Fix streaming APIs in Agents and Projects libraries

[srnagar]

This pull request introduces a new utility class, FluxInputStream, to bridge between Reactor's Flux<ByteBuffer> and Java's InputStream, and refactors HTTP response handling to use this class. This enables non-blocking, streaming response bodies while maintaining compatibility with existing interfaces. Additionally, the request context and threading behavior for HTTP calls are improved. Comprehensive tests for FluxInputStream are also added.

Core HTTP streaming improvements:

• Added the new FluxInputStream class, which allows reading from a Flux<ByteBuffer> as an InputStream, handling synchronization, backpressure, and error propagation.
• Updated AzureHttpResponseAdapter.body() in both azure-ai-agents and azure-ai-projects to use FluxInputStream instead of the previous .getBodyAsBinaryData().toStream(), preparing for future API changes and enabling true streaming. [1] [2]

Testing:

• Added FluxInputStreamTests, a comprehensive test suite covering normal operation, empty buffers, and error propagation for the new stream class.

Threading and context improvements:

• Ensured that HTTP response processing and continuations are moved off Netty/OkHttp I/O threads by using .publishOn(Schedulers.boundedElastic()), preventing blocking of event loop threads. [1] [2]
• Changed the request context in HttpClientHelper to no longer eagerly read responses, improving streaming and resource usage.

Code cleanup:

• Removed an unused logger field from AzureHttpResponseAdapter.

These changes collectively improve the efficiency, reliability, and test coverage of HTTP streaming in the SDK.

NOTE: FluxInputStream will be moved to azure-core and HttpResponse will be updated to provide API to get the InputStream directly. Agents and Projects will be updated to remove duplication when new version of azure-core is available.

[Copilot]

Pull request overview

This PR aims to enable true streaming HTTP response bodies (Flux<ByteBuffer> → InputStream) in the azure-ai-agents and azure-ai-projects libraries while improving request execution threading behavior to avoid completing futures on I/O event loop threads.

Changes:

• Added a FluxInputStream implementation (in both Agents and Projects) plus corresponding tests.
• Updated OpenAI HTTP response adapters to return a streaming InputStream backed by the underlying Azure response body Flux.
• Updated OpenAI HTTP client helper to avoid eager response reading and to complete requests on Schedulers.boundedElastic().

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 18 comments.

Show a summary per file

File	Description
sdk/core/azure-core/src/main/java/com/azure/core/http/HttpResponse.java	Adds a new getBodyStream() convenience API intended to expose streaming bodies as InputStream.
sdk/ai/azure-ai-projects/src/main/java/com/azure/ai/projects/implementation/http/FluxInputStream.java	New Flux→InputStream bridge used by Projects response adapter.
sdk/ai/azure-ai-projects/src/test/java/com/azure/ai/projects/implementation/http/FluxInputStreamTests.java	Tests for Projects FluxInputStream.
sdk/ai/azure-ai-projects/src/main/java/com/azure/ai/projects/implementation/http/AzureHttpResponseAdapter.java	Switches Projects adapter body() to streaming via Flux-backed InputStream.
sdk/ai/azure-ai-projects/src/main/java/com/azure/ai/projects/implementation/http/HttpClientHelper.java	Ensures completion/continuations don’t run on I/O threads; stops eager response reading.
sdk/ai/azure-ai-agents/src/main/java/com/azure/ai/agents/implementation/http/FluxInputStream.java	New Flux→InputStream bridge used by Agents response adapter.
sdk/ai/azure-ai-agents/src/test/java/com/azure/ai/agents/implementation/http/FluxInputStreamTests.java	Tests for Agents FluxInputStream.
sdk/ai/azure-ai-agents/src/main/java/com/azure/ai/agents/implementation/http/AzureHttpResponseAdapter.java	Switches Agents adapter body() to streaming via Flux-backed InputStream.
sdk/ai/azure-ai-agents/src/main/java/com/azure/ai/agents/implementation/http/HttpClientHelper.java	Ensures completion/continuations don’t run on I/O threads; stops eager response reading.