greenplumn ts_cache 源码
greenplumn ts_cache 代码
文件路径：/src/backend/utils/cache/ts_cache.c
/*-------------------------------------------------------------------------
*
* ts_cache.c
* Tsearch related object caches.
*
* Tsearch performance is very sensitive to performance of parsers,
* dictionaries and mapping, so lookups should be cached as much
* as possible.
*
* Once a backend has created a cache entry for a particular TS object OID,
* the cache entry will exist for the life of the backend; hence it is
* safe to hold onto a pointer to the cache entry while doing things that
* might result in recognizing a cache invalidation. Beware however that
* subsidiary information might be deleted and reallocated somewhere else
* if a cache inval and reval happens! This does not look like it will be
* a big problem as long as parser and dictionary methods do not attempt
* any database access.
*
*
* Copyright (c) 2006-2019, PostgreSQL Global Development Group
*
* IDENTIFICATION
* src/backend/utils/cache/ts_cache.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/genam.h"
#include "access/htup_details.h"
#include "access/table.h"
#include "access/xact.h"
#include "catalog/indexing.h"
#include "catalog/namespace.h"
#include "catalog/pg_ts_config.h"
#include "catalog/pg_ts_config_map.h"
#include "catalog/pg_ts_dict.h"
#include "catalog/pg_ts_parser.h"
#include "catalog/pg_ts_template.h"
#include "commands/defrem.h"
#include "miscadmin.h"
#include "tsearch/ts_cache.h"
#include "utils/builtins.h"
#include "utils/catcache.h"
#include "utils/fmgroids.h"
#include "utils/inval.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
#include "utils/regproc.h"
#include "utils/syscache.h"
/*
* MAXTOKENTYPE/MAXDICTSPERTT are arbitrary limits on the workspace size
* used in lookup_ts_config_cache(). We could avoid hardwiring a limit
* by making the workspace dynamically enlargeable, but it seems unlikely
* to be worth the trouble.
*/
#define MAXTOKENTYPE 256
#define MAXDICTSPERTT 100
static HTAB *TSParserCacheHash = NULL;
static TSParserCacheEntry *lastUsedParser = NULL;
static HTAB *TSDictionaryCacheHash = NULL;
static TSDictionaryCacheEntry *lastUsedDictionary = NULL;
static HTAB *TSConfigCacheHash = NULL;
static TSConfigCacheEntry *lastUsedConfig = NULL;
/*
* GUC default_text_search_config, and a cache of the current config's OID
*/
char *TSCurrentConfig = NULL;
static Oid TSCurrentConfigCache = InvalidOid;
/*
* We use this syscache callback to detect when a visible change to a TS
* catalog entry has been made, by either our own backend or another one.
*
* In principle we could just flush the specific cache entry that changed,
* but given that TS configuration changes are probably infrequent, it
* doesn't seem worth the trouble to determine that; we just flush all the
* entries of the related hash table.
*
* We can use the same function for all TS caches by passing the hash
* table address as the "arg".
*/
static void
InvalidateTSCacheCallBack(Datum arg, int cacheid, uint32 hashvalue)
{
HTAB *hash = (HTAB *) DatumGetPointer(arg);
HASH_SEQ_STATUS status;
TSAnyCacheEntry *entry;
hash_seq_init(&status, hash);
while ((entry = (TSAnyCacheEntry *) hash_seq_search(&status)) != NULL)
entry->isvalid = false;
/* Also invalidate the current-config cache if it's pg_ts_config */
if (hash == TSConfigCacheHash)
TSCurrentConfigCache = InvalidOid;
}
/*
* Fetch parser cache entry
*/
TSParserCacheEntry *
lookup_ts_parser_cache(Oid prsId)
{
TSParserCacheEntry *entry;
if (TSParserCacheHash == NULL)
{
/* First time through: initialize the hash table */
HASHCTL ctl;
MemSet(&ctl, 0, sizeof(ctl));
ctl.keysize = sizeof(Oid);
ctl.entrysize = sizeof(TSParserCacheEntry);
TSParserCacheHash = hash_create("Tsearch parser cache", 4,
&ctl, HASH_ELEM | HASH_BLOBS);
/* Flush cache on pg_ts_parser changes */
CacheRegisterSyscacheCallback(TSPARSEROID, InvalidateTSCacheCallBack,
PointerGetDatum(TSParserCacheHash));
/* Also make sure CacheMemoryContext exists */
if (!CacheMemoryContext)
CreateCacheMemoryContext();
}
/* Check single-entry cache */
if (lastUsedParser && lastUsedParser->prsId == prsId &&
lastUsedParser->isvalid)
return lastUsedParser;
/* Try to look up an existing entry */
entry = (TSParserCacheEntry *) hash_search(TSParserCacheHash,
(void *) &prsId,
HASH_FIND, NULL);
if (entry == NULL || !entry->isvalid)
{
/*
* If we didn't find one, we want to make one. But first look up the
* object to be sure the OID is real.
*/
HeapTuple tp;
Form_pg_ts_parser prs;
tp = SearchSysCache1(TSPARSEROID, ObjectIdGetDatum(prsId));
if (!HeapTupleIsValid(tp))
elog(ERROR, "cache lookup failed for text search parser %u",
prsId);
prs = (Form_pg_ts_parser) GETSTRUCT(tp);
/*
* Sanity checks
*/
if (!OidIsValid(prs->prsstart))
elog(ERROR, "text search parser %u has no prsstart method", prsId);
if (!OidIsValid(prs->prstoken))
elog(ERROR, "text search parser %u has no prstoken method", prsId);
if (!OidIsValid(prs->prsend))
elog(ERROR, "text search parser %u has no prsend method", prsId);
if (entry == NULL)
{
bool found;
/* Now make the cache entry */
entry = (TSParserCacheEntry *)
hash_search(TSParserCacheHash,
(void *) &prsId,
HASH_ENTER, &found);
Assert(!found); /* it wasn't there a moment ago */
}
MemSet(entry, 0, sizeof(TSParserCacheEntry));
entry->prsId = prsId;
entry->startOid = prs->prsstart;
entry->tokenOid = prs->prstoken;
entry->endOid = prs->prsend;
entry->headlineOid = prs->prsheadline;
entry->lextypeOid = prs->prslextype;
ReleaseSysCache(tp);
fmgr_info_cxt(entry->startOid, &entry->prsstart, CacheMemoryContext);
fmgr_info_cxt(entry->tokenOid, &entry->prstoken, CacheMemoryContext);
fmgr_info_cxt(entry->endOid, &entry->prsend, CacheMemoryContext);
if (OidIsValid(entry->headlineOid))
fmgr_info_cxt(entry->headlineOid, &entry->prsheadline,
CacheMemoryContext);
entry->isvalid = true;
}
lastUsedParser = entry;
return entry;
}
/*
* Fetch dictionary cache entry
*/
TSDictionaryCacheEntry *
lookup_ts_dictionary_cache(Oid dictId)
{
TSDictionaryCacheEntry *entry;
if (TSDictionaryCacheHash == NULL)
{
/* First time through: initialize the hash table */
HASHCTL ctl;
MemSet(&ctl, 0, sizeof(ctl));
ctl.keysize = sizeof(Oid);
ctl.entrysize = sizeof(TSDictionaryCacheEntry);
TSDictionaryCacheHash = hash_create("Tsearch dictionary cache", 8,
&ctl, HASH_ELEM | HASH_BLOBS);
/* Flush cache on pg_ts_dict and pg_ts_template changes */
CacheRegisterSyscacheCallback(TSDICTOID, InvalidateTSCacheCallBack,
PointerGetDatum(TSDictionaryCacheHash));
CacheRegisterSyscacheCallback(TSTEMPLATEOID, InvalidateTSCacheCallBack,
PointerGetDatum(TSDictionaryCacheHash));
/* Also make sure CacheMemoryContext exists */
if (!CacheMemoryContext)
CreateCacheMemoryContext();
}
/* Check single-entry cache */
if (lastUsedDictionary && lastUsedDictionary->dictId == dictId &&
lastUsedDictionary->isvalid)
return lastUsedDictionary;
/* Try to look up an existing entry */
entry = (TSDictionaryCacheEntry *) hash_search(TSDictionaryCacheHash,
(void *) &dictId,
HASH_FIND, NULL);
if (entry == NULL || !entry->isvalid)
{
/*
* If we didn't find one, we want to make one. But first look up the
* object to be sure the OID is real.
*/
HeapTuple tpdict,
tptmpl;
Form_pg_ts_dict dict;
Form_pg_ts_template template;
MemoryContext saveCtx;
tpdict = SearchSysCache1(TSDICTOID, ObjectIdGetDatum(dictId));
if (!HeapTupleIsValid(tpdict))
elog(ERROR, "cache lookup failed for text search dictionary %u",
dictId);
dict = (Form_pg_ts_dict) GETSTRUCT(tpdict);
/*
* Sanity checks
*/
if (!OidIsValid(dict->dicttemplate))
elog(ERROR, "text search dictionary %u has no template", dictId);
/*
* Retrieve dictionary's template
*/
tptmpl = SearchSysCache1(TSTEMPLATEOID,
ObjectIdGetDatum(dict->dicttemplate));
if (!HeapTupleIsValid(tptmpl))
elog(ERROR, "cache lookup failed for text search template %u",
dict->dicttemplate);
template = (Form_pg_ts_template) GETSTRUCT(tptmpl);
/*
* Sanity checks
*/
if (!OidIsValid(template->tmpllexize))
elog(ERROR, "text search template %u has no lexize method",
template->tmpllexize);
if (entry == NULL)
{
bool found;
/* Now make the cache entry */
entry = (TSDictionaryCacheEntry *)
hash_search(TSDictionaryCacheHash,
(void *) &dictId,
HASH_ENTER, &found);
Assert(!found); /* it wasn't there a moment ago */
/* Create private memory context the first time through */
saveCtx = AllocSetContextCreate(CacheMemoryContext,
"TS dictionary",
ALLOCSET_SMALL_SIZES);
MemoryContextCopyAndSetIdentifier(saveCtx, NameStr(dict->dictname));
}
else
{
/* Clear the existing entry's private context */
saveCtx = entry->dictCtx;
/* Don't let context's ident pointer dangle while we reset it */
MemoryContextSetIdentifier(saveCtx, NULL);
MemoryContextReset(saveCtx);
MemoryContextCopyAndSetIdentifier(saveCtx, NameStr(dict->dictname));
}
MemSet(entry, 0, sizeof(TSDictionaryCacheEntry));
entry->dictId = dictId;
entry->dictCtx = saveCtx;
entry->lexizeOid = template->tmpllexize;
if (OidIsValid(template->tmplinit))
{
List *dictoptions;
Datum opt;
bool isnull;
MemoryContext oldcontext;
/*
* Init method runs in dictionary's private memory context, and we
* make sure the options are stored there too
*/
oldcontext = MemoryContextSwitchTo(entry->dictCtx);
opt = SysCacheGetAttr(TSDICTOID, tpdict,
Anum_pg_ts_dict_dictinitoption,
&isnull);
if (isnull)
dictoptions = NIL;
else
dictoptions = deserialize_deflist(opt);
entry->dictData =
DatumGetPointer(OidFunctionCall1(template->tmplinit,
PointerGetDatum(dictoptions)));
MemoryContextSwitchTo(oldcontext);
}
ReleaseSysCache(tptmpl);
ReleaseSysCache(tpdict);
fmgr_info_cxt(entry->lexizeOid, &entry->lexize, entry->dictCtx);
entry->isvalid = true;
}
lastUsedDictionary = entry;
return entry;
}
/*
* Initialize config cache and prepare callbacks. This is split out of
* lookup_ts_config_cache because we need to activate the callback before
* caching TSCurrentConfigCache, too.
*/
static void
init_ts_config_cache(void)
{
HASHCTL ctl;
MemSet(&ctl, 0, sizeof(ctl));
ctl.keysize = sizeof(Oid);
ctl.entrysize = sizeof(TSConfigCacheEntry);
TSConfigCacheHash = hash_create("Tsearch configuration cache", 16,
&ctl, HASH_ELEM | HASH_BLOBS);
/* Flush cache on pg_ts_config and pg_ts_config_map changes */
CacheRegisterSyscacheCallback(TSCONFIGOID, InvalidateTSCacheCallBack,
PointerGetDatum(TSConfigCacheHash));
CacheRegisterSyscacheCallback(TSCONFIGMAP, InvalidateTSCacheCallBack,
PointerGetDatum(TSConfigCacheHash));
/* Also make sure CacheMemoryContext exists */
if (!CacheMemoryContext)
CreateCacheMemoryContext();
}
/*
* Fetch configuration cache entry
*/
TSConfigCacheEntry *
lookup_ts_config_cache(Oid cfgId)
{
TSConfigCacheEntry *entry;
if (TSConfigCacheHash == NULL)
{
/* First time through: initialize the hash table */
init_ts_config_cache();
}
/* Check single-entry cache */
if (lastUsedConfig && lastUsedConfig->cfgId == cfgId &&
lastUsedConfig->isvalid)
return lastUsedConfig;
/* Try to look up an existing entry */
entry = (TSConfigCacheEntry *) hash_search(TSConfigCacheHash,
(void *) &cfgId,
HASH_FIND, NULL);
if (entry == NULL || !entry->isvalid)
{
/*
* If we didn't find one, we want to make one. But first look up the
* object to be sure the OID is real.
*/
HeapTuple tp;
Form_pg_ts_config cfg;
Relation maprel;
Relation mapidx;
ScanKeyData mapskey;
SysScanDesc mapscan;
HeapTuple maptup;
ListDictionary maplists[MAXTOKENTYPE + 1];
Oid mapdicts[MAXDICTSPERTT];
int maxtokentype;
int ndicts;
int i;
tp = SearchSysCache1(TSCONFIGOID, ObjectIdGetDatum(cfgId));
if (!HeapTupleIsValid(tp))
elog(ERROR, "cache lookup failed for text search configuration %u",
cfgId);
cfg = (Form_pg_ts_config) GETSTRUCT(tp);
/*
* Sanity checks
*/
if (!OidIsValid(cfg->cfgparser))
elog(ERROR, "text search configuration %u has no parser", cfgId);
if (entry == NULL)
{
bool found;
/* Now make the cache entry */
entry = (TSConfigCacheEntry *)
hash_search(TSConfigCacheHash,
(void *) &cfgId,
HASH_ENTER, &found);
Assert(!found); /* it wasn't there a moment ago */
}
else
{
/* Cleanup old contents */
if (entry->map)
{
for (i = 0; i < entry->lenmap; i++)
if (entry->map[i].dictIds)
pfree(entry->map[i].dictIds);
pfree(entry->map);
}
}
MemSet(entry, 0, sizeof(TSConfigCacheEntry));
entry->cfgId = cfgId;
entry->prsId = cfg->cfgparser;
ReleaseSysCache(tp);
/*
* Scan pg_ts_config_map to gather dictionary list for each token type
*
* Because the index is on (mapcfg, maptokentype, mapseqno), we will
* see the entries in maptokentype order, and in mapseqno order for
* each token type, even though we didn't explicitly ask for that.
*/
MemSet(maplists, 0, sizeof(maplists));
maxtokentype = 0;
ndicts = 0;
ScanKeyInit(&mapskey,
Anum_pg_ts_config_map_mapcfg,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(cfgId));
maprel = table_open(TSConfigMapRelationId, AccessShareLock);
mapidx = index_open(TSConfigMapIndexId, AccessShareLock);
mapscan = systable_beginscan_ordered(maprel, mapidx,
NULL, 1, &mapskey);
while ((maptup = systable_getnext_ordered(mapscan, ForwardScanDirection)) != NULL)
{
Form_pg_ts_config_map cfgmap = (Form_pg_ts_config_map) GETSTRUCT(maptup);
int toktype = cfgmap->maptokentype;
if (toktype <= 0 || toktype > MAXTOKENTYPE)
elog(ERROR, "maptokentype value %d is out of range", toktype);
if (toktype < maxtokentype)
elog(ERROR, "maptokentype entries are out of order");
if (toktype > maxtokentype)
{
/* starting a new token type, but first save the prior data */
if (ndicts > 0)
{
maplists[maxtokentype].len = ndicts;
maplists[maxtokentype].dictIds = (Oid *)
MemoryContextAlloc(CacheMemoryContext,
sizeof(Oid) * ndicts);
memcpy(maplists[maxtokentype].dictIds, mapdicts,
sizeof(Oid) * ndicts);
}
maxtokentype = toktype;
mapdicts[0] = cfgmap->mapdict;
ndicts = 1;
}
else
{
/* continuing data for current token type */
if (ndicts >= MAXDICTSPERTT)
elog(ERROR, "too many pg_ts_config_map entries for one token type");
mapdicts[ndicts++] = cfgmap->mapdict;
}
}
systable_endscan_ordered(mapscan);
index_close(mapidx, AccessShareLock);
table_close(maprel, AccessShareLock);
if (ndicts > 0)
{
/* save the last token type's dictionaries */
maplists[maxtokentype].len = ndicts;
maplists[maxtokentype].dictIds = (Oid *)
MemoryContextAlloc(CacheMemoryContext,
sizeof(Oid) * ndicts);
memcpy(maplists[maxtokentype].dictIds, mapdicts,
sizeof(Oid) * ndicts);
/* and save the overall map */
entry->lenmap = maxtokentype + 1;
entry->map = (ListDictionary *)
MemoryContextAlloc(CacheMemoryContext,
sizeof(ListDictionary) * entry->lenmap);
memcpy(entry->map, maplists,
sizeof(ListDictionary) * entry->lenmap);
}
entry->isvalid = true;
}
lastUsedConfig = entry;
return entry;
}
/*---------------------------------------------------
* GUC variable "default_text_search_config"
*---------------------------------------------------
*/
Oid
getTSCurrentConfig(bool emitError)
{
/* if we have a cached value, return it */
if (OidIsValid(TSCurrentConfigCache))
return TSCurrentConfigCache;
/* fail if GUC hasn't been set up yet */
if (TSCurrentConfig == NULL || *TSCurrentConfig == '\0')
{
if (emitError)
elog(ERROR, "text search configuration isn't set");
else
return InvalidOid;
}
if (TSConfigCacheHash == NULL)
{
/* First time through: initialize the tsconfig inval callback */
init_ts_config_cache();
}
/* Look up the config */
TSCurrentConfigCache =
get_ts_config_oid(stringToQualifiedNameList(TSCurrentConfig),
!emitError);
return TSCurrentConfigCache;
}
/* GUC check_hook for default_text_search_config */
bool
check_TSCurrentConfig(char **newval, void **extra, GucSource source)
{
/*
* If we aren't inside a transaction, or connected to a database, we
* cannot do the catalog accesses necessary to verify the config name.
* Must accept it on faith.
*/
if (IsTransactionState() && MyDatabaseId != InvalidOid)
{
Oid cfgId;
HeapTuple tuple;
Form_pg_ts_config cfg;
char *buf;
cfgId = get_ts_config_oid(stringToQualifiedNameList(*newval), true);
/*
* When source == PGC_S_TEST, don't throw a hard error for a
* nonexistent configuration, only a NOTICE. See comments in guc.h.
*/
if (!OidIsValid(cfgId))
{
if (source == PGC_S_TEST)
{
ereport(NOTICE,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("text search configuration \"%s\" does not exist", *newval)));
return true;
}
else
return false;
}
/*
* Modify the actually stored value to be fully qualified, to ensure
* later changes of search_path don't affect it.
*/
tuple = SearchSysCache1(TSCONFIGOID, ObjectIdGetDatum(cfgId));
if (!HeapTupleIsValid(tuple))
elog(ERROR, "cache lookup failed for text search configuration %u",
cfgId);
cfg = (Form_pg_ts_config) GETSTRUCT(tuple);
buf = quote_qualified_identifier(get_namespace_name(cfg->cfgnamespace),
NameStr(cfg->cfgname));
ReleaseSysCache(tuple);
/* GUC wants it malloc'd not palloc'd */
free(*newval);
*newval = strdup(buf);
pfree(buf);
if (!*newval)
return false;
}
return true;
}
/* GUC assign_hook for default_text_search_config */
void
assign_TSCurrentConfig(const char *newval, void *extra)
{
/* Just reset the cache to force a lookup on first use */
TSCurrentConfigCache = InvalidOid;
}
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