Dodgy identity logging for compositiondanielsilverstone-ct/composition-logging

Signed-off-by: Daniel Silverstone <daniel.silverstone@codethink.co.uk>

1 files changed, 9 insertions, 0 deletions

diff --git a/src/buildstream/_yaml.py b/src/buildstream/_yaml.py
index cdab4269e..234fc7be1 100644
--- a/src/buildstream/_yaml.py
+++ b/src/buildstream/_yaml.py
@@ -31,6 +31,8 @@ from itertools import count
 from ruamel import yaml
 from ._exceptions import LoadError, LoadErrorReason
 
+import ujson
+import hashlib
 
 # Without this, pylint complains about all the `type(foo) is blah` checks
 # because it feels isinstance() is more idiomatic.  Sadly, it is much slower to
@@ -68,6 +70,10 @@ class Node(namedtuple('Node', ['value', 'file_index', 'line', 'column'])):
         # code which has access to such nodes would do this.
         return what in self[0]
 
+    def _identity(self):
+        ordered = node_sanitize(self)
+        ustring = ujson.dumps(ordered, sort_keys=True, escape_forward_slashes=False).encode('utf-8')
+        return hashlib.sha256(ustring).hexdigest()
 
 # File name handling
 _FILE_LIST = []
@@ -945,6 +951,9 @@ def composite(target, source):
     assert type(source[0]) is dict
     assert type(target[0]) is dict
 
+    with open("/tmp/composition.log", "a") as fh:
+        fh.write("{} <- {}\n".format(target._identity(), source._identity()))
+
     try:
         composite_dict(target, source)
     except CompositeError as e: