Fix 8.4 support of GIN (basically, multicolumn indexes)

diff --git a/README.gevel b/README.gevel
index 21230c1..4d7c2a5 100644 (file)
--- a/README.gevel
+++ b/README.gevel
@@ -124,6 +124,9 @@ regression=# select gist_tree('pix');
 (29 rows)
 
    * gin_stat(INDEXNAME) prints estimated counts for each indexed values
+        Note: since 8.4 gin_stat function has gin_stat(INDEXNAME, COLNUMBER) 
+        prototype, single-argument function will return result for a first
+        column of index
 
 # SELECT * FROM gin_stat('gin_idx') as t(value int, nrow int) where nrow > 250;
  value | nrow 

diff --git a/gevel.c b/gevel.c
index d9d8397..16e18d3 100644 (file)
--- a/gevel.c
+++ b/gevel.c
@@ -489,6 +489,7 @@ gist_print(PG_FUNCTION_ARGS) {
 typedef struct GinStatState {
        Relation                index;
        GinState                ginstate;
+       OffsetNumber    attnum;
 
        Buffer                  buffer;
        OffsetNumber    offset;
@@ -553,7 +554,9 @@ refindPosition(GinStatState *st)
 
        for(;;) {
                int     cmp;
+#if PG_VERSION_NUM < 80400
                bool    isnull;
+#endif
                Datum   datum;
                IndexTuple itup;
 
@@ -561,16 +564,25 @@ refindPosition(GinStatState *st)
                        return false;
 
                itup = (IndexTuple) PageGetItem(page, PageGetItemId(page, st->offset));
+#if PG_VERSION_NUM >= 80400
+               datum = gin_index_getattr(&st->ginstate, itup);
+
+               cmp = compareAttEntries(&st->ginstate,
+                                                                       st->attnum + 1, st->curval,
+                                                                       gintuple_get_attrnum(&st->ginstate, itup), datum);
+#else
                datum = index_getattr(itup, FirstOffsetNumber, st->ginstate.tupdesc, &isnull);
+
                cmp = DatumGetInt32(
                                FunctionCall2(
                                                &st->ginstate.compareFn,
                                                st->curval,
                                                datum
                                        ));
+#endif
                if ( cmp == 0 )
                {
-                       if ( !st->ginstate.tupdesc->attrs[0]->attbyval )
+                       if ( !st->index->rd_att->attrs[st->attnum]->attbyval )
                                pfree( (void*) st->curval );
                        return true;
                }
@@ -582,7 +594,7 @@ refindPosition(GinStatState *st)
 }
 
 static void
-gin_setup_firstcall(FuncCallContext  *funcctx, text *name) {
+gin_setup_firstcall(FuncCallContext  *funcctx, text *name, int attnum) {
        MemoryContext     oldcontext;
        GinStatState     *st;
        char *relname=t2c(name);
@@ -596,13 +608,21 @@ gin_setup_firstcall(FuncCallContext  *funcctx, text *name) {
                 makeRangeVarFromNameList(stringToQualifiedNameList(relname, "gin_stat")));
        initGinState( &st->ginstate, st->index );
 
+#if PG_VERSION_NUM >= 80400
+       if (attnum < 0 || attnum >= st->index->rd_att->natts)
+               elog(ERROR,"Wrong column's number");
+       st->attnum = attnum;
+#else
+       st->attnum = 0;
+#endif
+
        funcctx->user_fctx = (void*)st;
 
        tupdesc = CreateTemplateTupleDesc(2, false);
        TupleDescInitEntry(tupdesc, 1, "value", 
-                       st->index->rd_att->attrs[0]->atttypid, 
-                       st->index->rd_att->attrs[0]->atttypmod,
-                       st->index->rd_att->attrs[0]->attndims);
+                       st->index->rd_att->attrs[st->attnum]->atttypid, 
+                       st->index->rd_att->attrs[st->attnum]->atttypmod,
+                       st->index->rd_att->attrs[st->attnum]->attndims);
        TupleDescInitEntry(tupdesc, 2, "nrow", INT4OID, -1, 0);
 
        memset( st->nulls, ' ', 2*sizeof(char) );
@@ -620,15 +640,19 @@ gin_setup_firstcall(FuncCallContext  *funcctx, text *name) {
 static void
 processTuple( FuncCallContext  *funcctx,  GinStatState *st, IndexTuple itup ) {
        MemoryContext           oldcontext;
-       Datum                           datum;
+#if PG_VERSION_NUM < 80400
        bool                            isnull;
+#endif
 
-       datum = index_getattr(itup, FirstOffsetNumber, st->ginstate.tupdesc, &isnull);
        oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
        st->curval = datumCopy(
+#if PG_VERSION_NUM >= 80400
+                                       gin_index_getattr(&st->ginstate, itup),
+#else
                                        index_getattr(itup, FirstOffsetNumber, st->ginstate.tupdesc, &isnull),
-                                       st->ginstate.tupdesc->attrs[0]->attbyval,
-                                       st->ginstate.tupdesc->attrs[0]->attlen );
+#endif
+                                       st->index->rd_att->attrs[st->attnum]->attbyval,
+                                       st->index->rd_att->attrs[st->attnum]->attlen );
        MemoryContextSwitchTo(oldcontext);
 
        st->dvalues[0] = st->curval;
@@ -669,7 +693,7 @@ gin_stat(PG_FUNCTION_ARGS) {
        if (SRF_IS_FIRSTCALL()) {
                text    *name=PG_GETARG_TEXT_P(0);
                funcctx = SRF_FIRSTCALL_INIT();
-               gin_setup_firstcall(funcctx, name);
+               gin_setup_firstcall(funcctx, name, (PG_NARGS()==2) ? PG_GETARG_INT32(1) : 0 );
                PG_FREE_IF_COPY(name,0);
        }
 
@@ -683,17 +707,24 @@ gin_stat(PG_FUNCTION_ARGS) {
                SRF_RETURN_DONE(funcctx);
        }
 
-       st->offset++;
+       for(;;) {
+               st->offset++;
        
-       if (moveRightIfItNeeded(st)==false) { 
-               UnlockReleaseBuffer( st->buffer );
-               gin_index_close(st->index);
+               if (moveRightIfItNeeded(st)==false) { 
+                       UnlockReleaseBuffer( st->buffer );
+                       gin_index_close(st->index);
 
-               SRF_RETURN_DONE(funcctx);
-       }
+                       SRF_RETURN_DONE(funcctx);
+               }
+
+               page = BufferGetPage(st->buffer);
+               ituple = (IndexTuple) PageGetItem(page, PageGetItemId(page, st->offset)); 
 
-       page = BufferGetPage(st->buffer);
-       ituple = (IndexTuple) PageGetItem(page, PageGetItemId(page, st->offset)); 
+#if PG_VERSION_NUM >= 80400
+               if (st->attnum + 1 == gintuple_get_attrnum(&st->ginstate, ituple))
+#endif
+                       break;
+       }
 
        processTuple( funcctx,  st, ituple );
        

diff --git a/gevel.sql.in b/gevel.sql.in
index 5294f81..4a71188 100644 (file)
--- a/gevel.sql.in
+++ b/gevel.sql.in
@@ -31,6 +31,12 @@ create or replace function gin_stat(text)
         language 'C'
         with (isstrict); 
 
+create or replace function gin_stat(text, int)
+        returns setof record
+        as 'MODULE_PATHNAME'
+        language 'C'
+        with (isstrict); 
+
 create or replace function gin_count_estimate(text, tsquery)
         returns bigint 
         as 'MODULE_PATHNAME'