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-rw-r--r--contrib/pg_trgm/trgm_gist.c964
1 files changed, 964 insertions, 0 deletions
diff --git a/contrib/pg_trgm/trgm_gist.c b/contrib/pg_trgm/trgm_gist.c
new file mode 100644
index 0000000..6f28db7
--- /dev/null
+++ b/contrib/pg_trgm/trgm_gist.c
@@ -0,0 +1,964 @@
+/*
+ * contrib/pg_trgm/trgm_gist.c
+ */
+#include "postgres.h"
+
+#include "access/reloptions.h"
+#include "access/stratnum.h"
+#include "fmgr.h"
+#include "port/pg_bitutils.h"
+#include "trgm.h"
+
+/* gist_trgm_ops opclass options */
+typedef struct
+{
+ int32 vl_len_; /* varlena header (do not touch directly!) */
+ int siglen; /* signature length in bytes */
+} TrgmGistOptions;
+
+#define GET_SIGLEN() (PG_HAS_OPCLASS_OPTIONS() ? \
+ ((TrgmGistOptions *) PG_GET_OPCLASS_OPTIONS())->siglen : \
+ SIGLEN_DEFAULT)
+
+typedef struct
+{
+ /* most recent inputs to gtrgm_consistent */
+ StrategyNumber strategy;
+ text *query;
+ /* extracted trigrams for query */
+ TRGM *trigrams;
+ /* if a regex operator, the extracted graph */
+ TrgmPackedGraph *graph;
+
+ /*
+ * The "query" and "trigrams" are stored in the same palloc block as this
+ * cache struct, at MAXALIGN'ed offsets. The graph however isn't.
+ */
+} gtrgm_consistent_cache;
+
+#define GETENTRY(vec,pos) ((TRGM *) DatumGetPointer((vec)->vector[(pos)].key))
+
+
+PG_FUNCTION_INFO_V1(gtrgm_in);
+PG_FUNCTION_INFO_V1(gtrgm_out);
+PG_FUNCTION_INFO_V1(gtrgm_compress);
+PG_FUNCTION_INFO_V1(gtrgm_decompress);
+PG_FUNCTION_INFO_V1(gtrgm_consistent);
+PG_FUNCTION_INFO_V1(gtrgm_distance);
+PG_FUNCTION_INFO_V1(gtrgm_union);
+PG_FUNCTION_INFO_V1(gtrgm_same);
+PG_FUNCTION_INFO_V1(gtrgm_penalty);
+PG_FUNCTION_INFO_V1(gtrgm_picksplit);
+PG_FUNCTION_INFO_V1(gtrgm_options);
+
+
+Datum
+gtrgm_in(PG_FUNCTION_ARGS)
+{
+ elog(ERROR, "not implemented");
+ PG_RETURN_DATUM(0);
+}
+
+Datum
+gtrgm_out(PG_FUNCTION_ARGS)
+{
+ elog(ERROR, "not implemented");
+ PG_RETURN_DATUM(0);
+}
+
+static TRGM *
+gtrgm_alloc(bool isalltrue, int siglen, BITVECP sign)
+{
+ int flag = SIGNKEY | (isalltrue ? ALLISTRUE : 0);
+ int size = CALCGTSIZE(flag, siglen);
+ TRGM *res = palloc(size);
+
+ SET_VARSIZE(res, size);
+ res->flag = flag;
+
+ if (!isalltrue)
+ {
+ if (sign)
+ memcpy(GETSIGN(res), sign, siglen);
+ else
+ memset(GETSIGN(res), 0, siglen);
+ }
+
+ return res;
+}
+
+static void
+makesign(BITVECP sign, TRGM *a, int siglen)
+{
+ int32 k,
+ len = ARRNELEM(a);
+ trgm *ptr = GETARR(a);
+ int32 tmp = 0;
+
+ MemSet((void *) sign, 0, siglen);
+ SETBIT(sign, SIGLENBIT(siglen)); /* set last unused bit */
+ for (k = 0; k < len; k++)
+ {
+ CPTRGM(((char *) &tmp), ptr + k);
+ HASH(sign, tmp, siglen);
+ }
+}
+
+Datum
+gtrgm_compress(PG_FUNCTION_ARGS)
+{
+ GISTENTRY *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
+ int siglen = GET_SIGLEN();
+ GISTENTRY *retval = entry;
+
+ if (entry->leafkey)
+ { /* trgm */
+ TRGM *res;
+ text *val = DatumGetTextPP(entry->key);
+
+ res = generate_trgm(VARDATA_ANY(val), VARSIZE_ANY_EXHDR(val));
+ retval = (GISTENTRY *) palloc(sizeof(GISTENTRY));
+ gistentryinit(*retval, PointerGetDatum(res),
+ entry->rel, entry->page,
+ entry->offset, false);
+ }
+ else if (ISSIGNKEY(DatumGetPointer(entry->key)) &&
+ !ISALLTRUE(DatumGetPointer(entry->key)))
+ {
+ int32 i;
+ TRGM *res;
+ BITVECP sign = GETSIGN(DatumGetPointer(entry->key));
+
+ LOOPBYTE(siglen)
+ {
+ if ((sign[i] & 0xff) != 0xff)
+ PG_RETURN_POINTER(retval);
+ }
+
+ res = gtrgm_alloc(true, siglen, sign);
+ retval = (GISTENTRY *) palloc(sizeof(GISTENTRY));
+ gistentryinit(*retval, PointerGetDatum(res),
+ entry->rel, entry->page,
+ entry->offset, false);
+ }
+ PG_RETURN_POINTER(retval);
+}
+
+Datum
+gtrgm_decompress(PG_FUNCTION_ARGS)
+{
+ GISTENTRY *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
+ GISTENTRY *retval;
+ text *key;
+
+ key = DatumGetTextPP(entry->key);
+
+ if (key != (text *) DatumGetPointer(entry->key))
+ {
+ /* need to pass back the decompressed item */
+ retval = palloc(sizeof(GISTENTRY));
+ gistentryinit(*retval, PointerGetDatum(key),
+ entry->rel, entry->page, entry->offset, entry->leafkey);
+ PG_RETURN_POINTER(retval);
+ }
+ else
+ {
+ /* we can return the entry as-is */
+ PG_RETURN_POINTER(entry);
+ }
+}
+
+static int32
+cnt_sml_sign_common(TRGM *qtrg, BITVECP sign, int siglen)
+{
+ int32 count = 0;
+ int32 k,
+ len = ARRNELEM(qtrg);
+ trgm *ptr = GETARR(qtrg);
+ int32 tmp = 0;
+
+ for (k = 0; k < len; k++)
+ {
+ CPTRGM(((char *) &tmp), ptr + k);
+ count += GETBIT(sign, HASHVAL(tmp, siglen));
+ }
+
+ return count;
+}
+
+Datum
+gtrgm_consistent(PG_FUNCTION_ARGS)
+{
+ GISTENTRY *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
+ text *query = PG_GETARG_TEXT_P(1);
+ StrategyNumber strategy = (StrategyNumber) PG_GETARG_UINT16(2);
+
+ /* Oid subtype = PG_GETARG_OID(3); */
+ bool *recheck = (bool *) PG_GETARG_POINTER(4);
+ int siglen = GET_SIGLEN();
+ TRGM *key = (TRGM *) DatumGetPointer(entry->key);
+ TRGM *qtrg;
+ bool res;
+ Size querysize = VARSIZE(query);
+ gtrgm_consistent_cache *cache;
+ double nlimit;
+
+ /*
+ * We keep the extracted trigrams in cache, because trigram extraction is
+ * relatively CPU-expensive. When trying to reuse a cached value, check
+ * strategy number not just query itself, because trigram extraction
+ * depends on strategy.
+ *
+ * The cached structure is a single palloc chunk containing the
+ * gtrgm_consistent_cache header, then the input query (4-byte length
+ * word, uncompressed, starting at a MAXALIGN boundary), then the TRGM
+ * value (also starting at a MAXALIGN boundary). However we don't try to
+ * include the regex graph (if any) in that struct. (XXX currently, this
+ * approach can leak regex graphs across index rescans. Not clear if
+ * that's worth fixing.)
+ */
+ cache = (gtrgm_consistent_cache *) fcinfo->flinfo->fn_extra;
+ if (cache == NULL ||
+ cache->strategy != strategy ||
+ VARSIZE(cache->query) != querysize ||
+ memcmp((char *) cache->query, (char *) query, querysize) != 0)
+ {
+ gtrgm_consistent_cache *newcache;
+ TrgmPackedGraph *graph = NULL;
+ Size qtrgsize;
+
+ switch (strategy)
+ {
+ case SimilarityStrategyNumber:
+ case WordSimilarityStrategyNumber:
+ case StrictWordSimilarityStrategyNumber:
+ case EqualStrategyNumber:
+ qtrg = generate_trgm(VARDATA(query),
+ querysize - VARHDRSZ);
+ break;
+ case ILikeStrategyNumber:
+#ifndef IGNORECASE
+ elog(ERROR, "cannot handle ~~* with case-sensitive trigrams");
+#endif
+ /* FALL THRU */
+ case LikeStrategyNumber:
+ qtrg = generate_wildcard_trgm(VARDATA(query),
+ querysize - VARHDRSZ);
+ break;
+ case RegExpICaseStrategyNumber:
+#ifndef IGNORECASE
+ elog(ERROR, "cannot handle ~* with case-sensitive trigrams");
+#endif
+ /* FALL THRU */
+ case RegExpStrategyNumber:
+ qtrg = createTrgmNFA(query, PG_GET_COLLATION(),
+ &graph, fcinfo->flinfo->fn_mcxt);
+ /* just in case an empty array is returned ... */
+ if (qtrg && ARRNELEM(qtrg) <= 0)
+ {
+ pfree(qtrg);
+ qtrg = NULL;
+ }
+ break;
+ default:
+ elog(ERROR, "unrecognized strategy number: %d", strategy);
+ qtrg = NULL; /* keep compiler quiet */
+ break;
+ }
+
+ qtrgsize = qtrg ? VARSIZE(qtrg) : 0;
+
+ newcache = (gtrgm_consistent_cache *)
+ MemoryContextAlloc(fcinfo->flinfo->fn_mcxt,
+ MAXALIGN(sizeof(gtrgm_consistent_cache)) +
+ MAXALIGN(querysize) +
+ qtrgsize);
+
+ newcache->strategy = strategy;
+ newcache->query = (text *)
+ ((char *) newcache + MAXALIGN(sizeof(gtrgm_consistent_cache)));
+ memcpy((char *) newcache->query, (char *) query, querysize);
+ if (qtrg)
+ {
+ newcache->trigrams = (TRGM *)
+ ((char *) newcache->query + MAXALIGN(querysize));
+ memcpy((char *) newcache->trigrams, (char *) qtrg, qtrgsize);
+ /* release qtrg in case it was made in fn_mcxt */
+ pfree(qtrg);
+ }
+ else
+ newcache->trigrams = NULL;
+ newcache->graph = graph;
+
+ if (cache)
+ pfree(cache);
+ fcinfo->flinfo->fn_extra = (void *) newcache;
+ cache = newcache;
+ }
+
+ qtrg = cache->trigrams;
+
+ switch (strategy)
+ {
+ case SimilarityStrategyNumber:
+ case WordSimilarityStrategyNumber:
+ case StrictWordSimilarityStrategyNumber:
+
+ /*
+ * Similarity search is exact. (Strict) word similarity search is
+ * inexact
+ */
+ *recheck = (strategy != SimilarityStrategyNumber);
+
+ nlimit = index_strategy_get_limit(strategy);
+
+ if (GIST_LEAF(entry))
+ { /* all leafs contains orig trgm */
+ double tmpsml = cnt_sml(qtrg, key, *recheck);
+
+ res = (tmpsml >= nlimit);
+ }
+ else if (ISALLTRUE(key))
+ { /* non-leaf contains signature */
+ res = true;
+ }
+ else
+ { /* non-leaf contains signature */
+ int32 count = cnt_sml_sign_common(qtrg, GETSIGN(key), siglen);
+ int32 len = ARRNELEM(qtrg);
+
+ if (len == 0)
+ res = false;
+ else
+ res = (((((float8) count) / ((float8) len))) >= nlimit);
+ }
+ break;
+ case ILikeStrategyNumber:
+#ifndef IGNORECASE
+ elog(ERROR, "cannot handle ~~* with case-sensitive trigrams");
+#endif
+ /* FALL THRU */
+ case LikeStrategyNumber:
+ case EqualStrategyNumber:
+ /* Wildcard and equal search are inexact */
+ *recheck = true;
+
+ /*
+ * Check if all the extracted trigrams can be present in child
+ * nodes.
+ */
+ if (GIST_LEAF(entry))
+ { /* all leafs contains orig trgm */
+ res = trgm_contained_by(qtrg, key);
+ }
+ else if (ISALLTRUE(key))
+ { /* non-leaf contains signature */
+ res = true;
+ }
+ else
+ { /* non-leaf contains signature */
+ int32 k,
+ tmp = 0,
+ len = ARRNELEM(qtrg);
+ trgm *ptr = GETARR(qtrg);
+ BITVECP sign = GETSIGN(key);
+
+ res = true;
+ for (k = 0; k < len; k++)
+ {
+ CPTRGM(((char *) &tmp), ptr + k);
+ if (!GETBIT(sign, HASHVAL(tmp, siglen)))
+ {
+ res = false;
+ break;
+ }
+ }
+ }
+ break;
+ case RegExpICaseStrategyNumber:
+#ifndef IGNORECASE
+ elog(ERROR, "cannot handle ~* with case-sensitive trigrams");
+#endif
+ /* FALL THRU */
+ case RegExpStrategyNumber:
+ /* Regexp search is inexact */
+ *recheck = true;
+
+ /* Check regex match as much as we can with available info */
+ if (qtrg)
+ {
+ if (GIST_LEAF(entry))
+ { /* all leafs contains orig trgm */
+ bool *check;
+
+ check = trgm_presence_map(qtrg, key);
+ res = trigramsMatchGraph(cache->graph, check);
+ pfree(check);
+ }
+ else if (ISALLTRUE(key))
+ { /* non-leaf contains signature */
+ res = true;
+ }
+ else
+ { /* non-leaf contains signature */
+ int32 k,
+ tmp = 0,
+ len = ARRNELEM(qtrg);
+ trgm *ptr = GETARR(qtrg);
+ BITVECP sign = GETSIGN(key);
+ bool *check;
+
+ /*
+ * GETBIT() tests may give false positives, due to limited
+ * size of the sign array. But since trigramsMatchGraph()
+ * implements a monotone boolean function, false positives
+ * in the check array can't lead to false negative answer.
+ * So we can apply trigramsMatchGraph despite uncertainty,
+ * and that usefully improves the quality of the search.
+ */
+ check = (bool *) palloc(len * sizeof(bool));
+ for (k = 0; k < len; k++)
+ {
+ CPTRGM(((char *) &tmp), ptr + k);
+ check[k] = GETBIT(sign, HASHVAL(tmp, siglen));
+ }
+ res = trigramsMatchGraph(cache->graph, check);
+ pfree(check);
+ }
+ }
+ else
+ {
+ /* trigram-free query must be rechecked everywhere */
+ res = true;
+ }
+ break;
+ default:
+ elog(ERROR, "unrecognized strategy number: %d", strategy);
+ res = false; /* keep compiler quiet */
+ break;
+ }
+
+ PG_RETURN_BOOL(res);
+}
+
+Datum
+gtrgm_distance(PG_FUNCTION_ARGS)
+{
+ GISTENTRY *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
+ text *query = PG_GETARG_TEXT_P(1);
+ StrategyNumber strategy = (StrategyNumber) PG_GETARG_UINT16(2);
+
+ /* Oid subtype = PG_GETARG_OID(3); */
+ bool *recheck = (bool *) PG_GETARG_POINTER(4);
+ int siglen = GET_SIGLEN();
+ TRGM *key = (TRGM *) DatumGetPointer(entry->key);
+ TRGM *qtrg;
+ float8 res;
+ Size querysize = VARSIZE(query);
+ char *cache = (char *) fcinfo->flinfo->fn_extra;
+
+ /*
+ * Cache the generated trigrams across multiple calls with the same query.
+ */
+ if (cache == NULL ||
+ VARSIZE(cache) != querysize ||
+ memcmp(cache, query, querysize) != 0)
+ {
+ char *newcache;
+
+ qtrg = generate_trgm(VARDATA(query), querysize - VARHDRSZ);
+
+ newcache = MemoryContextAlloc(fcinfo->flinfo->fn_mcxt,
+ MAXALIGN(querysize) +
+ VARSIZE(qtrg));
+
+ memcpy(newcache, query, querysize);
+ memcpy(newcache + MAXALIGN(querysize), qtrg, VARSIZE(qtrg));
+
+ if (cache)
+ pfree(cache);
+ fcinfo->flinfo->fn_extra = newcache;
+ cache = newcache;
+ }
+
+ qtrg = (TRGM *) (cache + MAXALIGN(querysize));
+
+ switch (strategy)
+ {
+ case DistanceStrategyNumber:
+ case WordDistanceStrategyNumber:
+ case StrictWordDistanceStrategyNumber:
+ /* Only plain trigram distance is exact */
+ *recheck = (strategy != DistanceStrategyNumber);
+ if (GIST_LEAF(entry))
+ { /* all leafs contains orig trgm */
+
+ /*
+ * Prevent gcc optimizing the sml variable using volatile
+ * keyword. Otherwise res can differ from the
+ * word_similarity_dist_op() function.
+ */
+ float4 volatile sml = cnt_sml(qtrg, key, *recheck);
+
+ res = 1.0 - sml;
+ }
+ else if (ISALLTRUE(key))
+ { /* all leafs contains orig trgm */
+ res = 0.0;
+ }
+ else
+ { /* non-leaf contains signature */
+ int32 count = cnt_sml_sign_common(qtrg, GETSIGN(key), siglen);
+ int32 len = ARRNELEM(qtrg);
+
+ res = (len == 0) ? -1.0 : 1.0 - ((float8) count) / ((float8) len);
+ }
+ break;
+ default:
+ elog(ERROR, "unrecognized strategy number: %d", strategy);
+ res = 0; /* keep compiler quiet */
+ break;
+ }
+
+ PG_RETURN_FLOAT8(res);
+}
+
+static int32
+unionkey(BITVECP sbase, TRGM *add, int siglen)
+{
+ int32 i;
+
+ if (ISSIGNKEY(add))
+ {
+ BITVECP sadd = GETSIGN(add);
+
+ if (ISALLTRUE(add))
+ return 1;
+
+ LOOPBYTE(siglen)
+ sbase[i] |= sadd[i];
+ }
+ else
+ {
+ trgm *ptr = GETARR(add);
+ int32 tmp = 0;
+
+ for (i = 0; i < ARRNELEM(add); i++)
+ {
+ CPTRGM(((char *) &tmp), ptr + i);
+ HASH(sbase, tmp, siglen);
+ }
+ }
+ return 0;
+}
+
+
+Datum
+gtrgm_union(PG_FUNCTION_ARGS)
+{
+ GistEntryVector *entryvec = (GistEntryVector *) PG_GETARG_POINTER(0);
+ int32 len = entryvec->n;
+ int *size = (int *) PG_GETARG_POINTER(1);
+ int siglen = GET_SIGLEN();
+ int32 i;
+ TRGM *result = gtrgm_alloc(false, siglen, NULL);
+ BITVECP base = GETSIGN(result);
+
+ for (i = 0; i < len; i++)
+ {
+ if (unionkey(base, GETENTRY(entryvec, i), siglen))
+ {
+ result->flag = ALLISTRUE;
+ SET_VARSIZE(result, CALCGTSIZE(ALLISTRUE, siglen));
+ break;
+ }
+ }
+
+ *size = VARSIZE(result);
+
+ PG_RETURN_POINTER(result);
+}
+
+Datum
+gtrgm_same(PG_FUNCTION_ARGS)
+{
+ TRGM *a = (TRGM *) PG_GETARG_POINTER(0);
+ TRGM *b = (TRGM *) PG_GETARG_POINTER(1);
+ bool *result = (bool *) PG_GETARG_POINTER(2);
+ int siglen = GET_SIGLEN();
+
+ if (ISSIGNKEY(a))
+ { /* then b also ISSIGNKEY */
+ if (ISALLTRUE(a) && ISALLTRUE(b))
+ *result = true;
+ else if (ISALLTRUE(a))
+ *result = false;
+ else if (ISALLTRUE(b))
+ *result = false;
+ else
+ {
+ int32 i;
+ BITVECP sa = GETSIGN(a),
+ sb = GETSIGN(b);
+
+ *result = true;
+ LOOPBYTE(siglen)
+ {
+ if (sa[i] != sb[i])
+ {
+ *result = false;
+ break;
+ }
+ }
+ }
+ }
+ else
+ { /* a and b ISARRKEY */
+ int32 lena = ARRNELEM(a),
+ lenb = ARRNELEM(b);
+
+ if (lena != lenb)
+ *result = false;
+ else
+ {
+ trgm *ptra = GETARR(a),
+ *ptrb = GETARR(b);
+ int32 i;
+
+ *result = true;
+ for (i = 0; i < lena; i++)
+ if (CMPTRGM(ptra + i, ptrb + i))
+ {
+ *result = false;
+ break;
+ }
+ }
+ }
+
+ PG_RETURN_POINTER(result);
+}
+
+static int32
+sizebitvec(BITVECP sign, int siglen)
+{
+ return pg_popcount(sign, siglen);
+}
+
+static int
+hemdistsign(BITVECP a, BITVECP b, int siglen)
+{
+ int i,
+ diff,
+ dist = 0;
+
+ LOOPBYTE(siglen)
+ {
+ diff = (unsigned char) (a[i] ^ b[i]);
+ /* Using the popcount functions here isn't likely to win */
+ dist += pg_number_of_ones[diff];
+ }
+ return dist;
+}
+
+static int
+hemdist(TRGM *a, TRGM *b, int siglen)
+{
+ if (ISALLTRUE(a))
+ {
+ if (ISALLTRUE(b))
+ return 0;
+ else
+ return SIGLENBIT(siglen) - sizebitvec(GETSIGN(b), siglen);
+ }
+ else if (ISALLTRUE(b))
+ return SIGLENBIT(siglen) - sizebitvec(GETSIGN(a), siglen);
+
+ return hemdistsign(GETSIGN(a), GETSIGN(b), siglen);
+}
+
+Datum
+gtrgm_penalty(PG_FUNCTION_ARGS)
+{
+ GISTENTRY *origentry = (GISTENTRY *) PG_GETARG_POINTER(0); /* always ISSIGNKEY */
+ GISTENTRY *newentry = (GISTENTRY *) PG_GETARG_POINTER(1);
+ float *penalty = (float *) PG_GETARG_POINTER(2);
+ int siglen = GET_SIGLEN();
+ TRGM *origval = (TRGM *) DatumGetPointer(origentry->key);
+ TRGM *newval = (TRGM *) DatumGetPointer(newentry->key);
+ BITVECP orig = GETSIGN(origval);
+
+ *penalty = 0.0;
+
+ if (ISARRKEY(newval))
+ {
+ char *cache = (char *) fcinfo->flinfo->fn_extra;
+ TRGM *cachedVal = (TRGM *) (cache + MAXALIGN(siglen));
+ Size newvalsize = VARSIZE(newval);
+ BITVECP sign;
+
+ /*
+ * Cache the sign data across multiple calls with the same newval.
+ */
+ if (cache == NULL ||
+ VARSIZE(cachedVal) != newvalsize ||
+ memcmp(cachedVal, newval, newvalsize) != 0)
+ {
+ char *newcache;
+
+ newcache = MemoryContextAlloc(fcinfo->flinfo->fn_mcxt,
+ MAXALIGN(siglen) +
+ newvalsize);
+
+ makesign((BITVECP) newcache, newval, siglen);
+
+ cachedVal = (TRGM *) (newcache + MAXALIGN(siglen));
+ memcpy(cachedVal, newval, newvalsize);
+
+ if (cache)
+ pfree(cache);
+ fcinfo->flinfo->fn_extra = newcache;
+ cache = newcache;
+ }
+
+ sign = (BITVECP) cache;
+
+ if (ISALLTRUE(origval))
+ *penalty = ((float) (SIGLENBIT(siglen) - sizebitvec(sign, siglen))) / (float) (SIGLENBIT(siglen) + 1);
+ else
+ *penalty = hemdistsign(sign, orig, siglen);
+ }
+ else
+ *penalty = hemdist(origval, newval, siglen);
+ PG_RETURN_POINTER(penalty);
+}
+
+typedef struct
+{
+ bool allistrue;
+ BITVECP sign;
+} CACHESIGN;
+
+static void
+fillcache(CACHESIGN *item, TRGM *key, BITVECP sign, int siglen)
+{
+ item->allistrue = false;
+ item->sign = sign;
+ if (ISARRKEY(key))
+ makesign(item->sign, key, siglen);
+ else if (ISALLTRUE(key))
+ item->allistrue = true;
+ else
+ memcpy((void *) item->sign, (void *) GETSIGN(key), siglen);
+}
+
+#define WISH_F(a,b,c) (double)( -(double)(((a)-(b))*((a)-(b))*((a)-(b)))*(c) )
+typedef struct
+{
+ OffsetNumber pos;
+ int32 cost;
+} SPLITCOST;
+
+static int
+comparecost(const void *a, const void *b)
+{
+ if (((const SPLITCOST *) a)->cost == ((const SPLITCOST *) b)->cost)
+ return 0;
+ else
+ return (((const SPLITCOST *) a)->cost > ((const SPLITCOST *) b)->cost) ? 1 : -1;
+}
+
+
+static int
+hemdistcache(CACHESIGN *a, CACHESIGN *b, int siglen)
+{
+ if (a->allistrue)
+ {
+ if (b->allistrue)
+ return 0;
+ else
+ return SIGLENBIT(siglen) - sizebitvec(b->sign, siglen);
+ }
+ else if (b->allistrue)
+ return SIGLENBIT(siglen) - sizebitvec(a->sign, siglen);
+
+ return hemdistsign(a->sign, b->sign, siglen);
+}
+
+Datum
+gtrgm_picksplit(PG_FUNCTION_ARGS)
+{
+ GistEntryVector *entryvec = (GistEntryVector *) PG_GETARG_POINTER(0);
+ OffsetNumber maxoff = entryvec->n - 1;
+ GIST_SPLITVEC *v = (GIST_SPLITVEC *) PG_GETARG_POINTER(1);
+ int siglen = GET_SIGLEN();
+ OffsetNumber k,
+ j;
+ TRGM *datum_l,
+ *datum_r;
+ BITVECP union_l,
+ union_r;
+ int32 size_alpha,
+ size_beta;
+ int32 size_waste,
+ waste = -1;
+ int32 nbytes;
+ OffsetNumber seed_1 = 0,
+ seed_2 = 0;
+ OffsetNumber *left,
+ *right;
+ BITVECP ptr;
+ int i;
+ CACHESIGN *cache;
+ char *cache_sign;
+ SPLITCOST *costvector;
+
+ /* cache the sign data for each existing item */
+ cache = (CACHESIGN *) palloc(sizeof(CACHESIGN) * (maxoff + 1));
+ cache_sign = palloc(siglen * (maxoff + 1));
+
+ for (k = FirstOffsetNumber; k <= maxoff; k = OffsetNumberNext(k))
+ fillcache(&cache[k], GETENTRY(entryvec, k), &cache_sign[siglen * k],
+ siglen);
+
+ /* now find the two furthest-apart items */
+ for (k = FirstOffsetNumber; k < maxoff; k = OffsetNumberNext(k))
+ {
+ for (j = OffsetNumberNext(k); j <= maxoff; j = OffsetNumberNext(j))
+ {
+ size_waste = hemdistcache(&(cache[j]), &(cache[k]), siglen);
+ if (size_waste > waste)
+ {
+ waste = size_waste;
+ seed_1 = k;
+ seed_2 = j;
+ }
+ }
+ }
+
+ /* just in case we didn't make a selection ... */
+ if (seed_1 == 0 || seed_2 == 0)
+ {
+ seed_1 = 1;
+ seed_2 = 2;
+ }
+
+ /* initialize the result vectors */
+ nbytes = maxoff * sizeof(OffsetNumber);
+ v->spl_left = left = (OffsetNumber *) palloc(nbytes);
+ v->spl_right = right = (OffsetNumber *) palloc(nbytes);
+ v->spl_nleft = 0;
+ v->spl_nright = 0;
+
+ /* form initial .. */
+ datum_l = gtrgm_alloc(cache[seed_1].allistrue, siglen, cache[seed_1].sign);
+ datum_r = gtrgm_alloc(cache[seed_2].allistrue, siglen, cache[seed_2].sign);
+
+ union_l = GETSIGN(datum_l);
+ union_r = GETSIGN(datum_r);
+
+ /* sort before ... */
+ costvector = (SPLITCOST *) palloc(sizeof(SPLITCOST) * maxoff);
+ for (j = FirstOffsetNumber; j <= maxoff; j = OffsetNumberNext(j))
+ {
+ costvector[j - 1].pos = j;
+ size_alpha = hemdistcache(&(cache[seed_1]), &(cache[j]), siglen);
+ size_beta = hemdistcache(&(cache[seed_2]), &(cache[j]), siglen);
+ costvector[j - 1].cost = abs(size_alpha - size_beta);
+ }
+ qsort((void *) costvector, maxoff, sizeof(SPLITCOST), comparecost);
+
+ for (k = 0; k < maxoff; k++)
+ {
+ j = costvector[k].pos;
+ if (j == seed_1)
+ {
+ *left++ = j;
+ v->spl_nleft++;
+ continue;
+ }
+ else if (j == seed_2)
+ {
+ *right++ = j;
+ v->spl_nright++;
+ continue;
+ }
+
+ if (ISALLTRUE(datum_l) || cache[j].allistrue)
+ {
+ if (ISALLTRUE(datum_l) && cache[j].allistrue)
+ size_alpha = 0;
+ else
+ size_alpha = SIGLENBIT(siglen) -
+ sizebitvec((cache[j].allistrue) ? GETSIGN(datum_l) :
+ GETSIGN(cache[j].sign),
+ siglen);
+ }
+ else
+ size_alpha = hemdistsign(cache[j].sign, GETSIGN(datum_l), siglen);
+
+ if (ISALLTRUE(datum_r) || cache[j].allistrue)
+ {
+ if (ISALLTRUE(datum_r) && cache[j].allistrue)
+ size_beta = 0;
+ else
+ size_beta = SIGLENBIT(siglen) -
+ sizebitvec((cache[j].allistrue) ? GETSIGN(datum_r) :
+ GETSIGN(cache[j].sign),
+ siglen);
+ }
+ else
+ size_beta = hemdistsign(cache[j].sign, GETSIGN(datum_r), siglen);
+
+ if (size_alpha < size_beta + WISH_F(v->spl_nleft, v->spl_nright, 0.1))
+ {
+ if (ISALLTRUE(datum_l) || cache[j].allistrue)
+ {
+ if (!ISALLTRUE(datum_l))
+ MemSet((void *) GETSIGN(datum_l), 0xff, siglen);
+ }
+ else
+ {
+ ptr = cache[j].sign;
+ LOOPBYTE(siglen)
+ union_l[i] |= ptr[i];
+ }
+ *left++ = j;
+ v->spl_nleft++;
+ }
+ else
+ {
+ if (ISALLTRUE(datum_r) || cache[j].allistrue)
+ {
+ if (!ISALLTRUE(datum_r))
+ MemSet((void *) GETSIGN(datum_r), 0xff, siglen);
+ }
+ else
+ {
+ ptr = cache[j].sign;
+ LOOPBYTE(siglen)
+ union_r[i] |= ptr[i];
+ }
+ *right++ = j;
+ v->spl_nright++;
+ }
+ }
+
+ v->spl_ldatum = PointerGetDatum(datum_l);
+ v->spl_rdatum = PointerGetDatum(datum_r);
+
+ PG_RETURN_POINTER(v);
+}
+
+Datum
+gtrgm_options(PG_FUNCTION_ARGS)
+{
+ local_relopts *relopts = (local_relopts *) PG_GETARG_POINTER(0);
+
+ init_local_reloptions(relopts, sizeof(TrgmGistOptions));
+ add_local_int_reloption(relopts, "siglen",
+ "signature length in bytes",
+ SIGLEN_DEFAULT, 1, SIGLEN_MAX,
+ offsetof(TrgmGistOptions, siglen));
+
+ PG_RETURN_VOID();
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-12 22:01:42 +0000