/* ---------- * 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. * * Note that flattening does not mean expansion of short-header varlenas, * so in one sense toasting is allowed within composite datums. * ---------- */ Datum toast_flatten_tuple_attribute(Datum value, Oid typeId, int32 typeMod) { TupleDesc tupleDesc; HeapTupleHeader olddata; HeapTupleHeader new_data; int32 new_len; int32 new_data_len; HeapTupleData tmptup; Form_pg_attribute *att; int numAttrs; int i; bool need_change = false; bool has_nulls = false; Datum toast_values[MaxTupleAttributeNumber]; bool toast_isnull[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_deform_tuple(&tmptup, tupleDesc, toast_values, toast_isnull); memset(toast_free, 0, numAttrs * sizeof(bool)); for (i = 0; i < numAttrs; i++) { /* * Look at non-null varlena attributes */ if (toast_isnull[i]) has_nulls = true; else if (att[i]->attlen == -1) { struct varlena *new_value; new_value = (struct varlena *) DatumGetPointer(toast_values[i]); if (VARATT_IS_EXTERNAL(new_value) || VARATT_IS_COMPRESSED(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) { ReleaseTupleDesc(tupleDesc); 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_data_len = heap_compute_data_size(tupleDesc, toast_values, toast_isnull); new_len += new_data_len; 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); heap_fill_tuple(tupleDesc, toast_values, toast_isnull, (char *) new_data + olddata->t_hoff, new_data_len, &(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])); ReleaseTupleDesc(tupleDesc); return PointerGetDatum(new_data); }
/* * Generate a new on-disk tuple to be inserted in a BRIN index. * * See brin_form_placeholder_tuple if you touch this. */ BrinTuple * brin_form_tuple(BrinDesc *brdesc, BlockNumber blkno, BrinMemTuple *tuple, Size *size) { Datum *values; bool *nulls; bool anynulls = false; BrinTuple *rettuple; int keyno; int idxattno; uint16 phony_infomask = 0; bits8 *phony_nullbitmap; Size len, hoff, data_len; Assert(brdesc->bd_totalstored > 0); values = (Datum *) palloc(sizeof(Datum) * brdesc->bd_totalstored); nulls = (bool *) palloc0(sizeof(bool) * brdesc->bd_totalstored); phony_nullbitmap = (bits8 *) palloc(sizeof(bits8) * BITMAPLEN(brdesc->bd_totalstored)); /* * Set up the values/nulls arrays for heap_fill_tuple */ idxattno = 0; for (keyno = 0; keyno < brdesc->bd_tupdesc->natts; keyno++) { int datumno; /* * "allnulls" is set when there's no nonnull value in any row in the * column; when this happens, there is no data to store. Thus set the * nullable bits for all data elements of this column and we're done. */ if (tuple->bt_columns[keyno].bv_allnulls) { for (datumno = 0; datumno < brdesc->bd_info[keyno]->oi_nstored; datumno++) nulls[idxattno++] = true; anynulls = true; continue; } /* * The "hasnulls" bit is set when there are some null values in the * data. We still need to store a real value, but the presence of * this means we need a null bitmap. */ if (tuple->bt_columns[keyno].bv_hasnulls) anynulls = true; for (datumno = 0; datumno < brdesc->bd_info[keyno]->oi_nstored; datumno++) values[idxattno++] = tuple->bt_columns[keyno].bv_values[datumno]; } /* Assert we did not overrun temp arrays */ Assert(idxattno <= brdesc->bd_totalstored); /* compute total space needed */ len = SizeOfBrinTuple; if (anynulls) { /* * We need a double-length bitmap on an on-disk BRIN index tuple; the * first half stores the "allnulls" bits, the second stores * "hasnulls". */ len += BITMAPLEN(brdesc->bd_tupdesc->natts * 2); } len = hoff = MAXALIGN(len); data_len = heap_compute_data_size(brtuple_disk_tupdesc(brdesc), values, nulls); len += data_len; len = MAXALIGN(len); rettuple = palloc0(len); rettuple->bt_blkno = blkno; rettuple->bt_info = hoff; /* Assert that hoff fits in the space available */ Assert((rettuple->bt_info & BRIN_OFFSET_MASK) == hoff); /* * The infomask and null bitmap as computed by heap_fill_tuple are useless * to us. However, that function will not accept a null infomask; and we * need to pass a valid null bitmap so that it will correctly skip * outputting null attributes in the data area. */ heap_fill_tuple(brtuple_disk_tupdesc(brdesc), values, nulls, (char *) rettuple + hoff, data_len, &phony_infomask, phony_nullbitmap); /* done with these */ pfree(values); pfree(nulls); pfree(phony_nullbitmap); /* * Now fill in the real null bitmasks. allnulls first. */ if (anynulls) { bits8 *bitP; int bitmask; rettuple->bt_info |= BRIN_NULLS_MASK; /* * Note that we reverse the sense of null bits in this module: we * store a 1 for a null attribute rather than a 0. So we must reverse * the sense of the att_isnull test in br_deconstruct_tuple as well. */ bitP = ((bits8 *) ((char *) rettuple + SizeOfBrinTuple)) - 1; bitmask = HIGHBIT; for (keyno = 0; keyno < brdesc->bd_tupdesc->natts; keyno++) { if (bitmask != HIGHBIT) bitmask <<= 1; else { bitP += 1; *bitP = 0x0; bitmask = 1; } if (!tuple->bt_columns[keyno].bv_allnulls) continue; *bitP |= bitmask; } /* hasnulls bits follow */ for (keyno = 0; keyno < brdesc->bd_tupdesc->natts; keyno++) { if (bitmask != HIGHBIT) bitmask <<= 1; else { bitP += 1; *bitP = 0x0; bitmask = 1; } if (!tuple->bt_columns[keyno].bv_hasnulls) continue; *bitP |= bitmask; } bitP = ((bits8 *) (rettuple + SizeOfBrinTuple)) - 1; } if (tuple->bt_placeholder) rettuple->bt_info |= BRIN_PLACEHOLDER_MASK; *size = len; return rettuple; }
/* ---------- * toast_insert_or_update - * * Delete no-longer-used toast-entries and create new ones to * make the new tuple fit on INSERT or UPDATE * * Inputs: * newtup: the candidate new tuple to be inserted * oldtup: the old row version for UPDATE, or NULL for INSERT * options: options to be passed to heap_insert() for toast rows * Result: * either newtup if no toasting is needed, or a palloc'd modified tuple * that is what should actually get stored * * NOTE: neither newtup nor oldtup will be modified. This is a change * from the pre-8.1 API of this routine. * ---------- */ HeapTuple toast_insert_or_update(Relation rel, HeapTuple newtup, HeapTuple oldtup, int options) { HeapTuple result_tuple; TupleDesc tupleDesc; Form_pg_attribute *att; int numAttrs; int i; bool need_change = false; bool need_free = false; bool need_delold = false; bool has_nulls = false; Size maxDataLen; Size hoff; char toast_action[MaxHeapAttributeNumber]; bool toast_isnull[MaxHeapAttributeNumber]; bool toast_oldisnull[MaxHeapAttributeNumber]; Datum toast_values[MaxHeapAttributeNumber]; Datum toast_oldvalues[MaxHeapAttributeNumber]; int32 toast_sizes[MaxHeapAttributeNumber]; bool toast_free[MaxHeapAttributeNumber]; bool toast_delold[MaxHeapAttributeNumber]; /* * We should only ever be called for tuples of plain relations --- * recursing on a toast rel is bad news. */ Assert(rel->rd_rel->relkind == RELKIND_RELATION); /* * Get the tuple descriptor and break down the tuple(s) into fields. */ tupleDesc = rel->rd_att; att = tupleDesc->attrs; numAttrs = tupleDesc->natts; Assert(numAttrs <= MaxHeapAttributeNumber); heap_deform_tuple(newtup, tupleDesc, toast_values, toast_isnull); if (oldtup != NULL) heap_deform_tuple(oldtup, tupleDesc, toast_oldvalues, toast_oldisnull); /* ---------- * Then collect information about the values given * * NOTE: toast_action[i] can have these values: * ' ' default handling * 'p' already processed --- don't touch it * 'x' incompressible, but OK to move off * * NOTE: toast_sizes[i] is only made valid for varlena attributes with * toast_action[i] different from 'p'. * ---------- */ memset(toast_action, ' ', numAttrs * sizeof(char)); memset(toast_free, 0, numAttrs * sizeof(bool)); memset(toast_delold, 0, numAttrs * sizeof(bool)); for (i = 0; i < numAttrs; i++) { struct varlena *old_value; struct varlena *new_value; if (oldtup != NULL) { /* * For UPDATE get the old and new values of this attribute */ old_value = (struct varlena *) DatumGetPointer(toast_oldvalues[i]); new_value = (struct varlena *) DatumGetPointer(toast_values[i]); /* * If the old value is an external stored one, check if it has * changed so we have to delete it later. */ if (att[i]->attlen == -1 && !toast_oldisnull[i] && VARATT_IS_EXTERNAL(old_value)) { if (toast_isnull[i] || !VARATT_IS_EXTERNAL(new_value) || memcmp((char *) old_value, (char *) new_value, VARSIZE_EXTERNAL(old_value)) != 0) { /* * The old external stored value isn't needed any more * after the update */ toast_delold[i] = true; need_delold = true; } else { /* * This attribute isn't changed by this update so we reuse * the original reference to the old value in the new * tuple. */ toast_action[i] = 'p'; continue; } } } else { /* * For INSERT simply get the new value */ new_value = (struct varlena *) DatumGetPointer(toast_values[i]); } /* * Handle NULL attributes */ if (toast_isnull[i]) { toast_action[i] = 'p'; has_nulls = true; continue; } /* * Now look at varlena attributes */ if (att[i]->attlen == -1) { /* * If the table's attribute says PLAIN always, force it so. */ if (att[i]->attstorage == 'p') toast_action[i] = 'p'; /* * We took care of UPDATE above, so any external value we find * still in the tuple must be someone else's we cannot reuse. * Fetch it back (without decompression, unless we are forcing * PLAIN storage). If necessary, we'll push it out as a new * external value below. */ if (VARATT_IS_EXTERNAL(new_value)) { if (att[i]->attstorage == 'p') new_value = heap_tuple_untoast_attr(new_value); else new_value = heap_tuple_fetch_attr(new_value); toast_values[i] = PointerGetDatum(new_value); toast_free[i] = true; need_change = true; need_free = true; } /* * Remember the size of this attribute */ toast_sizes[i] = VARSIZE_ANY(new_value); } else { /* * Not a varlena attribute, plain storage always */ toast_action[i] = 'p'; } } /* ---------- * Compress and/or save external until data fits into target length * * 1: Inline compress attributes with attstorage 'x', and store very * large attributes with attstorage 'x' or 'e' external immediately * 2: Store attributes with attstorage 'x' or 'e' external * 3: Inline compress attributes with attstorage 'm' * 4: Store attributes with attstorage 'm' external * ---------- */ /* compute header overhead --- this should match heap_form_tuple() */ hoff = offsetof(HeapTupleHeaderData, t_bits); if (has_nulls) hoff += BITMAPLEN(numAttrs); if (newtup->t_data->t_infomask & HEAP_HASOID) hoff += sizeof(Oid); hoff = MAXALIGN(hoff); Assert(hoff == newtup->t_data->t_hoff); /* now convert to a limit on the tuple data size */ maxDataLen = TOAST_TUPLE_TARGET - hoff; /* * Look for attributes with attstorage 'x' to compress. Also find large * attributes with attstorage 'x' or 'e', and store them external. */ while (heap_compute_data_size(tupleDesc, toast_values, toast_isnull) > maxDataLen) { int biggest_attno = -1; int32 biggest_size = MAXALIGN(TOAST_POINTER_SIZE); Datum old_value; Datum new_value; /* * Search for the biggest yet unprocessed internal attribute */ for (i = 0; i < numAttrs; i++) { if (toast_action[i] != ' ') continue; if (VARATT_IS_EXTERNAL(DatumGetPointer(toast_values[i]))) continue; /* can't happen, toast_action would be 'p' */ if (VARATT_IS_COMPRESSED(DatumGetPointer(toast_values[i]))) continue; if (att[i]->attstorage != 'x' && att[i]->attstorage != 'e') continue; if (toast_sizes[i] > biggest_size) { biggest_attno = i; biggest_size = toast_sizes[i]; } } if (biggest_attno < 0) break; /* * Attempt to compress it inline, if it has attstorage 'x' */ i = biggest_attno; if (att[i]->attstorage == 'x') { old_value = toast_values[i]; new_value = toast_compress_datum(old_value); if (DatumGetPointer(new_value) != NULL) { /* successful compression */ if (toast_free[i]) pfree(DatumGetPointer(old_value)); toast_values[i] = new_value; toast_free[i] = true; toast_sizes[i] = VARSIZE(DatumGetPointer(toast_values[i])); need_change = true; need_free = true; } else { /* incompressible, ignore on subsequent compression passes */ toast_action[i] = 'x'; } } else { /* has attstorage 'e', ignore on subsequent compression passes */ toast_action[i] = 'x'; } /* * If this value is by itself more than maxDataLen (after compression * if any), push it out to the toast table immediately, if possible. * This avoids uselessly compressing other fields in the common case * where we have one long field and several short ones. * * XXX maybe the threshold should be less than maxDataLen? */ if (toast_sizes[i] > maxDataLen && rel->rd_rel->reltoastrelid != InvalidOid) { old_value = toast_values[i]; toast_action[i] = 'p'; toast_values[i] = toast_save_datum(rel, toast_values[i], options); if (toast_free[i]) pfree(DatumGetPointer(old_value)); toast_free[i] = true; need_change = true; need_free = true; } } /* * Second we look for attributes of attstorage 'x' or 'e' that are still * inline. But skip this if there's no toast table to push them to. */ while (heap_compute_data_size(tupleDesc, toast_values, toast_isnull) > maxDataLen && rel->rd_rel->reltoastrelid != InvalidOid) { int biggest_attno = -1; int32 biggest_size = MAXALIGN(TOAST_POINTER_SIZE); Datum old_value; /*------ * Search for the biggest yet inlined attribute with * attstorage equals 'x' or 'e' *------ */ for (i = 0; i < numAttrs; i++) { if (toast_action[i] == 'p') continue; if (VARATT_IS_EXTERNAL(DatumGetPointer(toast_values[i]))) continue; /* can't happen, toast_action would be 'p' */ if (att[i]->attstorage != 'x' && att[i]->attstorage != 'e') continue; if (toast_sizes[i] > biggest_size) { biggest_attno = i; biggest_size = toast_sizes[i]; } } if (biggest_attno < 0) break; /* * Store this external */ i = biggest_attno; old_value = toast_values[i]; toast_action[i] = 'p'; toast_values[i] = toast_save_datum(rel, toast_values[i], options); if (toast_free[i]) pfree(DatumGetPointer(old_value)); toast_free[i] = true; need_change = true; need_free = true; } /* * Round 3 - this time we take attributes with storage 'm' into * compression */ while (heap_compute_data_size(tupleDesc, toast_values, toast_isnull) > maxDataLen) { int biggest_attno = -1; int32 biggest_size = MAXALIGN(TOAST_POINTER_SIZE); Datum old_value; Datum new_value; /* * Search for the biggest yet uncompressed internal attribute */ for (i = 0; i < numAttrs; i++) { if (toast_action[i] != ' ') continue; if (VARATT_IS_EXTERNAL(DatumGetPointer(toast_values[i]))) continue; /* can't happen, toast_action would be 'p' */ if (VARATT_IS_COMPRESSED(DatumGetPointer(toast_values[i]))) continue; if (att[i]->attstorage != 'm') continue; if (toast_sizes[i] > biggest_size) { biggest_attno = i; biggest_size = toast_sizes[i]; } } if (biggest_attno < 0) break; /* * Attempt to compress it inline */ i = biggest_attno; old_value = toast_values[i]; new_value = toast_compress_datum(old_value); if (DatumGetPointer(new_value) != NULL) { /* successful compression */ if (toast_free[i]) pfree(DatumGetPointer(old_value)); toast_values[i] = new_value; toast_free[i] = true; toast_sizes[i] = VARSIZE(DatumGetPointer(toast_values[i])); need_change = true; need_free = true; } else { /* incompressible, ignore on subsequent compression passes */ toast_action[i] = 'x'; } } /* * Finally we store attributes of type 'm' externally. At this point we * increase the target tuple size, so that 'm' attributes aren't stored * externally unless really necessary. */ maxDataLen = TOAST_TUPLE_TARGET_MAIN - hoff; while (heap_compute_data_size(tupleDesc, toast_values, toast_isnull) > maxDataLen && rel->rd_rel->reltoastrelid != InvalidOid) { int biggest_attno = -1; int32 biggest_size = MAXALIGN(TOAST_POINTER_SIZE); Datum old_value; /*-------- * Search for the biggest yet inlined attribute with * attstorage = 'm' *-------- */ for (i = 0; i < numAttrs; i++) { if (toast_action[i] == 'p') continue; if (VARATT_IS_EXTERNAL(DatumGetPointer(toast_values[i]))) continue; /* can't happen, toast_action would be 'p' */ if (att[i]->attstorage != 'm') continue; if (toast_sizes[i] > biggest_size) { biggest_attno = i; biggest_size = toast_sizes[i]; } } if (biggest_attno < 0) break; /* * Store this external */ i = biggest_attno; old_value = toast_values[i]; toast_action[i] = 'p'; toast_values[i] = toast_save_datum(rel, toast_values[i], options); if (toast_free[i]) pfree(DatumGetPointer(old_value)); toast_free[i] = true; need_change = true; need_free = true; } /* * In the case we toasted any values, we need to build a new heap tuple * with the changed values. */ if (need_change) { HeapTupleHeader olddata = newtup->t_data; HeapTupleHeader new_data; int32 new_len; int32 new_data_len; /* * 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_data_len = heap_compute_data_size(tupleDesc, toast_values, toast_isnull); new_len += new_data_len; /* * Allocate and zero the space needed, and fill HeapTupleData fields. */ result_tuple = (HeapTuple) palloc0(HEAPTUPLESIZE + new_len); result_tuple->t_len = new_len; result_tuple->t_self = newtup->t_self; result_tuple->t_tableOid = newtup->t_tableOid; new_data = (HeapTupleHeader) ((char *) result_tuple + HEAPTUPLESIZE); result_tuple->t_data = new_data; /* * Put the existing tuple header and the changed values into place */ memcpy(new_data, olddata, olddata->t_hoff); heap_fill_tuple(tupleDesc, toast_values, toast_isnull, (char *) new_data + olddata->t_hoff, new_data_len, &(new_data->t_infomask), has_nulls ? new_data->t_bits : NULL); } else result_tuple = newtup; /* * Free allocated temp values */ if (need_free) for (i = 0; i < numAttrs; i++) if (toast_free[i]) pfree(DatumGetPointer(toast_values[i])); /* * Delete external values from the old tuple */ if (need_delold) for (i = 0; i < numAttrs; i++) if (toast_delold[i]) toast_delete_datum(rel, toast_oldvalues[i]); return result_tuple; }
/* ---------------- * index_form_tuple * * This shouldn't leak any memory; otherwise, callers such as * tuplesort_putindextuplevalues() will be very unhappy. * ---------------- */ IndexTuple index_form_tuple(TupleDesc tupleDescriptor, Datum *values, bool *isnull) { char *tp; /* tuple pointer */ IndexTuple tuple; /* return tuple */ Size size, data_size, hoff; int i; unsigned short infomask = 0; bool hasnull = false; uint16 tupmask = 0; int numberOfAttributes = tupleDescriptor->natts; #ifdef TOAST_INDEX_HACK Datum untoasted_values[INDEX_MAX_KEYS]; bool untoasted_free[INDEX_MAX_KEYS]; #endif if (numberOfAttributes > INDEX_MAX_KEYS) ereport(ERROR, (errcode(ERRCODE_TOO_MANY_COLUMNS), errmsg("number of index columns (%d) exceeds limit (%d)", numberOfAttributes, INDEX_MAX_KEYS))); #ifdef TOAST_INDEX_HACK for (i = 0; i < numberOfAttributes; i++) { Form_pg_attribute att = tupleDescriptor->attrs[i]; untoasted_values[i] = values[i]; untoasted_free[i] = false; /* Do nothing if value is NULL or not of varlena type */ if (isnull[i] || att->attlen != -1) continue; /* * If value is stored EXTERNAL, must fetch it so we are not depending * on outside storage. This should be improved someday. */ if (VARATT_IS_EXTERNAL(DatumGetPointer(values[i]))) { untoasted_values[i] = PointerGetDatum(heap_tuple_fetch_attr((struct varlena *) DatumGetPointer(values[i]))); untoasted_free[i] = true; } /* * If value is above size target, and is of a compressible datatype, * try to compress it in-line. */ if (!VARATT_IS_EXTENDED(DatumGetPointer(untoasted_values[i])) && VARSIZE(DatumGetPointer(untoasted_values[i])) > TOAST_INDEX_TARGET && (att->attstorage == 'x' || att->attstorage == 'm')) { Datum cvalue = toast_compress_datum(untoasted_values[i]); if (DatumGetPointer(cvalue) != NULL) { /* successful compression */ if (untoasted_free[i]) pfree(DatumGetPointer(untoasted_values[i])); untoasted_values[i] = cvalue; untoasted_free[i] = true; } } } #endif for (i = 0; i < numberOfAttributes; i++) { if (isnull[i]) { hasnull = true; break; } } if (hasnull) infomask |= INDEX_NULL_MASK; hoff = IndexInfoFindDataOffset(infomask); #ifdef TOAST_INDEX_HACK data_size = heap_compute_data_size(tupleDescriptor, untoasted_values, isnull); #else data_size = heap_compute_data_size(tupleDescriptor, values, isnull); #endif size = hoff + data_size; size = MAXALIGN(size); /* be conservative */ tp = (char *) palloc0(size); tuple = (IndexTuple) tp; heap_fill_tuple(tupleDescriptor, #ifdef TOAST_INDEX_HACK untoasted_values, #else values, #endif isnull, (char *) tp + hoff, data_size, &tupmask, (hasnull ? (bits8 *) tp + sizeof(IndexTupleData) : NULL)); #ifdef TOAST_INDEX_HACK for (i = 0; i < numberOfAttributes; i++) { if (untoasted_free[i]) pfree(DatumGetPointer(untoasted_values[i])); } #endif /* * We do this because heap_fill_tuple wants to initialize a "tupmask" * which is used for HeapTuples, but we want an indextuple infomask. The * only relevant info is the "has variable attributes" field. We have * already set the hasnull bit above. */ if (tupmask & HEAP_HASVARWIDTH) infomask |= INDEX_VAR_MASK; /* Also assert we got rid of external attributes */ #ifdef TOAST_INDEX_HACK Assert((tupmask & HEAP_HASEXTERNAL) == 0); #endif /* * Here we make sure that the size will fit in the field reserved for it * in t_info. */ if ((size & INDEX_SIZE_MASK) != size) ereport(ERROR, (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED), errmsg("index row requires %zu bytes, maximum size is %zu", size, (Size) INDEX_SIZE_MASK))); infomask |= size; /* * initialize metadata */ tuple->t_info = infomask; return tuple; }
/* ---------- * toast_insert_or_update - * * Delete no-longer-used toast-entries and create new ones to * make the new tuple fit on INSERT or UPDATE * * Inputs: * newtup: the candidate new tuple to be inserted * oldtup: the old row version for UPDATE, or NULL for INSERT * Result: * either newtup if no toasting is needed, or a palloc'd modified tuple * that is what should actually get stored * * NOTE: neither newtup nor oldtup will be modified. This is a change * from the pre-8.1 API of this routine. * ---------- */ HeapTuple toast_insert_or_update(Relation rel, HeapTuple newtup, HeapTuple oldtup) { HeapTuple result_tuple; TupleDesc tupleDesc; Form_pg_attribute *att; int numAttrs; int i; bool need_change = false; bool need_free = false; bool need_delold = false; bool has_nulls = false; Size maxDataLen; char toast_action[MaxHeapAttributeNumber]; bool toast_isnull[MaxHeapAttributeNumber]; bool toast_oldisnull[MaxHeapAttributeNumber]; Datum toast_values[MaxHeapAttributeNumber]; Datum toast_oldvalues[MaxHeapAttributeNumber]; int32 toast_sizes[MaxHeapAttributeNumber]; bool toast_free[MaxHeapAttributeNumber]; bool toast_delold[MaxHeapAttributeNumber]; /* * Get the tuple descriptor and break down the tuple(s) into fields. */ tupleDesc = rel->rd_att; att = tupleDesc->attrs; numAttrs = tupleDesc->natts; Assert(numAttrs <= MaxHeapAttributeNumber); heap_deform_tuple(newtup, tupleDesc, toast_values, toast_isnull); if (oldtup != NULL) heap_deform_tuple(oldtup, tupleDesc, toast_oldvalues, toast_oldisnull); /* ---------- * Then collect information about the values given * * NOTE: toast_action[i] can have these values: * ' ' default handling * 'p' already processed --- don't touch it * 'x' incompressible, but OK to move off * * NOTE: toast_sizes[i] is only made valid for varlena attributes with * toast_action[i] different from 'p'. * ---------- */ memset(toast_action, ' ', numAttrs * sizeof(char)); memset(toast_free, 0, numAttrs * sizeof(bool)); memset(toast_delold, 0, numAttrs * sizeof(bool)); for (i = 0; i < numAttrs; i++) { varattrib *old_value; varattrib *new_value; if (oldtup != NULL) { /* * For UPDATE get the old and new values of this attribute */ old_value = (varattrib *) DatumGetPointer(toast_oldvalues[i]); new_value = (varattrib *) DatumGetPointer(toast_values[i]); /* * If the old value is an external stored one, check if it has * changed so we have to delete it later. */ if (att[i]->attlen == -1 && !toast_oldisnull[i] && VARATT_IS_EXTERNAL(old_value)) { if (toast_isnull[i] || !VARATT_IS_EXTERNAL(new_value) || old_value->va_content.va_external.va_valueid != new_value->va_content.va_external.va_valueid || old_value->va_content.va_external.va_toastrelid != new_value->va_content.va_external.va_toastrelid) { /* * The old external stored value isn't needed any more * after the update */ toast_delold[i] = true; need_delold = true; } else { /* * This attribute isn't changed by this update so we reuse * the original reference to the old value in the new * tuple. */ toast_action[i] = 'p'; toast_sizes[i] = VARATT_SIZE(toast_values[i]); continue; } } } else { /* * For INSERT simply get the new value */ new_value = (varattrib *) DatumGetPointer(toast_values[i]); } /* * Handle NULL attributes */ if (toast_isnull[i]) { toast_action[i] = 'p'; has_nulls = true; continue; } /* * Now look at varlena attributes */ if (att[i]->attlen == -1) { /* * If the table's attribute says PLAIN always, force it so. */ if (att[i]->attstorage == 'p') toast_action[i] = 'p'; /* * We took care of UPDATE above, so any external value we find * 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(new_value)) { new_value = heap_tuple_untoast_attr(new_value); toast_values[i] = PointerGetDatum(new_value); toast_free[i] = true; need_change = true; need_free = true; } /* * Remember the size of this attribute */ toast_sizes[i] = VARATT_SIZE(new_value); } else { /* * Not a varlena attribute, plain storage always */ toast_action[i] = 'p'; } } /* ---------- * Compress and/or save external until data fits into target length * * 1: Inline compress attributes with attstorage 'x' * 2: Store attributes with attstorage 'x' or 'e' external * 3: Inline compress attributes with attstorage 'm' * 4: Store attributes with attstorage 'm' external * ---------- */ maxDataLen = offsetof(HeapTupleHeaderData, t_bits); if (has_nulls) maxDataLen += BITMAPLEN(numAttrs); maxDataLen = TOAST_TUPLE_TARGET - MAXALIGN(maxDataLen); /* * Look for attributes with attstorage 'x' to compress */ while (MAXALIGN(heap_compute_data_size(tupleDesc, toast_values, toast_isnull)) > maxDataLen) { int biggest_attno = -1; int32 biggest_size = MAXALIGN(sizeof(varattrib)); Datum old_value; Datum new_value; /* * Search for the biggest yet uncompressed internal attribute */ for (i = 0; i < numAttrs; i++) { if (toast_action[i] != ' ') continue; if (VARATT_IS_EXTENDED(toast_values[i])) continue; if (att[i]->attstorage != 'x') continue; if (toast_sizes[i] > biggest_size) { biggest_attno = i; biggest_size = toast_sizes[i]; } } if (biggest_attno < 0) break; /* * Attempt to compress it inline */ i = biggest_attno; old_value = toast_values[i]; new_value = toast_compress_datum(old_value); if (DatumGetPointer(new_value) != NULL) { /* successful compression */ if (toast_free[i]) pfree(DatumGetPointer(old_value)); toast_values[i] = new_value; toast_free[i] = true; toast_sizes[i] = VARATT_SIZE(toast_values[i]); need_change = true; need_free = true; } else { /* * incompressible data, ignore on subsequent compression passes */ toast_action[i] = 'x'; } } /* * Second we look for attributes of attstorage 'x' or 'e' that are still * inline. */ while (MAXALIGN(heap_compute_data_size(tupleDesc, toast_values, toast_isnull)) > maxDataLen && rel->rd_rel->reltoastrelid != InvalidOid) { int biggest_attno = -1; int32 biggest_size = MAXALIGN(sizeof(varattrib)); Datum old_value; /*------ * Search for the biggest yet inlined attribute with * attstorage equals 'x' or 'e' *------ */ for (i = 0; i < numAttrs; i++) { if (toast_action[i] == 'p') continue; if (VARATT_IS_EXTERNAL(toast_values[i])) continue; if (att[i]->attstorage != 'x' && att[i]->attstorage != 'e') continue; if (toast_sizes[i] > biggest_size) { biggest_attno = i; biggest_size = toast_sizes[i]; } } if (biggest_attno < 0) break; /* * Store this external */ i = biggest_attno; old_value = toast_values[i]; toast_action[i] = 'p'; toast_values[i] = toast_save_datum(rel, toast_values[i]); if (toast_free[i]) pfree(DatumGetPointer(old_value)); toast_free[i] = true; toast_sizes[i] = VARATT_SIZE(toast_values[i]); need_change = true; need_free = true; } /* * Round 3 - this time we take attributes with storage 'm' into * compression */ while (MAXALIGN(heap_compute_data_size(tupleDesc, toast_values, toast_isnull)) > maxDataLen) { int biggest_attno = -1; int32 biggest_size = MAXALIGN(sizeof(varattrib)); Datum old_value; Datum new_value; /* * Search for the biggest yet uncompressed internal attribute */ for (i = 0; i < numAttrs; i++) { if (toast_action[i] != ' ') continue; if (VARATT_IS_EXTENDED(toast_values[i])) continue; if (att[i]->attstorage != 'm') continue; if (toast_sizes[i] > biggest_size) { biggest_attno = i; biggest_size = toast_sizes[i]; } } if (biggest_attno < 0) break; /* * Attempt to compress it inline */ i = biggest_attno; old_value = toast_values[i]; new_value = toast_compress_datum(old_value); if (DatumGetPointer(new_value) != NULL) { /* successful compression */ if (toast_free[i]) pfree(DatumGetPointer(old_value)); toast_values[i] = new_value; toast_free[i] = true; toast_sizes[i] = VARATT_SIZE(toast_values[i]); need_change = true; need_free = true; } else { /* * incompressible data, ignore on subsequent compression passes */ toast_action[i] = 'x'; } } /* * Finally we store attributes of type 'm' external */ while (MAXALIGN(heap_compute_data_size(tupleDesc, toast_values, toast_isnull)) > maxDataLen && rel->rd_rel->reltoastrelid != InvalidOid) { int biggest_attno = -1; int32 biggest_size = MAXALIGN(sizeof(varattrib)); Datum old_value; /*-------- * Search for the biggest yet inlined attribute with * attstorage = 'm' *-------- */ for (i = 0; i < numAttrs; i++) { if (toast_action[i] == 'p') continue; if (VARATT_IS_EXTERNAL(toast_values[i])) continue; if (att[i]->attstorage != 'm') continue; if (toast_sizes[i] > biggest_size) { biggest_attno = i; biggest_size = toast_sizes[i]; } } if (biggest_attno < 0) break; /* * Store this external */ i = biggest_attno; old_value = toast_values[i]; toast_action[i] = 'p'; toast_values[i] = toast_save_datum(rel, toast_values[i]); if (toast_free[i]) pfree(DatumGetPointer(old_value)); toast_free[i] = true; toast_sizes[i] = VARATT_SIZE(toast_values[i]); need_change = true; need_free = true; } /* * In the case we toasted any values, we need to build a new heap tuple * with the changed values. */ if (need_change) { HeapTupleHeader olddata = newtup->t_data; HeapTupleHeader new_data; int32 new_len; /* * 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 += heap_compute_data_size(tupleDesc, toast_values, toast_isnull); /* * Allocate and zero the space needed, and fill HeapTupleData fields. */ result_tuple = (HeapTuple) palloc0(HEAPTUPLESIZE + new_len); result_tuple->t_len = new_len; result_tuple->t_self = newtup->t_self; result_tuple->t_tableOid = newtup->t_tableOid; result_tuple->t_datamcxt = CurrentMemoryContext; new_data = (HeapTupleHeader) ((char *) result_tuple + HEAPTUPLESIZE); result_tuple->t_data = new_data; /* * Put the existing tuple header and the changed values into place */ memcpy(new_data, olddata, olddata->t_hoff); heap_fill_tuple(tupleDesc, toast_values, toast_isnull, (char *) new_data + olddata->t_hoff, &(new_data->t_infomask), has_nulls ? new_data->t_bits : NULL); } else result_tuple = newtup; /* * Free allocated temp values */ if (need_free) for (i = 0; i < numAttrs; i++) if (toast_free[i]) pfree(DatumGetPointer(toast_values[i])); /* * Delete external values from the old tuple */ if (need_delold) for (i = 0; i < numAttrs; i++) if (toast_delold[i]) toast_delete_datum(rel, toast_oldvalues[i]); return result_tuple; }
/* * heap_formtuple * * construct a tuple from the given values[] and nulls[] arrays * * Null attributes are indicated by a 'n' in the appropriate byte * of nulls[]. Non-null attributes are indicated by a ' ' (space). * * OLD API with char 'n'/' ' convention for indicating nulls. * This is deprecated and should not be used in new code, but we keep it * around for use by old add-on modules. */ HeapTuple heap_formtuple(TupleDesc tupleDescriptor, Datum *values, char *nulls) { HeapTuple tuple; /* return tuple */ HeapTupleHeader td; /* tuple data */ Size len, data_len; int hoff; bool hasnull = false; Form_pg_attribute *att = tupleDescriptor->attrs; int numberOfAttributes = tupleDescriptor->natts; int i; if (numberOfAttributes > MaxTupleAttributeNumber) ereport(ERROR, (errcode(ERRCODE_TOO_MANY_COLUMNS), errmsg("number of columns (%d) exceeds limit (%d)", numberOfAttributes, MaxTupleAttributeNumber))); /* * Check for nulls and embedded tuples; expand any toasted attributes in * embedded tuples. This preserves the invariant that toasting can only * go one level deep. * * We can skip calling toast_flatten_tuple_attribute() if the attribute * couldn't possibly be of composite type. All composite datums are * varlena and have alignment 'd'; furthermore they aren't arrays. Also, * if an attribute is already toasted, it must have been sent to disk * already and so cannot contain toasted attributes. */ for (i = 0; i < numberOfAttributes; i++) { if (nulls[i] != ' ') hasnull = true; else if (att[i]->attlen == -1 && att[i]->attalign == 'd' && att[i]->attndims == 0 && !VARATT_IS_EXTENDED(values[i])) { values[i] = toast_flatten_tuple_attribute(values[i], att[i]->atttypid, att[i]->atttypmod); } } /* * Determine total space needed */ len = offsetof(HeapTupleHeaderData, t_bits); if (hasnull) len += BITMAPLEN(numberOfAttributes); if (tupleDescriptor->tdhasoid) len += sizeof(Oid); hoff = len = MAXALIGN(len); /* align user data safely */ data_len = ComputeDataSize(tupleDescriptor, values, nulls); len += data_len; /* * Allocate and zero the space needed. Note that the tuple body and * HeapTupleData management structure are allocated in one chunk. */ tuple = (HeapTuple) palloc0(HEAPTUPLESIZE + len); tuple->t_data = td = (HeapTupleHeader) ((char *) tuple + HEAPTUPLESIZE); /* * And fill in the information. Note we fill the Datum fields even though * this tuple may never become a Datum. */ tuple->t_len = len; ItemPointerSetInvalid(&(tuple->t_self)); HeapTupleHeaderSetDatumLength(td, len); HeapTupleHeaderSetTypeId(td, tupleDescriptor->tdtypeid); HeapTupleHeaderSetTypMod(td, tupleDescriptor->tdtypmod); HeapTupleHeaderSetNatts(td, numberOfAttributes); td->t_hoff = hoff; if (tupleDescriptor->tdhasoid) /* else leave infomask = 0 */ td->t_infomask = HEAP_HASOID; heap_fill_tuple(tupleDescriptor, values, nulls, (char *) td + hoff, data_len, &td->t_infomask, (hasnull ? td->t_bits : NULL)); return tuple; }
/* * heap_form_minimal_tuple * construct a MinimalTuple from the given values[] and isnull[] arrays, * which are of the length indicated by tupleDescriptor->natts * * This is exactly like heap_form_tuple() except that the result is a * "minimal" tuple lacking a HeapTupleData header as well as room for system * columns. * * The result is allocated in the current memory context. */ MinimalTuple heap_form_minimal_tuple(TupleDesc tupleDescriptor, Datum *values, bool *isnull) { MinimalTuple tuple; /* return tuple */ Size len, data_len; int hoff; bool hasnull = false; Form_pg_attribute *att = tupleDescriptor->attrs; int numberOfAttributes = tupleDescriptor->natts; int i; if (numberOfAttributes > MaxTupleAttributeNumber) ereport(ERROR, (errcode(ERRCODE_TOO_MANY_COLUMNS), errmsg("number of columns (%d) exceeds limit (%d)", numberOfAttributes, MaxTupleAttributeNumber))); /* * Check for nulls and embedded tuples; expand any toasted attributes in * embedded tuples. This preserves the invariant that toasting can only * go one level deep. * * We can skip calling toast_flatten_tuple_attribute() if the attribute * couldn't possibly be of composite type. All composite datums are * varlena and have alignment 'd'; furthermore they aren't arrays. Also, * if an attribute is already toasted, it must have been sent to disk * already and so cannot contain toasted attributes. */ for (i = 0; i < numberOfAttributes; i++) { if (isnull[i]) hasnull = true; else if (att[i]->attlen == -1 && att[i]->attalign == 'd' && att[i]->attndims == 0 && !VARATT_IS_EXTENDED(values[i])) { values[i] = toast_flatten_tuple_attribute(values[i], att[i]->atttypid, att[i]->atttypmod); } } /* * Determine total space needed */ len = offsetof(MinimalTupleData, t_bits); if (hasnull) len += BITMAPLEN(numberOfAttributes); if (tupleDescriptor->tdhasoid) len += sizeof(Oid); hoff = len = MAXALIGN(len); /* align user data safely */ data_len = heap_compute_data_size(tupleDescriptor, values, isnull); len += data_len; /* * Allocate and zero the space needed. */ tuple = (MinimalTuple) palloc0(len); /* * And fill in the information. */ tuple->t_len = len; HeapTupleHeaderSetNatts(tuple, numberOfAttributes); tuple->t_hoff = hoff + MINIMAL_TUPLE_OFFSET; if (tupleDescriptor->tdhasoid) /* else leave infomask = 0 */ tuple->t_infomask = HEAP_HASOID; heap_fill_tuple(tupleDescriptor, values, isnull, (char *) tuple + hoff, data_len, &tuple->t_infomask, (hasnull ? tuple->t_bits : NULL)); return tuple; }
/* * heap_form_tuple * construct a tuple from the given values[] and isnull[] arrays, * which are of the length indicated by tupleDescriptor->natts * * The result is allocated in the current memory context. */ HeapTuple heaptuple_form_to(TupleDesc tupleDescriptor, Datum *values, bool *isnull, HeapTuple dst, uint32 *dstlen) { HeapTuple tuple; /* return tuple */ HeapTupleHeader td; /* tuple data */ unsigned long len, predicted_len, actual_len; int hoff; bool hasnull = false; Form_pg_attribute *att = tupleDescriptor->attrs; int numberOfAttributes = tupleDescriptor->natts; int i; if (numberOfAttributes > MaxTupleAttributeNumber) ereport(ERROR, (errcode(ERRCODE_TOO_MANY_COLUMNS), errmsg("number of columns (%d) exceeds limit (%d)", numberOfAttributes, MaxTupleAttributeNumber))); /* * Check for nulls and embedded tuples; expand any toasted attributes in * embedded tuples. This preserves the invariant that toasting can only * go one level deep. * * We can skip calling toast_flatten_tuple_attribute() if the attribute * couldn't possibly be of composite type. All composite datums are * varlena and have alignment 'd'; furthermore they aren't arrays. Also, * if an attribute is already toasted, it must have been sent to disk * already and so cannot contain toasted attributes. */ for (i = 0; i < numberOfAttributes; i++) { if (isnull[i]) hasnull = true; else if (att[i]->attlen == -1 && att[i]->attalign == 'd' && att[i]->attndims == 0 && !VARATT_IS_EXTENDED_D(values[i])) { values[i] = toast_flatten_tuple_attribute(values[i], att[i]->atttypid, att[i]->atttypmod); } } /* * Determine total space needed */ len = offsetof(HeapTupleHeaderData, t_bits); if (hasnull) len += BITMAPLEN(numberOfAttributes); if (tupleDescriptor->tdhasoid) len += sizeof(Oid); hoff = len = MAXALIGN(len); /* align user data safely */ predicted_len = heap_compute_data_size(tupleDescriptor, values, isnull); len += predicted_len; if(dstlen && (*dstlen) < (HEAPTUPLESIZE + len)) { *dstlen = HEAPTUPLESIZE + len; return NULL; } if(dstlen) { *dstlen = HEAPTUPLESIZE + len; tuple = dst; } else tuple = (HeapTuple) palloc(HEAPTUPLESIZE + len); /* * Allocate and zero the space needed. Note that the tuple body and * HeapTupleData management structure are allocated in one chunk. */ tuple->t_data = td = (HeapTupleHeader) ((char *) tuple + HEAPTUPLESIZE); /* * And fill in the information. Note we fill the Datum fields even though * this tuple may never become a Datum. */ tuple->t_len = len; ItemPointerSetInvalid(&(tuple->t_self)); /* * The following 3 calls will setup the first 12 bytes of td (tuple->t_data) */ HeapTupleHeaderSetDatumLength(td, len); HeapTupleHeaderSetTypeId(td, tupleDescriptor->tdtypeid); HeapTupleHeaderSetTypMod(td, tupleDescriptor->tdtypmod); /* t_ctid does not matter */ /* num of attrs are stored in t_infomask2. Clear the other flags first */ td->t_infomask2 = 0; HeapTupleHeaderSetNatts(td, numberOfAttributes); /* * Set up t_hoff. This need to be done before set up t_infomask * because HeapTupleHeaderSetOid will use t_hoff */ td->t_hoff = hoff; if (tupleDescriptor->tdhasoid) { td->t_infomask = HEAP_HASOID; HeapTupleHeaderSetOid(td, InvalidOid); } else td->t_infomask = 0; /* Really fill in the data. */ actual_len = heap_fill_tuple(tupleDescriptor, values, isnull, (char *) td + hoff, &td->t_infomask, (hasnull ? td->t_bits : NULL)); Assert(predicted_len == actual_len); Assert(!is_heaptuple_memtuple(tuple)); return tuple; }