RFR: 7001133: OutOfMemoryError by CustomMediaSizeName implementation

[Prasanta Sadhukhan]

On Thu, 12 Oct 2023 15:51:28 GMT, Alexander Scherbatiy <alexsch at openjdk.org> wrote:

> Each time `CUPSPrinter.initMedia()` method is called it creates new `CustomMediaSizeName` objects which are all collected in static `CustomMediaSizeName.customEnumTable` field. A lot of created duplicated `CustomMediaSizeName` objects wastes java heap space and can lead to `PrintService.getAttributes()` method call time degradation especially when a lot of different printers are installed in the operation system.
> The same is true for `CustomMediaTray` class.
> 
> The fix adds a `create()` method and a hash map which allows to reuse created  `CustomMediaSizeName/CustomMediaTray` objects. It seems that adding `equals(...)` method to `CustomMediaSizeName/CustomMediaTray` classes violates parent `Media` class contract which compares media objects only by `value` fields. The fix adds inner classes which are used as a key in corresponding hash maps.
> 
> `test/jdk/javax/print` and `test/jdk/java/awt/print` automated tests were run to check the fix on Linux and macOS.

Marked as reviewed by psadhukhan (Reviewer).

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PR Review: https://git.openjdk.org/jdk/pull/16167#pullrequestreview-1752727535