typedef struct pgssSharedState
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{
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LWLockId lock; /* protects hashtable search/modification */
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int query_size; /* max query length in bytes */
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double cur_median_usage; /* current median usage in hashtable */
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} pgssSharedState;
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/*
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* Struct for tracking locations/lengths of constants during normalization
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*/
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typedef struct pgssLocationLen
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{
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int location; /* start offset in query text */
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int length; /* length in bytes, or -1 to ignore */
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} pgssLocationLen;
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/*
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* Working state for computing a query jumble and producing a normalized
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* query string
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*/
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typedef struct pgssJumbleState
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{
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/* Jumble of current query tree */
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unsigned char *jumble;
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/* Number of bytes used in jumble[] */
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Size jumble_len;
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/* Array of locations of constants that should be removed */
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pgssLocationLen *clocations;
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/* Allocated length of clocations array */
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int clocations_buf_size;
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/* Current number of valid entries in clocations array */
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int clocations_count;
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} pgssJumbleState;
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/*---- Local variables ----*/
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/* Current nesting depth of ExecutorRun+ProcessUtility calls */
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static int nested_level = 0;
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/* Saved hook values in case of unload */
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static shmem_startup_hook_type prev_shmem_startup_hook = NULL;
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static post_parse_analyze_hook_type prev_post_parse_analyze_hook = NULL;
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static ExecutorStart_hook_type prev_ExecutorStart = NULL;
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static ExecutorRun_hook_type prev_ExecutorRun = NULL;
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static ExecutorFinish_hook_type prev_ExecutorFinish = NULL;
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static ExecutorEnd_hook_type prev_ExecutorEnd = NULL;
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static ProcessUtility_hook_type prev_ProcessUtility = NULL;
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/* Links to shared memory state */
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static pgssSharedState *pgss = NULL;
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static HTAB *pgss_hash = NULL;
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/*---- GUC variables ----*/
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typedef enum
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{
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PGSS_TRACK_NONE, /* track no statements */
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PGSS_TRACK_TOP, /* only top level statements */
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PGSS_TRACK_ALL /* all statements, including nested ones */
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} PGSSTrackLevel;
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static const struct config_enum_entry track_options[] =
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{
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{"none", PGSS_TRACK_NONE, false},
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{"top", PGSS_TRACK_TOP, false},
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{"all", PGSS_TRACK_ALL, false},
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{NULL, 0, false}
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};
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static int pgss_max; /* max # statements to track */
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static int pgss_track; /* tracking level */
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static bool pgss_track_utility; /* whether to track utility commands */
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static bool pgss_save; /* whether to save stats across shutdown */
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#define pgss_enabled() \
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(pgss_track == PGSS_TRACK_ALL || \
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(pgss_track == PGSS_TRACK_TOP && nested_level == 0))
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/*---- Function declarations ----*/
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void _PG_init(void);
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void _PG_fini(void);
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Datum pg_stat_statements_reset(PG_FUNCTION_ARGS);
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Datum pg_stat_statements(PG_FUNCTION_ARGS);
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PG_FUNCTION_INFO_V1(pg_stat_statements_reset);
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PG_FUNCTION_INFO_V1(pg_stat_statements);
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static void pgss_shmem_startup(void);
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static void pgss_shmem_shutdown(int code, Datum arg);
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static void pgss_post_parse_analyze(ParseState *pstate, Query *query);
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static void pgss_ExecutorStart(QueryDesc *queryDesc, int eflags);
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static void pgss_ExecutorRun(QueryDesc *queryDesc,
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ScanDirection direction,
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long count);
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static void pgss_ExecutorFinish(QueryDesc *queryDesc);
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static void pgss_ExecutorEnd(QueryDesc *queryDesc);
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static void pgss_ProcessUtility(Node *parsetree,
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const char *queryString, ParamListInfo params,
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DestReceiver *dest, char *completionTag,
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ProcessUtilityContext context);
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static uint32 pgss_hash_fn(const void *key, Size keysize);
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static int pgss_match_fn(const void *key1, const void *key2, Size keysize);
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static uint32 pgss_hash_string(const char *str);
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static void pgss_store(const char *query, uint32 queryId,
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double total_time, uint64 rows,
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const BufferUsage *bufusage,
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pgssJumbleState *jstate);
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static Size pgss_memsize(void);
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static pgssEntry *entry_alloc(pgssHashKey *key, const char *query,
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int query_len, bool sticky);
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static void entry_dealloc(void);
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static void entry_reset(void);
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static void AppendJumble(pgssJumbleState *jstate,
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const unsigned char *item, Size size);
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static void JumbleQuery(pgssJumbleState *jstate, Query *query);
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static void JumbleRangeTable(pgssJumbleState *jstate, List *rtable);
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static void JumbleExpr(pgssJumbleState *jstate, Node *node);
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static void RecordConstLocation(pgssJumbleState *jstate, int location);
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static char *generate_normalized_query(pgssJumbleState *jstate, const char *query,
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int *query_len_p, int encoding);
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static void fill_in_constant_lengths(pgssJumbleState *jstate, const char *query);
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static int comp_location(const void *a, const void *b);
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/*
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* Module load callback
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*/
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void
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_PG_init(void)
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{
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/*
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* In order to create our shared memory area, we have to be loaded via
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* shared_preload_libraries. If not, fall out without hooking into any of
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* the main system. (We don't throw error here because it seems useful to
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* allow the pg_stat_statements functions to be created even when the
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* module isn't active. The functions must protect themselves against
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* being called then, however.)
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*/
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if (!process_shared_preload_libraries_in_progress)
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return;
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/*
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* Define (or redefine) custom GUC variables.
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*/
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DefineCustomIntVariable("pg_stat_statements.max",
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"Sets the maximum number of statements tracked by pg_stat_statements.",
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NULL,
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&pgss_max,
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1000,
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100,
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INT_MAX,
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PGC_POSTMASTER,
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0,
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NULL,
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NULL,
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NULL);
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DefineCustomEnumVariable("pg_stat_statements.track",
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"Selects which statements are tracked by pg_stat_statements.",
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NULL,
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&pgss_track,
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PGSS_TRACK_TOP,
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track_options,
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PGC_SUSET,
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0,
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NULL,
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NULL,
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NULL);
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DefineCustomBoolVariable("pg_stat_statements.track_utility",
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"Selects whether utility commands are tracked by pg_stat_statements.",
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NULL,
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&pgss_track_utility,
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true,
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PGC_SUSET,
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0,
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NULL,
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NULL,
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NULL);
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DefineCustomBoolVariable("pg_stat_statements.save",
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"Save pg_stat_statements statistics across server shutdowns.",
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NULL,
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&pgss_save,
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true,
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PGC_SIGHUP,
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0,
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NULL,
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NULL,
|
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NULL);
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EmitWarningsOnPlaceholders("pg_stat_statements");
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|
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/*
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* Request additional shared resources. (These are no-ops if we're not in
|
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* the postmaster process.) We'll allocate or attach to the shared
|
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* resources in pgss_shmem_startup().
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|
*/
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RequestAddinShmemSpace(pgss_memsize());
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RequestAddinLWLocks(1);
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|
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/*
|
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* Install hooks.
|
|
*/
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prev_shmem_startup_hook = shmem_startup_hook;
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shmem_startup_hook = pgss_shmem_startup;
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prev_post_parse_analyze_hook = post_parse_analyze_hook;
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post_parse_analyze_hook = pgss_post_parse_analyze;
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|
prev_ExecutorStart = ExecutorStart_hook;
|
|
ExecutorStart_hook = pgss_ExecutorStart;
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prev_ExecutorRun = ExecutorRun_hook;
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ExecutorRun_hook = pgss_ExecutorRun;
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|
prev_ExecutorFinish = ExecutorFinish_hook;
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|
ExecutorFinish_hook = pgss_ExecutorFinish;
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|
prev_ExecutorEnd = ExecutorEnd_hook;
|
|
ExecutorEnd_hook = pgss_ExecutorEnd;
|
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prev_ProcessUtility = ProcessUtility_hook;
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ProcessUtility_hook = pgss_ProcessUtility;
|
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}
|
|
|
|
/*
|
|
* Module unload callback
|
|
*/
|
|
void
|
|
_PG_fini(void)
|
|
{
|
|
/* Uninstall hooks. */
|
|
shmem_startup_hook = prev_shmem_startup_hook;
|
|
post_parse_analyze_hook = prev_post_parse_analyze_hook;
|
|
ExecutorStart_hook = prev_ExecutorStart;
|
|
ExecutorRun_hook = prev_ExecutorRun;
|
|
ExecutorFinish_hook = prev_ExecutorFinish;
|
|
ExecutorEnd_hook = prev_ExecutorEnd;
|
|
ProcessUtility_hook = prev_ProcessUtility;
|
|
}
|
|
|
|
/*
|
|
* shmem_startup hook: allocate or attach to shared memory,
|
|
* then load any pre-existing statistics from file.
|
|
*/
|
|
static void
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|
pgss_shmem_startup(void)
|
|
{
|
|
bool found;
|
|
HASHCTL info;
|
|
FILE *file;
|
|
uint32 header;
|
|
int32 num;
|
|
int32 i;
|
|
int query_size;
|
|
int buffer_size;
|
|
char *buffer = NULL;
|
|
|
|
if (prev_shmem_startup_hook)
|
|
prev_shmem_startup_hook();
|
|
|
|
/* reset in case this is a restart within the postmaster */
|
|
pgss = NULL;
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|
pgss_hash = NULL;
|
|
|
|
/*
|
|
* Create or attach to the shared memory state, including hash table
|
|
*/
|
|
LWLockAcquire(AddinShmemInitLock, LW_EXCLUSIVE);
|
|
|
|
pgss = ShmemInitStruct("pg_stat_statements",
|
|
sizeof(pgssSharedState),
|
|
&found);
|
|
|
|
if (!found)
|
|
{
|
|
/* First time through ... */
|
|
pgss->lock = LWLockAssign();
|
|
pgss->query_size = pgstat_track_activity_query_size;
|
|
pgss->cur_median_usage = ASSUMED_MEDIAN_INIT;
|
|
}
|
|
|
|
/* Be sure everyone agrees on the hash table entry size */
|
|
query_size = pgss->query_size;
|
|
|
|
memset(&info, 0, sizeof(info));
|
|
info.keysize = sizeof(pgssHashKey);
|
|
info.entrysize = offsetof(pgssEntry, query) +query_size;
|
|
info.hash = pgss_hash_fn;
|
|
info.match = pgss_match_fn;
|
|
pgss_hash = ShmemInitHash("pg_stat_statements hash",
|
|
pgss_max, pgss_max,
|
|
&info,
|
|
HASH_ELEM | HASH_FUNCTION | HASH_COMPARE);
|
|
|
|
LWLockRelease(AddinShmemInitLock);
|
|
|
|
/*
|
|
* If we're in the postmaster (or a standalone backend...), set up a shmem
|
|
* exit hook to dump the statistics to disk.
|
|
*/
|
|
if (!IsUnderPostmaster)
|
|
on_shmem_exit(pgss_shmem_shutdown, (Datum) 0);
|
|
|
|
/*
|
|
* Attempt to load old statistics from the dump file, if this is the first
|
|
* time through and we weren't told not to.
|
|
*/
|
|
if (found || !pgss_save)
|
|
return;
|
|
|
|
/*
|
|
* Note: we don't bother with locks here, because there should be no other
|
|
* processes running when this code is reached.
|
|
*/
|
|
file = AllocateFile(PGSS_DUMP_FILE, PG_BINARY_R);
|
|
if (file == NULL)
|
|
{
|
|
if (errno == ENOENT)
|
|
return; /* ignore not-found error */
|
|
goto error;
|
|
}
|
|
|
|
buffer_size = query_size;
|
|
buffer = (char *) palloc(buffer_size);
|
|
|
|
if (fread(&header, sizeof(uint32), 1, file) != 1 ||
|
|
header != PGSS_FILE_HEADER ||
|
|
fread(&num, sizeof(int32), 1, file) != 1)
|
|
goto error;
|
|
|
|
for (i = 0; i < num; i++)
|
|
{
|
|
pgssEntry temp;
|
|
pgssEntry *entry;
|
|
|
|
if (fread(&temp, offsetof(pgssEntry, mutex), 1, file) != 1)
|
|
goto error;
|
|
|
|
/* Encoding is the only field we can easily sanity-check */
|
|
if (!PG_VALID_BE_ENCODING(temp.key.encoding))
|
|
goto error;
|
|
|
|
/* Previous incarnation might have had a larger query_size */
|
|
if (temp.query_len >= buffer_size)
|
|
{
|
|
buffer = (char *) repalloc(buffer, temp.query_len + 1);
|
|
buffer_size = temp.query_len + 1;
|
|
}
|
|
|
|
if (fread(buffer, 1, temp.query_len, file) != temp.query_len)
|
|
goto error;
|
|
buffer[temp.query_len] = '\0';
|
|
|
|
/* Skip loading "sticky" entries */
|
|
if (temp.counters.calls == 0)
|
|
continue;
|
|
|
|
/* Clip to available length if needed */
|
|
if (temp.query_len >= query_size)
|
|
temp.query_len = pg_encoding_mbcliplen(temp.key.encoding,
|
|
buffer,
|
|
temp.query_len,
|
|
query_size - 1);
|
|
|
|
/* make the hashtable entry (discards old entries if too many) */
|
|
entry = entry_alloc(&temp.key, buffer, temp.query_len, false);
|
|
|
|
/* copy in the actual stats */
|
|
entry->counters = temp.counters;
|
|
}
|
|
|
|
pfree(buffer);
|
|
FreeFile(file);
|
|
|
|
/*
|
|
* Remove the file so it's not included in backups/replication slaves,
|
|
* etc. A new file will be written on next shutdown.
|
|
*/
|
|
unlink(PGSS_DUMP_FILE);
|
|
|
|
return;
|
|
|
|
error:
|
|
ereport(LOG,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not read pg_stat_statement file \"%s\": %m",
|
|
PGSS_DUMP_FILE)));
|
|
if (buffer)
|
|
pfree(buffer);
|
|
if (file)
|
|
FreeFile(file);
|
|
/* If possible, throw away the bogus file; ignore any error */
|
|
unlink(PGSS_DUMP_FILE);
|
|
}
|
|
|
|
/*
|
|
* shmem_shutdown hook: Dump statistics into file.
|
|
*
|
|
* Note: we don't bother with acquiring lock, because there should be no
|
|
* other processes running when this is called.
|
|
*/
|
|
static void
|
|
pgss_shmem_shutdown(int code, Datum arg)
|
|
{
|
|
FILE *file;
|
|
HASH_SEQ_STATUS hash_seq;
|
|
int32 num_entries;
|
|
pgssEntry *entry;
|
|
|
|
/* Don't try to dump during a crash. */
|
|
if (code)
|
|
return;
|
|
|
|
/* Safety check ... shouldn't get here unless shmem is set up. */
|
|
if (!pgss || !pgss_hash)
|
|
return;
|
|
|
|
/* Don't dump if told not to. */
|
|
if (!pgss_save)
|
|
return;
|
|
|
|
file = AllocateFile(PGSS_DUMP_FILE ".tmp", PG_BINARY_W);
|
|
if (file == NULL)
|
|
goto error;
|
|
|
|
if (fwrite(&PGSS_FILE_HEADER, sizeof(uint32), 1, file) != 1)
|
|
goto error;
|
|
num_entries = hash_get_num_entries(pgss_hash);
|
|
if (fwrite(&num_entries, sizeof(int32), 1, file) != 1)
|
|
goto error;
|
|
|
|
hash_seq_init(&hash_seq, pgss_hash);
|
|
while ((entry = hash_seq_search(&hash_seq)) != NULL)
|
|
{
|
|
int len = entry->query_len;
|
|
|
|
if (fwrite(entry, offsetof(pgssEntry, mutex), 1, file) != 1 ||
|
|
fwrite(entry->query, 1, len, file) != len)
|
|
goto error;
|
|
}
|
|
|
|
if (FreeFile(file))
|
|
{
|
|
file = NULL;
|
|
goto error;
|
|
}
|
|
|
|
/*
|
|
* Rename file into place, so we atomically replace the old one.
|
|
*/
|
|
if (rename(PGSS_DUMP_FILE ".tmp", PGSS_DUMP_FILE) != 0)
|
|
ereport(LOG,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not rename pg_stat_statement file \"%s\": %m",
|
|
PGSS_DUMP_FILE ".tmp")));
|
|
|
|
return;
|
|
|
|
error:
|
|
ereport(LOG,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not write pg_stat_statement file \"%s\": %m",
|
|
PGSS_DUMP_FILE ".tmp")));
|
|
if (file)
|
|
FreeFile(file);
|
|
unlink(PGSS_DUMP_FILE ".tmp");
|
|
}
|
|
|
|
/*
|
|
* Post-parse-analysis hook: mark query with a queryId
|
|
*/
|
|
static void
|
|
pgss_post_parse_analyze(ParseState *pstate, Query *query)
|
|
{
|
|
pgssJumbleState jstate;
|
|
|
|
/* Assert we didn't do this already */
|
|
Assert(query->queryId == 0);
|
|
|
|
/* Safety check... */
|
|
if (!pgss || !pgss_hash)
|
|
return;
|
|
|
|
/*
|
|
* Utility statements get queryId zero. We do this even in cases where
|
|
* the statement contains an optimizable statement for which a queryId
|
|
* could be derived (such as EXPLAIN or DECLARE CURSOR). For such cases,
|
|
* runtime control will first go through ProcessUtility and then the
|
|
* executor, and we don't want the executor hooks to do anything, since we
|
|
* are already measuring the statement's costs at the utility level.
|
|
*/
|
|
if (query->utilityStmt)
|
|
{
|
|
query->queryId = 0;
|
|
return;
|
|
}
|
|
|
|
/* Set up workspace for query jumbling */
|
|
jstate.jumble = (unsigned char *) palloc(JUMBLE_SIZE);
|
|
jstate.jumble_len = 0;
|
|
jstate.clocations_buf_size = 32;
|
|
jstate.clocations = (pgssLocationLen *)
|
|
palloc(jstate.clocations_buf_size * sizeof(pgssLocationLen));
|
|
jstate.clocations_count = 0;
|
|
|
|
/* Compute query ID and mark the Query node with it */
|
|
JumbleQuery(&jstate, query);
|
|
query->queryId = hash_any(jstate.jumble, jstate.jumble_len);
|
|
|
|
/*
|
|
* If we are unlucky enough to get a hash of zero, use 1 instead, to
|
|
* prevent confusion with the utility-statement case.
|
|
*/
|
|
if (query->queryId == 0)
|
|
query->queryId = 1;
|
|
|
|
/*
|
|
* If we were able to identify any ignorable constants, we immediately
|
|
* create a hash table entry for the query, so that we can record the
|
|
* normalized form of the query string. If there were no such constants,
|
|
* the normalized string would be the same as the query text anyway, so
|
|
* there's no need for an early entry.
|
|
*/
|
|
if (jstate.clocations_count > 0)
|
|
pgss_store(pstate->p_sourcetext,
|
|
query->queryId,
|
|
0,
|
|
0,
|
|
NULL,
|
|
&jstate);
|
|
}
|
|
|
|
/*
|
|
* ExecutorStart hook: start up tracking if needed
|
|
*/
|
|
static void
|
|
pgss_ExecutorStart(QueryDesc *queryDesc, int eflags)
|
|
{
|
|
if (prev_ExecutorStart)
|
|
prev_ExecutorStart(queryDesc, eflags);
|
|
else
|
|
standard_ExecutorStart(queryDesc, eflags);
|
|
|
|
/*
|
|
* If query has queryId zero, don't track it. This prevents double
|
|
* counting of optimizable statements that are directly contained in
|
|
* utility statements.
|
|
*/
|
|
if (pgss_enabled() && queryDesc->plannedstmt->queryId != 0)
|
|
{
|
|
/*
|
|
* Set up to track total elapsed time in ExecutorRun. Make sure the
|
|
* space is allocated in the per-query context so it will go away at
|
|
* ExecutorEnd.
|
|
*/
|
|
if (queryDesc->totaltime == NULL)
|
|
{
|
|
MemoryContext oldcxt;
|
|
|
|
oldcxt = MemoryContextSwitchTo(queryDesc->estate->es_query_cxt);
|
|
queryDesc->totaltime = InstrAlloc(1, INSTRUMENT_ALL);
|
|
MemoryContextSwitchTo(oldcxt);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* ExecutorRun hook: all we need do is track nesting depth
|
|
*/
|
|
static void
|
|
pgss_ExecutorRun(QueryDesc *queryDesc, ScanDirection direction, long count)
|
|
{
|
|
nested_level++;
|
|
PG_TRY();
|
|
{
|
|
if (prev_ExecutorRun)
|
|
prev_ExecutorRun(queryDesc, direction, count);
|
|
else
|
|
standard_ExecutorRun(queryDesc, direction, count);
|
|
nested_level--;
|
|
}
|
|
PG_CATCH();
|
|
{
|
|
nested_level--;
|
|
PG_RE_THROW();
|
|
}
|
|
PG_END_TRY();
|
|
}
|
|
|
|
/*
|
|
* ExecutorFinish hook: all we need do is track nesting depth
|
|
*/
|
|
static void
|
|
pgss_ExecutorFinish(QueryDesc *queryDesc)
|
|
{
|
|
nested_level++;
|
|
PG_TRY();
|
|
{
|
|
if (prev_ExecutorFinish)
|
|
prev_ExecutorFinish(queryDesc);
|
|
else
|
|
standard_ExecutorFinish(queryDesc);
|
|
nested_level--;
|
|
}
|
|
PG_CATCH();
|
|
{
|
|
nested_level--;
|
|
PG_RE_THROW();
|
|
}
|
|
PG_END_TRY();
|
|
}
|
|
|
|
/*
|
|
* ExecutorEnd hook: store results if needed
|
|
*/
|
|
static void
|
|
pgss_ExecutorEnd(QueryDesc *queryDesc)
|
|
{
|
|
uint32 queryId = queryDesc->plannedstmt->queryId;
|
|
|
|
if (queryId != 0 && queryDesc->totaltime && pgss_enabled())
|
|
{
|
|
/*
|
|
* Make sure stats accumulation is done. (Note: it's okay if several
|
|
* levels of hook all do this.)
|
|
*/
|
|
InstrEndLoop(queryDesc->totaltime);
|
|
|
|
pgss_store(queryDesc->sourceText,
|
|
queryId,
|
|
queryDesc->totaltime->total * 1000.0, /* convert to msec */
|
|
queryDesc->estate->es_processed,
|
|
&queryDesc->totaltime->bufusage,
|
|
NULL);
|
|
}
|
|
|
|
if (prev_ExecutorEnd)
|
|
prev_ExecutorEnd(queryDesc);
|
|
else
|
|
standard_ExecutorEnd(queryDesc);
|
|
}
|
|
|
|
/*
|
|
* ProcessUtility hook
|
|
*/
|
|
static void
|
|
pgss_ProcessUtility(Node *parsetree, const char *queryString,
|
|
ParamListInfo params, DestReceiver *dest,
|
|
char *completionTag, ProcessUtilityContext context)
|
|
{
|
|
/*
|
|
* If it's an EXECUTE statement, we don't track it and don't increment the
|
|
* nesting level. This allows the cycles to be charged to the underlying
|
|
* PREPARE instead (by the Executor hooks), which is much more useful.
|
|
*
|
|
* We also don't track execution of PREPARE. If we did, we would get one
|
|
* hash table entry for the PREPARE (with hash calculated from the query
|
|
* string), and then a different one with the same query string (but hash
|
|
* calculated from the query tree) would be used to accumulate costs of
|
|
* ensuing EXECUTEs. This would be confusing, and inconsistent with other
|
|
* cases where planning time is not included at all.
|
|
*/
|
|
if (pgss_track_utility && pgss_enabled() &&
|
|
!IsA(parsetree, ExecuteStmt) &&
|
|
!IsA(parsetree, PrepareStmt))
|
|
{
|
|
instr_time start;
|
|
instr_time duration;
|
|
uint64 rows = 0;
|
|
BufferUsage bufusage_start,
|
|
bufusage;
|
|
uint32 queryId;
|
|
|
|
bufusage_start = pgBufferUsage;
|
|
INSTR_TIME_SET_CURRENT(start);
|
|
|
|
nested_level++;
|
|
PG_TRY();
|
|
{
|
|
if (prev_ProcessUtility)
|
|
prev_ProcessUtility(parsetree, queryString, params,
|
|
dest, completionTag, context);
|
|
else
|
|
standard_ProcessUtility(parsetree, queryString, params,
|
|
dest, completionTag, context);
|
|
nested_level--;
|
|
}
|
|
PG_CATCH();
|
|
{
|
|
nested_level--;
|
|
PG_RE_THROW();
|
|
}
|
|
PG_END_TRY();
|
|
|
|
INSTR_TIME_SET_CURRENT(duration);
|
|
INSTR_TIME_SUBTRACT(duration, start);
|
|
|
|
/* parse command tag to retrieve the number of affected rows. */
|
|
if (completionTag &&
|
|
sscanf(completionTag, "COPY " UINT64_FORMAT, &rows) != 1)
|
|
rows = 0;
|
|
|
|
/* calc differences of buffer counters. */
|
|
bufusage.shared_blks_hit =
|
|
pgBufferUsage.shared_blks_hit - bufusage_start.shared_blks_hit;
|
|
bufusage.shared_blks_read =
|
|
pgBufferUsage.shared_blks_read - bufusage_start.shared_blks_read;
|
|
bufusage.shared_blks_dirtied =
|
|
pgBufferUsage.shared_blks_dirtied - bufusage_start.shared_blks_dirtied;
|
|
bufusage.shared_blks_written =
|
|
pgBufferUsage.shared_blks_written - bufusage_start.shared_blks_written;
|
|
bufusage.local_blks_hit =
|
|
pgBufferUsage.local_blks_hit - bufusage_start.local_blks_hit;
|
|
bufusage.local_blks_read =
|
|
pgBufferUsage.local_blks_read - bufusage_start.local_blks_read;
|
|
bufusage.local_blks_dirtied =
|
|
pgBufferUsage.local_blks_dirtied - bufusage_start.local_blks_dirtied;
|
|
bufusage.local_blks_written =
|
|
pgBufferUsage.local_blks_written - bufusage_start.local_blks_written;
|
|
bufusage.temp_blks_read =
|
|
pgBufferUsage.temp_blks_read - bufusage_start.temp_blks_read;
|
|
bufusage.temp_blks_written =
|
|
pgBufferUsage.temp_blks_written - bufusage_start.temp_blks_written;
|
|
bufusage.blk_read_time = pgBufferUsage.blk_read_time;
|
|
INSTR_TIME_SUBTRACT(bufusage.blk_read_time, bufusage_start.blk_read_time);
|
|
bufusage.blk_write_time = pgBufferUsage.blk_write_time;
|
|
INSTR_TIME_SUBTRACT(bufusage.blk_write_time, bufusage_start.blk_write_time);
|
|
|
|
/* For utility statements, we just hash the query string directly */
|
|
queryId = pgss_hash_string(queryString);
|
|
|
|
pgss_store(queryString,
|
|
queryId,
|
|
INSTR_TIME_GET_MILLISEC(duration),
|
|
rows,
|
|
&bufusage,
|
|
NULL);
|
|
}
|
|
else
|
|
{
|
|
if (prev_ProcessUtility)
|
|
prev_ProcessUtility(parsetree, queryString, params,
|
|
dest, completionTag, context);
|
|
else
|
|
standard_ProcessUtility(parsetree, queryString, params,
|
|
dest, completionTag, context);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Calculate hash value for a key
|
|
*/
|
|
static uint32
|
|
pgss_hash_fn(const void *key, Size keysize)
|
|
{
|
|
const pgssHashKey *k = (const pgssHashKey *) key;
|
|
|
|
/* we don't bother to include encoding in the hash */
|
|
return hash_uint32((uint32) k->userid) ^
|
|
hash_uint32((uint32) k->dbid) ^
|
|
hash_uint32((uint32) k->queryid);
|
|
}
|
|
|
|
/*
|
|
* Compare two keys - zero means match
|
|
*/
|
|
static int
|
|
pgss_match_fn(const void *key1, const void *key2, Size keysize)
|
|
{
|
|
const pgssHashKey *k1 = (const pgssHashKey *) key1;
|
|
const pgssHashKey *k2 = (const pgssHashKey *) key2;
|
|
|
|
if (k1->userid == k2->userid &&
|
|
k1->dbid == k2->dbid &&
|
|
k1->encoding == k2->encoding &&
|
|
k1->queryid == k2->queryid)
|
|
return 0;
|
|
else
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Given an arbitrarily long query string, produce a hash for the purposes of
|
|
* identifying the query, without normalizing constants. Used when hashing
|
|
* utility statements.
|
|
*/
|
|
static uint32
|
|
pgss_hash_string(const char *str)
|
|
{
|
|
return hash_any((const unsigned char *) str, strlen(str));
|
|
}
|
|
|
|
/*
|
|
* Store some statistics for a statement.
|
|
*
|
|
* If jstate is not NULL then we're trying to create an entry for which
|
|
* we have no statistics as yet; we just want to record the normalized
|
|
* query string. total_time, rows, bufusage are ignored in this case.
|
|
*/
|
|
static void
|
|
pgss_store(const char *query, uint32 queryId,
|
|
double total_time, uint64 rows,
|
|
const BufferUsage *bufusage,
|
|
pgssJumbleState *jstate)
|
|
{
|
|
pgssHashKey key;
|
|
pgssEntry *entry;
|
|
char *norm_query = NULL;
|
|
|
|
Assert(query != NULL);
|
|
|
|
/* Safety check... */
|
|
if (!pgss || !pgss_hash)
|
|
return;
|
|
|
|
/* Set up key for hashtable search */
|
|
key.userid = GetUserId();
|
|
key.dbid = MyDatabaseId;
|
|
key.encoding = GetDatabaseEncoding();
|
|
key.queryid = queryId;
|
|
|
|
/* Lookup the hash table entry with shared lock. */
|
|
LWLockAcquire(pgss->lock, LW_SHARED);
|
|
|
|
entry = (pgssEntry *) hash_search(pgss_hash, &key, HASH_FIND, NULL);
|
|
|
|
/* Create new entry, if not present */
|
|
if (!entry)
|
|
{
|
|
int query_len;
|
|
|
|
/*
|
|
* We'll need exclusive lock to make a new entry. There is no point
|
|
* in holding shared lock while we normalize the string, though.
|
|
*/
|
|
LWLockRelease(pgss->lock);
|
|
|
|
query_len = strlen(query);
|
|
|
|
if (jstate)
|
|
{
|
|
/* Normalize the string if enabled */
|
|
norm_query = generate_normalized_query(jstate, query,
|
|
&query_len,
|
|
key.encoding);
|
|
|
|
/* Acquire exclusive lock as required by entry_alloc() */
|
|
LWLockAcquire(pgss->lock, LW_EXCLUSIVE);
|
|
|
|
entry = entry_alloc(&key, norm_query, query_len, true);
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* We're just going to store the query string as-is; but we have
|
|
* to truncate it if over-length.
|
|
*/
|
|
if (query_len >= pgss->query_size)
|
|
query_len = pg_encoding_mbcliplen(key.encoding,
|
|
query,
|
|
query_len,
|
|
pgss->query_size - 1);
|
|
|
|
/* Acquire exclusive lock as required by entry_alloc() */
|
|
LWLockAcquire(pgss->lock, LW_EXCLUSIVE);
|
|
|
|
entry = entry_alloc(&key, query, query_len, false);
|
|
}
|
|
}
|
|
|
|
/* Increment the counts, except when jstate is not NULL */
|
|
if (!jstate)
|
|
{
|
|
/*
|
|
* Grab the spinlock while updating the counters (see comment about
|
|
* locking rules at the head of the file)
|
|
*/
|
|
volatile pgssEntry *e = (volatile pgssEntry *) entry;
|
|
|
|
SpinLockAcquire(&e->mutex);
|
|
|
|
/* "Unstick" entry if it was previously sticky */
|
|
if (e->counters.calls == 0)
|
|
e->counters.usage = USAGE_INIT;
|
|
|
|
e->counters.calls += 1;
|
|
e->counters.total_time += total_time;
|
|
e->counters.rows += rows;
|
|
e->counters.shared_blks_hit += bufusage->shared_blks_hit;
|
|
e->counters.shared_blks_read += bufusage->shared_blks_read;
|
|
e->counters.shared_blks_dirtied += bufusage->shared_blks_dirtied;
|
|
e->counters.shared_blks_written += bufusage->shared_blks_written;
|
|
e->counters.local_blks_hit += bufusage->local_blks_hit;
|
|
e->counters.local_blks_read += bufusage->local_blks_read;
|
|
e->counters.local_blks_dirtied += bufusage->local_blks_dirtied;
|
|
e->counters.local_blks_written += bufusage->local_blks_written;
|
|
e->counters.temp_blks_read += bufusage->temp_blks_read;
|
|
e->counters.temp_blks_written += bufusage->temp_blks_written;
|
|
e->counters.blk_read_time += INSTR_TIME_GET_MILLISEC(bufusage->blk_read_time);
|
|
e->counters.blk_write_time += INSTR_TIME_GET_MILLISEC(bufusage->blk_write_time);
|
|
e->counters.usage += USAGE_EXEC(total_time);
|
|
|
|
SpinLockRelease(&e->mutex);
|
|
}
|
|
|
|
LWLockRelease(pgss->lock);
|
|
|
|
/* We postpone this pfree until we're out of the lock */
|
|
if (norm_query)
|
|
pfree(norm_query);
|
|
}
|
|
|
|
/*
|
|
* Reset all statement statistics.
|
|
*/
|
|
Datum
|
|
pg_stat_statements_reset(PG_FUNCTION_ARGS)
|
|
{
|
|
if (!pgss || !pgss_hash)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
|
|
errmsg("pg_stat_statements must be loaded via shared_preload_libraries")));
|
|
entry_reset();
|
|
PG_RETURN_VOID();
|
|
}
|
|
|
|
#define PG_STAT_STATEMENTS_COLS_V1_0 14
|
|
#define PG_STAT_STATEMENTS_COLS 18
|
|
|
|
/*
|
|
* Retrieve statement statistics.
|
|
*/
|
|
Datum
|
|
pg_stat_statements(PG_FUNCTION_ARGS)
|
|
{
|
|
ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
|
|
TupleDesc tupdesc;
|
|
Tuplestorestate *tupstore;
|
|
MemoryContext per_query_ctx;
|
|
MemoryContext oldcontext;
|
|
Oid userid = GetUserId();
|
|
bool is_superuser = superuser();
|
|
HASH_SEQ_STATUS hash_seq;
|
|
pgssEntry *entry;
|
|
bool sql_supports_v1_1_counters = true;
|
|
|
|
if (!pgss || !pgss_hash)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
|
|
errmsg("pg_stat_statements must be loaded via shared_preload_libraries")));
|
|
|
|
/* check to see if caller supports us returning a tuplestore */
|
|
if (rsinfo == NULL || !IsA(rsinfo, ReturnSetInfo))
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
|
|
errmsg("set-valued function called in context that cannot accept a set")));
|
|
if (!(rsinfo->allowedModes & SFRM_Materialize))
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
|
|
errmsg("materialize mode required, but it is not " \
|
|
"allowed in this context")));
|
|
|
|
/* Build a tuple descriptor for our result type */
|
|
if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
|
|
elog(ERROR, "return type must be a row type");
|
|
if (tupdesc->natts == PG_STAT_STATEMENTS_COLS_V1_0)
|
|
sql_supports_v1_1_counters = false;
|
|
|
|
per_query_ctx = rsinfo->econtext->ecxt_per_query_memory;
|
|
oldcontext = MemoryContextSwitchTo(per_query_ctx);
|
|
|
|
tupstore = tuplestore_begin_heap(true, false, work_mem);
|
|
rsinfo->returnMode = SFRM_Materialize;
|
|
rsinfo->setResult = tupstore;
|
|
rsinfo->setDesc = tupdesc;
|
|
|
|
MemoryContextSwitchTo(oldcontext);
|
|
|
|
LWLockAcquire(pgss->lock, LW_SHARED);
|
|
|
|
hash_seq_init(&hash_seq, pgss_hash);
|
|
while ((entry = hash_seq_search(&hash_seq)) != NULL)
|
|
{
|
|
Datum values[PG_STAT_STATEMENTS_COLS];
|
|
bool nulls[PG_STAT_STATEMENTS_COLS];
|
|
int i = 0;
|
|
Counters tmp;
|
|
|
|
memset(values, 0, sizeof(values));
|
|
memset(nulls, 0, sizeof(nulls));
|
|
|
|
values[i++] = ObjectIdGetDatum(entry->key.userid);
|
|
values[i++] = ObjectIdGetDatum(entry->key.dbid);
|
|
|
|
if (is_superuser || entry->key.userid == userid)
|
|
{
|
|
char *qstr;
|
|
|
|
qstr = (char *)
|
|
pg_do_encoding_conversion((unsigned char *) entry->query,
|
|
entry->query_len,
|
|
entry->key.encoding,
|
|
GetDatabaseEncoding());
|
|
values[i++] = CStringGetTextDatum(qstr);
|
|
if (qstr != entry->query)
|
|
pfree(qstr);
|
|
}
|
|
else
|
|
values[i++] = CStringGetTextDatum("<insufficient privilege>");
|
|
|
|
/* copy counters to a local variable to keep locking time short */
|
|
{
|
|
volatile pgssEntry *e = (volatile pgssEntry *) entry;
|
|
|
|
SpinLockAcquire(&e->mutex);
|
|
tmp = e->counters;
|
|
SpinLockRelease(&e->mutex);
|
|
}
|
|
|
|
/* Skip entry if unexecuted (ie, it's a pending "sticky" entry) */
|
|
if (tmp.calls == 0)
|
|
continue;
|
|
|
|
values[i++] = Int64GetDatumFast(tmp.calls);
|
|
values[i++] = Float8GetDatumFast(tmp.total_time);
|
|
values[i++] = Int64GetDatumFast(tmp.rows);
|
|
values[i++] = Int64GetDatumFast(tmp.shared_blks_hit);
|
|
values[i++] = Int64GetDatumFast(tmp.shared_blks_read);
|
|
if (sql_supports_v1_1_counters)
|
|
values[i++] = Int64GetDatumFast(tmp.shared_blks_dirtied);
|
|
values[i++] = Int64GetDatumFast(tmp.shared_blks_written);
|
|
values[i++] = Int64GetDatumFast(tmp.local_blks_hit);
|
|
values[i++] = Int64GetDatumFast(tmp.local_blks_read);
|
|
if (sql_supports_v1_1_counters)
|
|
values[i++] = Int64GetDatumFast(tmp.local_blks_dirtied);
|
|
values[i++] = Int64GetDatumFast(tmp.local_blks_written);
|
|
values[i++] = Int64GetDatumFast(tmp.temp_blks_read);
|
|
values[i++] = Int64GetDatumFast(tmp.temp_blks_written);
|
|
if (sql_supports_v1_1_counters)
|
|
{
|
|
values[i++] = Float8GetDatumFast(tmp.blk_read_time);
|
|
values[i++] = Float8GetDatumFast(tmp.blk_write_time);
|
|
}
|
|
|
|
Assert(i == (sql_supports_v1_1_counters ?
|
|
PG_STAT_STATEMENTS_COLS : PG_STAT_STATEMENTS_COLS_V1_0));
|
|
|
|
tuplestore_putvalues(tupstore, tupdesc, values, nulls);
|
|
}
|
|
|
|
LWLockRelease(pgss->lock);
|
|
|
|
/* clean up and return the tuplestore */
|
|
tuplestore_donestoring(tupstore);
|
|
|
|
return (Datum) 0;
|
|
}
|
|
|
|
/*
|
|
* Estimate shared memory space needed.
|
|
*/
|
|
static Size
|
|
pgss_memsize(void)
|
|
{
|
|
Size size;
|
|
Size entrysize;
|
|
|
|
size = MAXALIGN(sizeof(pgssSharedState));
|
|
entrysize = offsetof(pgssEntry, query) +pgstat_track_activity_query_size;
|
|
size = add_size(size, hash_estimate_size(pgss_max, entrysize));
|
|
|
|
return size;
|
|
}
|
|
|
|
/*
|
|
* Allocate a new hashtable entry.
|
|
* caller must hold an exclusive lock on pgss->lock
|
|
*
|
|
* "query" need not be null-terminated; we rely on query_len instead
|
|
*
|
|
* If "sticky" is true, make the new entry artificially sticky so that it will
|
|
* probably still be there when the query finishes execution. We do this by
|
|
* giving it a median usage value rather than the normal value. (Strictly
|
|
* speaking, query strings are normalized on a best effort basis, though it
|
|
* would be difficult to demonstrate this even under artificial conditions.)
|
|
*
|
|
* Note: despite needing exclusive lock, it's not an error for the target
|
|
* entry to already exist. This is because pgss_store releases and
|
|
* reacquires lock after failing to find a match; so someone else could
|
|
* have made the entry while we waited to get exclusive lock.
|
|
*/
|
|
static pgssEntry *
|
|
entry_alloc(pgssHashKey *key, const char *query, int query_len, bool sticky)
|
|
{
|
|
pgssEntry *entry;
|
|
bool found;
|
|
|
|
/* Make space if needed */
|
|
while (hash_get_num_entries(pgss_hash) >= pgss_max)
|
|
entry_dealloc();
|
|
|
|
/* Find or create an entry with desired hash code */
|
|
entry = (pgssEntry *) hash_search(pgss_hash, key, HASH_ENTER, &found);
|
|
|
|
if (!found)
|
|
{
|
|
/* New entry, initialize it */
|
|
|
|
/* reset the statistics */
|
|
memset(&entry->counters, 0, sizeof(Counters));
|
|
/* set the appropriate initial usage count */
|
|
entry->counters.usage = sticky ? pgss->cur_median_usage : USAGE_INIT;
|
|
/* re-initialize the mutex each time ... we assume no one using it */
|
|
SpinLockInit(&entry->mutex);
|
|
/* ... and don't forget the query text */
|
|
Assert(query_len >= 0 && query_len < pgss->query_size);
|
|
entry->query_len = query_len;
|
|
memcpy(entry->query, query, query_len);
|
|
entry->query[query_len] = '\0';
|
|
}
|
|
|
|
return entry;
|
|
}
|
|
|
|
/*
|
|
* qsort comparator for sorting into increasing usage order
|
|
*/
|
|
static int
|
|
entry_cmp(const void *lhs, const void *rhs)
|
|
{
|
|
double l_usage = (*(pgssEntry *const *) lhs)->counters.usage;
|
|
double r_usage = (*(pgssEntry *const *) rhs)->counters.usage;
|
|
|
|
if (l_usage < r_usage)
|
|
return -1;
|
|
else if (l_usage > r_usage)
|
|
return +1;
|
|
else
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Deallocate least used entries.
|
|
* Caller must hold an exclusive lock on pgss->lock.
|
|
*/
|
|
static void
|
|
entry_dealloc(void)
|
|
{
|
|
HASH_SEQ_STATUS hash_seq;
|
|
pgssEntry **entries;
|
|
pgssEntry *entry;
|
|
int nvictims;
|
|
int i;
|
|
|
|
/*
|
|
* Sort entries by usage and deallocate USAGE_DEALLOC_PERCENT of them.
|
|
* While we're scanning the table, apply the decay factor to the usage
|
|
* values.
|
|
*/
|
|
|
|
entries = palloc(hash_get_num_entries(pgss_hash) * sizeof(pgssEntry *));
|
|
|
|
i = 0;
|
|
hash_seq_init(&hash_seq, pgss_hash);
|
|
while ((entry = hash_seq_search(&hash_seq)) != NULL)
|
|
{
|
|
entries[i++] = entry;
|
|
/* "Sticky" entries get a different usage decay rate. */
|
|
if (entry->counters.calls == 0)
|
|
entry->counters.usage *= STICKY_DECREASE_FACTOR;
|
|
else
|
|
entry->counters.usage *= USAGE_DECREASE_FACTOR;
|
|
}
|
|
|
|
qsort(entries, i, sizeof(pgssEntry *), entry_cmp);
|
|
|
|
/* Also, record the (approximate) median usage */
|
|
if (i > 0)
|
|
pgss->cur_median_usage = entries[i / 2]->counters.usage;
|
|
|
|
nvictims = Max(10, i * USAGE_DEALLOC_PERCENT / 100);
|
|
nvictims = Min(nvictims, i);
|
|
|
|
for (i = 0; i < nvictims; i++)
|
|
{
|
|
hash_search(pgss_hash, &entries[i]->key, HASH_REMOVE, NULL);
|
|
}
|
|
|
|
pfree(entries);
|
|
}
|
|
|
|
/*
|
|
* Release all entries.
|
|
*/
|
|
static void
|
|
entry_reset(void)
|
|
{
|
|
HASH_SEQ_STATUS hash_seq;
|
|
pgssEntry *entry;
|
|
|
|
LWLockAcquire(pgss->lock, LW_EXCLUSIVE);
|
|
|
|
hash_seq_init(&hash_seq, pgss_hash);
|
|
while ((entry = hash_seq_search(&hash_seq)) != NULL)
|
|
{
|
|
hash_search(pgss_hash, &entry->key, HASH_REMOVE, NULL);
|
|
}
|
|
|
|
LWLockRelease(pgss->lock);
|
|
}
|
|
|
|
/*
|
|
* AppendJumble: Append a value that is substantive in a given query to
|
|
* the current jumble.
|
|
*/
|
|
static void
|
|
AppendJumble(pgssJumbleState *jstate, const unsigned char *item, Size size)
|
|
{
|
|
unsigned char *jumble = jstate->jumble;
|
|
Size jumble_len = jstate->jumble_len;
|
|
|
|
/*
|
|
* Whenever the jumble buffer is full, we hash the current contents and
|
|
* reset the buffer to contain just that hash value, thus relying on the
|
|
* hash to summarize everything so far.
|
|
*/
|
|
while (size > 0)
|
|
{
|
|
Size part_size;
|
|
|
|
if (jumble_len >= JUMBLE_SIZE)
|
|
{
|
|
uint32 start_hash = hash_any(jumble, JUMBLE_SIZE);
|
|
|
|
memcpy(jumble, &start_hash, sizeof(start_hash));
|
|
jumble_len = sizeof(start_hash);
|
|
}
|
|
part_size = Min(size, JUMBLE_SIZE - jumble_len);
|
|
memcpy(jumble + jumble_len, item, part_size);
|
|
jumble_len += part_size;
|
|
item += part_size;
|
|
size -= part_size;
|
|
}
|
|
jstate->jumble_len = jumble_len;
|
|
}
|
|
|
|
/*
|
|
* Wrappers around AppendJumble to encapsulate details of serialization
|
|
* of individual local variable elements.
|
|
*/
|
|
#define APP_JUMB(item) \
|
|
AppendJumble(jstate, (const unsigned char *) &(item), sizeof(item))
|
|
#define APP_JUMB_STRING(str) \
|
|
AppendJumble(jstate, (const unsigned char *) (str), strlen(str) + 1)
|
|
|
|
/*
|
|
* JumbleQuery: Selectively serialize the query tree, appending significant
|
|
* data to the "query jumble" while ignoring nonsignificant data.
|
|
*
|
|
* Rule of thumb for what to include is that we should ignore anything not
|
|
* semantically significant (such as alias names) as well as anything that can
|
|
* be deduced from child nodes (else we'd just be double-hashing that piece
|
|
* of information).
|
|
*/
|
|
static void
|
|
JumbleQuery(pgssJumbleState *jstate, Query *query)
|
|
{
|
|
Assert(IsA(query, Query));
|
|
Assert(query->utilityStmt == NULL);
|
|
|
|
APP_JUMB(query->commandType);
|
|
/* resultRelation is usually predictable from commandType */
|
|
JumbleExpr(jstate, (Node *) query->cteList);
|
|
JumbleRangeTable(jstate, query->rtable);
|
|
JumbleExpr(jstate, (Node *) query->jointree);
|
|
JumbleExpr(jstate, (Node *) query->targetList);
|
|
JumbleExpr(jstate, (Node *) query->returningList);
|
|
JumbleExpr(jstate, (Node *) query->groupClause);
|
|
JumbleExpr(jstate, query->havingQual);
|
|
JumbleExpr(jstate, (Node *) query->windowClause);
|
|
JumbleExpr(jstate, (Node *) query->distinctClause);
|
|
JumbleExpr(jstate, (Node *) query->sortClause);
|
|
JumbleExpr(jstate, query->limitOffset);
|
|
JumbleExpr(jstate, query->limitCount);
|
|
/* we ignore rowMarks */
|
|
JumbleExpr(jstate, query->setOperations);
|
|
}
|
|
|
|
/*
|
|
* Jumble a range table
|
|
*/
|
|
static void
|
|
JumbleRangeTable(pgssJumbleState *jstate, List *rtable)
|
|
{
|
|
ListCell *lc;
|
|
|
|
foreach(lc, rtable)
|
|
{
|
|
RangeTblEntry *rte = (RangeTblEntry *) lfirst(lc);
|
|
|
|
Assert(IsA(rte, RangeTblEntry));
|
|
APP_JUMB(rte->rtekind);
|
|
switch (rte->rtekind)
|
|
{
|
|
case RTE_RELATION:
|
|
APP_JUMB(rte->relid);
|
|
break;
|
|
case RTE_SUBQUERY:
|
|
JumbleQuery(jstate, rte->subquery);
|
|
break;
|
|
case RTE_JOIN:
|
|
APP_JUMB(rte->jointype);
|
|
break;
|
|
case RTE_FUNCTION:
|
|
JumbleExpr(jstate, rte->funcexpr);
|
|
break;
|
|
case RTE_VALUES:
|
|
JumbleExpr(jstate, (Node *) rte->values_lists);
|
|
break;
|
|
case RTE_CTE:
|
|
|
|
/*
|
|
* Depending on the CTE name here isn't ideal, but it's the
|
|
* only info we have to identify the referenced WITH item.
|
|
*/
|
|
APP_JUMB_STRING(rte->ctename);
|
|
APP_JUMB(rte->ctelevelsup);
|
|
break;
|
|
default:
|
|
elog(ERROR, "unrecognized RTE kind: %d", (int) rte->rtekind);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Jumble an expression tree
|
|
*
|
|
* In general this function should handle all the same node types that
|
|
* expression_tree_walker() does, and therefore it's coded to be as parallel
|
|
* to that function as possible. However, since we are only invoked on
|
|
* queries immediately post-parse-analysis, we need not handle node types
|
|
* that only appear in planning.
|
|
*
|
|
* Note: the reason we don't simply use expression_tree_walker() is that the
|
|
* point of that function is to support tree walkers that don't care about
|
|
* most tree node types, but here we care about all types. We should complain
|
|
* about any unrecognized node type.
|
|
*/
|
|
static void
|
|
JumbleExpr(pgssJumbleState *jstate, Node *node)
|
|
{
|
|
ListCell *temp;
|
|
|
|
if (node == NULL)
|
|
return;
|
|
|
|
/* Guard against stack overflow due to overly complex expressions */
|
|
check_stack_depth();
|
|
|
|
/*
|
|
* We always emit the node's NodeTag, then any additional fields that are
|
|
* considered significant, and then we recurse to any child nodes.
|
|
*/
|
|
APP_JUMB(node->type);
|
|
|
|
switch (nodeTag(node))
|
|
{
|
|
case T_Var:
|
|
{
|
|
Var *var = (Var *) node;
|
|
|
|
APP_JUMB(var->varno);
|
|
APP_JUMB(var->varattno);
|
|
APP_JUMB(var->varlevelsup);
|
|
}
|
|
break;
|
|
case T_Const:
|
|
{
|
|
Const *c = (Const *) node;
|
|
|
|
/* We jumble only the constant's type, not its value */
|
|
APP_JUMB(c->consttype);
|
|
/* Also, record its parse location for query normalization */
|
|
RecordConstLocation(jstate, c->location);
|
|
}
|
|
break;
|
|
case T_Param:
|
|
{
|
|
Param *p = (Param *) node;
|
|
|
|
APP_JUMB(p->paramkind);
|
|
APP_JUMB(p->paramid);
|
|
APP_JUMB(p->paramtype);
|
|
}
|
|
break;
|
|
case T_Aggref:
|
|
{
|
|
Aggref *expr = (Aggref *) node;
|
|
|
|
APP_JUMB(expr->aggfnoid);
|
|
JumbleExpr(jstate, (Node *) expr->args);
|
|
JumbleExpr(jstate, (Node *) expr->aggorder);
|
|
JumbleExpr(jstate, (Node *) expr->aggdistinct);
|
|
}
|
|
break;
|
|
case T_WindowFunc:
|
|
{
|
|
WindowFunc *expr = (WindowFunc *) node;
|
|
|
|
APP_JUMB(expr->winfnoid);
|
|
APP_JUMB(expr->winref);
|
|
JumbleExpr(jstate, (Node *) expr->args);
|
|
}
|
|
break;
|
|
case T_ArrayRef:
|
|
{
|
|
ArrayRef *aref = (ArrayRef *) node;
|
|
|
|
JumbleExpr(jstate, (Node *) aref->refupperindexpr);
|
|
JumbleExpr(jstate, (Node *) aref->reflowerindexpr);
|
|
JumbleExpr(jstate, (Node *) aref->refexpr);
|
|
JumbleExpr(jstate, (Node *) aref->refassgnexpr);
|
|
}
|
|
break;
|
|
case T_FuncExpr:
|
|
{
|
|
FuncExpr *expr = (FuncExpr *) node;
|
|
|
|
APP_JUMB(expr->funcid);
|
|
JumbleExpr(jstate, (Node *) expr->args);
|
|
}
|
|
break;
|
|
case T_NamedArgExpr:
|
|
{
|
|
NamedArgExpr *nae = (NamedArgExpr *) node;
|
|
|
|
APP_JUMB(nae->argnumber);
|
|
JumbleExpr(jstate, (Node *) nae->arg);
|
|
}
|
|
break;
|
|
case T_OpExpr:
|
|
case T_DistinctExpr: /* struct-equivalent to OpExpr */
|
|
case T_NullIfExpr: /* struct-equivalent to OpExpr */
|
|
{
|
|
OpExpr *expr = (OpExpr *) node;
|
|
|
|
APP_JUMB(expr->opno);
|
|
JumbleExpr(jstate, (Node *) expr->args);
|
|
}
|
|
break;
|
|
case T_ScalarArrayOpExpr:
|
|
{
|
|
ScalarArrayOpExpr *expr = (ScalarArrayOpExpr *) node;
|
|
|
|
APP_JUMB(expr->opno);
|
|
APP_JUMB(expr->useOr);
|
|
JumbleExpr(jstate, (Node *) expr->args);
|
|
}
|
|
break;
|
|
case T_BoolExpr:
|
|
{
|
|
BoolExpr *expr = (BoolExpr *) node;
|
|
|
|
APP_JUMB(expr->boolop);
|
|
JumbleExpr(jstate, (Node *) expr->args);
|
|
}
|
|
break;
|
|
case T_SubLink:
|
|
{
|
|
SubLink *sublink = (SubLink *) node;
|
|
|
|
APP_JUMB(sublink->subLinkType);
|
|
JumbleExpr(jstate, (Node *) sublink->testexpr);
|
|
JumbleQuery(jstate, (Query *) sublink->subselect);
|
|
}
|
|
break;
|
|
case T_FieldSelect:
|
|
{
|
|
FieldSelect *fs = (FieldSelect *) node;
|
|
|
|
APP_JUMB(fs->fieldnum);
|
|
JumbleExpr(jstate, (Node *) fs->arg);
|
|
}
|
|
break;
|
|
case T_FieldStore:
|
|
{
|
|
FieldStore *fstore = (FieldStore *) node;
|
|
|
|
JumbleExpr(jstate, (Node *) fstore->arg);
|
|
JumbleExpr(jstate, (Node *) fstore->newvals);
|
|
}
|
|
break;
|
|
case T_RelabelType:
|
|
{
|
|
RelabelType *rt = (RelabelType *) node;
|
|
|
|
APP_JUMB(rt->resulttype);
|
|
JumbleExpr(jstate, (Node *) rt->arg);
|
|
}
|
|
break;
|
|
case T_CoerceViaIO:
|
|
{
|
|
CoerceViaIO *cio = (CoerceViaIO *) node;
|
|
|
|
APP_JUMB(cio->resulttype);
|
|
JumbleExpr(jstate, (Node *) cio->arg);
|
|
}
|
|
break;
|
|
case T_ArrayCoerceExpr:
|
|
{
|
|
ArrayCoerceExpr *acexpr = (ArrayCoerceExpr *) node;
|
|
|
|
APP_JUMB(acexpr->resulttype);
|
|
JumbleExpr(jstate, (Node *) acexpr->arg);
|
|
}
|
|
break;
|
|
case T_ConvertRowtypeExpr:
|
|
{
|
|
ConvertRowtypeExpr *crexpr = (ConvertRowtypeExpr *) node;
|
|
|
|
APP_JUMB(crexpr->resulttype);
|
|
JumbleExpr(jstate, (Node *) crexpr->arg);
|
|
}
|
|
break;
|
|
case T_CollateExpr:
|
|
{
|
|
CollateExpr *ce = (CollateExpr *) node;
|
|
|
|
APP_JUMB(ce->collOid);
|
|
JumbleExpr(jstate, (Node *) ce->arg);
|
|
}
|
|
break;
|
|
case T_CaseExpr:
|
|
{
|
|
CaseExpr *caseexpr = (CaseExpr *) node;
|
|
|
|
JumbleExpr(jstate, (Node *) caseexpr->arg);
|
|
foreach(temp, caseexpr->args)
|
|
{
|
|
CaseWhen *when = (CaseWhen *) lfirst(temp);
|
|
|
|
Assert(IsA(when, CaseWhen));
|
|
JumbleExpr(jstate, (Node *) when->expr);
|
|
JumbleExpr(jstate, (Node *) when->result);
|
|
}
|
|
JumbleExpr(jstate, (Node *) caseexpr->defresult);
|
|
}
|
|
break;
|
|
case T_CaseTestExpr:
|
|
{
|
|
CaseTestExpr *ct = (CaseTestExpr *) node;
|
|
|
|
APP_JUMB(ct->typeId);
|
|
}
|
|
break;
|
|
case T_ArrayExpr:
|
|
JumbleExpr(jstate, (Node *) ((ArrayExpr *) node)->elements);
|
|
break;
|
|
case T_RowExpr:
|
|
JumbleExpr(jstate, (Node *) ((RowExpr *) node)->args);
|
|
break;
|
|
case T_RowCompareExpr:
|
|
{
|
|
RowCompareExpr *rcexpr = (RowCompareExpr *) node;
|
|
|
|
APP_JUMB(rcexpr->rctype);
|
|
JumbleExpr(jstate, (Node *) rcexpr->largs);
|
|
JumbleExpr(jstate, (Node *) rcexpr->rargs);
|
|
}
|
|
break;
|
|
case T_CoalesceExpr:
|
|
JumbleExpr(jstate, (Node *) ((CoalesceExpr *) node)->args);
|
|
break;
|
|
case T_MinMaxExpr:
|
|
{
|
|
MinMaxExpr *mmexpr = (MinMaxExpr *) node;
|
|
|
|
APP_JUMB(mmexpr->op);
|
|
JumbleExpr(jstate, (Node *) mmexpr->args);
|
|
}
|
|
break;
|
|
case T_XmlExpr:
|
|
{
|
|
XmlExpr *xexpr = (XmlExpr *) node;
|
|
|
|
APP_JUMB(xexpr->op);
|
|
JumbleExpr(jstate, (Node *) xexpr->named_args);
|
|
JumbleExpr(jstate, (Node *) xexpr->args);
|
|
}
|
|
break;
|
|
case T_NullTest:
|
|
{
|
|
NullTest *nt = (NullTest *) node;
|
|
|
|
APP_JUMB(nt->nulltesttype);
|
|
JumbleExpr(jstate, (Node *) nt->arg);
|
|
}
|
|
break;
|
|
case T_BooleanTest:
|
|
{
|
|
BooleanTest *bt = (BooleanTest *) node;
|
|
|
|
APP_JUMB(bt->booltesttype);
|
|
JumbleExpr(jstate, (Node *) bt->arg);
|
|
}
|
|
break;
|
|
case T_CoerceToDomain:
|
|
{
|
|
CoerceToDomain *cd = (CoerceToDomain *) node;
|
|
|
|
APP_JUMB(cd->resulttype);
|
|
JumbleExpr(jstate, (Node *) cd->arg);
|
|
}
|
|
break;
|
|
case T_CoerceToDomainValue:
|
|
{
|
|
CoerceToDomainValue *cdv = (CoerceToDomainValue *) node;
|
|
|
|
APP_JUMB(cdv->typeId);
|
|
}
|
|
break;
|
|
case T_SetToDefault:
|
|
{
|
|
SetToDefault *sd = (SetToDefault *) node;
|
|
|
|
APP_JUMB(sd->typeId);
|
|
}
|
|
break;
|
|
case T_CurrentOfExpr:
|
|
{
|
|
CurrentOfExpr *ce = (CurrentOfExpr *) node;
|
|
|
|
APP_JUMB(ce->cvarno);
|
|
if (ce->cursor_name)
|
|
APP_JUMB_STRING(ce->cursor_name);
|
|
APP_JUMB(ce->cursor_param);
|
|
}
|
|
break;
|
|
case T_TargetEntry:
|
|
{
|
|
TargetEntry *tle = (TargetEntry *) node;
|
|
|
|
APP_JUMB(tle->resno);
|
|
APP_JUMB(tle->ressortgroupref);
|
|
JumbleExpr(jstate, (Node *) tle->expr);
|
|
}
|
|
break;
|
|
case T_RangeTblRef:
|
|
{
|
|
RangeTblRef *rtr = (RangeTblRef *) node;
|
|
|
|
APP_JUMB(rtr->rtindex);
|
|
}
|
|
break;
|
|
case T_JoinExpr:
|
|
{
|
|
JoinExpr *join = (JoinExpr *) node;
|
|
|
|
APP_JUMB(join->jointype);
|
|
APP_JUMB(join->isNatural);
|
|
APP_JUMB(join->rtindex);
|
|
JumbleExpr(jstate, join->larg);
|
|
JumbleExpr(jstate, join->rarg);
|
|
JumbleExpr(jstate, join->quals);
|
|
}
|
|
break;
|
|
case T_FromExpr:
|
|
{
|
|
FromExpr *from = (FromExpr *) node;
|
|
|
|
JumbleExpr(jstate, (Node *) from->fromlist);
|
|
JumbleExpr(jstate, from->quals);
|
|
}
|
|
break;
|
|
case T_List:
|
|
foreach(temp, (List *) node)
|
|
{
|
|
JumbleExpr(jstate, (Node *) lfirst(temp));
|
|
}
|
|
break;
|
|
case T_SortGroupClause:
|
|
{
|
|
SortGroupClause *sgc = (SortGroupClause *) node;
|
|
|
|
APP_JUMB(sgc->tleSortGroupRef);
|
|
APP_JUMB(sgc->eqop);
|
|
APP_JUMB(sgc->sortop);
|
|
APP_JUMB(sgc->nulls_first);
|
|
}
|
|
break;
|
|
case T_WindowClause:
|
|
{
|
|
WindowClause *wc = (WindowClause *) node;
|
|
|
|
APP_JUMB(wc->winref);
|
|
APP_JUMB(wc->frameOptions);
|
|
JumbleExpr(jstate, (Node *) wc->partitionClause);
|
|
JumbleExpr(jstate, (Node *) wc->orderClause);
|
|
JumbleExpr(jstate, wc->startOffset);
|
|
JumbleExpr(jstate, wc->endOffset);
|
|
}
|
|
break;
|
|
case T_CommonTableExpr:
|
|
{
|
|
CommonTableExpr *cte = (CommonTableExpr *) node;
|
|
|
|
/* we store the string name because RTE_CTE RTEs need it */
|
|
APP_JUMB_STRING(cte->ctename);
|
|
JumbleQuery(jstate, (Query *) cte->ctequery);
|
|
}
|
|
break;
|
|
case T_SetOperationStmt:
|
|
{
|
|
SetOperationStmt *setop = (SetOperationStmt *) node;
|
|
|
|
APP_JUMB(setop->op);
|
|
APP_JUMB(setop->all);
|
|
JumbleExpr(jstate, setop->larg);
|
|
JumbleExpr(jstate, setop->rarg);
|
|
}
|
|
break;
|
|
default:
|
|
/* Only a warning, since we can stumble along anyway */
|
|
elog(WARNING, "unrecognized node type: %d",
|
|
(int) nodeTag(node));
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Record location of constant within query string of query tree
|
|
* that is currently being walked.
|
|
*/
|
|
static void
|
|
RecordConstLocation(pgssJumbleState *jstate, int location)
|
|
{
|
|
/* -1 indicates unknown or undefined location */
|
|
if (location >= 0)
|
|
{
|
|
/* enlarge array if needed */
|
|
if (jstate->clocations_count >= jstate->clocations_buf_size)
|
|
{
|
|
jstate->clocations_buf_size *= 2;
|
|
jstate->clocations = (pgssLocationLen *)
|
|
repalloc(jstate->clocations,
|
|
jstate->clocations_buf_size *
|
|
sizeof(pgssLocationLen));
|
|
}
|
|
jstate->clocations[jstate->clocations_count].location = location;
|
|
/* initialize lengths to -1 to simplify fill_in_constant_lengths */
|
|
jstate->clocations[jstate->clocations_count].length = -1;
|
|
jstate->clocations_count++;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Generate a normalized version of the query string that will be used to
|
|
* represent all similar queries.
|
|
*
|
|
* Note that the normalized representation may well vary depending on
|
|
* just which "equivalent" query is used to create the hashtable entry.
|
|
* We assume this is OK.
|
|
*
|
|
* *query_len_p contains the input string length, and is updated with
|
|
* the result string length (which cannot be longer) on exit.
|
|
*
|
|
* Returns a palloc'd string, which is not necessarily null-terminated.
|
|
*/
|
|
static char *
|
|
generate_normalized_query(pgssJumbleState *jstate, const char *query,
|
|
int *query_len_p, int encoding)
|
|
{
|
|
char *norm_query;
|
|
int query_len = *query_len_p;
|
|
int max_output_len;
|
|
int i,
|
|
len_to_wrt, /* Length (in bytes) to write */
|
|
quer_loc = 0, /* Source query byte location */
|
|
n_quer_loc = 0, /* Normalized query byte location */
|
|
last_off = 0, /* Offset from start for previous tok */
|
|
last_tok_len = 0; /* Length (in bytes) of that tok */
|
|
|
|
/*
|
|
* Get constants' lengths (core system only gives us locations). Note
|
|
* this also ensures the items are sorted by location.
|
|
*/
|
|
fill_in_constant_lengths(jstate, query);
|
|
|
|
/* Allocate result buffer, ensuring we limit result to allowed size */
|
|
max_output_len = Min(query_len, pgss->query_size - 1);
|
|
norm_query = palloc(max_output_len);
|
|
|
|
for (i = 0; i < jstate->clocations_count; i++)
|
|
{
|
|
int off, /* Offset from start for cur tok */
|
|
tok_len; /* Length (in bytes) of that tok */
|
|
|
|
off = jstate->clocations[i].location;
|
|
tok_len = jstate->clocations[i].length;
|
|
|
|
if (tok_len < 0)
|
|
continue; /* ignore any duplicates */
|
|
|
|
/* Copy next chunk, or as much as will fit */
|
|
len_to_wrt = off - last_off;
|
|
len_to_wrt -= last_tok_len;
|
|
len_to_wrt = Min(len_to_wrt, max_output_len - n_quer_loc);
|
|
|
|
Assert(len_to_wrt >= 0);
|
|
memcpy(norm_query + n_quer_loc, query + quer_loc, len_to_wrt);
|
|
n_quer_loc += len_to_wrt;
|
|
|
|
if (n_quer_loc < max_output_len)
|
|
norm_query[n_quer_loc++] = '?';
|
|
|
|
quer_loc = off + tok_len;
|
|
last_off = off;
|
|
last_tok_len = tok_len;
|
|
|
|
/* If we run out of space, might as well stop iterating */
|
|
if (n_quer_loc >= max_output_len)
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* We've copied up until the last ignorable constant. Copy over the
|
|
* remaining bytes of the original query string, or at least as much as
|
|
* will fit.
|
|
*/
|
|
len_to_wrt = query_len - quer_loc;
|
|
len_to_wrt = Min(len_to_wrt, max_output_len - n_quer_loc);
|
|
|
|
Assert(len_to_wrt >= 0);
|
|
memcpy(norm_query + n_quer_loc, query + quer_loc, len_to_wrt);
|
|
n_quer_loc += len_to_wrt;
|
|
|
|
/*
|
|
* If we ran out of space, we need to do an encoding-aware truncation,
|
|
* just to make sure we don't have an incomplete character at the end.
|
|
*/
|
|
if (n_quer_loc >= max_output_len)
|
|
query_len = pg_encoding_mbcliplen(encoding,
|
|
norm_query,
|
|
n_quer_loc,
|
|
pgss->query_size - 1);
|
|
else
|
|
query_len = n_quer_loc;
|
|
|
|
*query_len_p = query_len;
|
|
return norm_query;
|
|
}
|
|
|
|
/*
|
|
* Given a valid SQL string and an array of constant-location records,
|
|
* fill in the textual lengths of those constants.
|
|
*
|
|
* The constants may use any allowed constant syntax, such as float literals,
|
|
* bit-strings, single-quoted strings and dollar-quoted strings. This is
|
|
* accomplished by using the public API for the core scanner.
|
|
*
|
|
* It is the caller's job to ensure that the string is a valid SQL statement
|
|
* with constants at the indicated locations. Since in practice the string
|
|
* has already been parsed, and the locations that the caller provides will
|
|
* have originated from within the authoritative parser, this should not be
|
|
* a problem.
|
|
*
|
|
* Duplicate constant pointers are possible, and will have their lengths
|
|
* marked as '-1', so that they are later ignored. (Actually, we assume the
|
|
* lengths were initialized as -1 to start with, and don't change them here.)
|
|
*
|
|
* N.B. There is an assumption that a '-' character at a Const location begins
|
|
* a negative numeric constant. This precludes there ever being another
|
|
* reason for a constant to start with a '-'.
|
|
*/
|
|
static void
|
|
fill_in_constant_lengths(pgssJumbleState *jstate, const char *query)
|
|
{
|
|
pgssLocationLen *locs;
|
|
core_yyscan_t yyscanner;
|
|
core_yy_extra_type yyextra;
|
|
core_YYSTYPE yylval;
|
|
YYLTYPE yylloc;
|
|
int last_loc = -1;
|
|
int i;
|
|
|
|
/*
|
|
* Sort the records by location so that we can process them in order while
|
|
* scanning the query text.
|
|
*/
|
|
if (jstate->clocations_count > 1)
|
|
qsort(jstate->clocations, jstate->clocations_count,
|
|
sizeof(pgssLocationLen), comp_location);
|
|
locs = jstate->clocations;
|
|
|
|
/* initialize the flex scanner --- should match raw_parser() */
|
|
yyscanner = scanner_init(query,
|
|
&yyextra,
|
|
ScanKeywords,
|
|
NumScanKeywords);
|
|
|
|
/* Search for each constant, in sequence */
|
|
for (i = 0; i < jstate->clocations_count; i++)
|
|
{
|
|
int loc = locs[i].location;
|
|
int tok;
|
|
|
|
Assert(loc >= 0);
|
|
|
|
if (loc <= last_loc)
|
|
continue; /* Duplicate constant, ignore */
|
|
|
|
/* Lex tokens until we find the desired constant */
|
|
for (;;)
|
|
{
|
|
tok = core_yylex(&yylval, &yylloc, yyscanner);
|
|
|
|
/* We should not hit end-of-string, but if we do, behave sanely */
|
|
if (tok == 0)
|
|
break; /* out of inner for-loop */
|
|
|
|
/*
|
|
* We should find the token position exactly, but if we somehow
|
|
* run past it, work with that.
|
|
*/
|
|
if (yylloc >= loc)
|
|
{
|
|
if (query[loc] == '-')
|
|
{
|
|
/*
|
|
* It's a negative value - this is the one and only case
|
|
* where we replace more than a single token.
|
|
*
|
|
* Do not compensate for the core system's special-case
|
|
* adjustment of location to that of the leading '-'
|
|
* operator in the event of a negative constant. It is
|
|
* also useful for our purposes to start from the minus
|
|
* symbol. In this way, queries like "select * from foo
|
|
* where bar = 1" and "select * from foo where bar = -2"
|
|
* will have identical normalized query strings.
|
|
*/
|
|
tok = core_yylex(&yylval, &yylloc, yyscanner);
|
|
if (tok == 0)
|
|
break; /* out of inner for-loop */
|
|
}
|
|
|
|
/*
|
|
* We now rely on the assumption that flex has placed a zero
|
|
* byte after the text of the current token in scanbuf.
|
|
*/
|
|
locs[i].length = strlen(yyextra.scanbuf + loc);
|
|
break; /* out of inner for-loop */
|
|
}
|
|
}
|
|
|
|
/* If we hit end-of-string, give up, leaving remaining lengths -1 */
|
|
if (tok == 0)
|
|
break;
|
|
|
|
last_loc = loc;
|
|
}
|
|
|
|
scanner_finish(yyscanner);
|
|
}
|
|
|
|
/*
|
|
* comp_location: comparator for qsorting pgssLocationLen structs by location
|
|
*/
|
|
static int
|
|
comp_location(const void *a, const void *b)
|
|
{
|
|
int l = ((const pgssLocationLen *) a)->location;
|
|
int r = ((const pgssLocationLen *) b)->location;
|
|
|
|
if (l < r)
|
|
return -1;
|
|
else if (l > r)
|
|
return +1;
|
|
else
|
|
return 0;
|
|
}
|