[Inference] Add the logic of the inference engine (#5173)

* add infer_struct and infer_config

* update codes

* change InferConfig

* Add hf_model_config to the engine

* rm _get_hf_model_config

* update codes

* made adjustments according to the feedback from the reviewer.

* update codes

* add ci test for config and struct

* Add the logic of the inference engine

* update engine and test

* Recover cache_manager.py

* add logger

* fix conflict

* update codes

* update codes

* update model and tokenizer

* fix add the logic about shardformer

* change kvcache_manager docstring

* add policy

* fix ci bug in test_kvcache_manager.py

* remove codes related o tokenizer and move model_policy

* fix  code style

* add ordered_set to requirements-infer.txt

* Delete extra empty lines

* add ordered_set to requirements-test.txt

tests/test_infer/test_inference_engine.py

@@ -0,0 +1,44 @@
+import pytest
+import transformers
+from transformers import AutoTokenizer
+
+import colossalai
+from colossalai.inference.config import InferenceConfig
+from colossalai.inference.core.engine import InferenceEngine
+from colossalai.testing import spawn
+
+
+def check_inference_engine():
+    model = transformers.LlamaForCausalLM(
+        transformers.LlamaConfig(
+            vocab_size=20000, hidden_size=512, intermediate_size=1536, num_attention_heads=4, num_hidden_layers=4
+        )
+    )
+    tokenizer = AutoTokenizer.from_pretrained("hf-internal-testing/llama-tokenizer")
+    inference_config = InferenceConfig()
+    inference_engine = InferenceEngine(model, tokenizer, inference_config, verbose=True)
+
+    inputs = [
+        "介绍一下北京",
+        "介绍一下武汉",
+    ]
+
+    inference_engine.add_request(prompts=inputs)
+    outputs = inference_engine.generate(None)
+
+    for s1, s2 in zip(inputs, outputs):
+        assert s1 == s2
+
+
+def run_dist(rank, world_size, port):
+    colossalai.launch(config={}, rank=rank, world_size=world_size, port=port, host="localhost")
+    check_inference_engine()
+
+
+@pytest.mark.dist
+def test_inference_engine():
+    spawn(run_dist, 1)
+
+
+if __name__ == "__main__":
+    test_inference_engine()