# Class: com.pnfsoftware.jeb.core.units.code.android.ir.AbstractDCollectionOptimizer Base class for `dexdec` \(DEX decompiler\) IR optimizer plugins working on a collection of IR contexts. Those plugins can access and modify the intermediate representation of a group of methods being decompiled. They can be used to implement a wide range of optimizations, from trivial code clean\-up to the most complex deobfuscation passes. Internally, `dexdec` uses IR optimizers to perform dead\-code removal, variable substitutions, immediate propagation, restructuring, constant folding, arithmetic operation simplifications, deobfuscations such as control\-flow unflattening, etc. Optimizers are usually managed by [master optimizers](IDMasterOptimizer) \(also called `orchestrators`\). Third\-party optimizer plugins can be automatically registered when creating an orchestrator. Refer to [createMasterOptimizer](IDGlobalContext#createMasterOptimizer(IDMethodContext)). Life\-cycle information: \- plugins are reused \(i.e. the [#performOnCollection()](#performOnCollection()) method is called multiple times\) \- thread\-safety: \-\- Python script plugins must be thread\-safe: a plugin instance may be executed by multiple threads concurrently \-\- Java plugins \(including Java script plugins\) are not required to be thread\-safe: a plugin instance will not be executed by multiple threads concurrently Note: Starting from JEB 5.28, collection optimizers are not enabled by default. You must set the option `.parsers.dcmp_dex.EnableCollectionOptimizers` to `true` to instruct the decompiler to execute them. ## Constructor: AbstractDCollectionOptimizer Description: Create a [standard](DOptimizerType#NORMAL) optimizer. ## Constructor: AbstractDCollectionOptimizer - parameter: `type`, type: `com.pnfsoftware.jeb.core.units.code.android.ir.DOptimizerType` Description: Create an optimizer. parameter: type: optimizer type, or null to use [DOptimizerType#NORMAL](DOptimizerType#NORMAL) ## Constructor: AbstractDCollectionOptimizer - parameter: `type`, type: `com.pnfsoftware.jeb.core.units.code.android.ir.DOptimizerType` - parameter: `name`, type: `java.lang.String` Description: Create an optimizer. parameter: type: optimizer type, or null to use [DOptimizerType#NORMAL](DOptimizerType#NORMAL) parameter: name: optional optimizer name ## Field: ctxlist Type: `java.util.List` Description: The list of IR method contexts available to the optimizer. A collection is not a class. Those IR contexts may represent methods from multiple classes. ## Field: decomp Type: `com.pnfsoftware.jeb.core.units.code.android.IDexDecompilerUnit` Description: Managing dex decompiler. ## Field: dex Type: `com.pnfsoftware.jeb.core.units.code.android.IDexUnit` Description: Underlying dex code. ## Field: g Type: `com.pnfsoftware.jeb.core.units.code.android.ir.IDGlobalContext` Description: IR global context. ## Field: of Type: `com.pnfsoftware.jeb.core.units.code.java.IJavaOperatorFactory` Description: IR/AST operation factory reference \(for convenience\). ## Field: tf Type: `com.pnfsoftware.jeb.core.units.code.java.IJavaTypeFactory` Description: IR/AST type factory reference \(for convenience\). ## Static Field: logger Type: `com.pnfsoftware.jeb.util.logging.ILogger` Description: Public logger accessible by the implementing optimizer. Writing to the logger should be favored over writing directly to `stdout`. ## Protected Method: addTag - parameter: `tag`, type: `java.lang.String` Description: Add an optimizer tag. parameter: tag: tag to add ## Method: assignLocalFields - parameter: `_ctxlist`, type: `java.util.List` Description: This convenience method can be used to assign the object's attributes from the values of the provided IR contexts. parameter: _ctxlist: an IR context ## Protected Method: checkInterrupted Description: Verify if an interruption request was made by the managing decompiler. This method may be called when potentially length computations are performed in a loop. ## Method: generatePerClassContextsMap - return type: `java.util.Map>` Description: Generate a per\-class map of method contexts. return: a map with key= class signature C, value= list of IR contexts for methods belonging to the class C ## Method: getName - return type: `java.lang.String` ## Method: getPluginInformation - return type: `com.pnfsoftware.jeb.core.EditablePluginInformation` ## Method: getPriority - return type: `double` ## Method: getTags - return type: `java.util.Set` ## Method: getType - return type: `com.pnfsoftware.jeb.core.units.code.android.ir.DOptimizerType` ## Method: isCollectionOptimizer - return type: `boolean` ## Method: isEnabled - return type: `boolean` ## Method: perform - parameter: `ctx`, type: `com.pnfsoftware.jeb.core.units.code.android.ir.IDMethodContext` - return type: `int` ## Method: performOnCollection - parameter: `ctxlist`, type: `java.util.List` - parameter: `pmcntmap`, type: `java.util.Map` - return type: `int` ## Method: performOnCollection - return type: `int` Description: An optimizer must implement this method. This method is called by a master optimizer to perform optimizations on the provided target contexts. return: total count of optimizations; it is also recommended to register per\-method optimizations with [#recordMethodOptimization(IDMethodContext, int)](#recordMethodOptimization(IDMethodContext, int)) ## Protected Method: recordMethodOptimization - parameter: `ctx`, type: `com.pnfsoftware.jeb.core.units.code.android.ir.IDMethodContext` - parameter: `cnt`, type: `int` Description: Record optimization counts for a method context. parameter: ctx: method context parameter: cnt: number of optimizations performed ## Protected Method: removeTag - parameter: `tag`, type: `java.lang.String` Description: Remove an optimizer tag. parameter: tag: tag to remove ## Method: resetLocalFields Description: Reset this object's attributes. Same as [assignLocalFields\(null\)](#assignLocalFields(List)). ## Method: setEnabled - parameter: `enabled`, type: `boolean` Description: Enable or disable this optimizer. This flag is checked by a [master optimizer](IDMasterOptimizer). parameter: enabled: true to enable this optimizer ## Protected Method: setName - parameter: `name`, type: `java.lang.String` Description: Set the optimizer name. To be used by the constructor. parameter: name: if null, a name will be auto\-generated ## Protected Method: setPriority - parameter: `priority`, type: `double` Description: Set the optimizer priority. To be used by the constructor. parameter: priority: the new priority \(high means higher priority\). When optimizers are managed and run by an orchestrator, the optimizers with a higher priority are run before those having a lower priority. The default priority is 0. ## Protected Method: setType - parameter: `type`, type: `com.pnfsoftware.jeb.core.units.code.android.ir.DOptimizerType` Description: Set the optimizer type. To be used by the constructor. parameter: type: if null, a [standard](DOptimizerType#NORMAL) optimizer is assumed