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Update tsearch regex memory management.

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Now that our regex engine uses palloc(), it's not necessary to set up a
special memory context callback to free compiled regexes.  The regex has
no resources other than the memory that is already going to be freed in
bulk.

Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CA%2BhUKGK3PGKwcKqzoosamn36YW-fsuTdOPPF1i_rtEO%3DnEYKSg%40mail.gmail.com
This commit is contained in:
Thomas Munro 2023-04-08 21:54:45 +12:00
parent bea3d7e383
commit 4f51429dd7
2 changed files with 13 additions and 39 deletions
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34
src/backend/tsearch/spell.c
View File

@ -655,17 +655,6 @@ FindWord(IspellDict *Conf, const char *word, const char *affixflag, int flag)
return 0;
}
/*
* Context reset/delete callback for a regular expression used in an affix
*/
static void
regex_affix_deletion_callback(void *arg)
{
aff_regex_struct *pregex = (aff_regex_struct *) arg;
pg_regfree(&(pregex->regex));
}
/*
* Adds a new affix rule to the Affix field.
*
@ -728,7 +717,6 @@ NIAddAffix(IspellDict *Conf, const char *flag, char flagflags, const char *mask,
int err;
pg_wchar *wmask;
char *tmask;
aff_regex_struct *pregex;
Affix->issimple = 0;
Affix->isregis = 0;
@ -743,31 +731,23 @@ NIAddAffix(IspellDict *Conf, const char *flag, char flagflags, const char *mask,
wmasklen = pg_mb2wchar_with_len(tmask, wmask, masklen);
/*
* The regex engine stores its stuff using malloc not palloc, so we
* must arrange to explicitly clean up the regex when the dictionary's
* context is cleared. That means the regex_t has to stay in a fixed
* location within the context; we can't keep it directly in the AFFIX
* struct, since we may sort and resize the array of AFFIXes.
* The regex and all internal state created by pg_regcomp are
* allocated in the dictionary's memory context, and will be freed
* automatically when it is destroyed.
*/
Affix->reg.pregex = pregex = palloc(sizeof(aff_regex_struct));
err = pg_regcomp(&(pregex->regex), wmask, wmasklen,
Affix->reg.pregex = palloc(sizeof(regex_t));
err = pg_regcomp(Affix->reg.pregex, wmask, wmasklen,
REG_ADVANCED | REG_NOSUB,
DEFAULT_COLLATION_OID);
if (err)
{
char errstr[100];
pg_regerror(err, &(pregex->regex), errstr, sizeof(errstr));
pg_regerror(err, Affix->reg.pregex, errstr, sizeof(errstr));
ereport(ERROR,
(errcode(ERRCODE_INVALID_REGULAR_EXPRESSION),
errmsg("invalid regular expression: %s", errstr)));
}
pregex->mcallback.func = regex_affix_deletion_callback;
pregex->mcallback.arg = (void *) pregex;
MemoryContextRegisterResetCallback(CurrentMemoryContext,
&pregex->mcallback);
}
Affix->flagflags = flagflags;
@ -2161,7 +2141,7 @@ CheckAffix(const char *word, size_t len, AFFIX *Affix, int flagflags, char *neww
data = (pg_wchar *) palloc((newword_len + 1) * sizeof(pg_wchar));
data_len = pg_mb2wchar_with_len(newword, data, newword_len);
if (pg_regexec(&(Affix->reg.pregex->regex), data, data_len,
if (pg_regexec(Affix->reg.pregex, data, data_len,
0, NULL, 0, NULL, 0) == REG_OKAY)
{
pfree(data);

18
src/include/tsearch/dicts/spell.h
View File

@ -81,17 +81,6 @@ typedef struct spell_struct
#define SPELLHDRSZ (offsetof(SPELL, word))
/*
* If an affix uses a regex, we have to store that separately in a struct
* that won't move around when arrays of affixes are enlarged or sorted.
* This is so that it can be found to be cleaned up at context destruction.
*/
typedef struct aff_regex_struct
{
regex_t regex;
MemoryContextCallback mcallback;
} aff_regex_struct;
/*
* Represents an entry in an affix list.
*/
@ -108,7 +97,12 @@ typedef struct aff_struct
char *repl;
union
{
aff_regex_struct *pregex;
/*
* Arrays of AFFIX are moved and sorted. We'll use a pointer to
* regex_t to keep this struct small, and avoid assuming that regex_t
* is movable.
*/
regex_t *pregex;
Regis regis;
} reg;
} AFFIX;