v1 milestone

venv/lib/python3.12/site-packages/asyncpg/pgproto/codecs/pg_snapshot.pyx

@@ -0,0 +1,63 @@
+# Copyright (C) 2016-present the asyncpg authors and contributors
+# <see AUTHORS file>
+#
+# This module is part of asyncpg and is released under
+# the Apache 2.0 License: http://www.apache.org/licenses/LICENSE-2.0
+
+
+cdef pg_snapshot_encode(CodecContext settings, WriteBuffer buf, obj):
+    cdef:
+        ssize_t nxip
+        uint64_t xmin
+        uint64_t xmax
+        int i
+        WriteBuffer xip_buf = WriteBuffer.new()
+
+    if not (cpython.PyTuple_Check(obj) or cpython.PyList_Check(obj)):
+        raise TypeError(
+            'list or tuple expected (got type {})'.format(type(obj)))
+
+    if len(obj) != 3:
+        raise ValueError(
+            'invalid number of elements in txid_snapshot tuple, expecting 4')
+
+    nxip = len(obj[2])
+    if nxip > _MAXINT32:
+        raise ValueError('txid_snapshot value is too long')
+
+    xmin = obj[0]
+    xmax = obj[1]
+
+    for i in range(nxip):
+        xip_buf.write_int64(
+            <int64_t>cpython.PyLong_AsUnsignedLongLong(obj[2][i]))
+
+    buf.write_int32(20 + xip_buf.len())
+
+    buf.write_int32(<int32_t>nxip)
+    buf.write_int64(<int64_t>xmin)
+    buf.write_int64(<int64_t>xmax)
+    buf.write_buffer(xip_buf)
+
+
+cdef pg_snapshot_decode(CodecContext settings, FRBuffer *buf):
+    cdef:
+        int32_t nxip
+        uint64_t xmin
+        uint64_t xmax
+        tuple xip_tup
+        int32_t i
+        object xip
+
+    nxip = hton.unpack_int32(frb_read(buf, 4))
+    xmin = <uint64_t>hton.unpack_int64(frb_read(buf, 8))
+    xmax = <uint64_t>hton.unpack_int64(frb_read(buf, 8))
+
+    xip_tup = cpython.PyTuple_New(nxip)
+    for i in range(nxip):
+        xip = cpython.PyLong_FromUnsignedLongLong(
+            <uint64_t>hton.unpack_int64(frb_read(buf, 8)))
+        cpython.Py_INCREF(xip)
+        cpython.PyTuple_SET_ITEM(xip_tup, i, xip)
+
+    return (xmin, xmax, xip_tup)