1 files changed, 98 insertions, 0 deletions
diff --git a/dom/media/webrtc/third_party_build/lookup_branch_head.py b/dom/media/webrtc/third_party_build/lookup_branch_head.py
new file mode 100644
index 0000000000..afd0e6c791
--- /dev/null
+++ b/dom/media/webrtc/third_party_build/lookup_branch_head.py
@@ -0,0 +1,98 @@
+# 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 argparse
+import json
+import os
+import pathlib
+import sys
+import urllib.request
+
+# default cache file location in STATE_DIR location
+default_cache_path = ".moz-fast-forward/milestone.cache"
+
+
+def fetch_branch_head_dict():
+    milestone_url = (
+        "https://chromiumdash.appspot.com/fetch_milestones?only_branched=true"
+    )
+    uf = urllib.request.urlopen(milestone_url)
+    html = uf.read()
+    milestone_dict = json.loads(html)
+
+    # There is more information in the json dictionary, but we only care
+    # about the milestone (version) to branch "name" (webrtc_branch)
+    # info.  For example:
+    #  v106 -> 5249 (which translates to branch-heads/5249)
+    #  v107 -> 5304 (which translates to branch-heads/5304)
+    #
+    # As returned from web query, milestones are integers and branch
+    # "names" are strings.
+    new_dict = {}
+    for row in milestone_dict:
+        new_dict[row["milestone"]] = row["webrtc_branch"]
+
+    return new_dict
+
+
+def read_dict_from_cache(cache_path):
+    if cache_path is not None and os.path.exists(cache_path):
+        with open(cache_path, "r") as ifile:
+            return json.loads(ifile.read(), object_hook=jsonKeys2int)
+    return {}
+
+
+def write_dict_to_cache(cache_path, milestones):
+    with open(cache_path, "w") as ofile:
+        ofile.write(json.dumps(milestones))
+
+
+def get_branch_head(milestone, cache_path=default_cache_path):
+    milestones = read_dict_from_cache(cache_path)
+
+    # if the cache didn't exist or is stale, try to fetch using a web query
+    if milestone not in milestones:
+        try:
+            milestones = fetch_branch_head_dict()
+            write_dict_to_cache(cache_path, milestones)
+        except Exception:
+            pass
+
+    if milestone in milestones:
+        return milestones[milestone]
+    return None
+
+
+# From https://stackoverflow.com/questions/1450957/pythons-json-module-converts-int-dictionary-keys-to-strings
+def jsonKeys2int(x):
+    if isinstance(x, dict):
+        return {int(k): v for k, v in x.items()}
+    return x
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser(
+        description="Get libwebrtc branch-head for given chromium milestone"
+    )
+    parser.add_argument(
+        "milestone", type=int, help="integer chromium milestone (example: 106)"
+    )
+    parser.add_argument("-v", "--verbose", action="store_true")
+    parser.add_argument("-c", "--cache", type=pathlib.Path, help="path to cache file")
+    args = parser.parse_args()
+
+    # if the user provided a cache path use it, otherwise use the default
+    local_cache_path = args.cache or default_cache_path
+
+    branch_head = get_branch_head(args.milestone, local_cache_path)
+    if branch_head is None:
+        sys.exit("error: chromium milestone '{}' is not found.".format(args.milestone))
+
+    if args.verbose:
+        print(
+            "chromium milestone {} uses branch-heads/{}".format(
+                args.milestone, branch_head
+            )
+        )
+    else:
+        print(branch_head)