Package org.apache.drill.exec.compile

Runtime code-generation, compilation and bytecode-manipulation utilities.

See: Description

Class Summary

Class	Description
AbstractClassCompiler
AsmUtil	Utilities commonly used with ASM.
CachedClassLoader	Class loader for "plain-old Java" generated classes.
CheckClassVisitorFsm	A ClassVisitor that verifies the required call sequence described in http://asm.ow2.org/asm50/javadoc/user/org/objectweb/asm/ClassVisitor.html .
CheckMethodVisitorFsm	A MethodVisitor that verifies the required call sequence according to http://asm.ow2.org/asm50/javadoc/user/org/objectweb/asm/MethodVisitor.html .
ClassBodyBuilder
ClassBuilder	Implements the "plain Java" method of code generation and compilation.
ClassCompilerSelector	Selects between the two supported Java compilers: Janino and the build-in Java compiler.
ClassTransformer	Compiles generated code, merges the resulting class with the template class, and performs byte-code cleanup on the resulting byte codes.
ClassTransformer.ClassNames
ClassTransformer.ClassSet
CodeCompiler	Global code compiler mechanism shared by all threads and operators.
CodeCompiler.CodeGenCompiler	Abstracts out the details of compiling code using the two available mechanisms.
CompilationConfig
DrillCheckClassAdapter	There's a bug in ASM's CheckClassAdapter.
DrillInitMethodVisitor
FsmCursor	Maintains state while traversing a finite state machine described by an FsmDescriptor.
FsmDescriptor	Describes a finite state machine in terms of a mapping of tokens to characters, a regular expression describing the valid transitions using the characters, and an end state.
InnerClassAccessStripper	An ASM ClassVisitor that strips class the access bits that are only possible on inner classes (ACC_PROTECTED, ACC_PRIVATE, and ACC_FINAL).
LogWriter	A simple Writer that will forward whole lines (lines ending with a newline) to a Logger.
QueryClassLoader	Per-compilation unit class loader that holds both caching and compilation steps.
RetargetableClassVisitor	An ASM ClassVisitor that allows for a late-bound delegate.
TemplateClassDefinition<T>	Defines a code generation "template" which consist of: An interface that defines the generated class. A template class which implements the interface to provide "generic" methods that need not be generated. A signature that lists the methods and vector holders used by the template.

Enum Summary

Enum	Description
ClassCompilerSelector.CompilerPolicy
ClassTransformer.ScalarReplacementOption

Package org.apache.drill.exec.compile Description

Runtime code-generation, compilation and bytecode-manipulation utilities. To achieve optimal performance in a dynamic schema environment, Drill includes a complete code generation system for generating type-specific Java code for most of its physical operators. This generated code is used for scalar expression evaluation as well as value transfers between record batches. As a new schema arrives at an operator, the schema change will be detected and prompt runtime code generation. This runtime-generated code will evaluate the expressions needed for the operator to process the incoming data. As the same code will often be run on a number of nodes in the cluster, compiled classes are stored in the distributed cache to avoid the need to re- compile and JIT-optimize the same code on every machine.