[Tools] Add script to identify new contributors from Phabricator (WIP)

[fhahn]

Summary

This is a script I built a while ago and I thought it might be good to
share it related to
http://lists.llvm.org/pipermail/llvm-dev/2017-August/116898.html.

If people think that it is useful, I would be happy to turn this into a
proper script.

[javed.absar]

I am not an expert in this so may be a wrong question - once a new contributor is identified by this script, it is added as subscriber to 'what' ?
As a broad brush, more features to phabricator seems a good idea as it is so commonly now used.
Thanks.

[fhahn]

In D37259#855359, @javed.absar wrote:

I am not an expert in this so may be a wrong question - once a new contributor is identified by this script, it is added as subscriber to 'what' ?

It currently adds myself as subscriber to the review, but I think the API allows us to do plenty of things, e.g. add a tag, comment, reviewers to the review.

tools/phabricator-helpers/new-contributors.py

+"""
+                    The LLVM Compiler Infrastructure
+
+This file is distributed under the University of Illinois Open Source
+License. See LICENSE.TXT for details.
+
+
+Requires the phabricator API package
+   pip install phabricator==0.7
+Add API token to ~/.arcrc
+   cat ~/.arcrc
+{
+ "hosts": {
+   "https://reviews.llvm.org/api/": {
+     "token": "api-insertYourAPITokenHere"
+   }
+ }
+}
+"""
+
+import os
+import sys
+
+from phabricator import Phabricator
+
+def read_time():
+    if not os.path.isfile('last_review.txt'):
+        print("no last_review.txt file found, starting from the beginning")
+        return 0
+
+    with open('last_review.txt', 'rt') as f:
+        return int(f.read())
+
+
+def write_time(t):
+    with open('last_review.txt', 'wt') as f:
+        f.write(t)
+
+
+SUBSCRIBER_FIELD = 'ccs'
+def add_subscriber(phab, review, user_id):
+    if user_id in review[SUBSCRIBER_FIELD]:
+        return
+
+    fields = {
+            'ccPHIDs': review[SUBSCRIBER_FIELD] + [user_id,],
+    }
+    phab.differential.updaterevision(
+            id=int(review['id']),
+            diffid=int(review['diffs'][0]),
+            fields=fields, message='')
+
+
+def handle_reviews():
+    phab = Phabricator()  # This will use your ~/.arcrc file
+
+    last_review = read_time()
+    new_reviews = phab.differential.query(
+        limit=100, order="order-created", status="status-open"
+    )
+
+    print('Last review timestamp: {}'.format(last_review))
+    new_reviews = [r for r in new_reviews if int(r['dateCreated']) > last_review]
+
+    if len(new_reviews) == 0:
+        print("No new reviews")
+        return
+
+    for r in new_reviews:
+        if len(phab.differential.query(limit=2, authors=[r['authorPHID']])) < 2:
+           print("Welcome new user "+r['uri'])
+           print('  * adding new subscriber')
+           # FIXME: user hardcoded to fhahn, add parameter.
+           add_subscriber(phab, r, 'PHID-USER-n4qjk3mn5cpkqytjhy7d')
+
+    write_time(new_reviews[0]['dateCreated'])
+
+handle_reviews()