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path: root/src/backend/storage/large_object/inv_api.c
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Diffstat (limited to 'src/backend/storage/large_object/inv_api.c')
-rw-r--r--src/backend/storage/large_object/inv_api.c161
1 files changed, 90 insertions, 71 deletions
diff --git a/src/backend/storage/large_object/inv_api.c b/src/backend/storage/large_object/inv_api.c
index bcf65f6004b..dba45d6590d 100644
--- a/src/backend/storage/large_object/inv_api.c
+++ b/src/backend/storage/large_object/inv_api.c
@@ -9,7 +9,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/storage/large_object/inv_api.c,v 1.85 2001/02/10 02:31:26 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/storage/large_object/inv_api.c,v 1.86 2001/03/22 03:59:45 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@@ -44,7 +44,7 @@
static int32
getbytealen(bytea *data)
{
- Assert(! VARATT_IS_EXTENDED(data));
+ Assert(!VARATT_IS_EXTENDED(data));
if (VARSIZE(data) < VARHDRSZ)
elog(ERROR, "getbytealen: VARSIZE(data) < VARHDRSZ. This is internal error.");
return (VARSIZE(data) - VARHDRSZ);
@@ -75,7 +75,8 @@ inv_create(int flags)
elog(ERROR, "inv_create: large object %u already exists. This is internal error.", file_oid);
/*
- * Create the LO by writing an empty first page for it in pg_largeobject
+ * Create the LO by writing an empty first page for it in
+ * pg_largeobject
*/
(void) LargeObjectCreate(file_oid);
@@ -93,13 +94,17 @@ inv_create(int flags)
retval->id = file_oid;
retval->offset = 0;
- if (flags & INV_WRITE) {
+ if (flags & INV_WRITE)
+ {
retval->flags = IFS_WRLOCK | IFS_RDLOCK;
retval->heap_r = heap_openr(LargeObjectRelationName, RowExclusiveLock);
- } else if (flags & INV_READ) {
+ }
+ else if (flags & INV_READ)
+ {
retval->flags = IFS_RDLOCK;
retval->heap_r = heap_openr(LargeObjectRelationName, AccessShareLock);
- } else
+ }
+ else
elog(ERROR, "inv_create: invalid flags: %d", flags);
retval->index_r = index_openr(LargeObjectLOidPNIndex);
@@ -118,21 +123,25 @@ inv_open(Oid lobjId, int flags)
{
LargeObjectDesc *retval;
- if (! LargeObjectExists(lobjId))
+ if (!LargeObjectExists(lobjId))
elog(ERROR, "inv_open: large object %u not found", lobjId);
-
+
retval = (LargeObjectDesc *) palloc(sizeof(LargeObjectDesc));
retval->id = lobjId;
retval->offset = 0;
- if (flags & INV_WRITE) {
+ if (flags & INV_WRITE)
+ {
retval->flags = IFS_WRLOCK | IFS_RDLOCK;
retval->heap_r = heap_openr(LargeObjectRelationName, RowExclusiveLock);
- } else if (flags & INV_READ) {
+ }
+ else if (flags & INV_READ)
+ {
retval->flags = IFS_RDLOCK;
retval->heap_r = heap_openr(LargeObjectRelationName, AccessShareLock);
- } else
+ }
+ else
elog(ERROR, "inv_open: invalid flags: %d", flags);
retval->index_r = index_openr(LargeObjectLOidPNIndex);
@@ -185,16 +194,16 @@ inv_drop(Oid lobjId)
static uint32
inv_getsize(LargeObjectDesc *obj_desc)
{
- bool found = false;
- uint32 lastbyte = 0;
- ScanKeyData skey[1];
- IndexScanDesc sd;
- RetrieveIndexResult indexRes;
- HeapTupleData tuple;
- Buffer buffer;
- Form_pg_largeobject data;
- bytea *datafield;
- bool pfreeit;
+ bool found = false;
+ uint32 lastbyte = 0;
+ ScanKeyData skey[1];
+ IndexScanDesc sd;
+ RetrieveIndexResult indexRes;
+ HeapTupleData tuple;
+ Buffer buffer;
+ Form_pg_largeobject data;
+ bytea *datafield;
+ bool pfreeit;
Assert(PointerIsValid(obj_desc));
@@ -210,10 +219,10 @@ inv_getsize(LargeObjectDesc *obj_desc)
tuple.t_data = NULL;
/*
- * Because the pg_largeobject index is on both loid and pageno,
- * but we constrain only loid, a backwards scan should visit all
- * pages of the large object in reverse pageno order. So, it's
- * sufficient to examine the first valid tuple (== last valid page).
+ * Because the pg_largeobject index is on both loid and pageno, but we
+ * constrain only loid, a backwards scan should visit all pages of the
+ * large object in reverse pageno order. So, it's sufficient to
+ * examine the first valid tuple (== last valid page).
*/
while ((indexRes = index_getnext(sd, BackwardScanDirection)))
{
@@ -238,7 +247,7 @@ inv_getsize(LargeObjectDesc *obj_desc)
ReleaseBuffer(buffer);
break;
}
-
+
index_endscan(sd);
if (!found)
@@ -259,15 +268,15 @@ inv_seek(LargeObjectDesc *obj_desc, int offset, int whence)
obj_desc->offset = offset;
break;
case SEEK_CUR:
- if (offset < 0 && obj_desc->offset < ((uint32) (- offset)))
+ if (offset < 0 && obj_desc->offset < ((uint32) (-offset)))
elog(ERROR, "inv_seek: invalid offset: %d", offset);
obj_desc->offset += offset;
break;
case SEEK_END:
{
- uint32 size = inv_getsize(obj_desc);
+ uint32 size = inv_getsize(obj_desc);
- if (offset < 0 && size < ((uint32) (- offset)))
+ if (offset < 0 && size < ((uint32) (-offset)))
elog(ERROR, "inv_seek: invalid offset: %d", offset);
obj_desc->offset = size + offset;
}
@@ -289,20 +298,20 @@ inv_tell(LargeObjectDesc *obj_desc)
int
inv_read(LargeObjectDesc *obj_desc, char *buf, int nbytes)
{
- int nread = 0;
- int n;
- int off;
- int len;
- int32 pageno = (int32) (obj_desc->offset / LOBLKSIZE);
- uint32 pageoff;
- ScanKeyData skey[2];
- IndexScanDesc sd;
- RetrieveIndexResult indexRes;
- HeapTupleData tuple;
- Buffer buffer;
- Form_pg_largeobject data;
- bytea *datafield;
- bool pfreeit;
+ int nread = 0;
+ int n;
+ int off;
+ int len;
+ int32 pageno = (int32) (obj_desc->offset / LOBLKSIZE);
+ uint32 pageoff;
+ ScanKeyData skey[2];
+ IndexScanDesc sd;
+ RetrieveIndexResult indexRes;
+ HeapTupleData tuple;
+ Buffer buffer;
+ Form_pg_largeobject data;
+ bytea *datafield;
+ bool pfreeit;
Assert(PointerIsValid(obj_desc));
Assert(buf != NULL);
@@ -335,13 +344,13 @@ inv_read(LargeObjectDesc *obj_desc, char *buf, int nbytes)
if (tuple.t_data == NULL)
continue;
-
+
data = (Form_pg_largeobject) GETSTRUCT(&tuple);
/*
* We assume the indexscan will deliver pages in order. However,
- * there may be missing pages if the LO contains unwritten "holes".
- * We want missing sections to read out as zeroes.
+ * there may be missing pages if the LO contains unwritten
+ * "holes". We want missing sections to read out as zeroes.
*/
pageoff = ((uint32) data->pageno) * LOBLKSIZE;
if (pageoff > obj_desc->offset)
@@ -393,28 +402,28 @@ inv_read(LargeObjectDesc *obj_desc, char *buf, int nbytes)
int
inv_write(LargeObjectDesc *obj_desc, char *buf, int nbytes)
{
- int nwritten = 0;
- int n;
- int off;
- int len;
- int32 pageno = (int32) (obj_desc->offset / LOBLKSIZE);
- ScanKeyData skey[2];
- IndexScanDesc sd;
- RetrieveIndexResult indexRes;
- HeapTupleData oldtuple;
- Buffer buffer;
- Form_pg_largeobject olddata;
- bool neednextpage;
- bytea *datafield;
- bool pfreeit;
- char workbuf[LOBLKSIZE + VARHDRSZ];
- char *workb = VARATT_DATA(workbuf);
- HeapTuple newtup;
- Datum values[Natts_pg_largeobject];
- char nulls[Natts_pg_largeobject];
- char replace[Natts_pg_largeobject];
- bool write_indices;
- Relation idescs[Num_pg_largeobject_indices];
+ int nwritten = 0;
+ int n;
+ int off;
+ int len;
+ int32 pageno = (int32) (obj_desc->offset / LOBLKSIZE);
+ ScanKeyData skey[2];
+ IndexScanDesc sd;
+ RetrieveIndexResult indexRes;
+ HeapTupleData oldtuple;
+ Buffer buffer;
+ Form_pg_largeobject olddata;
+ bool neednextpage;
+ bytea *datafield;
+ bool pfreeit;
+ char workbuf[LOBLKSIZE + VARHDRSZ];
+ char *workb = VARATT_DATA(workbuf);
+ HeapTuple newtup;
+ Datum values[Natts_pg_largeobject];
+ char nulls[Natts_pg_largeobject];
+ char replace[Natts_pg_largeobject];
+ bool write_indices;
+ Relation idescs[Num_pg_largeobject_indices];
Assert(PointerIsValid(obj_desc));
Assert(buf != NULL);
@@ -422,7 +431,7 @@ inv_write(LargeObjectDesc *obj_desc, char *buf, int nbytes)
if (nbytes <= 0)
return 0;
- write_indices = ! IsIgnoringSystemIndexes();
+ write_indices = !IsIgnoringSystemIndexes();
if (write_indices)
CatalogOpenIndices(Num_pg_largeobject_indices,
Name_pg_largeobject_indices,
@@ -450,6 +459,7 @@ inv_write(LargeObjectDesc *obj_desc, char *buf, int nbytes)
while (nwritten < nbytes)
{
+
/*
* If possible, get next pre-existing page of the LO. We assume
* the indexscan will deliver these in order --- but there may be
@@ -471,12 +481,14 @@ inv_write(LargeObjectDesc *obj_desc, char *buf, int nbytes)
}
neednextpage = false;
}
+
/*
* If we have a pre-existing page, see if it is the page we want
* to write, or a later one.
*/
if (olddata != NULL && olddata->pageno == pageno)
{
+
/*
* Update an existing page with fresh data.
*
@@ -495,12 +507,14 @@ inv_write(LargeObjectDesc *obj_desc, char *buf, int nbytes)
memcpy(workb, VARDATA(datafield), len);
if (pfreeit)
pfree(datafield);
+
/*
* Fill any hole
*/
off = (int) (obj_desc->offset % LOBLKSIZE);
if (off > len)
MemSet(workb + len, 0, off - len);
+
/*
* Insert appropriate portion of new data
*/
@@ -513,6 +527,7 @@ inv_write(LargeObjectDesc *obj_desc, char *buf, int nbytes)
/* compute valid length of new page */
len = (len >= off) ? len : off;
VARATT_SIZEP(workbuf) = len + VARHDRSZ;
+
/*
* Form and insert updated tuple
*/
@@ -528,6 +543,7 @@ inv_write(LargeObjectDesc *obj_desc, char *buf, int nbytes)
CatalogIndexInsert(idescs, Num_pg_largeobject_indices,
obj_desc->heap_r, newtup);
heap_freetuple(newtup);
+
/*
* We're done with this old page.
*/
@@ -539,6 +555,7 @@ inv_write(LargeObjectDesc *obj_desc, char *buf, int nbytes)
}
else
{
+
/*
* Write a brand new page.
*
@@ -547,6 +564,7 @@ inv_write(LargeObjectDesc *obj_desc, char *buf, int nbytes)
off = (int) (obj_desc->offset % LOBLKSIZE);
if (off > 0)
MemSet(workb, 0, off);
+
/*
* Insert appropriate portion of new data
*/
@@ -558,6 +576,7 @@ inv_write(LargeObjectDesc *obj_desc, char *buf, int nbytes)
/* compute valid length of new page */
len = off + n;
VARATT_SIZEP(workbuf) = len + VARHDRSZ;
+
/*
* Form and insert updated tuple
*/
@@ -585,8 +604,8 @@ inv_write(LargeObjectDesc *obj_desc, char *buf, int nbytes)
CatalogCloseIndices(Num_pg_largeobject_indices, idescs);
/*
- * Advance command counter so that my tuple updates will be seen by later
- * large-object operations in this transaction.
+ * Advance command counter so that my tuple updates will be seen by
+ * later large-object operations in this transaction.
*/
CommandCounterIncrement();
generated by cgit v1.2.3 (git 2.25.1) at 2025-05-20 12:34:12 +0000