void
initSpGistState(SpGistState *state, Relation index)
{
RegProcedure propOid;
Assert(index->rd_att->natts == 1);
propOid = index_getprocid(index, 1, SPGIST_PROP_PROC);
state->prop = *(SpGistOpClassProp*)DatumGetPointer(OidFunctionCall0Coll(propOid, InvalidOid));
fillTypeDesc(&state->attType, state->prop.leafType);
fillTypeDesc(&state->attNodeType, state->prop.nodeType);
fillTypeDesc(&state->attPrefixType, state->prop.prefixType);
fmgr_info_copy(&(state->chooseFn),
index_getprocinfo(index, 1, SPGIST_CHOOSE_PROC),
CurrentMemoryContext);
fmgr_info_copy(&(state->picksplitFn),
index_getprocinfo(index, 1, SPGIST_PICKSPLIT_PROC),
CurrentMemoryContext);
fmgr_info_copy(&(state->leafConsistentFn),
index_getprocinfo(index, 1, SPGIST_LEAFCONS_PROC),
CurrentMemoryContext);
fmgr_info_copy(&(state->innerConsistentFn),
index_getprocinfo(index, 1, SPGIST_INNERCONS_PROC),
CurrentMemoryContext);
state->nodeTupDesc = CreateTemplateTupleDesc(1, false);
TupleDescInitEntry(state->nodeTupDesc, (AttrNumber) 1, NULL,
state->attNodeType.type, -1, 0);
}
/*
* Fetch local cache of AM-specific info about the index, initializing it
* if necessary
*/
SpGistCache *
spgGetCache(Relation index)
{
SpGistCache *cache;
if (index->rd_amcache == NULL)
{
Oid atttype;
spgConfigIn in;
FmgrInfo *procinfo;
Buffer metabuffer;
SpGistMetaPageData *metadata;
cache = MemoryContextAllocZero(index->rd_indexcxt,
sizeof(SpGistCache));
/* SPGiST doesn't support multi-column indexes */
Assert(index->rd_att->natts == 1);
/*
* Get the actual data type of the indexed column from the index
* tupdesc. We pass this to the opclass config function so that
* polymorphic opclasses are possible.
*/
atttype = index->rd_att->attrs[0]->atttypid;
/* Call the config function to get config info for the opclass */
in.attType = atttype;
procinfo = index_getprocinfo(index, 1, SPGIST_CONFIG_PROC);
FunctionCall2Coll(procinfo,
index->rd_indcollation[0],
PointerGetDatum(&in),
PointerGetDatum(&cache->config));
/* Get the information we need about each relevant datatype */
fillTypeDesc(&cache->attType, atttype);
fillTypeDesc(&cache->attPrefixType, cache->config.prefixType);
fillTypeDesc(&cache->attLabelType, cache->config.labelType);
/* Last, get the lastUsedPages data from the metapage */
metabuffer = ReadBuffer(index, SPGIST_METAPAGE_BLKNO);
LockBuffer(metabuffer, BUFFER_LOCK_SHARE);
metadata = SpGistPageGetMeta(BufferGetPage(metabuffer));
if (metadata->magicNumber != SPGIST_MAGIC_NUMBER)
elog(ERROR, "index \"%s\" is not an SP-GiST index",
RelationGetRelationName(index));
cache->lastUsedPages = metadata->lastUsedPages;
UnlockReleaseBuffer(metabuffer);
index->rd_amcache = (void *) cache;
}
else
{
/* assume it's up to date */
cache = (SpGistCache *) index->rd_amcache;
}
return cache;
}