Cache

The cache module provides three-tier caching with TTL support and thread-safe operations:

1. SimpleCache — General-purpose in-memory cache
2. ExchangeInfoCache — Exchange metadata cache
3. MarketDataCache — Market data cache with hit rate tracking

SimpleCache

General-purpose thread-safe cache with TTL and size limits.

class SimpleCache:
    def __init__(
        self,
        default_ttl: float = 300.0,
        max_size: int = 10000,
        on_evict: Optional[Callable[[str, Any], None]] = None,
    ):

Methods

get(key: str, default: Any = None) -> Any

Retrieve a value. Returns default if not found or expired.

value = cache.get("BTCUSDT_ticker", default=None)

set(key: str, value: Any, ttl: Optional[float] = None) -> None

Store a value with optional TTL override.

cache.set("BTCUSDT_ticker", ticker_data, ttl=60.0)

delete(key: str) -> bool

Delete a key. Returns True if found and deleted.

deleted = cache.delete("BTCUSDT_ticker")

clear() -> None

Clear all entries.

cache.clear()

stats() -> Dict[str, Any]

Return cache statistics (hits, misses, size, hit rate).

stats = cache.stats()
# {"hits": 150, "misses": 10, "size": 42, "hit_rate": 0.937}

ExchangeInfoCache

Cache for exchange metadata (trading rules, symbol info, etc.).

cache = ExchangeInfoCache(default_ttl=3600.0)
cache.set_exchange_info("BINANCE", exchange_info)
info = cache.get_exchange_info("BINANCE")

MarketDataCache

Cache for market data with hit rate tracking per symbol.

cache = MarketDataCache(default_ttl=5.0)
cache.set_market_data("BTCUSDT", "ticker", ticker)
data = cache.get_market_data("BTCUSDT", "ticker")

Decorator: @cached

Function-level cache decorator.

from bt_api_base.cache import cached

@cached(ttl=60)
def fetch_exchange_info():
    return requests.get("/api/v3/exchangeInfo").json()

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中文

概述

cache 模块提供三级缓存，支持 TTL 和线程安全操作：

1. SimpleCache — 通用内存缓存
2. ExchangeInfoCache — 交易所元数据缓存
3. MarketDataCache — 市场数据缓存，带命中率追踪

SimpleCache

方法	说明
get(key, default)	获取值，不存在或过期返回 default
set(key, value, ttl)	存储值，可选 TTL 覆盖
delete(key)	删除键
clear()	清空所有条目
stats()	返回缓存统计（命中、未命中、大小、命中率）

@cached 装饰器

@cached(ttl=60)
def fetch_exchange_info():
    return requests.get("/api/v3/exchangeInfo").json()

使用示例

from bt_api_base.cache import SimpleCache

cache = SimpleCache(default_ttl=300.0, max_size=10000)
cache.set("key", value, ttl=60)
value = cache.get("key")
stats = cache.stats()