1 files changed, 316 insertions, 0 deletions
diff --git a/src/bin/psql/large_obj.c b/src/bin/psql/large_obj.c
new file mode 100644
index 0000000..c15fcc0
--- /dev/null
+++ b/src/bin/psql/large_obj.c
@@ -0,0 +1,316 @@
+/*
+ * psql - the PostgreSQL interactive terminal
+ *
+ * Copyright (c) 2000-2021, PostgreSQL Global Development Group
+ *
+ * src/bin/psql/large_obj.c
+ */
+#include "postgres_fe.h"
+
+#include "common.h"
+#include "common/logging.h"
+#include "fe_utils/cancel.h"
+#include "large_obj.h"
+#include "settings.h"
+
+static void print_lo_result(const char *fmt,...) pg_attribute_printf(1, 2);
+
+static void
+print_lo_result(const char *fmt,...)
+{
+	va_list		ap;
+
+	if (!pset.quiet)
+	{
+		if (pset.popt.topt.format == PRINT_HTML)
+			fputs("<p>", pset.queryFout);
+
+		va_start(ap, fmt);
+		vfprintf(pset.queryFout, fmt, ap);
+		va_end(ap);
+
+		if (pset.popt.topt.format == PRINT_HTML)
+			fputs("</p>\n", pset.queryFout);
+		else
+			fputs("\n", pset.queryFout);
+	}
+
+	if (pset.logfile)
+	{
+		va_start(ap, fmt);
+		vfprintf(pset.logfile, fmt, ap);
+		va_end(ap);
+		fputs("\n", pset.logfile);
+	}
+}
+
+
+/*
+ * Prepare to do a large-object operation.  We *must* be inside a transaction
+ * block for all these operations, so start one if needed.
+ *
+ * Returns true if okay, false if failed.  *own_transaction is set to indicate
+ * if we started our own transaction or not.
+ */
+static bool
+start_lo_xact(const char *operation, bool *own_transaction)
+{
+	PGTransactionStatusType tstatus;
+	PGresult   *res;
+
+	*own_transaction = false;
+
+	if (!pset.db)
+	{
+		pg_log_error("%s: not connected to a database", operation);
+		return false;
+	}
+
+	tstatus = PQtransactionStatus(pset.db);
+
+	switch (tstatus)
+	{
+		case PQTRANS_IDLE:
+			/* need to start our own xact */
+			if (!(res = PSQLexec("BEGIN")))
+				return false;
+			PQclear(res);
+			*own_transaction = true;
+			break;
+		case PQTRANS_INTRANS:
+			/* use the existing xact */
+			break;
+		case PQTRANS_INERROR:
+			pg_log_error("%s: current transaction is aborted", operation);
+			return false;
+		default:
+			pg_log_error("%s: unknown transaction status", operation);
+			return false;
+	}
+
+	return true;
+}
+
+/*
+ * Clean up after a successful LO operation
+ */
+static bool
+finish_lo_xact(const char *operation, bool own_transaction)
+{
+	PGresult   *res;
+
+	if (own_transaction && pset.autocommit)
+	{
+		/* close out our own xact */
+		if (!(res = PSQLexec("COMMIT")))
+		{
+			res = PSQLexec("ROLLBACK");
+			PQclear(res);
+			return false;
+		}
+		PQclear(res);
+	}
+
+	return true;
+}
+
+/*
+ * Clean up after a failed LO operation
+ */
+static bool
+fail_lo_xact(const char *operation, bool own_transaction)
+{
+	PGresult   *res;
+
+	if (own_transaction && pset.autocommit)
+	{
+		/* close out our own xact */
+		res = PSQLexec("ROLLBACK");
+		PQclear(res);
+	}
+
+	return false;				/* always */
+}
+
+
+/*
+ * do_lo_export()
+ *
+ * Write a large object to a file
+ */
+bool
+do_lo_export(const char *loid_arg, const char *filename_arg)
+{
+	int			status;
+	bool		own_transaction;
+
+	if (!start_lo_xact("\\lo_export", &own_transaction))
+		return false;
+
+	SetCancelConn(NULL);
+	status = lo_export(pset.db, atooid(loid_arg), filename_arg);
+	ResetCancelConn();
+
+	/* of course this status is documented nowhere :( */
+	if (status != 1)
+	{
+		pg_log_info("%s", PQerrorMessage(pset.db));
+		return fail_lo_xact("\\lo_export", own_transaction);
+	}
+
+	if (!finish_lo_xact("\\lo_export", own_transaction))
+		return false;
+
+	print_lo_result("lo_export");
+
+	return true;
+}
+
+
+/*
+ * do_lo_import()
+ *
+ * Copy large object from file to database
+ */
+bool
+do_lo_import(const char *filename_arg, const char *comment_arg)
+{
+	PGresult   *res;
+	Oid			loid;
+	char		oidbuf[32];
+	bool		own_transaction;
+
+	if (!start_lo_xact("\\lo_import", &own_transaction))
+		return false;
+
+	SetCancelConn(NULL);
+	loid = lo_import(pset.db, filename_arg);
+	ResetCancelConn();
+
+	if (loid == InvalidOid)
+	{
+		pg_log_info("%s", PQerrorMessage(pset.db));
+		return fail_lo_xact("\\lo_import", own_transaction);
+	}
+
+	/* insert description if given */
+	if (comment_arg)
+	{
+		char	   *cmdbuf;
+		char	   *bufptr;
+		size_t		slen = strlen(comment_arg);
+
+		cmdbuf = pg_malloc_extended(slen * 2 + 256, MCXT_ALLOC_NO_OOM);
+		if (!cmdbuf)
+			return fail_lo_xact("\\lo_import", own_transaction);
+		sprintf(cmdbuf, "COMMENT ON LARGE OBJECT %u IS '", loid);
+		bufptr = cmdbuf + strlen(cmdbuf);
+		bufptr += PQescapeStringConn(pset.db, bufptr, comment_arg, slen, NULL);
+		strcpy(bufptr, "'");
+
+		if (!(res = PSQLexec(cmdbuf)))
+		{
+			free(cmdbuf);
+			return fail_lo_xact("\\lo_import", own_transaction);
+		}
+
+		PQclear(res);
+		free(cmdbuf);
+	}
+
+	if (!finish_lo_xact("\\lo_import", own_transaction))
+		return false;
+
+	print_lo_result("lo_import %u", loid);
+
+	sprintf(oidbuf, "%u", loid);
+	SetVariable(pset.vars, "LASTOID", oidbuf);
+
+	return true;
+}
+
+
+/*
+ * do_lo_unlink()
+ *
+ * removes a large object out of the database
+ */
+bool
+do_lo_unlink(const char *loid_arg)
+{
+	int			status;
+	Oid			loid = atooid(loid_arg);
+	bool		own_transaction;
+
+	if (!start_lo_xact("\\lo_unlink", &own_transaction))
+		return false;
+
+	SetCancelConn(NULL);
+	status = lo_unlink(pset.db, loid);
+	ResetCancelConn();
+
+	if (status == -1)
+	{
+		pg_log_info("%s", PQerrorMessage(pset.db));
+		return fail_lo_xact("\\lo_unlink", own_transaction);
+	}
+
+	if (!finish_lo_xact("\\lo_unlink", own_transaction))
+		return false;
+
+	print_lo_result("lo_unlink %u", loid);
+
+	return true;
+}
+
+
+
+/*
+ * do_lo_list()
+ *
+ * Show all large objects in database with comments
+ */
+bool
+do_lo_list(void)
+{
+	PGresult   *res;
+	char		buf[1024];
+	printQueryOpt myopt = pset.popt;
+
+	if (pset.sversion >= 90000)
+	{
+		snprintf(buf, sizeof(buf),
+				 "SELECT oid as \"%s\",\n"
+				 "  pg_catalog.pg_get_userbyid(lomowner) as \"%s\",\n"
+				 "  pg_catalog.obj_description(oid, 'pg_largeobject') as \"%s\"\n"
+				 "  FROM pg_catalog.pg_largeobject_metadata "
+				 "  ORDER BY oid",
+				 gettext_noop("ID"),
+				 gettext_noop("Owner"),
+				 gettext_noop("Description"));
+	}
+	else
+	{
+		snprintf(buf, sizeof(buf),
+				 "SELECT loid as \"%s\",\n"
+				 "  pg_catalog.obj_description(loid, 'pg_largeobject') as \"%s\"\n"
+				 "FROM (SELECT DISTINCT loid FROM pg_catalog.pg_largeobject) x\n"
+				 "ORDER BY 1",
+				 gettext_noop("ID"),
+				 gettext_noop("Description"));
+	}
+
+	res = PSQLexec(buf);
+	if (!res)
+		return false;
+
+	myopt.topt.tuples_only = false;
+	myopt.nullPrint = NULL;
+	myopt.title = _("Large objects");
+	myopt.translate_header = true;
+
+	printQuery(res, &myopt, pset.queryFout, false, pset.logfile);
+
+	PQclear(res);
+	return true;
+}