Rest API

• API contract

  • Long to short url

    • Request payload

    • Response code

  • Short to long url

    • Request payload

    • Response code 301 vs 302

• API implementation (Base62 with globalId)

API contract

Long to short url

Request payload

• Post https://tinyurl.com/

data:
{
    original_url: xxxx,
    expired_date: xxxx, 
    ip: xxxx
}

Response code

• 200

Short to long url

Request payload

• Get https://tinyurl.com/xxxxx

Response code 301 vs 302

• 301: Permanent redirection.

• 302: Temporarily moved.

• Comparison:

  • Using a 302 response code, each time calling https://tinyurl.com/{shortened_Url} will call the server. It adds to the server load. However, if statistics about the short url is needed, then 301 will be better.

API implementation (Base62 with globalId)

class UrlShortener:

    def __init__():
        # Suppose that the hash seed is based on the auto-increment global id
        self.globalID = 0
    
        # Suppose that we truncate the hashed url by the mapping between short and long url
        self.shortToLongMap = dict()

        # Hardcode constants
        self.base62Str = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
        self.shortLength = 6
        self.domainName = https://tinyurl.com/" 

    # Suppose that we need to store the url map    
    def longToShort(longUrl: str) -> str:
        self.globalID += 1
        
        currId = self.globalID
        shortened = ""
        while currId > 0:
            shortened = ""
            index = currId % 62
            shortened += self.base62Str[index] 
            currId = currId // 62
        
        if len(shortened) < self.shortLength:
            shortened = "0" * (self.shortLength - len(shortened)) + shortened

        self.shortToLongMap[shortened] = longUrl

        return self.domainName + shortened

    def shortToLong(shortUrl: str) -> str:
        shortened = shortUrl[len(self.domainName):]
        return self.shortToLongMap[shortUrl]