[Benchmark] Add plot utility for parameter sweep (#27168)

Signed-off-by: DarkLight1337 <tlleungac@connect.ust.hk>

vllm/benchmarks/sweep/param_sweep.py

@@ -0,0 +1,91 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+import json
+import os
+from typing import Any
+
+
+class ParameterSweep(list["ParameterSweepItem"]):
+    @classmethod
+    def read_json(cls, filepath: os.PathLike):
+        with open(filepath, "rb") as f:
+            records = json.load(f)
+
+        return cls.from_records(records)
+
+    @classmethod
+    def from_records(cls, records: list[dict[str, object]]):
+        if not isinstance(records, list):
+            raise TypeError(
+                f"The parameter sweep should be a list of dictionaries, "
+                f"but found type: {type(records)}"
+            )
+
+        return cls(ParameterSweepItem.from_record(record) for record in records)
+
+
+class ParameterSweepItem(dict[str, object]):
+    @classmethod
+    def from_record(cls, record: dict[str, object]):
+        if not isinstance(record, dict):
+            raise TypeError(
+                f"Each item in the parameter sweep should be a dictionary, "
+                f"but found type: {type(record)}"
+            )
+
+        return cls(record)
+
+    def __or__(self, other: dict[str, Any]):
+        return type(self)(super().__or__(other))
+
+    # In JSON, we prefer "_"
+    def _iter_param_key_candidates(self, param_key: str):
+        # Inner config arguments are not converted by the CLI
+        if "." in param_key:
+            prefix, rest = param_key.split(".", 1)
+            for prefix_candidate in self._iter_param_key_candidates(prefix):
+                yield prefix_candidate + "." + rest
+
+            return
+
+        yield param_key
+        yield param_key.replace("-", "_")
+        yield param_key.replace("_", "-")
+
+    # In CLI, we prefer "-"
+    def _iter_cmd_key_candidates(self, param_key: str):
+        for k in reversed(tuple(self._iter_param_key_candidates(param_key))):
+            yield "--" + k
+
+    def _normalize_cmd_key(self, param_key: str):
+        return next(self._iter_cmd_key_candidates(param_key))
+
+    def has_param(self, param_key: str) -> bool:
+        return any(k in self for k in self._iter_param_key_candidates(param_key))
+
+    def apply_to_cmd(self, cmd: list[str]) -> list[str]:
+        cmd = list(cmd)
+
+        for k, v in self.items():
+            for k_candidate in self._iter_cmd_key_candidates(k):
+                try:
+                    k_idx = cmd.index(k_candidate)
+
+                    if isinstance(v, bool):
+                        cmd[k_idx] = self._normalize_cmd_key(k if v else "no-" + k)
+                    else:
+                        cmd[k_idx + 1] = str(v)
+
+                    break
+                except ValueError:
+                    continue
+            else:
+                if isinstance(v, bool):
+                    cmd.append(self._normalize_cmd_key(k if v else "no-" + k))
+                else:
+                    cmd.extend([self._normalize_cmd_key(k), str(v)])
+
+        return cmd
+
+    def as_text(self, sep: str = ", ") -> str:
+        return sep.join(f"{k}={v}" for k, v in self.items())