diff options
Diffstat (limited to 'src/backend/access/heap/tuptoaster.c')
| -rw-r--r-- | src/backend/access/heap/tuptoaster.c | 133 |
1 files changed, 128 insertions, 5 deletions
diff --git a/src/backend/access/heap/tuptoaster.c b/src/backend/access/heap/tuptoaster.c index f206a3f28eb..c36cc42309e 100644 --- a/src/backend/access/heap/tuptoaster.c +++ b/src/backend/access/heap/tuptoaster.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/access/heap/tuptoaster.c,v 1.42 2004/06/04 20:35:21 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/access/heap/tuptoaster.c,v 1.43 2004/06/05 01:55:04 tgl Exp $ * * * INTERFACE ROUTINES @@ -35,6 +35,7 @@ #include "utils/builtins.h" #include "utils/fmgroids.h" #include "utils/pg_lzcompress.h" +#include "utils/typcache.h" #undef TOAST_DEBUG @@ -458,10 +459,10 @@ toast_insert_or_update(Relation rel, HeapTuple newtup, HeapTuple oldtup) * still in the tuple must be someone else's we cannot reuse. * Expand it to plain (and, probably, toast it again below). */ - if (VARATT_IS_EXTERNAL(DatumGetPointer(toast_values[i]))) + if (VARATT_IS_EXTERNAL(new_value)) { - toast_values[i] = PointerGetDatum(heap_tuple_untoast_attr( - (varattrib *) DatumGetPointer(toast_values[i]))); + new_value = heap_tuple_untoast_attr(new_value); + toast_values[i] = PointerGetDatum(new_value); toast_free[i] = true; need_change = true; need_free = true; @@ -470,7 +471,7 @@ toast_insert_or_update(Relation rel, HeapTuple newtup, HeapTuple oldtup) /* * Remember the size of this attribute */ - toast_sizes[i] = VARATT_SIZE(DatumGetPointer(toast_values[i])); + toast_sizes[i] = VARATT_SIZE(new_value); } else { @@ -786,6 +787,128 @@ toast_insert_or_update(Relation rel, HeapTuple newtup, HeapTuple oldtup) /* ---------- + * toast_flatten_tuple_attribute - + * + * If a Datum is of composite type, "flatten" it to contain no toasted fields. + * This must be invoked on any potentially-composite field that is to be + * inserted into a tuple. Doing this preserves the invariant that toasting + * goes only one level deep in a tuple. + * ---------- + */ +Datum +toast_flatten_tuple_attribute(Datum value, + Oid typeId, int32 typeMod) +{ + TupleDesc tupleDesc; + HeapTupleHeader olddata; + HeapTupleHeader new_data; + int32 new_len; + HeapTupleData tmptup; + Form_pg_attribute *att; + int numAttrs; + int i; + bool need_change = false; + bool has_nulls = false; + Datum toast_values[MaxTupleAttributeNumber]; + char toast_nulls[MaxTupleAttributeNumber]; + bool toast_free[MaxTupleAttributeNumber]; + + /* + * See if it's a composite type, and get the tupdesc if so. + */ + tupleDesc = lookup_rowtype_tupdesc_noerror(typeId, typeMod, true); + if (tupleDesc == NULL) + return value; /* not a composite type */ + + att = tupleDesc->attrs; + numAttrs = tupleDesc->natts; + + /* + * Break down the tuple into fields. + */ + olddata = DatumGetHeapTupleHeader(value); + Assert(typeId == HeapTupleHeaderGetTypeId(olddata)); + Assert(typeMod == HeapTupleHeaderGetTypMod(olddata)); + /* Build a temporary HeapTuple control structure */ + tmptup.t_len = HeapTupleHeaderGetDatumLength(olddata); + ItemPointerSetInvalid(&(tmptup.t_self)); + tmptup.t_tableOid = InvalidOid; + tmptup.t_data = olddata; + + Assert(numAttrs <= MaxTupleAttributeNumber); + heap_deformtuple(&tmptup, tupleDesc, toast_values, toast_nulls); + + memset(toast_free, 0, numAttrs * sizeof(bool)); + + for (i = 0; i < numAttrs; i++) + { + /* + * Look at non-null varlena attributes + */ + if (toast_nulls[i] == 'n') + has_nulls = true; + else if (att[i]->attlen == -1) + { + varattrib *new_value; + + new_value = (varattrib *) DatumGetPointer(toast_values[i]); + if (VARATT_IS_EXTENDED(new_value)) + { + new_value = heap_tuple_untoast_attr(new_value); + toast_values[i] = PointerGetDatum(new_value); + toast_free[i] = true; + need_change = true; + } + } + } + + /* + * If nothing to untoast, just return the original tuple. + */ + if (!need_change) + return value; + + /* + * Calculate the new size of the tuple. Header size should not + * change, but data size might. + */ + new_len = offsetof(HeapTupleHeaderData, t_bits); + if (has_nulls) + new_len += BITMAPLEN(numAttrs); + if (olddata->t_infomask & HEAP_HASOID) + new_len += sizeof(Oid); + new_len = MAXALIGN(new_len); + Assert(new_len == olddata->t_hoff); + new_len += ComputeDataSize(tupleDesc, toast_values, toast_nulls); + + new_data = (HeapTupleHeader) palloc0(new_len); + + /* + * Put the tuple header and the changed values into place + */ + memcpy(new_data, olddata, olddata->t_hoff); + + HeapTupleHeaderSetDatumLength(new_data, new_len); + + DataFill((char *) new_data + olddata->t_hoff, + tupleDesc, + toast_values, + toast_nulls, + &(new_data->t_infomask), + has_nulls ? new_data->t_bits : NULL); + + /* + * Free allocated temp values + */ + for (i = 0; i < numAttrs; i++) + if (toast_free[i]) + pfree(DatumGetPointer(toast_values[i])); + + return PointerGetDatum(new_data); +} + + +/* ---------- * toast_compress_datum - * * Create a compressed version of a varlena datum |