Image Cache with Download Manager | Dataford Interview Questions

Create an ImageManager that downloads an image from a URL and returns it from cache if it was downloaded previously.

Asked in the technical phone screen stage. CoderPad; discussed concurrency, edge cases, and cache memory issues.

Input and Output

Implement get_image(url, cache, downloads). url is a string, cache is a mutable dictionary mapping URLs to image data, and downloads is a dictionary simulating the downloader. Return the cached value when present; otherwise read downloads[url], store it in cache, and return it. Assume the URL exists in downloads.

Constraints

url is a string and exists in downloads
cache and downloads are dictionaries
Cache lookup and insertion are average O(1)
Image data may be any Python value, including empty bytes

Function Signature

def get_image(url, cache, downloads):

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