llama : add llama_model_ftype_name() (#25134)

• llama : add llama_model_ftype_name()

Expose the model file type (quantization) name, e.g. "Q8_0" or "Q4_K - Medium", through a new public C API. The returned pointer is valid for the lifetime of the model and nullptr when the model is invalid or the file type is unknown.

Signed-off-by: Adrien Gallouët [email protected]

• Export enum

Signed-off-by: Adrien Gallouët [email protected]

• s/llama_model_ftype_name/llama_ftype_name/

Signed-off-by: Adrien Gallouët [email protected]

• Move "(guessed)" to the front in llama_ftype_name

Prepend the "(guessed)" label instead of appending it. This allows removing the non-thread-safe static std::string, making the function allocation-free.

Signed-off-by: Adrien Gallouët [email protected]

• Add LLAMA_FTYPE_PREFIX

Signed-off-by: Adrien Gallouët [email protected]

• Dont check for model

Signed-off-by: Adrien Gallouët [email protected]

Signed-off-by: Adrien Gallouët [email protected]