Add threading configuration

Adds a configuration option for inter_threads and intra_threads to Argos
Translate that is passed to CTranslate2

https://community.libretranslate.com/t/unable-to-task-more-than-4-threads/1188

argostranslate/settings.py

@@ -100,3 +100,7 @@ class ModelProvider(Enum):
 
 # Supported values: cpu and cuda
 device = os.environ.get("ARGOS_DEVICE_TYPE", "cpu")
+
+# https://opennmt.net/CTranslate2/python/ctranslate2.Translator.html
+inter_threads = int(os.environ.get("ARGOS_INTER_THREADS", "1"))
+intra_threads = int(os.environ.get("ARGOS_INTRA_THREADS", "0"))

argostranslate/translate.py

@@ -166,7 +166,12 @@ def __init__(self, from_lang: Language, to_lang: Language, pkg: Package):
     def hypotheses(self, input_text: str, num_hypotheses: int = 4) -> list[Hypothesis]:
         if self.translator is None:
             model_path = str(self.pkg.package_path / "model")
-            self.translator = ctranslate2.Translator(model_path, device=settings.device)
+            self.translator = ctranslate2.Translator(
+                model_path,
+                device=settings.device,
+                inter_threads=settings.inter_threads,
+                intra_threads=settings.intra_threads,
+            )
         paragraphs = ITranslation.split_into_paragraphs(input_text)
         info("paragraphs:", paragraphs)
         translated_paragraphs = []