Sampling: Add XTC support

Matches with upstream.

Signed-off-by: kingbri <bdashore3@proton.me>

backends/exllamav2/model.py

@@ -958,6 +958,13 @@ def check_unsupported_settings(self, **kwargs):
         Meant for dev wheels!
         """
 
+        if unwrap(kwargs.get("xtc_probability"), 0.0) > 0.0 and not hasattr(
+            ExLlamaV2Sampler.Settings, "xtc_probability"
+        ):
+            logger.warning(
+                "XTC is not supported by the currently " "installed ExLlamaV2 version."
+            )
+
         return kwargs
 
     async def generate_gen(
@@ -1003,6 +1010,14 @@ async def generate_gen(
         gen_settings.mirostat = unwrap(kwargs.get("mirostat"), False)
         gen_settings.skew = unwrap(kwargs.get("skew"), 0)
 
+        # XTC
+        xtc_probability = unwrap(kwargs.get("xtc_probability"), 0.0)
+        if xtc_probability > 0.0:
+            gen_settings.xtc_probability = xtc_probability
+
+            # 0.1 is the default for this value
+            gen_settings.xtc_threshold = unwrap(kwargs.get("xtc_threshold", 0.1))
+
         # DynaTemp settings
         max_temp = unwrap(kwargs.get("max_temp"), 1.0)
         min_temp = unwrap(kwargs.get("min_temp"), 1.0)

common/sampling.py

@@ -110,6 +110,14 @@ class BaseSamplerRequest(BaseModel):
         examples=[0.0],
     )
 
+    xtc_probability: Optional[float] = Field(
+        default_factory=lambda: get_default_sampler_value("xtc_probability", 0.0),
+    )
+
+    xtc_threshold: Optional[float] = Field(
+        default_factory=lambda: get_default_sampler_value("xtc_threshold", 0.1)
+    )
+
     frequency_penalty: Optional[float] = Field(
         default_factory=lambda: get_default_sampler_value("frequency_penalty", 0.0)
     )
@@ -366,6 +374,8 @@ def to_gen_params(self, **kwargs):
             "min_p": self.min_p,
             "tfs": self.tfs,
             "skew": self.skew,
+            "xtc_probability": self.xtc_probability,
+            "xtc_threshold": self.xtc_threshold,
             "frequency_penalty": self.frequency_penalty,
             "presence_penalty": self.presence_penalty,
             "repetition_penalty": self.repetition_penalty,

sampler_overrides/sample_preset.yml

@@ -79,6 +79,12 @@ typical:
 skew:
   override: 0.0
   force: false
+xtc_probability:
+  override: 0.0
+  force: false
+xtc_threshold:
+  override: 0.1
+  force: false
 
 # MARK: Penalty settings
 frequency_penalty: