Optimize new ArrayList() allocations whenever possible
#10573
Conversation
To avoid resizing at runtime, it is better to use `ArrayList` with a predefined size. In some cases it is possible from the context of the list we are creating * Fix typos in Javadocs of the affected classes according to IDE suggestions * Use diamond operators for modern Java in the affected classes * pattern matching expressions for `if` where IDE suggested * Use `switch` in one place instead of `if..else`. Again: good suggestion from IDE * Fix Nullability for the router hierarchy * Have to add "redundant" cast in the `XPathRouter` to make NullAway happy
|
Let me know if this disturbanly long for review! |
cppwfs
left a comment
cppwfs
left a comment
There was a problem hiding this comment.
Fantastic!
Thank you for doing this.
Just some nitpicks.
|
|
||
| private List<HandlerMethodArgumentResolver> buildArgumentResolvers(boolean listCapable) { | ||
| List<HandlerMethodArgumentResolver> resolvers = new ArrayList<>(); | ||
| List<HandlerMethodArgumentResolver> resolvers = new ArrayList<>(6); |
There was a problem hiding this comment.
I know this is being a bit picky but I think a constant would be better here than the number 6.
| if (incomingCorrelationId != null) { | ||
| if (incomingSequenceDetails == null) { | ||
| incomingSequenceDetails = new ArrayList<>(); | ||
| incomingSequenceDetails = new ArrayList<>(1); |
There was a problem hiding this comment.
Can we use a constant here?
| validate(); | ||
|
|
||
| final List<FileListFilter<File>> filtersNeeded = new ArrayList<>(); | ||
| final List<FileListFilter<File>> filtersNeeded = new ArrayList<>(3); |
| public abstract class HttpRequestHandlingEndpointSupport extends BaseHttpInboundEndpoint { | ||
|
|
||
| private final List<HttpMessageConverter<?>> defaultMessageConverters = new ArrayList<>(); | ||
| private final List<HttpMessageConverter<?>> defaultMessageConverters = new ArrayList<>(10); |
| public void afterPropertiesSet() { | ||
| List<Object> converters = new ArrayList<>(); | ||
| List<Object> converters = | ||
| new ArrayList<>(7 + (this.customConverters != null ? this.customConverters.length : 0)); |
There was a problem hiding this comment.
Use constant instead of 7.
I know Picky picky :-)
|
Any reasons asking for those constants? |
|
Why 6? I read the code and I understand why. But is there a constant we could use to add clarity? |
|
Again: those lists are local variables. Sorry, to say that but I wish you just bite this bullet and let the "magic number" a shot! Any other reasons not just clarity? |
cppwfs
left a comment
cppwfs
left a comment
There was a problem hiding this comment.
LGTM
Thank you for the optimizations. This is great!
2 participants
To avoid resizing at runtime, it is better to use
ArrayListwith a predefined size. In some cases it is possible from the context of the list we are creatingifwhere IDE suggestedswitchin one place instead ofif..else. Again: good suggestion from IDEXPathRouterto make NullAway happy