MINIFICPP-2752 - Register processors one-by-one

[adamdebreceni]

depends on

• MINIFICPP-2715 - Use symbols to check api compatibility #2105

Used by

• MINIFICPP-2708 Controller Service C API #2096
  • MINIFICPP-2764 Controller Service CPP API #2152
    • MINIFICPP-2765 Move GCP Extension to stable C API #2153

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[martinzink]

great improvement 👍

[szaszm]

I'm thinking maybe we should call this MinifiRegisterExtension, since we're calling the extension-side code "init", and init normally comes at the same time or shortly after create.

[adamdebreceni]

renamed

[szaszm]

It would be nice to have a comment explaining to readers why this is a macro

[adamdebreceni]

added comment

[Copilot]

Pull request overview

Refactors the stable C extension initialization flow so extensions are created once and then processors can be registered incrementally, aligning better with extensions that discover/register processors dynamically.

Changes:

• Updates the stable C API to introduce MinifiExtensionContext, change MinifiCreateExtension to return an extension handle, and add MinifiRegisterProcessor.
• Adjusts core extension initialization to pass an extension context into MinifiInit*Extension entrypoints and updates built-in extensions/loaders accordingly.
• Updates Windows export definitions, integration tests, and the extensions guide example for the new registration model.

Reviewed changes

Copilot reviewed 17 out of 17 changed files in this pull request and generated 7 comments.

Show a summary per file

File	Description
minifi-api/minifi-c-api.def	Exports new MinifiRegisterProcessor symbol on Windows.
minifi-api/include/minifi-c/minifi-c.h	C API signature updates: add MinifiExtensionContext, change create signature, add register API, update config access signature.
libminifi/src/minifi-c.cpp	Implements new MinifiCreateExtension return type + MinifiRegisterProcessor, updates MinifiConfigGet to use context.
libminifi/src/core/extension/Extension.cpp	Switches extension init entrypoint to MinifiExtensionContext* and wires context-based creation/config access.
libminifi/include/core/extension/Extension.h	Introduces Extension::Context and changes info access.
extensions/llamacpp/processors/ExtensionInitializer.cpp	Updates C extension init to create once + register processor.
extensions/ExtensionInitializer.cpp	Updates generic C++ extension init signature to take context.
extensions/opencv/OpenCVLoader.cpp	Updates C++ extension init signature to take context.
extensions/python/pythonloader/PyProcLoader.cpp	Uses context-based MinifiConfigGet and updated init signature.
extensions/python/pythonlibloader/PythonLibLoader.cpp	Uses context-based MinifiConfigGet and updated init signature.
extensions/sftp/SFTPLoader.cpp	Updates C++ extension init signature to take context.
extension-framework/include/utils/ExtensionInitUtils.h	Updates helper wrapper to call new create signature.
libminifi/test/integration/extension-verification-test/ExtensionVerificationTests.cpp	Updates custom create hook signature used by tests.
libminifi/test/integration/extension-verification-test/CreateNotCalled.cpp	Updates C extension init signature for “create not called” test.
libminifi/test/integration/extension-verification-test/CppApiExtension.cpp	Updates C++ extension init signature + create info initialization.
libminifi/test/integration/extension-verification-test/CApiExtension.cpp	Updates C extension init signature + create info initialization.
Extensions.md	Updates C-extension example to create once and register processors one-by-one.

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[Copilot]

MinifiCreateExtension() can return MINIFI_NULL (e.g., if creation fails or is called more than once). The returned pointer is used unconditionally in MinifiRegisterProcessor, which will hit gsl_Assert(extension_handle) and abort. Please guard extension and handle the error path (or check the returned MinifiStatus) before registering processors.

Suggested change

	auto* extension = MinifiCreateExtension(extension_context, &ext_create_info);
	auto* extension = MinifiCreateExtension(extension_context, &ext_create_info);
	if (extension == MINIFI_NULL) {
	return;
	}