Support for guided decoding for offline LLM (#6878)

Co-authored-by: Cyrus Leung <cyrus.tl.leung@gmail.com>

tests/entrypoints/llm/test_guided_generate.py

@@ -0,0 +1,142 @@
+import json
+import re
+import weakref
+
+import jsonschema
+import pytest
+
+from vllm.entrypoints.llm import LLM
+from vllm.outputs import RequestOutput
+from vllm.sampling_params import SamplingParams
+
+from ...conftest import cleanup
+
+MODEL_NAME = "HuggingFaceH4/zephyr-7b-beta"
+
+
+@pytest.fixture(scope="module")
+def llm():
+    # pytest caches the fixture so we use weakref.proxy to
+    # enable garbage collection
+    llm = LLM(model=MODEL_NAME, max_model_len=1024)
+
+    with llm.deprecate_legacy_api():
+        yield weakref.proxy(llm)
+        del llm
+    cleanup()
+
+
+@pytest.mark.skip_global_cleanup
+def test_guided_regex(sample_regex, llm):
+    sampling_params = SamplingParams(
+        temperature=0.8,
+        top_p=0.95,
+    )
+    outputs = llm.generate(
+        prompts=[
+            f"Give an example IPv4 address with this regex: {sample_regex}"
+        ] * 2,
+        sampling_params=sampling_params,
+        use_tqdm=True,
+        guided_options_request=dict(guided_regex=sample_regex))
+
+    assert outputs is not None
+    for output in outputs:
+        assert output is not None
+        assert isinstance(output, RequestOutput)
+        prompt = output.prompt
+        generated_text = output.outputs[0].text
+        print(generated_text)
+        assert generated_text is not None
+        assert re.fullmatch(sample_regex, generated_text) is not None
+        print(f"Prompt: {prompt!r}, Generated text: {generated_text!r}")
+
+
+@pytest.mark.skip_global_cleanup
+def test_guided_json_completion(sample_json_schema, llm):
+    sampling_params = SamplingParams(
+        temperature=1.0,
+        max_tokens=1000,
+    )
+    outputs = llm.generate(
+        prompts=[
+            f"Give an example JSON for an employee profile "
+            f"that fits this schema: {sample_json_schema}"
+        ] * 2,
+        sampling_params=sampling_params,
+        use_tqdm=True,
+        guided_options_request=dict(guided_json=sample_json_schema))
+
+    assert outputs is not None
+
+    for output in outputs:
+        assert output is not None
+        assert isinstance(output, RequestOutput)
+        prompt = output.prompt
+
+        generated_text = output.outputs[0].text
+        assert generated_text is not None
+        print(f"Prompt: {prompt!r}, Generated text: {generated_text!r}")
+        output_json = json.loads(generated_text)
+        jsonschema.validate(instance=output_json, schema=sample_json_schema)
+
+
+@pytest.mark.skip_global_cleanup
+def test_guided_choice_completion(sample_guided_choice, llm):
+    sampling_params = SamplingParams(
+        temperature=0.8,
+        top_p=0.95,
+    )
+    outputs = llm.generate(
+        prompts="The best language for type-safe systems programming is ",
+        sampling_params=sampling_params,
+        use_tqdm=True,
+        guided_options_request=dict(guided_choice=sample_guided_choice))
+
+    assert outputs is not None
+    for output in outputs:
+        assert output is not None
+        assert isinstance(output, RequestOutput)
+        prompt = output.prompt
+        generated_text = output.outputs[0].text
+        print(generated_text)
+        assert generated_text is not None
+        assert generated_text in sample_guided_choice
+        print(f"Prompt: {prompt!r}, Generated text: {generated_text!r}")
+
+
+@pytest.mark.skip_global_cleanup
+def test_guided_grammar(sample_sql_statements, llm):
+
+    sampling_params = SamplingParams(
+        temperature=0.8,
+        top_p=0.95,
+        max_tokens=1000,
+    )
+    outputs = llm.generate(
+        prompts=("Generate a sql state that select col_1 from "
+                 "table_1 where it is equals to 1"),
+        sampling_params=sampling_params,
+        use_tqdm=True,
+        guided_options_request=dict(guided_grammar=sample_sql_statements))
+
+    assert outputs is not None
+    for output in outputs:
+        assert output is not None
+        assert isinstance(output, RequestOutput)
+        prompt = output.prompt
+
+        generated_text = output.outputs[0].text
+        assert generated_text is not None
+        # use Lark to parse the output, and make sure it's a valid parse tree
+        from lark import Lark
+        parser = Lark(sample_sql_statements)
+        parser.parse(generated_text)
+
+        # remove spaces for comparison b/c we removed them in the grammar
+        ground_truth = "SELECT col_1 from table_1 where col_1 = 1".replace(
+            " ", "")
+
+        assert generated_text.strip() == ground_truth
+
+        print(f"Prompt: {prompt!r}, Generated text: {generated_text!r}")