1 files changed, 71 insertions, 0 deletions
diff --git a/dom/base/usecounters.py b/dom/base/usecounters.py
new file mode 100644
index 000000000..b93f02f80
--- /dev/null
+++ b/dom/base/usecounters.py
@@ -0,0 +1,71 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import buildconfig
+import collections
+import re
+import StringIO
+import sys
+
+def read_conf(conf_filename):
+    # Can't read/write from a single StringIO, so make a new one for reading.
+    stream = open(conf_filename, 'rU')
+
+    def parse_counters(stream):
+        for line_num, line in enumerate(stream):
+            line = line.rstrip('\n')
+            if not line or line.startswith('//'):
+                # empty line or comment
+                continue
+            m = re.match(r'method ([A-Za-z0-9]+)\.([A-Za-z0-9]+)$', line)
+            if m:
+                interface_name, method_name = m.groups()
+                yield { 'type': 'method',
+                        'interface_name': interface_name,
+                        'method_name': method_name }
+                continue
+            m = re.match(r'attribute ([A-Za-z0-9]+)\.([A-Za-z0-9]+)$', line)
+            if m:
+                interface_name, attribute_name = m.groups()
+                yield { 'type': 'attribute',
+                        'interface_name': interface_name,
+                        'attribute_name': attribute_name }
+                continue
+            m = re.match(r'property ([A-Za-z0-9]+)$', line)
+            if m:
+                property_name = m.group(1)
+                yield { 'type': 'property',
+                        'property_name': property_name }
+                continue
+            raise ValueError('error parsing %s at line %d' % (conf_filename, line_num))
+
+    return parse_counters(stream)
+
+def generate_histograms(filename):
+    # The mapping for use counters to telemetry histograms depends on the
+    # ordering of items in the dictionary.
+    items = collections.OrderedDict()
+    for counter in read_conf(filename):
+        def append_counter(name, desc):
+            items[name] = { 'expires_in_version': 'never',
+                            'kind' : 'boolean',
+                            'description': desc }
+
+        def append_counters(name, desc):
+            append_counter('USE_COUNTER2_%s_DOCUMENT' % name, 'Whether a document %s' % desc)
+            append_counter('USE_COUNTER2_%s_PAGE' % name, 'Whether a page %s' % desc)
+
+        if counter['type'] == 'method':
+            method = '%s.%s' % (counter['interface_name'], counter['method_name'])
+            append_counters(method.replace('.', '_').upper(), 'called %s' % method)
+        elif counter['type'] == 'attribute':
+            attr = '%s.%s' % (counter['interface_name'], counter['attribute_name'])
+            counter_name = attr.replace('.', '_').upper()
+            append_counters('%s_getter' % counter_name, 'got %s' % attr)
+            append_counters('%s_setter' % counter_name, 'set %s' % attr)
+        elif counter['type'] == 'property':
+            prop = counter['property_name']
+            append_counters('PROPERTY_%s' % prop.replace('-', '_').upper(), "used the '%s' property" % prop)
+
+    return items