Exl3: Add token encode, decode, and special token fetch

Base class methods

Signed-off-by: kingbri <8082010+kingbri1@users.noreply.github.com>

backends/exllamav3/model.py

@@ -18,6 +18,7 @@ from common.multimodal import MultimodalEmbeddingWrapper
 from common.sampling import BaseSamplerRequest
 from common.templating import PromptTemplate
 from common.transformers_utils import GenerationConfig
+from common.utils import unwrap
 from endpoints.core.types.model import ModelCard
 
 from exllamav3 import Config, Model, Cache, Tokenizer
@@ -175,7 +176,11 @@ class ExllamaV3Container(BaseModelContainer):
             A list of integer token IDs.
         """
 
-        pass
+        return self.tokenizer.encode(
+            text,
+            add_bos=unwrap(kwargs.get("add_bos_token"), True),
+            encode_special_tokens=unwrap(kwargs.get("encode_special_tokens"), True),
+        ).flatten().tolist()
 
     def decode_tokens(self, ids: List[int], **kwargs) -> str:
         """
@@ -189,9 +194,15 @@ class ExllamaV3Container(BaseModelContainer):
             The decoded text string.
         """
 
-        pass
+        ids = torch.tensor([ids])
+        return self.tokenizer.decode(
+            ids,
+            decode_special_tokens=unwrap(kwargs.get("decode_special_tokens"), True),
+        )[0]
 
-    def get_special_tokens(self, **kwargs) -> Dict[str, Any]:
+    def get_special_tokens(
+        self, add_bos_token: bool = True, ban_eos_token: bool = False
+    ):
         """
         Gets special tokens used by the model/tokenizer.
 
@@ -203,7 +214,12 @@ class ExllamaV3Container(BaseModelContainer):
             to their string or ID representation.
         """
 
-        pass
+        return {
+            "bos_token": self.tokenizer.bos_token if add_bos_token else "",
+            "eos_token": self.tokenizer.eos_token if not ban_eos_token else "",
+            "pad_token": self.tokenizer.pad_token,
+            "unk_token": self.tokenizer.unk_token,
+        }
 
     def model_info(self) -> ModelCard:
         """