Create handler.py (#4)

- Create handler.py (da1ea7155eb354e4c417ab1270e5e154ad34bb24)

handler.py

@@ -0,0 +1,52 @@
+import torch
+from typing import Dict, List, Any
+from transformers import AutoTokenizer, AutoModelForCausalLM, pipeline
+
+# check for GPU
+device = 0 if torch.cuda.is_available() else -1
+
+
+format_input = (
+    "Below is an instruction that describes a task. "
+    "Write a response that appropriately completes the request.\n\n"
+    "### Instruction:\n{instruction}\n\n### Response:"
+)
+
+
+class EndpointHandler:
+    def __init__(self, path=""):
+        # load the model
+        tokenizer = AutoTokenizer.from_pretrained(path)
+        model = AutoModelForCausalLM.from_pretrained(
+            path,
+            device_map="auto",
+            torch_dtype=torch.float16,
+        )
+        # create inference pipeline
+        self.pipeline = pipeline(
+            "text-generation",
+            model=model,
+            tokenizer=tokenizer,
+            device=device,
+            max_length=256,
+        )
+
+    def __call__(self, data: Any) -> List[List[Dict[str, float]]]:
+        inputs = data.pop("inputs", data)
+        parameters = data.pop("parameters", None)
+
+        text_input = format_input.format(instruction=inputs)
+
+        # pass inputs with all kwargs in data
+        if parameters is not None:
+            prediction = self.pipeline(text_input, **parameters)
+        else:
+            prediction = self.pipeline(text_input)
+
+        # postprocess the prediction
+        output = [
+            {"generated_text": pred["generated_text"].split("### Response:")[1].strip()}
+            for pred in prediction
+        ]
+
+        return output