On Wed, 30 Oct 2024 12:02:14 GMT, Andrey Turbanov <aturba...@openjdk.org> wrote:
> If a thread-safe implementation is not needed, it is recommended to use
> HashMap instead of legacy synchronized Hashtable.
> Map `CSS.htmlAttrToCssAttrMap` is modified only within static initialization
> block and then only `get` method is called.
>
> The only subtle difference is that Hashtable doesn't allow `null` keys and
> throws NPE from `get` method.
> I've checked all possible keys which are passed to `htmlAttrToCssAttrMap.get`.
> Currently 3 different execution paths are possible:
>
> **1,2**
> When `HTML.Attribute.BORDER` is passed as a key. It's definitely non-null.
>
> javax.swing.text.html.CSS#translateHTMLToCSS
> translateAttribute(HTML.Attribute.BORDER, "1", cssAttrSet);
> CSS.Attribute[] cssAttrList = getCssAttribute(key);
>
>
> javax.swing.text.html.CSS#translateAttributes
> translateAttribute(HTML.Attribute.BORDER, Integer.toString(borderWidth),
> cssAttrSet);
> CSS.Attribute[] cssAttrList = getCssAttribute(key);`
>
>
> **3**
> When non-null `key` is passed as a key.
>
> javax.swing.text.html.CSS#translateAttributes
>
> if (name instanceof HTML.Attribute) { // from this `instanceof` we know
> that it's non-null
> HTML.Attribute key = (HTML.Attribute)name;
>
> translateAttribute(key, (String) htmlAttrSet.getAttribute(key),
> cssAttrSet);
> CSS.Attribute[] cssAttrList = getCssAttribute(key);
>
>
> 
>
>
> I've used HashMap.newHashMap method instead of constructor to avoid resizing
> of internal HashMap array.
If there are no initialisation circularities between
[`javax.swing.text.html.CSS`] and [`javax.swing.text.html.HTML`], then it might
be possible to use [`Map.of(…)`] instead, given that these maps aren’t written
to after startup.
[`javax.swing.text.html.CSS`]:
https://docs.oracle.com/en/java/javase/23/docs/api/java.desktop/javax/swing/text/html/CSS.html
[`javax.swing.text.html.HTML`]:
https://docs.oracle.com/en/java/javase/23/docs/api/java.desktop/javax/swing/text/html/HTML.html
[`Map.of(…)`]:
https://docs.oracle.com/en/java/javase/23/docs/api/java.base/java/util/Map.html#ofEntries(java.util.Map.Entry...)
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PR Comment: https://git.openjdk.org/jdk/pull/21785#issuecomment-2451961348
