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Cleanup the contrib/lo module: there is no need anymore to implement

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a physically separate type.  Defining 'lo' as a domain over OID works
just fine and is more efficient.  Improve documentation and fix up the
test script.  (Would like to turn test script into a proper regression
test, but right now its output is not constant because of numeric OIDs;
plus it makes Unix-specific assumptions about files it can import.)
This commit is contained in:
Tom Lane
2005-06-23 00:06:37 +00:00
parent d20763dbee
commit 5b0c9d3603
6 changed files with 90 additions and 202 deletions
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128
contrib/lo/lo.c
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@ -1,7 +1,7 @@
/*
* PostgreSQL type definitions for managed LargeObjects.
* PostgreSQL definitions for managed Large Objects.
*
* $PostgreSQL: pgsql/contrib/lo/lo.c,v 1.14 2003/11/29 19:51:35 pgsql Exp $
* $PostgreSQL: pgsql/contrib/lo/lo.c,v 1.15 2005/06/23 00:06:37 tgl Exp $
*
*/
@ -21,117 +21,12 @@
#define atooid(x) ((Oid) strtoul((x), NULL, 10))
/*
* This is the internal storage format for managed large objects
*
*/
/* forward declarations */
Datum lo_manage(PG_FUNCTION_ARGS);
typedef Oid Blob;
/*
* Various forward declarations:
*/
Blob *lo_in(char *str); /* Create from String */
char *lo_out(Blob * addr); /* Output oid as String */
Oid lo_oid(Blob * addr); /* Return oid as an oid */
Blob *lo(Oid oid); /* Return Blob based on oid */
Datum lo_manage(PG_FUNCTION_ARGS); /* Trigger handler */
/*
* This creates a large object, and sets its OID to the value in the
* supplied string.
*
* If the string is empty, then a new LargeObject is created, and its oid
* is placed in the resulting lo.
*/
Blob *
lo_in(char *str)
{
Blob *result;
Oid oid;
int count;
if (strlen(str) > 0)
{
count = sscanf(str, "%u", &oid);
if (count < 1)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("error in parsing \"%s\"", str)));
if (oid == InvalidOid)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("illegal oid: \"%s\"", str)));
}
else
{
/*
* There is no Oid passed, so create a new one
*/
oid = DatumGetObjectId(DirectFunctionCall1(lo_creat,
Int32GetDatum(INV_READ | INV_WRITE)));
if (oid == InvalidOid)
/* internal error */
elog(ERROR, "InvalidOid returned from lo_creat");
}
result = (Blob *) palloc(sizeof(Blob));
*result = oid;
return (result);
}
/*
* This simply outputs the Oid of the Blob as a string.
*/
char *
lo_out(Blob * addr)
{
char *result;
if (addr == NULL)
return (NULL);
result = (char *) palloc(32);
snprintf(result, 32, "%u", *addr);
return (result);
}
/*
* This function converts Blob to oid.
*
* eg: select lo_export(raster::oid,'/path/file') from table;
*
*/
Oid
lo_oid(Blob * addr)
{
if (addr == NULL)
return InvalidOid;
return (Oid) (*addr);
}
/*
* This function is used so we can convert oid's to lo's
*
* ie: insert into table values(lo_import('/path/file')::lo);
*
*/
Blob *
lo(Oid oid)
{
Blob *result = (Blob *) palloc(sizeof(Blob));
*result = oid;
return (result);
}
/*
* This handles the trigger that protects us from orphaned large objects
* This is the trigger that protects us from orphaned large objects
*/
PG_FUNCTION_INFO_V1(lo_manage);
@ -144,11 +39,10 @@ lo_manage(PG_FUNCTION_ARGS)
TupleDesc tupdesc; /* Tuple Descriptor */
HeapTuple rettuple; /* Tuple to be returned */
bool isdelete; /* are we deleting? */
HeapTuple newtuple = NULL; /* The new value for tuple */
HeapTuple newtuple; /* The new value for tuple */
HeapTuple trigtuple; /* The original value of tuple */
if (!CALLED_AS_TRIGGER(fcinfo))
/* internal error */
if (!CALLED_AS_TRIGGER(fcinfo)) /* internal error */
elog(ERROR, "not fired by trigger manager");
/*
@ -168,9 +62,12 @@ lo_manage(PG_FUNCTION_ARGS)
/* Are we deleting the row? */
isdelete = TRIGGER_FIRED_BY_DELETE(trigdata->tg_event);
/* Get the column were interested in */
/* Get the column we're interested in */
attnum = SPI_fnumber(tupdesc, args[0]);
if (attnum <= 0)
elog(ERROR, "column \"%s\" does not exist", args[0]);
/*
* Handle updates
*
@ -182,7 +79,7 @@ lo_manage(PG_FUNCTION_ARGS)
char *orig = SPI_getvalue(trigtuple, tupdesc, attnum);
char *newv = SPI_getvalue(newtuple, tupdesc, attnum);
if (orig != NULL && (newv == NULL || strcmp(orig, newv)))
if (orig != NULL && (newv == NULL || strcmp(orig, newv) != 0))
DirectFunctionCall1(lo_unlink,
ObjectIdGetDatum(atooid(orig)));
@ -196,7 +93,6 @@ lo_manage(PG_FUNCTION_ARGS)
* Handle deleting of rows
*
* Here, we unlink the large object associated with the managed attribute
*
*/
if (isdelete)
{