)]}'
{
  "log": [
    {
      "commit": "552a13415573da19eafa46e1ac00fb0eb68f2b23",
      "tree": "8cae5f3602d8f8e65cd3cbc349af17d785128605",
      "parents": [
        "0dda8c84938d6bb4ce5a1707e5e109ea187fc33d"
      ],
      "author": {
        "name": "Vladimir Marko",
        "email": "vmarko@google.com",
        "time": "Tue Oct 31 10:56:47 2017 +0000"
      },
      "committer": {
        "name": "Vladimir Marko",
        "email": "vmarko@google.com",
        "time": "Thu May 16 14:44:09 2019 +0000"
      },
      "message": "ART: Optimize StringBuilder append pattern.\n\nRecognize appending with StringBuilder and replace the\nentire expression with a runtime call that perfoms the\nappend in a more efficient manner.\n\nFor now, require the entire pattern to be in a single block\nand be very strict about the StringBuilder environment uses.\nAlso, do not accept StringBuilder/char[]/Object/float/double\narguments as they throw non-OOME exceptions and/or require a\ncall from the entrypoint back to a helper function in Java;\nthese shall be implemented later.\n\nBoot image size for aosp_taimen-userdebug:\n - before:\n   arm/boot*.oat: 19653872\n   arm64/boot*.oat: 23292784\n   oat/arm64/services.odex: 22408664\n - after:\n   arm/boot*.oat: 19432184 (-216KiB)\n   arm64/boot*.oat: 22992488 (-293KiB)\n   oat/arm64/services.odex: 22376776 (-31KiB)\nNote that const-string in compiled boot image methods cannot\nthrow, but for apps it can and therefore its environment can\nprevent the optimization for apps. We could implement either\na simple carve-out for const-string or generic environment\npruning to allow this pattern to be applied more often.\n\nResults for the new StringBuilderAppendBenchmark on taimen:\n  timeAppendLongStrings: ~700ns -\u003e ~200ns\n  timeAppendStringAndInt: ~220ns -\u003e ~140ns\n  timeAppendStrings: ~200ns -\u003e 130ns\n\nBug: 19575890\nTest: 697-checker-string-append\nTest: m test-art-host-gtest\nTest: testrunner.py --host --optimizing\nTest: aosp_taimen-userdebug boots.\nTest: run-gtests.sh\nTest: testrunner.py --target --optimizing\nTest: vogar --benchmark art/benchmark/stringbuilder-append/src/StringBuilderAppendBenchmark.java\nChange-Id: I51789bf299f5219f68ada4c077b6a1d3fe083964\n"
    }
  ]
}