[Feat] QWen-1M context support[2/2]: Update block sparse attention backend (#5949)

examples/runtime/engine/offline_batch_inference_qwen_1m.py

@@ -0,0 +1,74 @@
+"""
+Usage:
+python3 offline_batch_inference.py
+"""
+
+from urllib.request import urlopen
+
+import sglang as sgl
+
+
+def load_prompt() -> str:
+    # Test cases with various lengths can be found at:
+    #
+    # https://qianwen-res.oss-cn-beijing.aliyuncs.com/Qwen2.5-1M/test-data/64k.txt
+    # https://qianwen-res.oss-cn-beijing.aliyuncs.com/Qwen2.5-1M/test-data/200k.txt
+    # https://qianwen-res.oss-cn-beijing.aliyuncs.com/Qwen2.5-1M/test-data/600k.txt
+    # https://qianwen-res.oss-cn-beijing.aliyuncs.com/Qwen2.5-1M/test-data/1m.txt
+
+    with urlopen(
+        "https://qianwen-res.oss-cn-beijing.aliyuncs.com"
+        "/Qwen2.5-1M/test-data/64k.txt",
+        timeout=5,
+    ) as response:
+        prompt = response.read().decode("utf-8")
+    return prompt
+
+
+# Processing the prompt.
+def process_requests(llm: sgl.Engine, prompts: list[str]) -> None:
+    # Create a sampling params object.
+    sampling_params = {
+        "temperature": 0.7,
+        "top_p": 0.8,
+        "top_k": 20,
+        "repetition_penalty": 1.05,
+        "max_new_tokens": 256,
+    }
+    # Generate texts from the prompts.
+    outputs = llm.generate(prompts, sampling_params)
+    # Print the outputs.
+    for output in outputs:
+        prompt_token_ids = output["meta_info"]["prompt_tokens"]
+        generated_text = output["text"]
+        print(
+            f"Prompt length: {prompt_token_ids}, " f"Generated text: {generated_text!r}"
+        )
+
+
+# Create an LLM.
+def initialize_engine() -> sgl.Engine:
+    llm = sgl.Engine(
+        model_path="Qwen/Qwen2.5-7B-Instruct-1M",
+        context_length=1048576,
+        page_size=256,
+        attention_backend="dual_chunk_flash_attn",
+        tp_size=4,
+        disable_radix_cache=True,
+        enable_mixed_chunk=False,
+        enable_torch_compile=False,
+        chunked_prefill_size=131072,
+        mem_fraction_static=0.6,
+        log_level="DEBUG",
+    )
+    return llm
+
+
+def main():
+    llm = initialize_engine()
+    prompt = load_prompt()
+    process_requests(llm, [prompt])
+
+
+if __name__ == "__main__":
+    main()