WIP: TOAST with first chunk stored inline

Author: Nikita Glukhov

src/backend/access/brin/brin_tuple.c

@@ -211,6 +211,7 @@ brin_form_tuple(BrinDesc *brdesc, BlockNumber blkno, BrinMemTuple *tuple,
 			if (!VARATT_IS_EXTENDED(DatumGetPointer(value)) &&
 				VARSIZE(DatumGetPointer(value)) > TOAST_INDEX_TARGET &&
 				(atttype->typstorage == TYPSTORAGE_EXTENDED ||
+				 atttype->typstorage == TYPSTORAGE_TAPAS ||
 				 atttype->typstorage == TYPSTORAGE_MAIN))
 			{
 				Datum		cvalue = toast_compress_datum(value);

src/backend/access/common/detoast.c

@@ -45,7 +45,7 @@ detoast_external_attr(struct varlena *attr)
 {
 	struct varlena *result;
 
-	if (VARATT_IS_EXTERNAL_ONDISK(attr))
+	if (VARATT_IS_EXTERNAL_ONDISK(attr) || VARATT_IS_EXTERNAL_ONDISK_INLINE(attr))
 	{
 		/*
 		 * This is an external stored plain value
@@ -114,7 +114,7 @@ detoast_external_attr(struct varlena *attr)
 struct varlena *
 detoast_attr(struct varlena *attr)
 {
-	if (VARATT_IS_EXTERNAL_ONDISK(attr))
+	if (VARATT_IS_EXTERNAL_ONDISK(attr) || VARATT_IS_EXTERNAL_ONDISK_INLINE(attr))
 	{
 		/*
 		 * This is an externally stored datum --- fetch it back from there
@@ -208,6 +208,9 @@ detoast_attr_slice(struct varlena *attr,
 	char	   *attrdata;
 	int32		attrsize;
 
+	if (VARATT_IS_EXTERNAL_ONDISK_INLINE(attr))
+		elog(ERROR, "slicing of chunked attributes is not yet supported"); /* FIXME */
+
 	if (VARATT_IS_EXTERNAL_ONDISK(attr))
 	{
 		struct varatt_external toast_pointer;
@@ -324,15 +327,33 @@ create_detoast_iterator(struct varlena *attr)
 {
 	struct varatt_external toast_pointer;
 	DetoastIterator iter;
-	if (VARATT_IS_EXTERNAL_ONDISK(attr))
+	if (VARATT_IS_EXTERNAL_ONDISK(attr) || VARATT_IS_EXTERNAL_ONDISK_INLINE(attr))
 	{
+		int32		inlineSize;
+
 		iter = (DetoastIterator) palloc0(sizeof(DetoastIteratorData));
 		iter->done = false;
 		iter->nrefs = 1;
 
 		/* This is an externally stored datum --- initialize fetch datum iterator */
 		iter->fetch_datum_iterator = create_fetch_datum_iterator(attr);
-		VARATT_EXTERNAL_GET_POINTER(toast_pointer, attr);
+
+		/* Must copy to access aligned fields */
+		if (VARATT_IS_EXTERNAL_ONDISK_INLINE(attr))
+		{
+			//VARATT_EXTERNAL_GET_POINTER(toast_pointer_inline, attr);
+			struct varatt_external_inline toast_pointer_inline;
+
+			memcpy(&toast_pointer_inline, VARDATA_EXTERNAL(attr), sizeof(toast_pointer_inline));
+			toast_pointer = toast_pointer_inline.va_external;
+			inlineSize = toast_pointer_inline.va_inline_size;
+		}
+		else
+		{
+			VARATT_EXTERNAL_GET_POINTER(toast_pointer, attr);
+			inlineSize = 0;
+		}
+
 		if (VARATT_EXTERNAL_IS_COMPRESSED(toast_pointer))
 		{
 			iter->compressed = true;
@@ -353,6 +374,14 @@ create_detoast_iterator(struct varlena *attr)
 			/* point the buffer directly at the raw data */
 			iter->buf = iter->fetch_datum_iterator->buf;
 		}
+
+		if (inlineSize > 0)
+		{
+			memcpy((void *) iter->fetch_datum_iterator->buf->limit,
+				   VARDATA_EXTERNAL_INLINE(attr), inlineSize);
+			iter->fetch_datum_iterator->buf->limit += inlineSize;
+		}
+
 		return iter;
 	}
 	else if (VARATT_IS_EXTERNAL_INDIRECT(attr))
@@ -431,14 +460,27 @@ toast_fetch_datum(struct varlena *attr)
 {
 	Relation	toastrel;
 	struct varlena *result;
+	struct varatt_external_inline toast_pointer_inline;
 	struct varatt_external toast_pointer;
 	int32		attrsize;
+	int32		inlineSize;
 
-	if (!VARATT_IS_EXTERNAL_ONDISK(attr))
+	if (!VARATT_IS_EXTERNAL_ONDISK(attr) && !VARATT_IS_EXTERNAL_ONDISK_INLINE(attr))
 		elog(ERROR, "toast_fetch_datum shouldn't be called for non-ondisk datums");
 
 	/* Must copy to access aligned fields */
-	VARATT_EXTERNAL_GET_POINTER(toast_pointer, attr);
+	if (VARATT_IS_EXTERNAL_ONDISK_INLINE(attr))
+	{
+		//VARATT_EXTERNAL_GET_POINTER(toast_pointer_inline, attr);
+		memcpy(&toast_pointer_inline, VARDATA_EXTERNAL(attr), sizeof(toast_pointer_inline));
+		toast_pointer = toast_pointer_inline.va_external;
+		inlineSize = toast_pointer_inline.va_inline_size;
+	}
+	else
+	{
+		VARATT_EXTERNAL_GET_POINTER(toast_pointer, attr);
+		inlineSize = 0;
+	}
 
 	attrsize = toast_pointer.va_extsize;
 
@@ -453,14 +495,18 @@ toast_fetch_datum(struct varlena *attr)
 		return result;			/* Probably shouldn't happen, but just in
 								 * case. */
 
+	if (inlineSize)
+		memcpy(VARDATA(result), VARDATA_EXTERNAL_INLINE(attr), inlineSize);
+
 	/*
 	 * Open the toast relation and its indexes
 	 */
 	toastrel = table_open(toast_pointer.va_toastrelid, AccessShareLock);
 
 	/* Fetch all chunks */
 	table_relation_fetch_toast_slice(toastrel, toast_pointer.va_valueid,
-									 attrsize, 0, attrsize, result);
+									 attrsize - inlineSize, 0, attrsize - inlineSize,
+									 (struct varlena *)((char *) result + inlineSize));
 
 	/* Close toast table */
 	table_close(toastrel, AccessShareLock);
@@ -488,7 +534,7 @@ toast_fetch_datum_slice(struct varlena *attr, int32 sliceoffset,
 	struct varatt_external toast_pointer;
 	int32		attrsize;
 
-	if (!VARATT_IS_EXTERNAL_ONDISK(attr))
+	if (!VARATT_IS_EXTERNAL_ONDISK(attr))	/* FIXME */
 		elog(ERROR, "toast_fetch_datum_slice shouldn't be called for non-ondisk datums");
 
 	/* Must copy to access aligned fields */
@@ -611,7 +657,7 @@ toast_raw_datum_size(Datum value)
 	struct varlena *attr = (struct varlena *) DatumGetPointer(value);
 	Size		result;
 
-	if (VARATT_IS_EXTERNAL_ONDISK(attr))
+	if (VARATT_IS_EXTERNAL_ONDISK(attr) || VARATT_IS_EXTERNAL_ONDISK_INLINE(attr))
 	{
 		/* va_rawsize is the size of the original datum -- including header */
 		struct varatt_external toast_pointer;
@@ -679,6 +725,13 @@ toast_datum_size(Datum value)
 		VARATT_EXTERNAL_GET_POINTER(toast_pointer, attr);
 		result = toast_pointer.va_extsize;
 	}
+	else if (VARATT_IS_EXTERNAL_ONDISK_INLINE(attr))
+	{
+		struct varatt_external toast_pointer;
+
+		memcpy(&toast_pointer, VARDATA_EXTERNAL(attr), sizeof(toast_pointer));
+		result = toast_pointer.va_extsize;
+	}
 	else if (VARATT_IS_EXTERNAL_INDIRECT(attr))
 	{
 		struct varatt_indirect toast_pointer;

src/backend/access/common/indextuple.c

@@ -101,6 +101,7 @@ index_form_tuple(TupleDesc tupleDescriptor,
 		if (!VARATT_IS_EXTENDED(DatumGetPointer(untoasted_values[i])) &&
 			VARSIZE(DatumGetPointer(untoasted_values[i])) > TOAST_INDEX_TARGET &&
 			(att->attstorage == TYPSTORAGE_EXTENDED ||
+			 att->attstorage == TYPSTORAGE_TAPAS ||
 			 att->attstorage == TYPSTORAGE_MAIN))
 		{
 			Datum		cvalue = toast_compress_datum(untoasted_values[i]);