/* ----------
* toast_delete -
*
* Cascaded delete toast-entries on DELETE
* ----------
*/
static void
toast_delete(Relation rel, HeapTuple oldtup)
{
TupleDesc tupleDesc;
Form_pg_attribute *att;
int numAttrs;
int i;
Datum value;
bool isnull;
/*
* Get the tuple descriptor, the number of and attribute descriptors.
*/
tupleDesc = rel->rd_att;
numAttrs = tupleDesc->natts;
att = tupleDesc->attrs;
/*
* Check for external stored attributes and delete them from the
* secondary relation.
*/
for (i = 0; i < numAttrs; i++)
{
if (att[i]->attlen == -1)
{
value = heap_getattr(oldtup, i + 1, tupleDesc, &isnull);
if (!isnull && VARATT_IS_EXTERNAL(value))
toast_delete_datum(rel, value);
}
}
}
/* ----------
* toast_delete -
*
* Cascaded delete toast-entries on DELETE
* ----------
*/
void
toast_delete(Relation rel, HeapTuple oldtup, MemTupleBinding *pbind)
{
TupleDesc tupleDesc;
Form_pg_attribute *att;
int numAttrs;
int i;
Datum toast_values[MaxHeapAttributeNumber];
bool toast_isnull[MaxHeapAttributeNumber];
bool ismemtuple = is_heaptuple_memtuple(oldtup);
AssertImply(ismemtuple, pbind);
AssertImply(!ismemtuple, !pbind);
/*
* 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 into fields.
*
* NOTE: it's debatable whether to use heap_deform_tuple() here or just
* heap_getattr() only the varlena columns. The latter could win if there
* are few varlena columns and many non-varlena ones. However,
* heap_deform_tuple costs only O(N) while the heap_getattr way would cost
* O(N^2) if there are many varlena columns, so it seems better to err on
* the side of linear cost. (We won't even be here unless there's at
* least one varlena column, by the way.)
*/
tupleDesc = rel->rd_att;
att = tupleDesc->attrs;
numAttrs = tupleDesc->natts;
Assert(numAttrs <= MaxHeapAttributeNumber);
if(ismemtuple)
memtuple_deform((MemTuple) oldtup, pbind, toast_values, toast_isnull);
else
heap_deform_tuple(oldtup, tupleDesc, toast_values, toast_isnull);
/*
* Check for external stored attributes and delete them from the secondary
* relation.
*/
for (i = 0; i < numAttrs; i++)
{
if (att[i]->attlen == -1)
{
Datum value = toast_values[i];
if (!toast_isnull[i] && VARATT_IS_EXTERNAL_D(value))
toast_delete_datum(rel, value);
}
}
}
/* ----------
* toast_delete -
*
* Cascaded delete toast-entries on DELETE
* ----------
*/
void
toast_delete(Relation rel, HeapTuple oldtup)
{
TupleDesc tupleDesc;
Form_pg_attribute *att;
int numAttrs;
int i;
Datum toast_values[MaxHeapAttributeNumber];
bool toast_isnull[MaxHeapAttributeNumber];
/*
* Get the tuple descriptor and break down the tuple into fields.
*
* NOTE: it's debatable whether to use heap_deformtuple() here or just
* heap_getattr() only the varlena columns. The latter could win if there
* are few varlena columns and many non-varlena ones. However,
* heap_deformtuple costs only O(N) while the heap_getattr way would cost
* O(N^2) if there are many varlena columns, so it seems better to err on
* the side of linear cost. (We won't even be here unless there's at
* least one varlena column, by the way.)
*/
tupleDesc = rel->rd_att;
att = tupleDesc->attrs;
numAttrs = tupleDesc->natts;
Assert(numAttrs <= MaxHeapAttributeNumber);
heap_deform_tuple(oldtup, tupleDesc, toast_values, toast_isnull);
/*
* Check for external stored attributes and delete them from the secondary
* relation.
*/
for (i = 0; i < numAttrs; i++)
{
if (att[i]->attlen == -1)
{
Datum value = toast_values[i];
if (!toast_isnull[i] && VARATT_IS_EXTERNAL(value))
toast_delete_datum(rel, value);
}
}
}
/* ----------
* 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;
}
/* ----------
* toast_insert_or_update -
*
* Delete no-longer-used toast-entries and create new ones to
* make the new tuple fit on INSERT or UPDATE
* ----------
*/
static void
toast_insert_or_update(Relation rel, HeapTuple newtup, HeapTuple oldtup)
{
TupleDesc tupleDesc;
Form_pg_attribute *att;
int numAttrs;
int i;
bool old_isnull;
bool new_isnull;
bool need_change = false;
bool need_free = false;
bool need_delold = false;
bool has_nulls = false;
Size maxDataLen;
char toast_action[MaxHeapAttributeNumber];
char toast_nulls[MaxHeapAttributeNumber];
Datum toast_values[MaxHeapAttributeNumber];
int32 toast_sizes[MaxHeapAttributeNumber];
bool toast_free[MaxHeapAttributeNumber];
bool toast_delold[MaxHeapAttributeNumber];
/*
* Get the tuple descriptor, the number of and attribute descriptors
* and the location of the tuple values.
*/
tupleDesc = rel->rd_att;
numAttrs = tupleDesc->natts;
att = tupleDesc->attrs;
/* ----------
* 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
* ----------
*/
memset(toast_action, ' ', numAttrs * sizeof(char));
memset(toast_nulls, ' ', 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(
heap_getattr(oldtup, i + 1, tupleDesc, &old_isnull));
toast_values[i] =
heap_getattr(newtup, i + 1, tupleDesc, &new_isnull);
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 (!old_isnull && att[i]->attlen == -1 &&
VARATT_IS_EXTERNAL(old_value))
{
if (new_isnull || !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 store 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
*/
toast_values[i] =
heap_getattr(newtup, i + 1, tupleDesc, &new_isnull);
}
/*
* Handle NULL attributes
*/
if (new_isnull)
{
toast_action[i] = 'p';
toast_nulls[i] = 'n';
has_nulls = true;
continue;
}
/*
* Now look at varsize 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(DatumGetPointer(toast_values[i])))
{
toast_values[i] = PointerGetDatum(heap_tuple_untoast_attr(
(varattrib *) DatumGetPointer(toast_values[i])));
toast_free[i] = true;
need_change = true;
need_free = true;
}
/*
* Remember the size of this attribute
*/
toast_sizes[i] = VARATT_SIZE(DatumGetPointer(toast_values[i]));
}
else
{
/*
* Not a variable size attribute, plain storage always
*/
toast_action[i] = 'p';
toast_sizes[i] = att[i]->attlen;
}
}
/* ----------
* 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(ComputeDataSize(tupleDesc, toast_values, toast_nulls)) >
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(ComputeDataSize(tupleDesc, toast_values, toast_nulls)) >
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(ComputeDataSize(tupleDesc, toast_values, toast_nulls)) >
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(ComputeDataSize(tupleDesc, toast_values, toast_nulls)) >
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;
char *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 += ComputeDataSize(tupleDesc, toast_values, toast_nulls);
/*
* Allocate new tuple in same context as old one.
*/
new_data = (char *) MemoryContextAlloc(newtup->t_datamcxt, new_len);
newtup->t_data = (HeapTupleHeader) new_data;
newtup->t_len = new_len;
/*
* Put the tuple header and the changed values into place
*/
memcpy(new_data, olddata, olddata->t_hoff);
DataFill((char *) new_data + olddata->t_hoff,
tupleDesc,
toast_values,
toast_nulls,
&(newtup->t_data->t_infomask),
has_nulls ? newtup->t_data->t_bits : NULL);
/*
* In the case we modified a previously modified tuple again, free
* the memory from the previous run
*/
if ((char *) olddata != ((char *) newtup + HEAPTUPLESIZE))
pfree(olddata);
}
/*
* 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,
heap_getattr(oldtup, i + 1, tupleDesc, &old_isnull));
}
/* ----------
* 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;
}
