add cache example about titiler HOT 4 CLOSED

"""Custom Cached."""
import aiocache
from starlette.responses import Response

class cached(aiocache.cached):
    """Custom Cached Decorator."""

    async def get_from_cache(self, key):
        """update headers."""
        try:
            value = await self.cache.get(key)
            if isinstance(value, Response):
                value.headers["X-Cache"] = "HIT"
            return value
        except Exception:
            aiocache.logger.exception("Couldn't retrieve %s, unexpected error", key)

    async def decorator(
        self, f, *args, cache_read=True, cache_write=True, aiocache_wait_for_write=True, **kwargs
    ):
        """add non-async compat."""
        key = self.get_cache_key(f, args, kwargs)

        if cache_read:
            value = await self.get_from_cache(key)
            if value is not None:
                return value

        if is_coroutine_callable(f):
            result = await f(*args, **kwargs)
        else:
            result = f(*args, **kwargs)

        if cache_write:
            if aiocache_wait_for_write:
                await self.set_in_cache(key, result)
            else:
                asyncio.ensure_future(self.set_in_cache(key, result))

        return result

        if is_coroutine_callable(f):
            result = await f(*args, **kwargs)
        else:
            result = f(*args, **kwargs)