first commit based on psycopg2 2.9 version

psycopg/libpq_support.c

@@ -0,0 +1,105 @@
+/* libpq_support.c - functions not provided by libpq, but which are
+ * required for advanced communication with the server, such as
+ * streaming replication
+ *
+ * Copyright (C) 2003-2019 Federico Di Gregorio <fog@debian.org>
+ * Copyright (C) 2020-2021 The Psycopg Team
+ *
+ * This file is part of psycopg.
+ *
+ * psycopg2 is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * In addition, as a special exception, the copyright holders give
+ * permission to link this program with the OpenSSL library (or with
+ * modified versions of OpenSSL that use the same license as OpenSSL),
+ * and distribute linked combinations including the two.
+ *
+ * You must obey the GNU Lesser General Public License in all respects for
+ * all of the code used other than OpenSSL.
+ *
+ * psycopg2 is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
+ * License for more details.
+ */
+
+#define PSYCOPG_MODULE
+#include "psycopg/psycopg.h"
+
+#include "psycopg/libpq_support.h"
+
+/* htonl(), ntohl() */
+#ifdef _WIN32
+#include <winsock2.h>
+/* gettimeofday() */
+#include "psycopg/win32_support.h"
+#else
+#include <arpa/inet.h>
+#endif
+
+/* support routines taken from pg_basebackup/streamutil.c */
+
+/*
+ * Frontend version of GetCurrentTimestamp(), since we are not linked with
+ * backend code. The protocol always uses integer timestamps, regardless of
+ * server setting.
+ */
+int64_t
+feGetCurrentTimestamp(void)
+{
+    int64_t result;
+    struct timeval tp;
+
+    gettimeofday(&tp, NULL);
+
+    result = (int64_t) tp.tv_sec -
+        ((POSTGRES_EPOCH_JDATE - UNIX_EPOCH_JDATE) * SECS_PER_DAY);
+
+    result = (result * USECS_PER_SEC) + tp.tv_usec;
+
+    return result;
+}
+
+/*
+ * Converts an int64 to network byte order.
+ */
+void
+fe_sendint64(int64_t i, char *buf)
+{
+    uint32_t n32;
+
+    /* High order half first, since we're doing MSB-first */
+    n32 = (uint32_t) (i >> 32);
+    n32 = htonl(n32);
+    memcpy(&buf[0], &n32, 4);
+
+    /* Now the low order half */
+    n32 = (uint32_t) i;
+    n32 = htonl(n32);
+    memcpy(&buf[4], &n32, 4);
+}
+
+/*
+ * Converts an int64 from network byte order to native format.
+ */
+int64_t
+fe_recvint64(char *buf)
+{
+    int64_t result;
+    uint32_t h32;
+    uint32_t l32;
+
+    memcpy(&h32, buf, 4);
+    memcpy(&l32, buf + 4, 4);
+    h32 = ntohl(h32);
+    l32 = ntohl(l32);
+
+    result = h32;
+    result <<= 32;
+    result |= l32;
+
+    return result;
+}