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gerrit.openfyde.cn / chromium.googlesource.com / aosp / platform / system / libbase / b5153ebc79a80ec08cb5eb8255b0789d69f260e3
commitb5153ebc79a80ec08cb5eb8255b0789d69f260e3[log] [tgz]
authorElliott Hughes <enh@google.com>Wed Apr 29 14:10:12 2020 -0700
committerElliott Hughes <enh@google.com>Wed Apr 29 16:49:13 2020 -0700
treef647c2306e843acdf705db93e6cdda153ecafd32
parentb162ddf9d80918d41e875d2511c8f51bbc18576b [diff]
Avoid zero-initializing our most-used buffers.

The StringPrintf one is heavily used and brings the overhead versus
fmtlib down to 1.5x rather than 2x. I don't have a convenient benchmark
for the other two.

Test: libbase tests & benchmarks
Bug: http://b/155324241
Change-Id: I9e704a360846d5520c53f668e7c315b0c0ea55f8
(cherry picked from commit 8c253d4d42018d77b78de8f8c70c6204f5aa6d0e)
3 files changed
tree: f647c2306e843acdf705db93e6cdda153ecafd32
  1. include/
  2. .clang-format ⇨ ../.clang-format-2
  3. abi_compatibility.cpp
  4. Android.bp
  5. chrono_utils.cpp
  6. chrono_utils_test.cpp
  7. cmsg.cpp
  8. cmsg_test.cpp
  9. CPPLINT.cfg
  10. endian_test.cpp
  11. errors_test.cpp
  12. errors_unix.cpp
  13. errors_windows.cpp
  14. expected_test.cpp
  15. file.cpp
  16. file_test.cpp
  17. format_benchmark.cpp
  18. liblog_symbols.cpp
  19. liblog_symbols.h
  20. logging.cpp
  21. logging_splitters.h
  22. logging_splitters_test.cpp
  23. logging_test.cpp
  24. macros_test.cpp
  25. mapped_file.cpp
  26. mapped_file_test.cpp
  27. no_destructor_test.cpp
  28. OWNERS
  29. parsebool.cpp
  30. parsebool_test.cpp
  31. parsedouble_test.cpp
  32. parseint_test.cpp
  33. parsenetaddress.cpp
  34. parsenetaddress_test.cpp
  35. process.cpp
  36. process_test.cpp
  37. properties.cpp
  38. properties_test.cpp
  39. README.md
  40. result_test.cpp
  41. scopeguard_test.cpp
  42. stringprintf.cpp
  43. stringprintf_test.cpp
  44. strings.cpp
  45. strings_test.cpp
  46. test_main.cpp
  47. test_utils.cpp
  48. test_utils_test.cpp
  49. threads.cpp
  50. utf8.cpp
  51. utf8_test.cpp
README.md

libbase

Who is this library for?

This library is a collection of convenience functions to make common tasks easier and less error-prone.

In this context, "error-prone" covers both "hard to do correctly" and "hard to do with good performance", but as a general purpose library, libbase's primary focus is on making it easier to do things easily and correctly when a compromise has to be made between "simplest API" on the one hand and "fastest implementation" on the other. Though obviously the ideal is to have both.

Should my routine be added?

The intention is to cover the 80% use cases, not be all things to all users.

If you have a routine that's really useful in your project, congratulations. But that doesn't mean it should be here rather than just in your project.

The question for libbase is "should everyone be doing this?"/"does this make everyone's code cleaner/safer?". Historically we've considered the bar for inclusion to be "are there at least three unrelated projects that would be cleaned up by doing so".

If your routine is actually something from a future C++ standard (that isn't yet in libc++), or it's widely used in another library, that helps show that there's precedent. Being able to say "so-and-so has used this API for n years" is a good way to reduce concerns about API choices.

Any other restrictions?

Unlike most Android code, code in libbase has to build for Mac and Windows too.

Code here is also expected to have good test coverage.

By its nature, it's difficult to change libbase API. It's often best to start using your routine just in your project, and let it "graduate" after you're certain that the API is solid.