InMemoryCache Class — langchain Architecture

Architecture documentation for the InMemoryCache class in test_cache.py from the langchain codebase.

Class python

Entity Profile

Dependency Diagram

graph TD
  529e5351_16cb_1794_4aeb_22c5d8662e85["InMemoryCache"]
  374b7b0c_f4fd_ba00_b93d_1a3cbb3b05cb["BaseCache"]
  529e5351_16cb_1794_4aeb_22c5d8662e85 -->|extends| 374b7b0c_f4fd_ba00_b93d_1a3cbb3b05cb
  60cdbc8d_9b5c_7e23_99e6_15dcd889c805["test_cache.py"]
  529e5351_16cb_1794_4aeb_22c5d8662e85 -->|defined in| 60cdbc8d_9b5c_7e23_99e6_15dcd889c805
  23971525_1dd2_c01c_54aa_960de3cb5a61["__init__()"]
  529e5351_16cb_1794_4aeb_22c5d8662e85 -->|method| 23971525_1dd2_c01c_54aa_960de3cb5a61
  e89fc862_11ab_4610_7cc9_434f08faa451["lookup()"]
  529e5351_16cb_1794_4aeb_22c5d8662e85 -->|method| e89fc862_11ab_4610_7cc9_434f08faa451
  c2a7293d_50d8_58a9_0b47_29bcb93bad8e["update()"]
  529e5351_16cb_1794_4aeb_22c5d8662e85 -->|method| c2a7293d_50d8_58a9_0b47_29bcb93bad8e
  4008d2b6_eb90_dd51_09cc_e52fafaef92f["clear()"]
  529e5351_16cb_1794_4aeb_22c5d8662e85 -->|method| 4008d2b6_eb90_dd51_09cc_e52fafaef92f

Relationship Graph

Source Code

libs/core/tests/unit_tests/language_models/chat_models/test_cache.py lines 21–39

class InMemoryCache(BaseCache):
    """In-memory cache used for testing purposes."""

    def __init__(self) -> None:
        """Initialize with empty cache."""
        self._cache: dict[tuple[str, str], RETURN_VAL_TYPE] = {}

    def lookup(self, prompt: str, llm_string: str) -> RETURN_VAL_TYPE | None:
        """Look up based on `prompt` and `llm_string`."""
        return self._cache.get((prompt, llm_string), None)

    def update(self, prompt: str, llm_string: str, return_val: RETURN_VAL_TYPE) -> None:
        """Update cache based on `prompt` and `llm_string`."""
        self._cache[prompt, llm_string] = return_val

    @override
    def clear(self, **kwargs: Any) -> None:
        """Clear cache."""
        self._cache = {}