com.android.build.gradle.shrinker

Class AbstractShrinker<T>

java.lang.Object

com.android.build.gradle.shrinker.AbstractShrinker<T>

Direct Known Subclasses:

FullRunShrinker, IncrementalShrinker

public abstract class AbstractShrinker<T>
extends java.lang.Object

Common code for both types of shrinker runs, FullRunShrinker and IncrementalShrinker.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	AbstractShrinker.CounterSet Set of counters, for keeping different sets of reachable nodes for different purposes.

Field Summary

Fields

Modifier and Type	Field and Description
protected com.android.ide.common.internal.WaitableExecutor	mExecutor
protected ShrinkerGraph<T>	mGraph
protected ShrinkerLogger	mShrinkerLogger

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractShrinker(ShrinkerGraph<T> graph, com.android.ide.common.internal.WaitableExecutor executor, ShrinkerLogger shrinkerLogger, BytecodeVersion bytecodeVersion)

Method Summary

Modifier and Type	Method and Description
protected java.util.Optional<java.io.File>	chooseOutputFile(T klass, java.io.File classFile, java.lang.Iterable<com.android.build.api.transform.TransformInput> inputs, com.android.build.api.transform.TransformOutputProvider output) Tries to determine the output class file, for rewriting the given class file.
protected static java.util.Collection<java.io.File>	getAllDirectories(com.android.build.api.transform.TransformInput input) Determines all directories where class files can be found in the given TransformInput.
protected static java.util.Collection<java.io.File>	getAllJars(com.android.build.api.transform.TransformInput input) Determines all directories where class files can be found in the given TransformInput.
protected void	incrementCounter(T node, DependencyType dependencyType, AbstractShrinker.CounterSet counterSet, Tracer<T> tracer, Trace<T> trace) Increments the counter on the given graph node.
protected boolean	isProgramClass(T klass)
static void	logTime(java.lang.String section, com.google.common.base.Stopwatch stopwatch)
protected void	resolveReferences(java.lang.Iterable<com.android.build.gradle.shrinker.PostProcessingData.UnresolvedReference<T>> unresolvedReferences) Finds existing methods or fields (graph nodes) which encountered opcodes refer to.
protected byte[]	rewrite(java.lang.String className, java.io.File classFile, java.util.Set<java.lang.String> membersToKeep, java.util.function.Predicate<java.lang.String> keepInterface) Rewrites the given class (read from file) to only include used methods and fields and interfaces.
protected void	setCounters(AbstractShrinker.CounterSet counterSet, Tracer<T> tracer) Walks the entire graph, starting from the roots, and increments counters for reachable nodes.
protected void	updateClassFiles(java.lang.Iterable<T> classesToWrite, java.lang.Iterable<java.io.File> classFilesToDelete, java.lang.Iterable<com.android.build.api.transform.TransformInput> inputs, com.android.build.api.transform.TransformOutputProvider output) Writes updates class files to the outputs.
protected void	waitForAllTasks()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

mExecutor

protected final com.android.ide.common.internal.WaitableExecutor mExecutor

mGraph

protected final ShrinkerGraph<T> mGraph

mShrinkerLogger

protected final ShrinkerLogger mShrinkerLogger

Constructor Detail

AbstractShrinker

protected AbstractShrinker(@NonNull
                           ShrinkerGraph<T> graph,
                           @NonNull
                           com.android.ide.common.internal.WaitableExecutor executor,
                           @NonNull
                           ShrinkerLogger shrinkerLogger,
                           @Nullable
                           BytecodeVersion bytecodeVersion)

Method Detail

chooseOutputFile

@NonNull
protected java.util.Optional<java.io.File> chooseOutputFile(@NonNull
                                                                     T klass,
                                                                     @NonNull
                                                                     java.io.File classFile,
                                                                     @NonNull
                                                                     java.lang.Iterable<com.android.build.api.transform.TransformInput> inputs,
                                                                     @NonNull
                                                                     com.android.build.api.transform.TransformOutputProvider output)

Tries to determine the output class file, for rewriting the given class file.

This will return Optional.empty() if the class is not part of the program to shrink (e.g. comes from a platform JAR).

getAllDirectories

@NonNull
protected static java.util.Collection<java.io.File> getAllDirectories(@NonNull
                                                                               com.android.build.api.transform.TransformInput input)

Determines all directories where class files can be found in the given TransformInput.

getAllJars

@NonNull
protected static java.util.Collection<java.io.File> getAllJars(@NonNull
                                                                        com.android.build.api.transform.TransformInput input)

Determines all directories where class files can be found in the given TransformInput.

incrementCounter

protected void incrementCounter(@NonNull
                                T node,
                                @NonNull
                                DependencyType dependencyType,
                                @NonNull
                                AbstractShrinker.CounterSet counterSet,
                                @NonNull
                                Tracer<T> tracer,
                                @NonNull
                                Trace<T> trace)

Increments the counter on the given graph node. If the node just became reachable, keeps on walking the graph to find newly reachable nodes.

Parameters:

node - node to increment

dependencyType - type of counter to increment

counterSet - set of counters to work on

tracer - tracer for recording paths to nodes

trace - trace of how we got here

resolveReferences

protected void resolveReferences(@NonNull
                                 java.lang.Iterable<com.android.build.gradle.shrinker.PostProcessingData.UnresolvedReference<T>> unresolvedReferences)

Finds existing methods or fields (graph nodes) which encountered opcodes refer to. Updates the graph with additional edges accordingly.

isProgramClass

protected boolean isProgramClass(@NonNull
                                 T klass)

rewrite

@NonNull
protected byte[] rewrite(@NonNull
                                  java.lang.String className,
                                  @NonNull
                                  java.io.File classFile,
                                  @NonNull
                                  java.util.Set<java.lang.String> membersToKeep,
                                  @NonNull
                                  java.util.function.Predicate<java.lang.String> keepInterface)
                           throws java.io.IOException

Rewrites the given class (read from file) to only include used methods and fields and interfaces. Returns the new class bytecode as byte[].

Throws:

java.io.IOException

setCounters

protected void setCounters(@NonNull
                           AbstractShrinker.CounterSet counterSet,
                           @NonNull
                           Tracer<T> tracer)

Walks the entire graph, starting from the roots, and increments counters for reachable nodes.

updateClassFiles

protected void updateClassFiles(@NonNull
                                java.lang.Iterable<T> classesToWrite,
                                @NonNull
                                java.lang.Iterable<java.io.File> classFilesToDelete,
                                @NonNull
                                java.lang.Iterable<com.android.build.api.transform.TransformInput> inputs,
                                @NonNull
                                com.android.build.api.transform.TransformOutputProvider output)
                         throws java.io.IOException

Writes updates class files to the outputs.

Throws:

java.io.IOException

waitForAllTasks

protected void waitForAllTasks()

logTime

public static void logTime(java.lang.String section,
                           com.google.common.base.Stopwatch stopwatch)