/* * Serialize a tuple directly into a buffer. * * We're called with at least enough space for a tuple-chunk-header. */ int SerializeTupleDirect(GenericTuple gtuple, SerTupInfo *pSerInfo, struct directTransportBuffer *b) { int natts; int dataSize = TUPLE_CHUNK_HEADER_SIZE; TupleDesc tupdesc; AssertArg(gtuple != NULL); AssertArg(pSerInfo != NULL); AssertArg(b != NULL); tupdesc = pSerInfo->tupdesc; natts = tupdesc->natts; do { if (natts == 0) { /* TC_EMTPY is just one chunk */ SetChunkType(b->pri, TC_EMPTY); SetChunkDataSize(b->pri, 0); break; } /* easy case */ if (is_memtuple(gtuple)) { MemTuple tuple = (MemTuple) gtuple; int tupleSize; int paddedSize; tupleSize = memtuple_get_size(tuple); paddedSize = TYPEALIGN(TUPLE_CHUNK_ALIGN, tupleSize); if (paddedSize + TUPLE_CHUNK_HEADER_SIZE > b->prilen) return 0; /* will fit. */ memcpy(b->pri + TUPLE_CHUNK_HEADER_SIZE, tuple, tupleSize); memset(b->pri + TUPLE_CHUNK_HEADER_SIZE + tupleSize, 0, paddedSize - tupleSize); dataSize += paddedSize; SetChunkType(b->pri, TC_WHOLE); SetChunkDataSize(b->pri, dataSize - TUPLE_CHUNK_HEADER_SIZE); break; } else { HeapTuple tuple = (HeapTuple) gtuple; TupSerHeader tsh; unsigned int datalen; unsigned int nullslen; HeapTupleHeader t_data = tuple->t_data; unsigned char *pos; datalen = tuple->t_len - t_data->t_hoff; if (HeapTupleHasNulls(tuple)) nullslen = BITMAPLEN(HeapTupleHeaderGetNatts(t_data)); else nullslen = 0; tsh.tuplen = sizeof(TupSerHeader) + TYPEALIGN(TUPLE_CHUNK_ALIGN, nullslen) + TYPEALIGN(TUPLE_CHUNK_ALIGN, datalen); tsh.natts = HeapTupleHeaderGetNatts(t_data); tsh.infomask = t_data->t_infomask; if (dataSize + tsh.tuplen > b->prilen || (tsh.infomask & HEAP_HASEXTERNAL) != 0) return 0; pos = b->pri + TUPLE_CHUNK_HEADER_SIZE; memcpy(pos, (char *)&tsh, sizeof(TupSerHeader)); pos += sizeof(TupSerHeader); if (nullslen) { memcpy(pos, (char *)t_data->t_bits, nullslen); pos += nullslen; memset(pos, 0, TYPEALIGN(TUPLE_CHUNK_ALIGN, nullslen) - nullslen); pos += TYPEALIGN(TUPLE_CHUNK_ALIGN, nullslen) - nullslen; } memcpy(pos, (char *)t_data + t_data->t_hoff, datalen); pos += datalen; memset(pos, 0, TYPEALIGN(TUPLE_CHUNK_ALIGN, datalen) - datalen); pos += TYPEALIGN(TUPLE_CHUNK_ALIGN, datalen) - datalen; dataSize += tsh.tuplen; SetChunkType(b->pri, TC_WHOLE); SetChunkDataSize(b->pri, dataSize - TUPLE_CHUNK_HEADER_SIZE); break; } /* tuple that we can't handle here (big ?) -- do the older "out-of-line" serialization */ return 0; } while (0); return dataSize; }
GenericTuple CvtChunksToTup(TupleChunkList tcList, SerTupInfo *pSerInfo, TupleRemapper *remapper) { StringInfoData serData; TupleChunkListItem tcItem; int i; GenericTuple tup; TupleChunkType tcType; AssertArg(tcList != NULL); AssertArg(tcList->p_first != NULL); AssertArg(pSerInfo != NULL); tcItem = tcList->p_first; if (tcList->num_chunks == 1) { GetChunkType(tcItem, &tcType); if (tcType == TC_EMPTY) { /* * the sender is indicating that there was a row with no attributes: * return a NULL tuple */ clearTCList(NULL, tcList); return (GenericTuple) heap_form_tuple(pSerInfo->tupdesc, pSerInfo->values, pSerInfo->nulls); } } /* * Dump all of the data in the tuple chunk list into a single StringInfo, * so that we can convert it into a HeapTuple. Check chunk types based on * whether there is only one chunk, or multiple chunks. * * We know roughly how much space we'll need, allocate all in one go. * */ initStringInfoOfSize(&serData, tcList->num_chunks * tcList->max_chunk_length); i = 0; do { /* Make sure that the type of this tuple chunk is correct! */ GetChunkType(tcItem, &tcType); if (i == 0) { if (tcItem->p_next == NULL) { if (tcType != TC_WHOLE) { ereport(ERROR, (errcode(ERRCODE_PROTOCOL_VIOLATION), errmsg("Single chunk's type must be TC_WHOLE."))); } } else /* tcItem->p_next != NULL */ { if (tcType != TC_PARTIAL_START) { ereport(ERROR, (errcode(ERRCODE_PROTOCOL_VIOLATION), errmsg("First chunk of collection must have type" " TC_PARTIAL_START."))); } } } else /* i > 0 */ { if (tcItem->p_next == NULL) { if (tcType != TC_PARTIAL_END) { ereport(ERROR, (errcode(ERRCODE_PROTOCOL_VIOLATION), errmsg("Last chunk of collection must have type" " TC_PARTIAL_END."))); } } else /* tcItem->p_next != NULL */ { if (tcType != TC_PARTIAL_MID) { ereport(ERROR, (errcode(ERRCODE_PROTOCOL_VIOLATION), errmsg("Last chunk of collection must have type" " TC_PARTIAL_MID."))); } } } /* Copy this chunk into the tuple data. Don't include the header! */ appendBinaryStringInfo(&serData, (const char *) GetChunkDataPtr(tcItem) + TUPLE_CHUNK_HEADER_SIZE, tcItem->chunk_length - TUPLE_CHUNK_HEADER_SIZE); /* Go to the next chunk. */ tcItem = tcItem->p_next; i++; } while (tcItem != NULL); /* we've finished with the TCList, free it now. */ clearTCList(NULL, tcList); { TupSerHeader *tshp; unsigned int datalen; unsigned int nullslen; unsigned int hoff; HeapTupleHeader t_data; char *pos = (char *)serData.data; tshp = (TupSerHeader *)pos; if (!(tshp->tuplen & MEMTUP_LEAD_BIT) && tshp->natts == RECORD_CACHE_MAGIC_NATTS && tshp->infomask == RECORD_CACHE_MAGIC_INFOMASK) { uint32 tuplen = tshp->tuplen & ~MEMTUP_LEAD_BIT; /* a special tuple with record type cache */ List * typelist = (List *) deserializeNode(pos + sizeof(TupSerHeader), tuplen - sizeof(TupSerHeader)); TRHandleTypeLists(remapper, typelist); /* Free up memory we used. */ pfree(serData.data); return NULL; } if ((tshp->tuplen & MEMTUP_LEAD_BIT) != 0) { uint32 tuplen = memtuple_size_from_uint32(tshp->tuplen); tup = (GenericTuple) palloc(tuplen); memcpy(tup, pos, tuplen); pos += TYPEALIGN(TUPLE_CHUNK_ALIGN,tuplen); } else { HeapTuple htup; pos += sizeof(TupSerHeader); /* * if the tuple had toasted elements we have to deserialize the * old slow way. */ if ((tshp->infomask & HEAP_HASEXTERNAL) != 0) { serData.cursor += sizeof(TupSerHeader); tup = (GenericTuple) DeserializeTuple(pSerInfo, &serData); /* Free up memory we used. */ pfree(serData.data); return tup; } /* reconstruct lengths of null bitmap and data part */ if (tshp->infomask & HEAP_HASNULL) nullslen = BITMAPLEN(tshp->natts); else nullslen = 0; if (tshp->tuplen < sizeof(TupSerHeader) + nullslen) ereport(ERROR, (errcode(ERRCODE_GP_INTERCONNECTION_ERROR), errmsg("Interconnect error: cannot convert chunks to a heap tuple."), errdetail("tuple len %d < nullslen %d + headersize (%d)", tshp->tuplen, nullslen, (int)sizeof(TupSerHeader)))); datalen = tshp->tuplen - sizeof(TupSerHeader) - TYPEALIGN(TUPLE_CHUNK_ALIGN, nullslen); /* determine overhead size of tuple (should match heap_form_tuple) */ hoff = offsetof(HeapTupleHeaderData, t_bits) + TYPEALIGN(TUPLE_CHUNK_ALIGN, nullslen); if (tshp->infomask & HEAP_HASOID) hoff += sizeof(Oid); hoff = MAXALIGN(hoff); /* Allocate the space in one chunk, like heap_form_tuple */ htup = (HeapTuple) palloc(HEAPTUPLESIZE + hoff + datalen); tup = (GenericTuple) htup; t_data = (HeapTupleHeader) ((char *)htup + HEAPTUPLESIZE); /* make sure unused header fields are zeroed */ MemSetAligned(t_data, 0, hoff); /* reconstruct the HeapTupleData fields */ htup->t_len = hoff + datalen; ItemPointerSetInvalid(&(htup->t_self)); htup->t_data = t_data; /* reconstruct the HeapTupleHeaderData fields */ ItemPointerSetInvalid(&(t_data->t_ctid)); HeapTupleHeaderSetNatts(t_data, tshp->natts); t_data->t_infomask = tshp->infomask & ~HEAP_XACT_MASK; t_data->t_infomask |= HEAP_XMIN_INVALID | HEAP_XMAX_INVALID; t_data->t_hoff = hoff; if (nullslen) { memcpy((void *)t_data->t_bits, pos, nullslen); pos += TYPEALIGN(TUPLE_CHUNK_ALIGN,nullslen); } /* does the tuple descriptor expect an OID ? Note: we don't * have to set the oid itself, just the flag! (see heap_formtuple()) */ if (pSerInfo->tupdesc->tdhasoid) /* else leave infomask = 0 */ { t_data->t_infomask |= HEAP_HASOID; } /* and now the data proper (it would be nice if we could just * point our caller into our existing buffer in-place, but * we'll leave that for another day) */ memcpy((char *)t_data + hoff, pos, datalen); } } /* Free up memory we used. */ pfree(serData.data); return tup; }
/* * Convert a HeapTuple into a byte-sequence, and store it directly * into a chunklist for transmission. * * This code is based on the printtup_internal_20() function in printtup.c. */ void SerializeTupleIntoChunks(HeapTuple tuple, SerTupInfo * pSerInfo, TupleChunkList tcList) { TupleChunkListItem tcItem = NULL; MemoryContext oldCtxt; TupleDesc tupdesc; int i, natts; bool fHandled; AssertArg(tcList != NULL); AssertArg(tuple != NULL); AssertArg(pSerInfo != NULL); tupdesc = pSerInfo->tupdesc; natts = tupdesc->natts; /* get ready to go */ tcList->p_first = NULL; tcList->p_last = NULL; tcList->num_chunks = 0; tcList->serialized_data_length = 0; tcList->max_chunk_length = Gp_max_tuple_chunk_size; if (natts == 0) { tcItem = getChunkFromCache(&pSerInfo->chunkCache); if (tcItem == NULL) { ereport(FATAL, (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("Could not allocate space for first chunk item in new chunk list."))); } /* TC_EMTPY is just one chunk */ SetChunkType(tcItem->chunk_data, TC_EMPTY); tcItem->chunk_length = TUPLE_CHUNK_HEADER_SIZE; appendChunkToTCList(tcList, tcItem); return; } tcItem = getChunkFromCache(&pSerInfo->chunkCache); if (tcItem == NULL) { ereport(FATAL, (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("Could not allocate space for first chunk item in new chunk list."))); } /* assume that we'll take a single chunk */ SetChunkType(tcItem->chunk_data, TC_WHOLE); tcItem->chunk_length = TUPLE_CHUNK_HEADER_SIZE; appendChunkToTCList(tcList, tcItem); AssertState(s_tupSerMemCtxt != NULL); if (is_heaptuple_memtuple(tuple)) { addByteStringToChunkList(tcList, (char *)tuple, memtuple_get_size((MemTuple)tuple, NULL), &pSerInfo->chunkCache); addPadding(tcList, &pSerInfo->chunkCache, memtuple_get_size((MemTuple)tuple, NULL)); } else { TupSerHeader tsh; unsigned int datalen; unsigned int nullslen; HeapTupleHeader t_data = tuple->t_data; datalen = tuple->t_len - t_data->t_hoff; if (HeapTupleHasNulls(tuple)) nullslen = BITMAPLEN(HeapTupleHeaderGetNatts(t_data)); else nullslen = 0; tsh.tuplen = sizeof(TupSerHeader) + TYPEALIGN(TUPLE_CHUNK_ALIGN,nullslen) + datalen; tsh.natts = HeapTupleHeaderGetNatts(t_data); tsh.infomask = t_data->t_infomask; addByteStringToChunkList(tcList, (char *)&tsh, sizeof(TupSerHeader), &pSerInfo->chunkCache); /* If we don't have any attributes which have been toasted, we * can be very very simple: just send the raw data. */ if ((tsh.infomask & (HEAP_HASEXTERNAL | HEAP_HASEXTENDED)) == 0) { if (nullslen) { addByteStringToChunkList(tcList, (char *)t_data->t_bits, nullslen, &pSerInfo->chunkCache); addPadding(tcList,&pSerInfo->chunkCache,nullslen); } addByteStringToChunkList(tcList, (char *)t_data + t_data->t_hoff, datalen, &pSerInfo->chunkCache); addPadding(tcList,&pSerInfo->chunkCache,datalen); } else { /* We have to be more careful when we have tuples that * have been toasted. Ideally we'd like to send the * untoasted attributes in as "raw" a format as possible * but that makes rebuilding the tuple harder . */ oldCtxt = MemoryContextSwitchTo(s_tupSerMemCtxt); /* deconstruct the tuple (faster than a heap_getattr loop) */ heap_deform_tuple(tuple, tupdesc, pSerInfo->values, pSerInfo->nulls); MemoryContextSwitchTo(oldCtxt); /* Send the nulls character-array. */ addByteStringToChunkList(tcList, pSerInfo->nulls, natts, &pSerInfo->chunkCache); addPadding(tcList,&pSerInfo->chunkCache,natts); /* * send the attributes of this tuple: NOTE anything which allocates * temporary space (e.g. could result in a PG_DETOAST_DATUM) should be * executed with the memory context set to s_tupSerMemCtxt */ for (i = 0; i < natts; ++i) { SerAttrInfo *attrInfo = pSerInfo->myinfo + i; Datum origattr = pSerInfo->values[i], attr; bytea *outputbytes=0; /* skip null attributes (already taken care of above) */ if (pSerInfo->nulls[i]) continue; /* * If we have a toasted datum, forcibly detoast it here to avoid * memory leakage: we want to force the detoast allocation(s) to * happen in our reset-able serialization context. */ if (attrInfo->typisvarlena) { oldCtxt = MemoryContextSwitchTo(s_tupSerMemCtxt); /* we want to detoast but leave compressed, if * possible, but we have to handle varlena * attributes (and others ?) differently than we * currently do (first step is to use * heap_tuple_fetch_attr() instead of * PG_DETOAST_DATUM()). */ attr = PointerGetDatum(PG_DETOAST_DATUM(origattr)); MemoryContextSwitchTo(oldCtxt); } else attr = origattr; /* * Assume that the data's output will be handled by the special IO * code, and if not then we can handle it the slow way. */ fHandled = true; switch (attrInfo->atttypid) { case INT4OID: addInt32ToChunkList(tcList, DatumGetInt32(attr), &pSerInfo->chunkCache); break; case CHAROID: addCharToChunkList(tcList, DatumGetChar(attr), &pSerInfo->chunkCache); addPadding(tcList,&pSerInfo->chunkCache,1); break; case BPCHAROID: case VARCHAROID: case INT2VECTOROID: /* postgres serialization logic broken, use our own */ case OIDVECTOROID: /* postgres serialization logic broken, use our own */ case ANYARRAYOID: { text *pText = DatumGetTextP(attr); int32 textSize = VARSIZE(pText) - VARHDRSZ; addInt32ToChunkList(tcList, textSize, &pSerInfo->chunkCache); addByteStringToChunkList(tcList, (char *) VARDATA(pText), textSize, &pSerInfo->chunkCache); addPadding(tcList,&pSerInfo->chunkCache,textSize); break; } case DATEOID: { DateADT date = DatumGetDateADT(attr); addByteStringToChunkList(tcList, (char *) &date, sizeof(DateADT), &pSerInfo->chunkCache); break; } case NUMERICOID: { /* * Treat the numeric as a varlena variable, and just push * the whole shebang to the output-buffer. We don't care * about the guts of the numeric. */ Numeric num = DatumGetNumeric(attr); int32 numSize = VARSIZE(num) - VARHDRSZ; addInt32ToChunkList(tcList, numSize, &pSerInfo->chunkCache); addByteStringToChunkList(tcList, (char *) VARDATA(num), numSize, &pSerInfo->chunkCache); addPadding(tcList,&pSerInfo->chunkCache,numSize); break; } case ACLITEMOID: { AclItem *aip = DatumGetAclItemP(attr); char *outputstring; int32 aclSize ; outputstring = DatumGetCString(DirectFunctionCall1(aclitemout, PointerGetDatum(aip))); aclSize = strlen(outputstring); addInt32ToChunkList(tcList, aclSize, &pSerInfo->chunkCache); addByteStringToChunkList(tcList, outputstring,aclSize, &pSerInfo->chunkCache); addPadding(tcList,&pSerInfo->chunkCache,aclSize); break; } case 210: /* storage manager */ { char *smgrstr; int32 strsize; smgrstr = DatumGetCString(DirectFunctionCall1(smgrout, 0)); strsize = strlen(smgrstr); addInt32ToChunkList(tcList, strsize, &pSerInfo->chunkCache); addByteStringToChunkList(tcList, smgrstr, strsize, &pSerInfo->chunkCache); addPadding(tcList,&pSerInfo->chunkCache,strsize); break; } default: fHandled = false; } if (fHandled) continue; /* * the FunctionCall2 call into the send function may result in some * allocations which we'd like to have contained by our reset-able * context */ oldCtxt = MemoryContextSwitchTo(s_tupSerMemCtxt); /* Call the attribute type's binary input converter. */ if (attrInfo->send_finfo.fn_nargs == 1) outputbytes = DatumGetByteaP(FunctionCall1(&attrInfo->send_finfo, attr)); else if (attrInfo->send_finfo.fn_nargs == 2) outputbytes = DatumGetByteaP(FunctionCall2(&attrInfo->send_finfo, attr, ObjectIdGetDatum(attrInfo->send_typio_param))); else if (attrInfo->send_finfo.fn_nargs == 3) outputbytes = DatumGetByteaP(FunctionCall3(&attrInfo->send_finfo, attr, ObjectIdGetDatum(attrInfo->send_typio_param), Int32GetDatum(tupdesc->attrs[i]->atttypmod))); else { ereport(ERROR, (errcode(ERRCODE_INVALID_BINARY_REPRESENTATION), errmsg("Conversion function takes %d args",attrInfo->recv_finfo.fn_nargs))); } MemoryContextSwitchTo(oldCtxt); /* We assume the result will not have been toasted */ addInt32ToChunkList(tcList, VARSIZE(outputbytes) - VARHDRSZ, &pSerInfo->chunkCache); addByteStringToChunkList(tcList, VARDATA(outputbytes), VARSIZE(outputbytes) - VARHDRSZ, &pSerInfo->chunkCache); addPadding(tcList,&pSerInfo->chunkCache,VARSIZE(outputbytes) - VARHDRSZ); /* * this was allocated in our reset-able context, but we *are* done * with it; and for tuples with several large columns it'd be nice to * free the memory back to the context */ pfree(outputbytes); } MemoryContextReset(s_tupSerMemCtxt); } } /* * if we have more than 1 chunk we have to set the chunk types on our * first chunk and last chunk */ if (tcList->num_chunks > 1) { TupleChunkListItem first, last; first = tcList->p_first; last = tcList->p_last; Assert(first != NULL); Assert(first != last); Assert(last != NULL); SetChunkType(first->chunk_data, TC_PARTIAL_START); SetChunkType(last->chunk_data, TC_PARTIAL_END); /* * any intervening chunks are already set to TC_PARTIAL_MID when * allocated */ } return; }
/* * Convert a HeapTuple into a byte-sequence, and store it directly * into a chunklist for transmission. * * This code is based on the printtup_internal_20() function in printtup.c. */ void SerializeTupleIntoChunks(GenericTuple gtuple, SerTupInfo *pSerInfo, TupleChunkList tcList) { TupleChunkListItem tcItem = NULL; MemoryContext oldCtxt; TupleDesc tupdesc; int i, natts; AssertArg(tcList != NULL); AssertArg(gtuple != NULL); AssertArg(pSerInfo != NULL); tupdesc = pSerInfo->tupdesc; natts = tupdesc->natts; /* get ready to go */ tcList->p_first = NULL; tcList->p_last = NULL; tcList->num_chunks = 0; tcList->serialized_data_length = 0; tcList->max_chunk_length = Gp_max_tuple_chunk_size; if (natts == 0) { tcItem = getChunkFromCache(&pSerInfo->chunkCache); if (tcItem == NULL) { ereport(FATAL, (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("Could not allocate space for first chunk item in new chunk list."))); } /* TC_EMTPY is just one chunk */ SetChunkType(tcItem->chunk_data, TC_EMPTY); tcItem->chunk_length = TUPLE_CHUNK_HEADER_SIZE; appendChunkToTCList(tcList, tcItem); return; } tcItem = getChunkFromCache(&pSerInfo->chunkCache); if (tcItem == NULL) { ereport(FATAL, (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("Could not allocate space for first chunk item in new chunk list."))); } /* assume that we'll take a single chunk */ SetChunkType(tcItem->chunk_data, TC_WHOLE); tcItem->chunk_length = TUPLE_CHUNK_HEADER_SIZE; appendChunkToTCList(tcList, tcItem); AssertState(s_tupSerMemCtxt != NULL); if (is_memtuple(gtuple)) { MemTuple mtuple = (MemTuple) gtuple; addByteStringToChunkList(tcList, (char *) mtuple, memtuple_get_size(mtuple), &pSerInfo->chunkCache); addPadding(tcList, &pSerInfo->chunkCache, memtuple_get_size(mtuple)); } else { HeapTuple tuple = (HeapTuple) gtuple; HeapTupleHeader t_data = tuple->t_data; TupSerHeader tsh; unsigned int datalen; unsigned int nullslen; datalen = tuple->t_len - t_data->t_hoff; if (HeapTupleHasNulls(tuple)) nullslen = BITMAPLEN(HeapTupleHeaderGetNatts(t_data)); else nullslen = 0; tsh.tuplen = sizeof(TupSerHeader) + TYPEALIGN(TUPLE_CHUNK_ALIGN,nullslen) + datalen; tsh.natts = HeapTupleHeaderGetNatts(t_data); tsh.infomask = t_data->t_infomask; addByteStringToChunkList(tcList, (char *)&tsh, sizeof(TupSerHeader), &pSerInfo->chunkCache); /* If we don't have any attributes which have been toasted, we * can be very very simple: just send the raw data. */ if ((tsh.infomask & HEAP_HASEXTERNAL) == 0) { if (nullslen) { addByteStringToChunkList(tcList, (char *)t_data->t_bits, nullslen, &pSerInfo->chunkCache); addPadding(tcList,&pSerInfo->chunkCache,nullslen); } addByteStringToChunkList(tcList, (char *)t_data + t_data->t_hoff, datalen, &pSerInfo->chunkCache); addPadding(tcList,&pSerInfo->chunkCache,datalen); } else { /* We have to be more careful when we have tuples that * have been toasted. Ideally we'd like to send the * untoasted attributes in as "raw" a format as possible * but that makes rebuilding the tuple harder . */ oldCtxt = MemoryContextSwitchTo(s_tupSerMemCtxt); /* deconstruct the tuple (faster than a heap_getattr loop) */ heap_deform_tuple(tuple, tupdesc, pSerInfo->values, pSerInfo->nulls); MemoryContextSwitchTo(oldCtxt); /* Send the nulls character-array. */ addByteStringToChunkList(tcList, pSerInfo->nulls, natts, &pSerInfo->chunkCache); addPadding(tcList,&pSerInfo->chunkCache,natts); /* * send the attributes of this tuple: NOTE anything which allocates * temporary space (e.g. could result in a PG_DETOAST_DATUM) should be * executed with the memory context set to s_tupSerMemCtxt */ for (i = 0; i < natts; ++i) { SerAttrInfo *attrInfo = pSerInfo->myinfo + i; Datum origattr = pSerInfo->values[i], attr; /* skip null attributes (already taken care of above) */ if (pSerInfo->nulls[i]) continue; if (attrInfo->typlen == -1) { int32 sz; char *data; /* * If we have a toasted datum, forcibly detoast it here to avoid * memory leakage: we want to force the detoast allocation(s) to * happen in our reset-able serialization context. */ oldCtxt = MemoryContextSwitchTo(s_tupSerMemCtxt); attr = PointerGetDatum(PG_DETOAST_DATUM_PACKED(origattr)); MemoryContextSwitchTo(oldCtxt); sz = VARSIZE_ANY_EXHDR(attr); data = VARDATA_ANY(attr); /* Send length first, then data */ addInt32ToChunkList(tcList, sz, &pSerInfo->chunkCache); addByteStringToChunkList(tcList, data, sz, &pSerInfo->chunkCache); addPadding(tcList, &pSerInfo->chunkCache, sz); } else if (attrInfo->typlen == -2) { int32 sz; char *data; /* CString, we would send the string with the terminating '\0' */ data = DatumGetCString(origattr); sz = strlen(data) + 1; /* Send length first, then data */ addInt32ToChunkList(tcList, sz, &pSerInfo->chunkCache); addByteStringToChunkList(tcList, data, sz, &pSerInfo->chunkCache); addPadding(tcList, &pSerInfo->chunkCache, sz); } else if (attrInfo->typbyval) { /* * We send a full-width Datum for all pass-by-value types, regardless of * the actual size. */ addByteStringToChunkList(tcList, (char *) &origattr, sizeof(Datum), &pSerInfo->chunkCache); addPadding(tcList, &pSerInfo->chunkCache, sizeof(Datum)); } else { addByteStringToChunkList(tcList, DatumGetPointer(origattr), attrInfo->typlen, &pSerInfo->chunkCache); addPadding(tcList, &pSerInfo->chunkCache, attrInfo->typlen); attr = origattr; } } MemoryContextReset(s_tupSerMemCtxt); } } /* * if we have more than 1 chunk we have to set the chunk types on our * first chunk and last chunk */ if (tcList->num_chunks > 1) { TupleChunkListItem first, last; first = tcList->p_first; last = tcList->p_last; Assert(first != NULL); Assert(first != last); Assert(last != NULL); SetChunkType(first->chunk_data, TC_PARTIAL_START); SetChunkType(last->chunk_data, TC_PARTIAL_END); /* * any intervening chunks are already set to TC_PARTIAL_MID when * allocated */ } return; }
/* * 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_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; }
/* ---------- * 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; #ifdef PGXC result_tuple->t_xc_node_id = newtup->t_xc_node_id; #endif 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; }
/* ---------- * 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; #ifdef PGXC tmptup.t_xc_node_id = 0; #endif 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); }
/* ---------- * 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 * ---------- */ /* compute header overhead --- this should match heap_form_tuple() */ maxDataLen = offsetof(HeapTupleHeaderData, t_bits); if (has_nulls) maxDataLen += BITMAPLEN(numAttrs); if (newtup->t_data->t_infomask & HEAP_HASOID) maxDataLen += sizeof(Oid); maxDataLen = MAXALIGN(maxDataLen); Assert(maxDataLen == newtup->t_data->t_hoff); /* now convert to a limit on the tuple data size */ maxDataLen = TOAST_TUPLE_TARGET - maxDataLen; /* * Look for attributes with attstorage 'x' to compress */ while (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 (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 (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 (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; 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; }
/* * 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; }
/* * 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; }
Datum tuple_data_split(PG_FUNCTION_ARGS) { Oid relid; bytea *raw_data; uint16 t_infomask; uint16 t_infomask2; char *t_bits_str; bool do_detoast = false; bits8 *t_bits = NULL; Datum res; relid = PG_GETARG_OID(0); raw_data = PG_ARGISNULL(1) ? NULL : PG_GETARG_BYTEA_P(1); t_infomask = PG_GETARG_INT16(2); t_infomask2 = PG_GETARG_INT16(3); t_bits_str = PG_ARGISNULL(4) ? NULL : text_to_cstring(PG_GETARG_TEXT_PP(4)); if (PG_NARGS() >= 6) do_detoast = PG_GETARG_BOOL(5); if (!superuser()) ereport(ERROR, (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), errmsg("must be superuser to use raw page functions"))); if (!raw_data) PG_RETURN_NULL(); /* * Convert t_bits string back to the bits8 array as represented in the * tuple header. */ if (t_infomask & HEAP_HASNULL) { int bits_str_len; int bits_len; bits_len = BITMAPLEN(t_infomask2 & HEAP_NATTS_MASK) * BITS_PER_BYTE; if (!t_bits_str) ereport(ERROR, (errcode(ERRCODE_DATA_CORRUPTED), errmsg("argument of t_bits is null, but it is expected to be null and %d character long", bits_len))); bits_str_len = strlen(t_bits_str); if (bits_len != bits_str_len) ereport(ERROR, (errcode(ERRCODE_DATA_CORRUPTED), errmsg("unexpected length of t_bits %u, expected %d", bits_str_len, bits_len))); /* do the conversion */ t_bits = text_to_bits(t_bits_str, bits_str_len); } else { if (t_bits_str) ereport(ERROR, (errcode(ERRCODE_DATA_CORRUPTED), errmsg("t_bits string is expected to be NULL, but instead it is %zu bytes length", strlen(t_bits_str)))); } /* Split tuple data */ res = tuple_data_split_internal(relid, (char *) raw_data + VARHDRSZ, VARSIZE(raw_data) - VARHDRSZ, t_infomask, t_infomask2, t_bits, do_detoast); if (t_bits) pfree(t_bits); PG_RETURN_ARRAYTYPE_P(res); }
Datum heap_page_items(PG_FUNCTION_ARGS) { bytea *raw_page = PG_GETARG_BYTEA_P(0); heap_page_items_state *inter_call_data = NULL; FuncCallContext *fctx; int raw_page_size; if (!superuser()) ereport(ERROR, (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), (errmsg("must be superuser to use raw page functions")))); raw_page_size = VARSIZE(raw_page) - VARHDRSZ; if (SRF_IS_FIRSTCALL()) { TupleDesc tupdesc; MemoryContext mctx; if (raw_page_size < SizeOfPageHeaderData) ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("input page too small (%d bytes)", raw_page_size))); fctx = SRF_FIRSTCALL_INIT(); mctx = MemoryContextSwitchTo(fctx->multi_call_memory_ctx); inter_call_data = palloc(sizeof(heap_page_items_state)); /* Build a tuple descriptor for our result type */ if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE) elog(ERROR, "return type must be a row type"); inter_call_data->tupd = tupdesc; inter_call_data->offset = FirstOffsetNumber; inter_call_data->page = VARDATA(raw_page); fctx->max_calls = PageGetMaxOffsetNumber(inter_call_data->page); fctx->user_fctx = inter_call_data; MemoryContextSwitchTo(mctx); } fctx = SRF_PERCALL_SETUP(); inter_call_data = fctx->user_fctx; if (fctx->call_cntr < fctx->max_calls) { Page page = inter_call_data->page; HeapTuple resultTuple; Datum result; ItemId id; Datum values[14]; bool nulls[14]; uint16 lp_offset; uint16 lp_flags; uint16 lp_len; memset(nulls, 0, sizeof(nulls)); /* Extract information from the line pointer */ id = PageGetItemId(page, inter_call_data->offset); lp_offset = ItemIdGetOffset(id); lp_flags = ItemIdGetFlags(id); lp_len = ItemIdGetLength(id); values[0] = UInt16GetDatum(inter_call_data->offset); values[1] = UInt16GetDatum(lp_offset); values[2] = UInt16GetDatum(lp_flags); values[3] = UInt16GetDatum(lp_len); /* * We do just enough validity checking to make sure we don't reference * data outside the page passed to us. The page could be corrupt in * many other ways, but at least we won't crash. */ if (ItemIdHasStorage(id) && lp_len >= MinHeapTupleSize && lp_offset == MAXALIGN(lp_offset) && lp_offset + lp_len <= raw_page_size) { HeapTupleHeader tuphdr; bytea *tuple_data_bytea; int tuple_data_len; /* Extract information from the tuple header */ tuphdr = (HeapTupleHeader) PageGetItem(page, id); values[4] = UInt32GetDatum(HeapTupleHeaderGetRawXmin(tuphdr)); values[5] = UInt32GetDatum(HeapTupleHeaderGetRawXmax(tuphdr)); /* shared with xvac */ values[6] = UInt32GetDatum(HeapTupleHeaderGetRawCommandId(tuphdr)); values[7] = PointerGetDatum(&tuphdr->t_ctid); values[8] = UInt32GetDatum(tuphdr->t_infomask2); values[9] = UInt32GetDatum(tuphdr->t_infomask); values[10] = UInt8GetDatum(tuphdr->t_hoff); /* Copy raw tuple data into bytea attribute */ tuple_data_len = lp_len - tuphdr->t_hoff; tuple_data_bytea = (bytea *) palloc(tuple_data_len + VARHDRSZ); SET_VARSIZE(tuple_data_bytea, tuple_data_len + VARHDRSZ); memcpy(VARDATA(tuple_data_bytea), (char *) tuphdr + tuphdr->t_hoff, tuple_data_len); values[13] = PointerGetDatum(tuple_data_bytea); /* * We already checked that the item is completely within the raw * page passed to us, with the length given in the line pointer. * Let's check that t_hoff doesn't point over lp_len, before using * it to access t_bits and oid. */ if (tuphdr->t_hoff >= SizeofHeapTupleHeader && tuphdr->t_hoff <= lp_len && tuphdr->t_hoff == MAXALIGN(tuphdr->t_hoff)) { if (tuphdr->t_infomask & HEAP_HASNULL) { int bits_len; bits_len = BITMAPLEN(HeapTupleHeaderGetNatts(tuphdr)) * BITS_PER_BYTE; values[11] = CStringGetTextDatum( bits_to_text(tuphdr->t_bits, bits_len)); } else nulls[11] = true; if (tuphdr->t_infomask & HEAP_HASOID_OLD) values[12] = HeapTupleHeaderGetOidOld(tuphdr); else nulls[12] = true; } else { nulls[11] = true; nulls[12] = true; } } else { /* * The line pointer is not used, or it's invalid. Set the rest of * the fields to NULL */ int i; for (i = 4; i <= 13; i++) nulls[i] = true; } /* Build and return the result tuple. */ resultTuple = heap_form_tuple(inter_call_data->tupd, values, nulls); result = HeapTupleGetDatum(resultTuple); inter_call_data->offset++; SRF_RETURN_NEXT(fctx, result); } else SRF_RETURN_DONE(fctx); }