void addDexingSteps()

in src/com/facebook/buck/android/AndroidBinaryRule.java [1073:1176]
66 lines of code
3 McCabe index (conditional complexity)

  void addDexingSteps(
      Set<String> classpathEntriesToDex,
      ImmutableSet.Builder<String> secondaryDexDirectories,
      ImmutableList.Builder<Step> steps,
      String primaryDexPath,
      Function<SourcePath, Path> sourcePathResolver) {
    final Set<String> primaryInputsToDex;
    final Optional<String> secondaryDexDir;
    final Optional<String> secondaryInputsDir;

    if (shouldSplitDex()) {
      Optional<Path> proguardMappingFile = Optional.absent();
      if (packageType.isBuildWithObfuscation()) {
        proguardMappingFile = Optional.of(getPathForProGuardDirectory().resolve("mapping.txt"));
      }

      // DexLibLoader expects that metadata.txt and secondary jar files are under this dir
      // in assets.
      String magicSecondaryDexSubdir = "assets/secondary-program-dex-jars";

      // Intermediate directory holding the primary split-zip jar.
      String splitZipDir = getBinPath("__%s_split_zip__");
      steps.add(new MakeCleanDirectoryStep(splitZipDir));
      String primaryJarPath = splitZipDir + "/primary.jar";

      String secondaryJarMetaDirParent = splitZipDir + "/secondary_meta/";
      String secondaryJarMetaDir = secondaryJarMetaDirParent + magicSecondaryDexSubdir;
      steps.add(new MakeCleanDirectoryStep(secondaryJarMetaDir));
      String secondaryJarMeta = secondaryJarMetaDir + "/metadata.txt";

      // Intermediate directory holding _ONLY_ the secondary split-zip jar files.  This is
      // important because SmartDexingCommand will try to dx every entry in this directory.  It
      // does this because it's impossible to know what outputs split-zip will generate until it
      // runs.
      String secondaryZipDir = getBinPath("__%s_secondary_zip__");
      steps.add(new MakeCleanDirectoryStep(secondaryZipDir));

      // Run the split-zip command which is responsible for dividing the large set of input
      // classpaths into a more compact set of jar files such that no one jar file when dexed will
      // yield a dex artifact too large for dexopt or the dx method limit to handle.
      String zipSplitReportDir = getBinPath("__%s_split_zip_report__");
      steps.add(new MakeCleanDirectoryStep(zipSplitReportDir));
      SplitZipStep splitZipCommand = new SplitZipStep(
          classpathEntriesToDex,
          secondaryJarMeta,
          primaryJarPath,
          secondaryZipDir,
          "secondary-%d.jar",
          proguardMappingFile,
          primaryDexSubstrings,
          primaryDexClassesFile.transform(sourcePathResolver),
          dexSplitMode.getDexSplitStrategy(),
          dexSplitMode.getDexStore(),
          zipSplitReportDir,
          dexSplitMode.useLinearAllocSplitDex(),
          linearAllocHardLimit);
      steps.add(splitZipCommand);

      // Add the secondary dex directory that has yet to be created, but will be by the
      // smart dexing command.  Smart dex will handle "cleaning" this directory properly.
      String secondaryDexParentDir = getBinPath("__%s_secondary_dex__/");
      secondaryDexDir = Optional.of(secondaryDexParentDir + magicSecondaryDexSubdir);
      steps.add(new MkdirStep(secondaryDexDir.get()));

      secondaryDexDirectories.add(secondaryJarMetaDirParent);
      secondaryDexDirectories.add(secondaryDexParentDir);

      // Adjust smart-dex inputs for the split-zip case.
      primaryInputsToDex = ImmutableSet.of(primaryJarPath);
      secondaryInputsDir = Optional.of(secondaryZipDir);
    } else {
      // Simple case where our inputs are the natural classpath directories and we don't have
      // to worry about secondary jar/dex files.
      primaryInputsToDex = classpathEntriesToDex;
      secondaryDexDir = Optional.absent();
      secondaryInputsDir = Optional.absent();
    }

    // Stores checksum information from each invocation to intelligently decide when dx needs
    // to be re-run.
    Path successDir = Paths.get(getBinPath("__%s_smart_dex__/.success"));
    steps.add(new MkdirStep(successDir));

    // Add the smart dexing tool that is capable of avoiding the external dx invocation(s) if
    // it can be shown that the inputs have not changed.  It also parallelizes dx invocations
    // where applicable.
    //
    // Note that by not specifying the number of threads this command will use it will select an
    // optimal default regardless of the value of --num-threads.  This decision was made with the
    // assumption that --num-threads specifies the threading of build rule execution and does not
    // directly apply to the internal threading/parallelization details of various build commands
    // being executed.  For example, aapt is internally threaded by default when preprocessing
    // images.
    SmartDexingStep smartDexingCommand = new SmartDexingStep(
        primaryDexPath,
        primaryInputsToDex,
        secondaryDexDir,
        secondaryInputsDir,
        successDir,
        Optional.<Integer>absent(),
        dexSplitMode.getDexStore(),
        /* optimize */ PackageType.RELEASE.equals(packageType));
    steps.add(smartDexingCommand);
  }