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Rationalize format-picture caching logic in formatting.c.

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Add a validity flag to DCHCacheEntry and NUMCacheEntry entries, and
do not set it true until after we've parsed the supplied format string.
This allows dealing with possible errors while parsing the format
without the baroque hack that was there before (which only covered
errors within NUMDesc_prepare, anyway).  We can get rid of the PG_TRY in
NUMDesc_prepare, as well as last_NUMCacheEntry and NUM_cache_remove.
(Essentially, this reverts commit ff783fbae in favor of a less fragile
solution; the problems with that approach are well illustrated by later
hacking such as 55f927a46.)

In passing, define the size of these caches as DCH_CACHE_ENTRIES not
DCH_CACHE_FIELDS + 1 (whoever thought that was a good definition?)
and likewise for the NUM cache.  Also const-ify format string parameters
where convenient, and merge duplicated cache lookup logic.

This is primarily driven by a proposed patch from Artur Zakirov,
which introduced some ereport's into format string parsing for
the datetime case.  He proposed preventing the creation of invalid
cache entries by parsing the format string first into a local-variable
array, and then copying that to a cache entry.  That seemed a bit
ugly to me, and anyway randomly different from the way the identical
problem had been solved for the numeric case.  Let's make the two
sets of code more similar not less so.

I'm not sure whether we'll adopt the new error conditions Artur proposes,
but this patch seems like good code cleanup and future-proofing in any
case.  The existing code is critically (and undocumented-ly) dependent on
no elog being thrown out of several nontrivial functions, which is trouble
waiting to happen, though it doesn't seem to be actively broken today.

Discussion: <b2a39359-3282-b402-f4a3-057aae500ee7@postgrespro.ru>
pull/17/head
Tom Lane 9 years ago
parent d3cd36a133
commit 83bed06be4
1 changed files with 292 additions and 310 deletions
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
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  1. 602
      src/backend/utils/adt/formatting.c

602
src/backend/utils/adt/formatting.c
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@ -354,21 +354,27 @@ typedef struct
/* ----------
* Format picture cache
* (cache size:
* Number part = NUM_CACHE_SIZE * NUM_CACHE_FIELDS
* Date-time part = DCH_CACHE_SIZE * DCH_CACHE_FIELDS
* )
*
* We will cache datetime format pictures up to DCH_CACHE_SIZE bytes long;
* likewise number format pictures up to NUM_CACHE_SIZE bytes long.
*
* For simplicity, the cache entries are fixed-size, so they allow for the
* worst case of a FormatNode for each byte in the picture string.
*
* The max number of entries in the caches is DCH_CACHE_ENTRIES
* resp. NUM_CACHE_ENTRIES.
* ----------
*/
#define NUM_CACHE_SIZE 64
#define NUM_CACHE_FIELDS 16
#define NUM_CACHE_ENTRIES 20
#define DCH_CACHE_SIZE 128
#define DCH_CACHE_FIELDS 16
#define DCH_CACHE_ENTRIES 20
typedef struct
{
FormatNode format[DCH_CACHE_SIZE + 1];
char str[DCH_CACHE_SIZE + 1];
bool valid;
int age;
} DCHCacheEntry;
@ -376,22 +382,20 @@ typedef struct
{
FormatNode format[NUM_CACHE_SIZE + 1];
char str[NUM_CACHE_SIZE + 1];
bool valid;
int age;
NUMDesc Num;
} NUMCacheEntry;
/* global cache for --- date/time part */
static DCHCacheEntry DCHCache[DCH_CACHE_FIELDS + 1];
static int n_DCHCache = 0; /* number of entries */
static int DCHCounter = 0;
/* global cache for --- number part */
static NUMCacheEntry NUMCache[NUM_CACHE_FIELDS + 1];
/* global cache for date/time format pictures */
static DCHCacheEntry DCHCache[DCH_CACHE_ENTRIES];
static int n_DCHCache = 0; /* current number of entries */
static int DCHCounter = 0; /* aging-event counter */
static int n_NUMCache = 0; /* number of entries */
static int NUMCounter = 0;
static NUMCacheEntry *last_NUMCacheEntry = NUMCache + 0;
/* global cache for number format pictures */
static NUMCacheEntry NUMCache[NUM_CACHE_ENTRIES];
static int n_NUMCache = 0; /* current number of entries */
static int NUMCounter = 0; /* aging-event counter */
/* ----------
* For char->date/time conversion
@ -944,11 +948,11 @@ typedef struct NUMProc
* Functions
* ----------
*/
static const KeyWord *index_seq_search(char *str, const KeyWord *kw,
static const KeyWord *index_seq_search(const char *str, const KeyWord *kw,
const int *index);
static const KeySuffix *suff_search(char *str, const KeySuffix *suf, int type);
static const KeySuffix *suff_search(const char *str, const KeySuffix *suf, int type);
static void NUMDesc_prepare(NUMDesc *num, FormatNode *n);
static void parse_format(FormatNode *node, char *str, const KeyWord *kw,
static void parse_format(FormatNode *node, const char *str, const KeyWord *kw,
const KeySuffix *suf, const int *index, int ver, NUMDesc *Num);
static void DCH_to_char(FormatNode *node, bool is_interval,
@ -982,12 +986,12 @@ static void NUM_numpart_to_char(NUMProc *Np, int id);
static char *NUM_processor(FormatNode *node, NUMDesc *Num, char *inout,
char *number, int from_char_input_len, int to_char_out_pre_spaces,
int sign, bool is_to_char, Oid collid);
static DCHCacheEntry *DCH_cache_search(char *str);
static DCHCacheEntry *DCH_cache_getnew(char *str);
static NUMCacheEntry *NUM_cache_search(char *str);
static NUMCacheEntry *NUM_cache_getnew(char *str);
static void NUM_cache_remove(NUMCacheEntry *ent);
static DCHCacheEntry *DCH_cache_getnew(const char *str);
static DCHCacheEntry *DCH_cache_search(const char *str);
static DCHCacheEntry *DCH_cache_fetch(const char *str);
static NUMCacheEntry *NUM_cache_getnew(const char *str);
static NUMCacheEntry *NUM_cache_search(const char *str);
static NUMCacheEntry *NUM_cache_fetch(const char *str);
/* ----------
@ -997,7 +1001,7 @@ static void NUM_cache_remove(NUMCacheEntry *ent);
* ----------
*/
static const KeyWord *
index_seq_search(char *str, const KeyWord *kw, const int *index)
index_seq_search(const char *str, const KeyWord *kw, const int *index)
{
int poz;
@ -1021,7 +1025,7 @@ index_seq_search(char *str, const KeyWord *kw, const int *index)
}
static const KeySuffix *
suff_search(char *str, const KeySuffix *suf, int type)
suff_search(const char *str, const KeySuffix *suf, int type)
{
const KeySuffix *s;
@ -1046,182 +1050,166 @@ NUMDesc_prepare(NUMDesc *num, FormatNode *n)
if (n->type != NODE_TYPE_ACTION)
return;
/*
* In case of an error, we need to remove the numeric from the cache. Use
* a PG_TRY block to ensure that this happens.
*/
PG_TRY();
{
if (IS_EEEE(num) && n->key->id != NUM_E)
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("\"EEEE\" must be the last pattern used")));
switch (n->key->id)
{
case NUM_9:
if (IS_BRACKET(num))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("\"9\" must be ahead of \"PR\"")));
if (IS_MULTI(num))
{
++num->multi;
break;
}
if (IS_DECIMAL(num))
++num->post;
else
++num->pre;
break;
case NUM_0:
if (IS_BRACKET(num))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("\"0\" must be ahead of \"PR\"")));
if (!IS_ZERO(num) && !IS_DECIMAL(num))
{
num->flag |= NUM_F_ZERO;
num->zero_start = num->pre + 1;
}
if (!IS_DECIMAL(num))
++num->pre;
else
++num->post;
num->zero_end = num->pre + num->post;
break;
if (IS_EEEE(num) && n->key->id != NUM_E)
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("\"EEEE\" must be the last pattern used")));
case NUM_B:
if (num->pre == 0 && num->post == 0 && (!IS_ZERO(num)))
num->flag |= NUM_F_BLANK;
switch (n->key->id)
{
case NUM_9:
if (IS_BRACKET(num))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("\"9\" must be ahead of \"PR\"")));
if (IS_MULTI(num))
{
++num->multi;
break;
}
if (IS_DECIMAL(num))
++num->post;
else
++num->pre;
break;
case NUM_D:
num->flag |= NUM_F_LDECIMAL;
num->need_locale = TRUE;
/* FALLTHROUGH */
case NUM_DEC:
if (IS_DECIMAL(num))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("multiple decimal points")));
if (IS_MULTI(num))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
case NUM_0:
if (IS_BRACKET(num))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("\"0\" must be ahead of \"PR\"")));
if (!IS_ZERO(num) && !IS_DECIMAL(num))
{
num->flag |= NUM_F_ZERO;
num->zero_start = num->pre + 1;
}
if (!IS_DECIMAL(num))
++num->pre;
else
++num->post;
num->zero_end = num->pre + num->post;
break;
case NUM_B:
if (num->pre == 0 && num->post == 0 && (!IS_ZERO(num)))
num->flag |= NUM_F_BLANK;
break;
case NUM_D:
num->flag |= NUM_F_LDECIMAL;
num->need_locale = TRUE;
/* FALLTHROUGH */
case NUM_DEC:
if (IS_DECIMAL(num))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("multiple decimal points")));
if (IS_MULTI(num))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("cannot use \"V\" and decimal point together")));
num->flag |= NUM_F_DECIMAL;
break;
case NUM_FM:
num->flag |= NUM_F_FILLMODE;
break;
num->flag |= NUM_F_DECIMAL;
break;
case NUM_S:
if (IS_LSIGN(num))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("cannot use \"S\" twice")));
if (IS_PLUS(num) || IS_MINUS(num) || IS_BRACKET(num))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("cannot use \"S\" and \"PL\"/\"MI\"/\"SG\"/\"PR\" together")));
if (!IS_DECIMAL(num))
{
num->lsign = NUM_LSIGN_PRE;
num->pre_lsign_num = num->pre;
num->need_locale = TRUE;
num->flag |= NUM_F_LSIGN;
}
else if (num->lsign == NUM_LSIGN_NONE)
{
num->lsign = NUM_LSIGN_POST;
num->need_locale = TRUE;
num->flag |= NUM_F_LSIGN;
}
break;
case NUM_MI:
if (IS_LSIGN(num))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("cannot use \"S\" and \"MI\" together")));
num->flag |= NUM_F_MINUS;
if (IS_DECIMAL(num))
num->flag |= NUM_F_MINUS_POST;
break;
case NUM_PL:
if (IS_LSIGN(num))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("cannot use \"S\" and \"PL\" together")));
num->flag |= NUM_F_PLUS;
if (IS_DECIMAL(num))
num->flag |= NUM_F_PLUS_POST;
break;
case NUM_SG:
if (IS_LSIGN(num))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("cannot use \"S\" and \"SG\" together")));
num->flag |= NUM_F_MINUS;
num->flag |= NUM_F_PLUS;
break;
case NUM_PR:
if (IS_LSIGN(num) || IS_PLUS(num) || IS_MINUS(num))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("cannot use \"PR\" and \"S\"/\"PL\"/\"MI\"/\"SG\" together")));
num->flag |= NUM_F_BRACKET;
break;
case NUM_rn:
case NUM_RN:
num->flag |= NUM_F_ROMAN;
break;
case NUM_FM:
num->flag |= NUM_F_FILLMODE;
break;
case NUM_L:
case NUM_G:
case NUM_S:
if (IS_LSIGN(num))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("cannot use \"S\" twice")));
if (IS_PLUS(num) || IS_MINUS(num) || IS_BRACKET(num))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("cannot use \"S\" and \"PL\"/\"MI\"/\"SG\"/\"PR\" together")));
if (!IS_DECIMAL(num))
{
num->lsign = NUM_LSIGN_PRE;
num->pre_lsign_num = num->pre;
num->need_locale = TRUE;
break;
num->flag |= NUM_F_LSIGN;
}
else if (num->lsign == NUM_LSIGN_NONE)
{
num->lsign = NUM_LSIGN_POST;
num->need_locale = TRUE;
num->flag |= NUM_F_LSIGN;
}
break;
case NUM_V:
if (IS_DECIMAL(num))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
case NUM_MI:
if (IS_LSIGN(num))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("cannot use \"S\" and \"MI\" together")));
num->flag |= NUM_F_MINUS;
if (IS_DECIMAL(num))
num->flag |= NUM_F_MINUS_POST;
break;
case NUM_PL:
if (IS_LSIGN(num))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("cannot use \"S\" and \"PL\" together")));
num->flag |= NUM_F_PLUS;
if (IS_DECIMAL(num))
num->flag |= NUM_F_PLUS_POST;
break;
case NUM_SG:
if (IS_LSIGN(num))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("cannot use \"S\" and \"SG\" together")));
num->flag |= NUM_F_MINUS;
num->flag |= NUM_F_PLUS;
break;
case NUM_PR:
if (IS_LSIGN(num) || IS_PLUS(num) || IS_MINUS(num))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("cannot use \"PR\" and \"S\"/\"PL\"/\"MI\"/\"SG\" together")));
num->flag |= NUM_F_BRACKET;
break;
case NUM_rn:
case NUM_RN:
num->flag |= NUM_F_ROMAN;
break;
case NUM_L:
case NUM_G:
num->need_locale = TRUE;
break;
case NUM_V:
if (IS_DECIMAL(num))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("cannot use \"V\" and decimal point together")));
num->flag |= NUM_F_MULTI;
break;
num->flag |= NUM_F_MULTI;
break;
case NUM_E:
if (IS_EEEE(num))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("cannot use \"EEEE\" twice")));
if (IS_BLANK(num) || IS_FILLMODE(num) || IS_LSIGN(num) ||
IS_BRACKET(num) || IS_MINUS(num) || IS_PLUS(num) ||
IS_ROMAN(num) || IS_MULTI(num))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
case NUM_E:
if (IS_EEEE(num))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("cannot use \"EEEE\" twice")));
if (IS_BLANK(num) || IS_FILLMODE(num) || IS_LSIGN(num) ||
IS_BRACKET(num) || IS_MINUS(num) || IS_PLUS(num) ||
IS_ROMAN(num) || IS_MULTI(num))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("\"EEEE\" is incompatible with other formats"),
errdetail("\"EEEE\" may only be used together with digit and decimal point patterns.")));
num->flag |= NUM_F_EEEE;
break;
}
}
PG_CATCH();
{
NUM_cache_remove(last_NUMCacheEntry);
PG_RE_THROW();
errdetail("\"EEEE\" may only be used together with digit and decimal point patterns.")));
num->flag |= NUM_F_EEEE;
break;
}
PG_END_TRY();
return;
}
/* ----------
@ -1232,7 +1220,7 @@ NUMDesc_prepare(NUMDesc *num, FormatNode *n)
* ----------
*/
static void
parse_format(FormatNode *node, char *str, const KeyWord *kw,
parse_format(FormatNode *node, const char *str, const KeyWord *kw,
const KeySuffix *suf, const int *index, int ver, NUMDesc *Num)
{
const KeySuffix *s;
@ -1350,7 +1338,6 @@ parse_format(FormatNode *node, char *str, const KeyWord *kw,
n->type = NODE_TYPE_END;
n->suffix = 0;
return;
}
/* ----------
@ -3210,41 +3197,51 @@ DCH_from_char(FormatNode *node, char *in, TmFromChar *out)
}
}
/* select a DCHCacheEntry to hold the given format picture */
static DCHCacheEntry *
DCH_cache_getnew(char *str)
DCH_cache_getnew(const char *str)
{
DCHCacheEntry *ent;
/* counter overflow check - paranoia? */
if (DCHCounter >= (INT_MAX - DCH_CACHE_FIELDS - 1))
if (DCHCounter >= (INT_MAX - DCH_CACHE_ENTRIES))
{
DCHCounter = 0;
for (ent = DCHCache; ent <= (DCHCache + DCH_CACHE_FIELDS); ent++)
for (ent = DCHCache; ent < (DCHCache + DCH_CACHE_ENTRIES); ent++)
ent->age = (++DCHCounter);
}
/*
* If cache is full, remove oldest entry
* If cache is full, remove oldest entry (or recycle first not-valid one)
*/
if (n_DCHCache > DCH_CACHE_FIELDS)
if (n_DCHCache >= DCH_CACHE_ENTRIES)
{
DCHCacheEntry *old = DCHCache + 0;
#ifdef DEBUG_TO_FROM_CHAR
elog(DEBUG_elog_output, "cache is full (%d)", n_DCHCache);
#endif
for (ent = DCHCache + 1; ent <= (DCHCache + DCH_CACHE_FIELDS); ent++)
if (old->valid)
{
if (ent->age < old->age)
old = ent;
for (ent = DCHCache + 1; ent < (DCHCache + DCH_CACHE_ENTRIES); ent++)
{
if (!ent->valid)
{
old = ent;
break;
}
if (ent->age < old->age)
old = ent;
}
}
#ifdef DEBUG_TO_FROM_CHAR
elog(DEBUG_elog_output, "OLD: '%s' AGE: %d", old->str, old->age);
#endif
old->valid = false;
StrNCpy(old->str, str, DCH_CACHE_SIZE + 1);
/* old->format fill parser */
old->age = (++DCHCounter);
/* caller is expected to fill format, then set valid */
return old;
}
else
@ -3253,32 +3250,34 @@ DCH_cache_getnew(char *str)
elog(DEBUG_elog_output, "NEW (%d)", n_DCHCache);
#endif
ent = DCHCache + n_DCHCache;
ent->valid = false;
StrNCpy(ent->str, str, DCH_CACHE_SIZE + 1);
/* ent->format fill parser */
ent->age = (++DCHCounter);
/* caller is expected to fill format, then set valid */
++n_DCHCache;
return ent;
}
}
/* look for an existing DCHCacheEntry matching the given format picture */
static DCHCacheEntry *
DCH_cache_search(char *str)
DCH_cache_search(const char *str)
{
int i;
DCHCacheEntry *ent;
/* counter overflow check - paranoia? */
if (DCHCounter >= (INT_MAX - DCH_CACHE_FIELDS - 1))
if (DCHCounter >= (INT_MAX - DCH_CACHE_ENTRIES))
{
DCHCounter = 0;
for (ent = DCHCache; ent <= (DCHCache + DCH_CACHE_FIELDS); ent++)
for (ent = DCHCache; ent < (DCHCache + DCH_CACHE_ENTRIES); ent++)
ent->age = (++DCHCounter);
}
for (i = 0, ent = DCHCache; i < n_DCHCache; i++, ent++)
{
if (strcmp(ent->str, str) == 0)
if (ent->valid && strcmp(ent->str, str) == 0)
{
ent->age = (++DCHCounter);
return ent;
@ -3288,6 +3287,29 @@ DCH_cache_search(char *str)
return NULL;
}
/* Find or create a DCHCacheEntry for the given format picture */
static DCHCacheEntry *
DCH_cache_fetch(const char *str)
{
DCHCacheEntry *ent;
if ((ent = DCH_cache_search(str)) == NULL)
{
/*
* Not in the cache, must run parser and save a new format-picture to
* the cache. Do not mark the cache entry valid until parsing
* succeeds.
*/
ent = DCH_cache_getnew(str);
parse_format(ent->format, str, DCH_keywords,
DCH_suff, DCH_index, DCH_TYPE, NULL);
ent->valid = true;
}
return ent;
}
/*
* Format a date/time or interval into a string according to fmt.
* We parse fmt into a list of FormatNodes. This is then passed to DCH_to_char
@ -3315,47 +3337,27 @@ datetime_to_char_body(TmToChar *tmtc, text *fmt, bool is_interval, Oid collid)
result = palloc((fmt_len * DCH_MAX_ITEM_SIZ) + 1);
*result = '\0';
/*
* Allocate new memory if format picture is bigger than static cache and
* not use cache (call parser always)
*/
if (fmt_len > DCH_CACHE_SIZE)
{
format = (FormatNode *) palloc((fmt_len + 1) * sizeof(FormatNode));
/*
* Allocate new memory if format picture is bigger than static cache
* and do not use cache (call parser always)
*/
incache = FALSE;
format = (FormatNode *) palloc((fmt_len + 1) * sizeof(FormatNode));
parse_format(format, fmt_str, DCH_keywords,
DCH_suff, DCH_index, DCH_TYPE, NULL);
(format + fmt_len)->type = NODE_TYPE_END; /* Paranoia? */
}
else
{
/*
* Use cache buffers
*/
DCHCacheEntry *ent;
DCHCacheEntry *ent = DCH_cache_fetch(fmt_str);
incache = TRUE;
if ((ent = DCH_cache_search(fmt_str)) == NULL)
{
ent = DCH_cache_getnew(fmt_str);
/*
* Not in the cache, must run parser and save a new format-picture
* to the cache.
*/
parse_format(ent->format, fmt_str, DCH_keywords,
DCH_suff, DCH_index, DCH_TYPE, NULL);
(ent->format + fmt_len)->type = NODE_TYPE_END; /* Paranoia? */
#ifdef DEBUG_TO_FROM_CHAR
/* dump_node(ent->format, fmt_len); */
/* dump_index(DCH_keywords, DCH_index); */
#endif
}
format = ent->format;
}
@ -3584,7 +3586,7 @@ do_to_timestamp(text *date_txt, text *fmt,
{
/*
* Allocate new memory if format picture is bigger than static
* cache and not use cache (call parser always)
* cache and do not use cache (call parser always)
*/
incache = FALSE;
@ -3592,31 +3594,15 @@ do_to_timestamp(text *date_txt, text *fmt,
parse_format(format, fmt_str, DCH_keywords,
DCH_suff, DCH_index, DCH_TYPE, NULL);
(format + fmt_len)->type = NODE_TYPE_END; /* Paranoia? */
}
else
{
/*
* Use cache buffers
*/
DCHCacheEntry *ent;
DCHCacheEntry *ent = DCH_cache_fetch(fmt_str);
incache = TRUE;
if ((ent = DCH_cache_search(fmt_str)) == NULL)
{
/*
* Not in the cache, must run parser and save a new
* format-picture to the cache.
*/
ent = DCH_cache_getnew(fmt_str);
parse_format(ent->format, fmt_str, DCH_keywords,
DCH_suff, DCH_index, DCH_TYPE, NULL);
(ent->format + fmt_len)->type = NODE_TYPE_END; /* Paranoia? */
}
format = ent->format;
}
@ -3878,51 +3864,52 @@ do { \
(_n)->zero_end = 0; \
} while(0)
/* select a NUMCacheEntry to hold the given format picture */
static NUMCacheEntry *
NUM_cache_getnew(char *str)
NUM_cache_getnew(const char *str)
{
NUMCacheEntry *ent;
/* counter overflow check - paranoia? */
if (NUMCounter >= (INT_MAX - NUM_CACHE_FIELDS - 1))
if (NUMCounter >= (INT_MAX - NUM_CACHE_ENTRIES))
{
NUMCounter = 0;
for (ent = NUMCache; ent <= (NUMCache + NUM_CACHE_FIELDS); ent++)
for (ent = NUMCache; ent < (NUMCache + NUM_CACHE_ENTRIES); ent++)
ent->age = (++NUMCounter);
}
/*
* If cache is full, remove oldest entry
* If cache is full, remove oldest entry (or recycle first not-valid one)
*/
if (n_NUMCache > NUM_CACHE_FIELDS)
if (n_NUMCache >= NUM_CACHE_ENTRIES)
{
NUMCacheEntry *old = NUMCache + 0;
#ifdef DEBUG_TO_FROM_CHAR
elog(DEBUG_elog_output, "Cache is full (%d)", n_NUMCache);
#endif
for (ent = NUMCache; ent <= (NUMCache + NUM_CACHE_FIELDS); ent++)
if (old->valid)
{
/*
* entry removed via NUM_cache_remove() can be used here, which is
* why it's worth scanning first entry again
*/
if (ent->str[0] == '\0')
for (ent = NUMCache + 1; ent < (NUMCache + NUM_CACHE_ENTRIES); ent++)
{
old = ent;
break;
if (!ent->valid)
{
old = ent;
break;
}
if (ent->age < old->age)
old = ent;
}
if (ent->age < old->age)
old = ent;
}
#ifdef DEBUG_TO_FROM_CHAR
elog(DEBUG_elog_output, "OLD: \"%s\" AGE: %d", old->str, old->age);
#endif
old->valid = false;
StrNCpy(old->str, str, NUM_CACHE_SIZE + 1);
/* old->format fill parser */
old->age = (++NUMCounter);
ent = old;
/* caller is expected to fill format and Num, then set valid */
return old;
}
else
{
@ -3930,39 +3917,36 @@ NUM_cache_getnew(char *str)
elog(DEBUG_elog_output, "NEW (%d)", n_NUMCache);
#endif
ent = NUMCache + n_NUMCache;
ent->valid = false;
StrNCpy(ent->str, str, NUM_CACHE_SIZE + 1);
/* ent->format fill parser */
ent->age = (++NUMCounter);
/* caller is expected to fill format and Num, then set valid */
++n_NUMCache;
return ent;
}
zeroize_NUM(&ent->Num);
last_NUMCacheEntry = ent;
return ent;
}
/* look for an existing NUMCacheEntry matching the given format picture */
static NUMCacheEntry *
NUM_cache_search(char *str)
NUM_cache_search(const char *str)
{
int i;
NUMCacheEntry *ent;
/* counter overflow check - paranoia? */
if (NUMCounter >= (INT_MAX - NUM_CACHE_FIELDS - 1))
if (NUMCounter >= (INT_MAX - NUM_CACHE_ENTRIES))
{
NUMCounter = 0;
for (ent = NUMCache; ent <= (NUMCache + NUM_CACHE_FIELDS); ent++)
for (ent = NUMCache; ent < (NUMCache + NUM_CACHE_ENTRIES); ent++)
ent->age = (++NUMCounter);
}
for (i = 0, ent = NUMCache; i < n_NUMCache; i++, ent++)
{
if (strcmp(ent->str, str) == 0)
if (ent->valid && strcmp(ent->str, str) == 0)
{
ent->age = (++NUMCounter);
last_NUMCacheEntry = ent;
return ent;
}
}
@ -3970,14 +3954,29 @@ NUM_cache_search(char *str)
return NULL;
}
static void
NUM_cache_remove(NUMCacheEntry *ent)
/* Find or create a NUMCacheEntry for the given format picture */
static NUMCacheEntry *
NUM_cache_fetch(const char *str)
{
#ifdef DEBUG_TO_FROM_CHAR
elog(DEBUG_elog_output, "REMOVING ENTRY (%s)", ent->str);
#endif
ent->str[0] = '\0';
ent->age = 0;
NUMCacheEntry *ent;
if ((ent = NUM_cache_search(str)) == NULL)
{
/*
* Not in the cache, must run parser and save a new format-picture to
* the cache. Do not mark the cache entry valid until parsing
* succeeds.
*/
ent = NUM_cache_getnew(str);
zeroize_NUM(&ent->Num);
parse_format(ent->format, str, NUM_keywords,
NULL, NUM_index, NUM_TYPE, &ent->Num);
ent->valid = true;
}
return ent;
}
/* ----------
@ -3992,13 +3991,12 @@ NUM_cache(int len, NUMDesc *Num, text *pars_str, bool *shouldFree)
str = text_to_cstring(pars_str);
/*
* Allocate new memory if format picture is bigger than static cache and
* not use cache (call parser always). This branches sets shouldFree to
* true, accordingly.
*/
if (len > NUM_CACHE_SIZE)
{
/*
* Allocate new memory if format picture is bigger than static cache
* and do not use cache (call parser always)
*/
format = (FormatNode *) palloc((len + 1) * sizeof(FormatNode));
*shouldFree = true;
@ -4007,32 +4005,16 @@ NUM_cache(int len, NUMDesc *Num, text *pars_str, bool *shouldFree)
parse_format(format, str, NUM_keywords,
NULL, NUM_index, NUM_TYPE, Num);
(format + len)->type = NODE_TYPE_END; /* Paranoia? */
}
else
{
/*
* Use cache buffers
*/
NUMCacheEntry *ent;
NUMCacheEntry *ent = NUM_cache_fetch(str);
*shouldFree = false;
if ((ent = NUM_cache_search(str)) == NULL)
{
ent = NUM_cache_getnew(str);
/*
* Not in the cache, must run parser and save a new format-picture
* to the cache.
*/
parse_format(ent->format, str, NUM_keywords,
NULL, NUM_index, NUM_TYPE, &ent->Num);
(ent->format + len)->type = NODE_TYPE_END; /* Paranoia? */
}
format = ent->format;
/*

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