Sandbox::https://github.com/github/codeql/blob/main/java/ql/src/Performance/InefficientOutputStream.ql

Repository navigation

43 lines (40 loc) · 1.4 KB

/**

* @name Inefficient output stream

* @description Using the default implementation of 'write(byte[],int,int)'

* provided by 'java.io.OutputStream' is very inefficient.

* @kind problem

* @problem.severity warning

* @precision very-high

* @id java/inefficient-output-stream

* @tags quality

* reliability

* performance

* efficiency

import java

class InefficientWriteBytes extends Class {

InefficientWriteBytes() {

this.hasQualifiedName("java.io", "OutputStream") or

this.hasQualifiedName("java.io", "FilterOutputStream")

}

from Class c, Method m

where

not c.isAbstract() and

not c instanceof InefficientWriteBytes and

c.getASupertype() instanceof InefficientWriteBytes and

c.getAMethod() = m and

m.getName() = "write" and

m.getNumberOfParameters() = 1 and

m.getParameterType(0).(PrimitiveType).getName() = "int" and

exists(Method m2 | c.inherits(m2) |

m2.getName() = "write" and

m2.getNumberOfParameters() = 3 and

m2.getDeclaringType() instanceof InefficientWriteBytes

) and

// If that method doesn't call write itself, then we don't have a problem.

// This is the case is some dummy implementations.

exists(MethodCall ma | ma.getEnclosingCallable() = m | ma.getMethod().getName() = "write")

select c,

"This class extends 'java.io.OutputStream' and implements $@, but does not override 'write(byte[],int,int)'.",

m, m.getName()