[jira] [Updated] (WW-5674) Make SecurityMemberAccess.isClassBelongsToPackages allocation-free

["Lukasz Lenart (Jira)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/WW-5674?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Lukasz Lenart updated WW-5674:
------------------------------
    Description: 
Sub-task of WW-5667.

{{SecurityMemberAccess.isClassBelongsToPackages(Class, Set)}} runs on the OGNL member-access hot path and allocates heavily on every call. It splits the package name with a regex-based {{String.split("\\.")}}, wraps the result in a {{List}}, then streams over the prefixes and builds a brand-new joined {{String}} for every one of them before probing the set. For a class in {{org.apache.struts2.ognl}} that is one array plus four {{String.join}} allocations.

It is invoked up to four times per {{isAccessible()}} call — once for the excluded-package check and once for the allowlist check, for both the member's declaring class and the target class (see {{isExcludedPackageNames}}, {{isClassAllowlisted}}).

This matches JFR sample 1 on the parent ticket:

{noformat}
java.lang.String.split(String)
SecurityMemberAccess.isClassBelongsToPackages(Class, Set) :390
SecurityMemberAccess.isExcludedPackageNames(Class) :386
SecurityMemberAccess.isPackageExcluded(Class) :371
{noformat}

The same prefix-matching can be done by walking the package name from each {{'.'}} and probing the set with a substring, with no array, stream, or join allocations.

This is the OGNL security gate, so the change must preserve exact allow/deny semantics. Equivalence tests are required for: the default package (empty package name), single-segment packages, exact matches, sub-package matches, and near-misses that share a character prefix but not a package boundary (e.g. {{org.apache.struts2x}} must not match {{org.apache.struts2}}).

  was:
Sub-task of WW-5667.

{{SecurityMemberAccess.isClassBelongsToPackages(Class, Set)}} runs on the OGNL member-access hot path and allocates heavily on every call:

{code:java}
public static boolean isClassBelongsToPackages(Class[?] clazz, Set[String] matchingPackages) {
    List[String] packageParts = List.of(toPackageName(clazz).split("\\."));
    return IntStream.range(0, packageParts.size())
            .mapToObj(i -> String.join(".", packageParts.subList(0, i + 1)))
            .anyMatch(matchingPackages::contains);
}
{code}

Per call this performs a regex-based {{String.split}}, wraps the result in a {{List}}, and then builds a brand-new joined {{String}} for every package prefix. For a class in {{org.apache.struts2.ognl}} that is one array plus four {{String.join}} allocations.

It is invoked up to four times per {{isAccessible()}} call — once for the excluded-package check and once for the allowlist check, for both the member's declaring class and the target class (see {{isExcludedPackageNames}}, {{isClassAllowlisted}}).

This matches JFR sample 1 on the parent ticket:

{noformat}
java.lang.String.split(String)
SecurityMemberAccess.isClassBelongsToPackages(Class, Set) :390
SecurityMemberAccess.isExcludedPackageNames(Class) :386
SecurityMemberAccess.isPackageExcluded(Class) :371
{noformat}

The same prefix-matching can be done by walking the package name backwards from each {{'.'}} and probing the set with a substring, with no array, stream, or join allocations.

This is the OGNL security gate, so the change must preserve exact allow/deny semantics. Equivalence tests are required for: the default package (empty package name), single-segment packages, exact matches, sub-package matches, and near-misses that share a character prefix but not a package boundary (e.g. {{org.apache.struts2x}} must not match {{org.apache.struts2}}).


> Make SecurityMemberAccess.isClassBelongsToPackages allocation-free
> ------------------------------------------------------------------
>
>                 Key: WW-5674
>                 URL: https://issues.apache.org/jira/browse/WW-5674
>             Project: Struts 2
>          Issue Type: Sub-task
>            Reporter: Lukasz Lenart
>            Priority: Major
>
> Sub-task of WW-5667.
> {{SecurityMemberAccess.isClassBelongsToPackages(Class, Set)}} runs on the OGNL member-access hot path and allocates heavily on every call. It splits the package name with a regex-based {{String.split("\\.")}}, wraps the result in a {{List}}, then streams over the prefixes and builds a brand-new joined {{String}} for every one of them before probing the set. For a class in {{org.apache.struts2.ognl}} that is one array plus four {{String.join}} allocations.
> It is invoked up to four times per {{isAccessible()}} call — once for the excluded-package check and once for the allowlist check, for both the member's declaring class and the target class (see {{isExcludedPackageNames}}, {{isClassAllowlisted}}).
> This matches JFR sample 1 on the parent ticket:
> {noformat}
> java.lang.String.split(String)
> SecurityMemberAccess.isClassBelongsToPackages(Class, Set) :390
> SecurityMemberAccess.isExcludedPackageNames(Class) :386
> SecurityMemberAccess.isPackageExcluded(Class) :371
> {noformat}
> The same prefix-matching can be done by walking the package name from each {{'.'}} and probing the set with a substring, with no array, stream, or join allocations.
> This is the OGNL security gate, so the change must preserve exact allow/deny semantics. Equivalence tests are required for: the default package (empty package name), single-segment packages, exact matches, sub-package matches, and near-misses that share a character prefix but not a package boundary (e.g. {{org.apache.struts2x}} must not match {{org.apache.struts2}}).



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