1 files changed, 93 insertions, 0 deletions
diff --git a/src/backend/utils/init/miscinit.c b/src/backend/utils/init/miscinit.c
index bf3871a774b..683f616b1a8 100644
--- a/src/backend/utils/init/miscinit.c
+++ b/src/backend/utils/init/miscinit.c
@@ -936,6 +936,99 @@ GetUserNameFromId(Oid roleid, bool noerr)
 	return result;
 }
 
+/* ------------------------------------------------------------------------
+ *				Client connection state shared with parallel workers
+ *
+ * ClientConnectionInfo contains pieces of information about the client that
+ * need to be synced to parallel workers when they initialize.
+ *-------------------------------------------------------------------------
+ */
+
+ClientConnectionInfo MyClientConnectionInfo;
+
+/*
+ * Intermediate representation of ClientConnectionInfo for easier
+ * serialization.  Variable-length fields are allocated right after this
+ * header.
+ */
+typedef struct SerializedClientConnectionInfo
+{
+	int32		authn_id_len;	/* strlen(authn_id), or -1 if NULL */
+	UserAuth	auth_method;
+} SerializedClientConnectionInfo;
+
+/*
+ * Calculate the space needed to serialize MyClientConnectionInfo.
+ */
+Size
+EstimateClientConnectionInfoSpace(void)
+{
+	Size		size = 0;
+
+	size = add_size(size, sizeof(SerializedClientConnectionInfo));
+
+	if (MyClientConnectionInfo.authn_id)
+		size = add_size(size, strlen(MyClientConnectionInfo.authn_id) + 1);
+
+	return size;
+}
+
+/*
+ * Serialize MyClientConnectionInfo for use by parallel workers.
+ */
+void
+SerializeClientConnectionInfo(Size maxsize, char *start_address)
+{
+	SerializedClientConnectionInfo serialized = {0};
+
+	serialized.authn_id_len = -1;
+	serialized.auth_method = MyClientConnectionInfo.auth_method;
+
+	if (MyClientConnectionInfo.authn_id)
+		serialized.authn_id_len = strlen(MyClientConnectionInfo.authn_id);
+
+	/* Copy serialized representation to buffer */
+	Assert(maxsize >= sizeof(serialized));
+	memcpy(start_address, &serialized, sizeof(serialized));
+
+	maxsize -= sizeof(serialized);
+	start_address += sizeof(serialized);
+
+	/* Copy authn_id into the space after the struct */
+	if (serialized.authn_id_len >= 0)
+	{
+		Assert(maxsize >= (serialized.authn_id_len + 1));
+		memcpy(start_address,
+			   MyClientConnectionInfo.authn_id,
+		/* include the NULL terminator to ease deserialization */
+			   serialized.authn_id_len + 1);
+	}
+}
+
+/*
+ * Restore MyClientConnectionInfo from its serialized representation.
+ */
+void
+RestoreClientConnectionInfo(char *conninfo)
+{
+	SerializedClientConnectionInfo serialized;
+
+	memcpy(&serialized, conninfo, sizeof(serialized));
+
+	/* Copy the fields back into place */
+	MyClientConnectionInfo.authn_id = NULL;
+	MyClientConnectionInfo.auth_method = serialized.auth_method;
+
+	if (serialized.authn_id_len >= 0)
+	{
+		char	   *authn_id;
+
+		authn_id = conninfo + sizeof(serialized);
+		MyClientConnectionInfo.authn_id = MemoryContextStrdup(TopMemoryContext,
+															  authn_id);
+	}
+}
+
 
 /*-------------------------------------------------------------------------
  *				Interlock-file support