Add `isBuffered` methods on `BinaryData` and `HttpResponse`

[lmolkova]

1. boolean HttpResponse.isBuffered() method? It'd allow to optimize stuff here and in HttpResponseLogger
2. something like HttpResponse.addCloseHook(BiSupplier<HttpResponse, Throwable> hook) - this would help us avoid wrapping streams

Not strictly related, but I think BinaryData should also have isBuffered or isBufferable and close to optimize/allow more control to close streams under (e.g. when I don't want to read full content)

Originally posted by @lmolkova in #38013 (comment)

Use cases:

• Logging: when we log response body, we want to know when response body has been received. Today we have to wrap HttpResponse object into LoggingHttpResponse to achieve it
• Tracing: the same
• HttpClients sending request body: can safely do BinaryData.toBytes() is content is already buffered. Today they have to switch over all content implementations. We had some cases in the past where we forgot to update all the places when we added new content types.

Before:

azure-sdk-for-java/sdk/core/azure-core-http-okhttp/src/main/java/com/azure/core/http/okhttp/OkHttpAsyncHttpClient.java

Lines 170 to 177 in 3a1a3c8

	BinaryDataContent content = BinaryDataHelper.getContent(bodyContent);
	if (content instanceof ByteArrayContent
	|| content instanceof StringContent
	|| content instanceof SerializableContent
	|| content instanceof ByteBufferContent) {
	return RequestBody.create(content.toBytes(), mediaType);
	} else {

After

if (bodyContent.isBuffered()) {
    return RequestBody.create(content.toBytes(), mediaType);
} else {

In logging/tracing:

Before

return next.process()
    .doOnSuccess(response -> updateSpan(response, span))
    .map(response -> new TraceableResponse(response, span))

After:

return next.process()
    .doOnSuccess(response -> updateSpan(response, span))
    .map(response ->  {
           if (response.isBuffered()) {
                 endSpan(span);
                 return response;
           }
           return new TraceableResponse(response, span);
     })

[lmolkova]

The alternative to HttpResponse.isBuffered would be on-close hook, like

return next.process()
    .doOnSuccess(response -> updateSpan(response, span))
    .doOnNext(response ->  {
           response.doOnClose(() -> endSpan(span))
     })

[github-actions]

Hi @lmolkova, we deeply appreciate your input into this project. Regrettably, this issue has remained unresolved for over 2 years and inactive for 30 days, leading us to the decision to close it. We've implemented this policy to maintain the relevance of our issue queue and facilitate easier navigation for new contributors. If you still believe this topic requires attention, please feel free to create a new issue, referencing this one. Thank you for your understanding and ongoing support.