toolkit/components/telemetry/build_scripts/gen_userinteraction_phf.py

   1 # This Source Code Form is subject to the terms of the Mozilla Public
   2 # License, v. 2.0. If a copy of the MPL was not distributed with this
   3 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
   4
   5 from mozparsers.shared_telemetry_utils import ParserError
   6 from perfecthash import PerfectHash
   7
   8 PHFSIZE = 1024
   9
  10 import sys
  11
  12 from mozparsers import parse_user_interactions
  13
  14 banner = """/* This file is auto-generated, see gen_userinteraction_phf.py.  */
  15 """
  16
  17 header = """
  18 #ifndef mozilla_TelemetryUserInteractionNameMap_h
  19 #define mozilla_TelemetryUserInteractionNameMap_h
  20
  21 #include "mozilla/PerfectHash.h"
  22
  23 namespace mozilla {
  24 namespace Telemetry {
  25 """
  26
  27 footer = """
  28 } // namespace mozilla
  29 } // namespace Telemetry
  30 #endif // mozilla_TelemetryUserInteractionNameMap_h
  31 """
  32
  33
  34 def main(output, *filenames):
  35     """
  36     Generate a Perfect Hash Table for the UserInteraction name -> UserInteraction ID lookup.
  37     The table is immutable once generated and we can avoid any dynamic memory allocation.
  38     """
  39
  40     output.write(banner)
  41     output.write(header)
  42
  43     try:
  44         user_interactions = list(parse_user_interactions.from_files(filenames))
  45     except ParserError as ex:
  46         print("\nError processing UserInteractions:\n" + str(ex) + "\n")
  47         sys.exit(1)
  48
  49     user_interactions = [
  50         (bytearray(ui.label, "ascii"), idx)
  51         for (idx, ui) in enumerate(user_interactions)
  52     ]
  53     name_phf = PerfectHash(user_interactions, PHFSIZE)
  54
  55     output.write(
  56         name_phf.cxx_codegen(
  57             name="UserInteractionIDByNameLookup",
  58             entry_type="uint32_t",
  59             lower_entry=lambda x: str(x[1]),
  60             key_type="const nsACString&",
  61             key_bytes="aKey.BeginReading()",
  62             key_length="aKey.Length()",
  63         )
  64     )
  65
  66     output.write(footer)
  67
  68
  69 if __name__ == "__main__":
  70     main(sys.stdout, *sys.argv[1:])