ovsdb-server: Add support for a built-in _Server database.

The _Server database is valuable primarily because it provides database
clients a way to find out the details of changes to databases, schemas,
etc. in a granular, natural way.  Until now, the only way that the server
could notify clients about these kinds of changes was to close the session;
when the client reconnects, it is expected to reassess the server's state.
One way to provide this kind of granular information would be to add
specific JSON-RPC requests to obtain notifications for different kinds of
changes, but since ovsdb-server already provides granular and flexible
notification support for databases, using a database for the purpose is
convenient and avoids duplicating functionality.

Initially this database only reports databases' names and schemas, but
when clustering support is added in a later commit it will also report
important aspects of clustering and cluster status.  Thus, this database
also reduces the need to add JSON-RPC calls to retrieve information about
new features.

Signed-off-by: Ben Pfaff <blp@ovn.org>

2 files changed, 27 insertions, 1 deletions

diff --git a/build-aux/automake.mk b/build-aux/automake.mk
index 6baafab0e..a1f2f856f 100644
--- a/build-aux/automake.mk
+++ b/build-aux/automake.mk
@@ -1,4 +1,14 @@
-# This file is purely used for checking the style of the python build tools.
+EXTRA_DIST += \
+	build-aux/calculate-schema-cksum \
+	build-aux/cccl \
+	build-aux/cksum-schema-check \
+	build-aux/dist-docs \
+	build-aux/dpdkstrip.py \
+	build-aux/sodepends.py \
+	build-aux/soexpand.py \
+	build-aux/text2c \
+	build-aux/xml2nroff
+
 FLAKE8_PYFILES += \
     $(srcdir)/build-aux/xml2nroff \
     build-aux/dpdkstrip.py \
diff --git a/build-aux/text2c b/build-aux/text2c
new file mode 100755
index 000000000..cb1f256f1
--- /dev/null
+++ b/build-aux/text2c
@@ -0,0 +1,16 @@
+#! /usr/bin/python
+
+import re
+import sys
+
+"""This utility reads its input, which should be plain text, and
+prints it back transformed into quoted strings that may be #included
+into C source code."""
+
+while True:
+    line = sys.stdin.readline()
+    if not line:
+        break
+
+    s = line.replace("\\", "\\\\").replace('"', '\\"').replace("\n", "\\n")
+    print('"' + s + '"')