Ejemplo n.º 1
0
Archivo: tupser.c Proyecto: 50wu/gpdb
/*
 * 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) == 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;
}
Ejemplo n.º 2
0
/*
 * 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;
}