| 1 | # SPDX-License-Identifier: Apache-2.0 |
| 2 | # SPDX-FileCopyrightText: Copyright contributors to the vLLM project |
| 3 | """Helper functions to work with nested JSON structures.""" |
| 4 | |
| 5 | from collections.abc import Callable, Iterable |
| 6 | from functools import reduce |
| 7 | from typing import TYPE_CHECKING, Any, TypeAlias, TypeVar, overload |
| 8 | |
| 9 | if TYPE_CHECKING: |
| 10 | import torch |
| 11 | |
| 12 | from vllm.multimodal.inputs import BatchedTensorInputs |
| 13 | |
| 14 | _T = TypeVar("_T") |
| 15 | _U = TypeVar("_U") |
| 16 | |
| 17 | JSONTree: TypeAlias = ( |
| 18 | dict[str, "JSONTree[_T]"] | list["JSONTree[_T]"] | tuple["JSONTree[_T]", ...] | _T |
| 19 | ) |
| 20 | """A nested JSON structure where the leaves need not be JSON-serializable.""" |
| 21 | |
| 22 | _JSONTree: TypeAlias = ( |
| 23 | dict[str, "JSONTree[_T]"] |
| 24 | | list["JSONTree[_T]"] |
| 25 | | tuple["JSONTree[_T]", ...] |
| 26 | | dict[str, _T] |
| 27 | | list[_T] |
| 28 | | tuple[_T, ...] |
| 29 | | _T |
| 30 | ) |
| 31 | """ |
| 32 | Same as `JSONTree` but with additional `Union` members to satisfy overloads. |
| 33 | """ |
| 34 | |
| 35 | |
| 36 | def json_iter_leaves(value: JSONTree[_T]) -> Iterable[_T]: |
| 37 | """Iterate through each leaf in a nested JSON structure.""" |
| 38 | if isinstance(value, dict): |
| 39 | for v in value.values(): |
| 40 | yield from json_iter_leaves(v) |
| 41 | elif isinstance(value, (list, tuple)): |
| 42 | for v in value: |
| 43 | yield from json_iter_leaves(v) |
| 44 | else: |
| 45 | yield value |
| 46 | |
| 47 | |
| 48 | @overload |
| 49 | def json_map_leaves( |
| 50 | func: Callable[["torch.Tensor"], "torch.Tensor"], |
| 51 | value: "BatchedTensorInputs", |
| 52 | ) -> "BatchedTensorInputs": ... |
| 53 | |
| 54 | |
| 55 | @overload |
| 56 | def json_map_leaves( |
| 57 | func: Callable[[_T], _U], |
| 58 | value: _T | dict[str, _T], |
| 59 | ) -> _U | dict[str, _U]: ... |
| 60 | |
| 61 | |
| 62 | @overload |
| 63 | def json_map_leaves( |
| 64 | func: Callable[[_T], _U], |
| 65 | value: _T | list[_T], |
| 66 | ) -> _U | list[_U]: ... |
| 67 | |
| 68 | |
| 69 | @overload |
| 70 | def json_map_leaves( |
| 71 | func: Callable[[_T], _U], |
| 72 | value: _T | tuple[_T, ...], |
| 73 | ) -> _U | tuple[_U, ...]: ... |
| 74 | |
| 75 | |
| 76 | @overload |
| 77 | def json_map_leaves( |
| 78 | func: Callable[[_T], _U], |
| 79 | value: JSONTree[_T], |
| 80 | ) -> JSONTree[_U]: ... |
| 81 | |
| 82 | |
| 83 | def json_map_leaves( |
| 84 | func: Callable[[_T], _U], |
| 85 | value: Any, |
| 86 | ) -> "BatchedTensorInputs" | _JSONTree[_U]: |
| 87 | """Apply a function to each leaf in a nested JSON structure.""" |
| 88 | if isinstance(value, dict): |
| 89 | return {k: json_map_leaves(func, v) for k, v in value.items()} # type: ignore |
| 90 | elif isinstance(value, list): |
| 91 | return [json_map_leaves(func, v) for v in value] # type: ignore |
| 92 | elif isinstance(value, tuple): |
| 93 | return tuple(json_map_leaves(func, v) for v in value) |
| 94 | else: |
| 95 | return func(value) |
| 96 | |
| 97 | |
| 98 | @overload |
| 99 | def json_reduce_leaves( |
| 100 | func: Callable[[_T, _T], _T], |
| 101 | value: _T | dict[str, _T], |
| 102 | /, |
| 103 | ) -> _T: ... |
| 104 | |
| 105 | |
| 106 | @overload |
| 107 | def json_reduce_leaves( |
| 108 | func: Callable[[_T, _T], _T], |
| 109 | value: _T | list[_T], |
| 110 | /, |
| 111 | ) -> _T: ... |
| 112 | |
| 113 | |
| 114 | @overload |
| 115 | def json_reduce_leaves( |
| 116 | func: Callable[[_T, _T], _T], |
| 117 | value: _T | tuple[_T, ...], |
| 118 | /, |
| 119 | ) -> _T: ... |
| 120 | |
| 121 | |
| 122 | @overload |
| 123 | def json_reduce_leaves( |
| 124 | func: Callable[[_T, _T], _T], |
| 125 | value: JSONTree[_T], |
| 126 | /, |
| 127 | ) -> _T: ... |
| 128 | |
| 129 | |
| 130 | @overload |
| 131 | def json_reduce_leaves( |
| 132 | func: Callable[[_U, _T], _U], |
| 133 | value: JSONTree[_T], |
| 134 | initial: _U, |
| 135 | /, |
| 136 | ) -> _U: ... |
| 137 | |
| 138 | |
| 139 | def json_reduce_leaves( |
| 140 | func: Callable[[_T, _T], _T] | Callable[[_U, _T], _U], |
| 141 | value: _JSONTree[_T], |
| 142 | initial: _U = ..., # type: ignore[assignment] |
| 143 | /, |
| 144 | ) -> _T | _U: |
| 145 | """Apply a function of two arguments cumulatively to each leaf in a |
| 146 | nested JSON structure, from left to right, so as to reduce the |
| 147 | sequence to a single value. |
| 148 | """ |
| 149 | if initial is ...: |
| 150 | return reduce(func, json_iter_leaves(value)) # type: ignore |
| 151 | |
| 152 | return reduce(func, json_iter_leaves(value), initial) # type: ignore |
| 153 | |
| 154 | |
| 155 | def json_count_leaves(value: JSONTree[_T]) -> int: |
| 156 | """Count the number of leaves in a nested JSON structure.""" |
| 157 | return sum(1 for _ in json_iter_leaves(value)) |