mirror of
https://git.postgresql.org/git/postgresql.git
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ca3b37487b
Backpatch-through: 9.5
865 lines
20 KiB
C
865 lines
20 KiB
C
/*-------------------------------------------------------------------------
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*
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* be-fsstubs.c
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* Builtin functions for open/close/read/write operations on large objects
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*
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* Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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*
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* IDENTIFICATION
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* src/backend/libpq/be-fsstubs.c
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*
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* NOTES
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* This should be moved to a more appropriate place. It is here
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* for lack of a better place.
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*
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* These functions store LargeObjectDesc structs in a private MemoryContext,
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* which means that large object descriptors hang around until we destroy
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* the context at transaction end. It'd be possible to prolong the lifetime
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* of the context so that LO FDs are good across transactions (for example,
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* we could release the context only if we see that no FDs remain open).
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* But we'd need additional state in order to do the right thing at the
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* end of an aborted transaction. FDs opened during an aborted xact would
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* still need to be closed, since they might not be pointing at valid
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* relations at all. Locking semantics are also an interesting problem
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* if LOs stay open across transactions. For now, we'll stick with the
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* existing documented semantics of LO FDs: they're only good within a
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* transaction.
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*
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* As of PostgreSQL 8.0, much of the angst expressed above is no longer
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* relevant, and in fact it'd be pretty easy to allow LO FDs to stay
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* open across transactions. (Snapshot relevancy would still be an issue.)
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* However backwards compatibility suggests that we should stick to the
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* status quo.
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*
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*-------------------------------------------------------------------------
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*/
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#include "postgres.h"
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#include <fcntl.h>
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#include <sys/stat.h>
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#include <unistd.h>
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#include "libpq/be-fsstubs.h"
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#include "libpq/libpq-fs.h"
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#include "miscadmin.h"
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#include "storage/fd.h"
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#include "storage/large_object.h"
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#include "utils/acl.h"
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#include "utils/builtins.h"
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#include "utils/memutils.h"
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/* define this to enable debug logging */
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/* #define FSDB 1 */
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/* chunk size for lo_import/lo_export transfers */
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#define BUFSIZE 8192
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/*
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* LO "FD"s are indexes into the cookies array.
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*
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* A non-null entry is a pointer to a LargeObjectDesc allocated in the
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* LO private memory context "fscxt". The cookies array itself is also
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* dynamically allocated in that context. Its current allocated size is
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* cookies_size entries, of which any unused entries will be NULL.
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*/
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static LargeObjectDesc **cookies = NULL;
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static int cookies_size = 0;
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static MemoryContext fscxt = NULL;
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#define CreateFSContext() \
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do { \
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if (fscxt == NULL) \
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fscxt = AllocSetContextCreate(TopMemoryContext, \
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"Filesystem", \
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ALLOCSET_DEFAULT_SIZES); \
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} while (0)
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static int newLOfd(LargeObjectDesc *lobjCookie);
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static void deleteLOfd(int fd);
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static Oid lo_import_internal(text *filename, Oid lobjOid);
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/*****************************************************************************
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* File Interfaces for Large Objects
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*****************************************************************************/
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Datum
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be_lo_open(PG_FUNCTION_ARGS)
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{
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Oid lobjId = PG_GETARG_OID(0);
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int32 mode = PG_GETARG_INT32(1);
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LargeObjectDesc *lobjDesc;
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int fd;
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#ifdef FSDB
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elog(DEBUG4, "lo_open(%u,%d)", lobjId, mode);
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#endif
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CreateFSContext();
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lobjDesc = inv_open(lobjId, mode, fscxt);
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fd = newLOfd(lobjDesc);
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PG_RETURN_INT32(fd);
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}
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Datum
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be_lo_close(PG_FUNCTION_ARGS)
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{
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int32 fd = PG_GETARG_INT32(0);
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if (fd < 0 || fd >= cookies_size || cookies[fd] == NULL)
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ereport(ERROR,
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(errcode(ERRCODE_UNDEFINED_OBJECT),
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errmsg("invalid large-object descriptor: %d", fd)));
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#ifdef FSDB
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elog(DEBUG4, "lo_close(%d)", fd);
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#endif
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inv_close(cookies[fd]);
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deleteLOfd(fd);
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PG_RETURN_INT32(0);
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}
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/*****************************************************************************
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* Bare Read/Write operations --- these are not fmgr-callable!
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*
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* We assume the large object supports byte oriented reads and seeks so
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* that our work is easier.
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*
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*****************************************************************************/
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int
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lo_read(int fd, char *buf, int len)
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{
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int status;
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LargeObjectDesc *lobj;
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if (fd < 0 || fd >= cookies_size || cookies[fd] == NULL)
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ereport(ERROR,
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(errcode(ERRCODE_UNDEFINED_OBJECT),
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errmsg("invalid large-object descriptor: %d", fd)));
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lobj = cookies[fd];
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/*
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* Check state. inv_read() would throw an error anyway, but we want the
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* error to be about the FD's state not the underlying privilege; it might
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* be that the privilege exists but user forgot to ask for read mode.
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*/
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if ((lobj->flags & IFS_RDLOCK) == 0)
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ereport(ERROR,
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(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
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errmsg("large object descriptor %d was not opened for reading",
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fd)));
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status = inv_read(lobj, buf, len);
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return status;
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}
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int
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lo_write(int fd, const char *buf, int len)
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{
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int status;
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LargeObjectDesc *lobj;
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if (fd < 0 || fd >= cookies_size || cookies[fd] == NULL)
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ereport(ERROR,
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(errcode(ERRCODE_UNDEFINED_OBJECT),
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errmsg("invalid large-object descriptor: %d", fd)));
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lobj = cookies[fd];
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/* see comment in lo_read() */
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if ((lobj->flags & IFS_WRLOCK) == 0)
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ereport(ERROR,
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(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
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errmsg("large object descriptor %d was not opened for writing",
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fd)));
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status = inv_write(lobj, buf, len);
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return status;
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}
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Datum
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be_lo_lseek(PG_FUNCTION_ARGS)
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{
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int32 fd = PG_GETARG_INT32(0);
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int32 offset = PG_GETARG_INT32(1);
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int32 whence = PG_GETARG_INT32(2);
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int64 status;
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if (fd < 0 || fd >= cookies_size || cookies[fd] == NULL)
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ereport(ERROR,
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(errcode(ERRCODE_UNDEFINED_OBJECT),
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errmsg("invalid large-object descriptor: %d", fd)));
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status = inv_seek(cookies[fd], offset, whence);
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/* guard against result overflow */
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if (status != (int32) status)
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ereport(ERROR,
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(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
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errmsg("lo_lseek result out of range for large-object descriptor %d",
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fd)));
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PG_RETURN_INT32((int32) status);
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}
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Datum
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be_lo_lseek64(PG_FUNCTION_ARGS)
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{
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int32 fd = PG_GETARG_INT32(0);
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int64 offset = PG_GETARG_INT64(1);
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int32 whence = PG_GETARG_INT32(2);
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int64 status;
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if (fd < 0 || fd >= cookies_size || cookies[fd] == NULL)
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ereport(ERROR,
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(errcode(ERRCODE_UNDEFINED_OBJECT),
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errmsg("invalid large-object descriptor: %d", fd)));
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status = inv_seek(cookies[fd], offset, whence);
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PG_RETURN_INT64(status);
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}
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Datum
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be_lo_creat(PG_FUNCTION_ARGS)
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{
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Oid lobjId;
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/*
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* We don't actually need to store into fscxt, but create it anyway to
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* ensure that AtEOXact_LargeObject knows there is state to clean up
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*/
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CreateFSContext();
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lobjId = inv_create(InvalidOid);
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PG_RETURN_OID(lobjId);
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}
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Datum
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be_lo_create(PG_FUNCTION_ARGS)
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{
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Oid lobjId = PG_GETARG_OID(0);
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/*
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* We don't actually need to store into fscxt, but create it anyway to
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* ensure that AtEOXact_LargeObject knows there is state to clean up
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*/
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CreateFSContext();
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lobjId = inv_create(lobjId);
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PG_RETURN_OID(lobjId);
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}
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Datum
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be_lo_tell(PG_FUNCTION_ARGS)
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{
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int32 fd = PG_GETARG_INT32(0);
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int64 offset;
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if (fd < 0 || fd >= cookies_size || cookies[fd] == NULL)
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ereport(ERROR,
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(errcode(ERRCODE_UNDEFINED_OBJECT),
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errmsg("invalid large-object descriptor: %d", fd)));
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offset = inv_tell(cookies[fd]);
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/* guard against result overflow */
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if (offset != (int32) offset)
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ereport(ERROR,
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(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
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errmsg("lo_tell result out of range for large-object descriptor %d",
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fd)));
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PG_RETURN_INT32((int32) offset);
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}
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Datum
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be_lo_tell64(PG_FUNCTION_ARGS)
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{
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int32 fd = PG_GETARG_INT32(0);
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int64 offset;
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if (fd < 0 || fd >= cookies_size || cookies[fd] == NULL)
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ereport(ERROR,
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(errcode(ERRCODE_UNDEFINED_OBJECT),
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errmsg("invalid large-object descriptor: %d", fd)));
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offset = inv_tell(cookies[fd]);
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PG_RETURN_INT64(offset);
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}
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Datum
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be_lo_unlink(PG_FUNCTION_ARGS)
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{
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Oid lobjId = PG_GETARG_OID(0);
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/*
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* Must be owner of the large object. It would be cleaner to check this
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* in inv_drop(), but we want to throw the error before not after closing
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* relevant FDs.
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*/
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if (!lo_compat_privileges &&
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!pg_largeobject_ownercheck(lobjId, GetUserId()))
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ereport(ERROR,
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(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
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errmsg("must be owner of large object %u", lobjId)));
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/*
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* If there are any open LO FDs referencing that ID, close 'em.
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*/
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if (fscxt != NULL)
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{
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int i;
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for (i = 0; i < cookies_size; i++)
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{
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if (cookies[i] != NULL && cookies[i]->id == lobjId)
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{
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inv_close(cookies[i]);
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deleteLOfd(i);
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}
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}
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}
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/*
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* inv_drop does not create a need for end-of-transaction cleanup and
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* hence we don't need to have created fscxt.
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*/
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PG_RETURN_INT32(inv_drop(lobjId));
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}
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/*****************************************************************************
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* Read/Write using bytea
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*****************************************************************************/
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Datum
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be_loread(PG_FUNCTION_ARGS)
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{
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int32 fd = PG_GETARG_INT32(0);
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int32 len = PG_GETARG_INT32(1);
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bytea *retval;
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int totalread;
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if (len < 0)
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len = 0;
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retval = (bytea *) palloc(VARHDRSZ + len);
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totalread = lo_read(fd, VARDATA(retval), len);
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SET_VARSIZE(retval, totalread + VARHDRSZ);
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PG_RETURN_BYTEA_P(retval);
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}
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Datum
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be_lowrite(PG_FUNCTION_ARGS)
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{
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int32 fd = PG_GETARG_INT32(0);
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bytea *wbuf = PG_GETARG_BYTEA_PP(1);
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int bytestowrite;
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int totalwritten;
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bytestowrite = VARSIZE_ANY_EXHDR(wbuf);
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totalwritten = lo_write(fd, VARDATA_ANY(wbuf), bytestowrite);
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PG_RETURN_INT32(totalwritten);
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}
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/*****************************************************************************
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* Import/Export of Large Object
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*****************************************************************************/
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/*
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* lo_import -
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* imports a file as an (inversion) large object.
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*/
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Datum
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be_lo_import(PG_FUNCTION_ARGS)
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{
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text *filename = PG_GETARG_TEXT_PP(0);
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PG_RETURN_OID(lo_import_internal(filename, InvalidOid));
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}
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/*
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* lo_import_with_oid -
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* imports a file as an (inversion) large object specifying oid.
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*/
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Datum
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be_lo_import_with_oid(PG_FUNCTION_ARGS)
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{
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text *filename = PG_GETARG_TEXT_PP(0);
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Oid oid = PG_GETARG_OID(1);
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PG_RETURN_OID(lo_import_internal(filename, oid));
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}
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static Oid
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lo_import_internal(text *filename, Oid lobjOid)
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{
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int fd;
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int nbytes,
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tmp PG_USED_FOR_ASSERTS_ONLY;
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char buf[BUFSIZE];
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char fnamebuf[MAXPGPATH];
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LargeObjectDesc *lobj;
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Oid oid;
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CreateFSContext();
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/*
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* open the file to be read in
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*/
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text_to_cstring_buffer(filename, fnamebuf, sizeof(fnamebuf));
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fd = OpenTransientFile(fnamebuf, O_RDONLY | PG_BINARY);
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if (fd < 0)
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ereport(ERROR,
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(errcode_for_file_access(),
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errmsg("could not open server file \"%s\": %m",
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fnamebuf)));
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/*
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* create an inversion object
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*/
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oid = inv_create(lobjOid);
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/*
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* read in from the filesystem and write to the inversion object
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*/
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lobj = inv_open(oid, INV_WRITE, fscxt);
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while ((nbytes = read(fd, buf, BUFSIZE)) > 0)
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{
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tmp = inv_write(lobj, buf, nbytes);
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Assert(tmp == nbytes);
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}
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if (nbytes < 0)
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ereport(ERROR,
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(errcode_for_file_access(),
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errmsg("could not read server file \"%s\": %m",
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fnamebuf)));
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inv_close(lobj);
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if (CloseTransientFile(fd) != 0)
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ereport(ERROR,
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(errcode_for_file_access(),
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errmsg("could not close file \"%s\": %m",
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fnamebuf)));
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return oid;
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}
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|
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/*
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* lo_export -
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* exports an (inversion) large object.
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*/
|
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Datum
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be_lo_export(PG_FUNCTION_ARGS)
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{
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Oid lobjId = PG_GETARG_OID(0);
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text *filename = PG_GETARG_TEXT_PP(1);
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int fd;
|
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int nbytes,
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tmp;
|
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char buf[BUFSIZE];
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char fnamebuf[MAXPGPATH];
|
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LargeObjectDesc *lobj;
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mode_t oumask;
|
|
|
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CreateFSContext();
|
|
|
|
/*
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* open the inversion object (no need to test for failure)
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*/
|
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lobj = inv_open(lobjId, INV_READ, fscxt);
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|
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/*
|
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* open the file to be written to
|
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*
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* Note: we reduce backend's normal 077 umask to the slightly friendlier
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* 022. This code used to drop it all the way to 0, but creating
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* world-writable export files doesn't seem wise.
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*/
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text_to_cstring_buffer(filename, fnamebuf, sizeof(fnamebuf));
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oumask = umask(S_IWGRP | S_IWOTH);
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PG_TRY();
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{
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fd = OpenTransientFilePerm(fnamebuf, O_CREAT | O_WRONLY | O_TRUNC | PG_BINARY,
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S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
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}
|
|
PG_FINALLY();
|
|
{
|
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umask(oumask);
|
|
}
|
|
PG_END_TRY();
|
|
if (fd < 0)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not create server file \"%s\": %m",
|
|
fnamebuf)));
|
|
|
|
/*
|
|
* read in from the inversion file and write to the filesystem
|
|
*/
|
|
while ((nbytes = inv_read(lobj, buf, BUFSIZE)) > 0)
|
|
{
|
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tmp = write(fd, buf, nbytes);
|
|
if (tmp != nbytes)
|
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ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not write server file \"%s\": %m",
|
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fnamebuf)));
|
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}
|
|
|
|
if (CloseTransientFile(fd) != 0)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not close file \"%s\": %m",
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fnamebuf)));
|
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|
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inv_close(lobj);
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|
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PG_RETURN_INT32(1);
|
|
}
|
|
|
|
/*
|
|
* lo_truncate -
|
|
* truncate a large object to a specified length
|
|
*/
|
|
static void
|
|
lo_truncate_internal(int32 fd, int64 len)
|
|
{
|
|
LargeObjectDesc *lobj;
|
|
|
|
if (fd < 0 || fd >= cookies_size || cookies[fd] == NULL)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_UNDEFINED_OBJECT),
|
|
errmsg("invalid large-object descriptor: %d", fd)));
|
|
lobj = cookies[fd];
|
|
|
|
/* see comment in lo_read() */
|
|
if ((lobj->flags & IFS_WRLOCK) == 0)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
|
|
errmsg("large object descriptor %d was not opened for writing",
|
|
fd)));
|
|
|
|
inv_truncate(lobj, len);
|
|
}
|
|
|
|
Datum
|
|
be_lo_truncate(PG_FUNCTION_ARGS)
|
|
{
|
|
int32 fd = PG_GETARG_INT32(0);
|
|
int32 len = PG_GETARG_INT32(1);
|
|
|
|
lo_truncate_internal(fd, len);
|
|
PG_RETURN_INT32(0);
|
|
}
|
|
|
|
Datum
|
|
be_lo_truncate64(PG_FUNCTION_ARGS)
|
|
{
|
|
int32 fd = PG_GETARG_INT32(0);
|
|
int64 len = PG_GETARG_INT64(1);
|
|
|
|
lo_truncate_internal(fd, len);
|
|
PG_RETURN_INT32(0);
|
|
}
|
|
|
|
/*
|
|
* AtEOXact_LargeObject -
|
|
* prepares large objects for transaction commit
|
|
*/
|
|
void
|
|
AtEOXact_LargeObject(bool isCommit)
|
|
{
|
|
int i;
|
|
|
|
if (fscxt == NULL)
|
|
return; /* no LO operations in this xact */
|
|
|
|
/*
|
|
* Close LO fds and clear cookies array so that LO fds are no longer good.
|
|
* On abort we skip the close step.
|
|
*/
|
|
for (i = 0; i < cookies_size; i++)
|
|
{
|
|
if (cookies[i] != NULL)
|
|
{
|
|
if (isCommit)
|
|
inv_close(cookies[i]);
|
|
deleteLOfd(i);
|
|
}
|
|
}
|
|
|
|
/* Needn't actually pfree since we're about to zap context */
|
|
cookies = NULL;
|
|
cookies_size = 0;
|
|
|
|
/* Release the LO memory context to prevent permanent memory leaks. */
|
|
MemoryContextDelete(fscxt);
|
|
fscxt = NULL;
|
|
|
|
/* Give inv_api.c a chance to clean up, too */
|
|
close_lo_relation(isCommit);
|
|
}
|
|
|
|
/*
|
|
* AtEOSubXact_LargeObject
|
|
* Take care of large objects at subtransaction commit/abort
|
|
*
|
|
* Reassign LOs created/opened during a committing subtransaction
|
|
* to the parent subtransaction. On abort, just close them.
|
|
*/
|
|
void
|
|
AtEOSubXact_LargeObject(bool isCommit, SubTransactionId mySubid,
|
|
SubTransactionId parentSubid)
|
|
{
|
|
int i;
|
|
|
|
if (fscxt == NULL) /* no LO operations in this xact */
|
|
return;
|
|
|
|
for (i = 0; i < cookies_size; i++)
|
|
{
|
|
LargeObjectDesc *lo = cookies[i];
|
|
|
|
if (lo != NULL && lo->subid == mySubid)
|
|
{
|
|
if (isCommit)
|
|
lo->subid = parentSubid;
|
|
else
|
|
{
|
|
/*
|
|
* Make sure we do not call inv_close twice if it errors out
|
|
* for some reason. Better a leak than a crash.
|
|
*/
|
|
deleteLOfd(i);
|
|
inv_close(lo);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/*****************************************************************************
|
|
* Support routines for this file
|
|
*****************************************************************************/
|
|
|
|
static int
|
|
newLOfd(LargeObjectDesc *lobjCookie)
|
|
{
|
|
int i,
|
|
newsize;
|
|
|
|
/* Try to find a free slot */
|
|
for (i = 0; i < cookies_size; i++)
|
|
{
|
|
if (cookies[i] == NULL)
|
|
{
|
|
cookies[i] = lobjCookie;
|
|
return i;
|
|
}
|
|
}
|
|
|
|
/* No free slot, so make the array bigger */
|
|
if (cookies_size <= 0)
|
|
{
|
|
/* First time through, arbitrarily make 64-element array */
|
|
i = 0;
|
|
newsize = 64;
|
|
cookies = (LargeObjectDesc **)
|
|
MemoryContextAllocZero(fscxt, newsize * sizeof(LargeObjectDesc *));
|
|
cookies_size = newsize;
|
|
}
|
|
else
|
|
{
|
|
/* Double size of array */
|
|
i = cookies_size;
|
|
newsize = cookies_size * 2;
|
|
cookies = (LargeObjectDesc **)
|
|
repalloc(cookies, newsize * sizeof(LargeObjectDesc *));
|
|
MemSet(cookies + cookies_size, 0,
|
|
(newsize - cookies_size) * sizeof(LargeObjectDesc *));
|
|
cookies_size = newsize;
|
|
}
|
|
|
|
Assert(cookies[i] == NULL);
|
|
cookies[i] = lobjCookie;
|
|
return i;
|
|
}
|
|
|
|
static void
|
|
deleteLOfd(int fd)
|
|
{
|
|
cookies[fd] = NULL;
|
|
}
|
|
|
|
/*****************************************************************************
|
|
* Wrappers oriented toward SQL callers
|
|
*****************************************************************************/
|
|
|
|
/*
|
|
* Read [offset, offset+nbytes) within LO; when nbytes is -1, read to end.
|
|
*/
|
|
static bytea *
|
|
lo_get_fragment_internal(Oid loOid, int64 offset, int32 nbytes)
|
|
{
|
|
LargeObjectDesc *loDesc;
|
|
int64 loSize;
|
|
int64 result_length;
|
|
int total_read PG_USED_FOR_ASSERTS_ONLY;
|
|
bytea *result = NULL;
|
|
|
|
/*
|
|
* We don't actually need to store into fscxt, but create it anyway to
|
|
* ensure that AtEOXact_LargeObject knows there is state to clean up
|
|
*/
|
|
CreateFSContext();
|
|
|
|
loDesc = inv_open(loOid, INV_READ, fscxt);
|
|
|
|
/*
|
|
* Compute number of bytes we'll actually read, accommodating nbytes == -1
|
|
* and reads beyond the end of the LO.
|
|
*/
|
|
loSize = inv_seek(loDesc, 0, SEEK_END);
|
|
if (loSize > offset)
|
|
{
|
|
if (nbytes >= 0 && nbytes <= loSize - offset)
|
|
result_length = nbytes; /* request is wholly inside LO */
|
|
else
|
|
result_length = loSize - offset; /* adjust to end of LO */
|
|
}
|
|
else
|
|
result_length = 0; /* request is wholly outside LO */
|
|
|
|
/*
|
|
* A result_length calculated from loSize may not fit in a size_t. Check
|
|
* that the size will satisfy this and subsequently-enforced size limits.
|
|
*/
|
|
if (result_length > MaxAllocSize - VARHDRSZ)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
|
|
errmsg("large object read request is too large")));
|
|
|
|
result = (bytea *) palloc(VARHDRSZ + result_length);
|
|
|
|
inv_seek(loDesc, offset, SEEK_SET);
|
|
total_read = inv_read(loDesc, VARDATA(result), result_length);
|
|
Assert(total_read == result_length);
|
|
SET_VARSIZE(result, result_length + VARHDRSZ);
|
|
|
|
inv_close(loDesc);
|
|
|
|
return result;
|
|
}
|
|
|
|
/*
|
|
* Read entire LO
|
|
*/
|
|
Datum
|
|
be_lo_get(PG_FUNCTION_ARGS)
|
|
{
|
|
Oid loOid = PG_GETARG_OID(0);
|
|
bytea *result;
|
|
|
|
result = lo_get_fragment_internal(loOid, 0, -1);
|
|
|
|
PG_RETURN_BYTEA_P(result);
|
|
}
|
|
|
|
/*
|
|
* Read range within LO
|
|
*/
|
|
Datum
|
|
be_lo_get_fragment(PG_FUNCTION_ARGS)
|
|
{
|
|
Oid loOid = PG_GETARG_OID(0);
|
|
int64 offset = PG_GETARG_INT64(1);
|
|
int32 nbytes = PG_GETARG_INT32(2);
|
|
bytea *result;
|
|
|
|
if (nbytes < 0)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
|
|
errmsg("requested length cannot be negative")));
|
|
|
|
result = lo_get_fragment_internal(loOid, offset, nbytes);
|
|
|
|
PG_RETURN_BYTEA_P(result);
|
|
}
|
|
|
|
/*
|
|
* Create LO with initial contents given by a bytea argument
|
|
*/
|
|
Datum
|
|
be_lo_from_bytea(PG_FUNCTION_ARGS)
|
|
{
|
|
Oid loOid = PG_GETARG_OID(0);
|
|
bytea *str = PG_GETARG_BYTEA_PP(1);
|
|
LargeObjectDesc *loDesc;
|
|
int written PG_USED_FOR_ASSERTS_ONLY;
|
|
|
|
CreateFSContext();
|
|
|
|
loOid = inv_create(loOid);
|
|
loDesc = inv_open(loOid, INV_WRITE, fscxt);
|
|
written = inv_write(loDesc, VARDATA_ANY(str), VARSIZE_ANY_EXHDR(str));
|
|
Assert(written == VARSIZE_ANY_EXHDR(str));
|
|
inv_close(loDesc);
|
|
|
|
PG_RETURN_OID(loOid);
|
|
}
|
|
|
|
/*
|
|
* Update range within LO
|
|
*/
|
|
Datum
|
|
be_lo_put(PG_FUNCTION_ARGS)
|
|
{
|
|
Oid loOid = PG_GETARG_OID(0);
|
|
int64 offset = PG_GETARG_INT64(1);
|
|
bytea *str = PG_GETARG_BYTEA_PP(2);
|
|
LargeObjectDesc *loDesc;
|
|
int written PG_USED_FOR_ASSERTS_ONLY;
|
|
|
|
CreateFSContext();
|
|
|
|
loDesc = inv_open(loOid, INV_WRITE, fscxt);
|
|
|
|
/* Permission check */
|
|
if (!lo_compat_privileges &&
|
|
pg_largeobject_aclcheck_snapshot(loDesc->id,
|
|
GetUserId(),
|
|
ACL_UPDATE,
|
|
loDesc->snapshot) != ACLCHECK_OK)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
|
|
errmsg("permission denied for large object %u",
|
|
loDesc->id)));
|
|
|
|
inv_seek(loDesc, offset, SEEK_SET);
|
|
written = inv_write(loDesc, VARDATA_ANY(str), VARSIZE_ANY_EXHDR(str));
|
|
Assert(written == VARSIZE_ANY_EXHDR(str));
|
|
inv_close(loDesc);
|
|
|
|
PG_RETURN_VOID();
|
|
}
|