Short Link Analysis

Oct 24, 2024#项目分析99

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AI-generated summary

The document discusses the generation of short links, primarily used in long connection scenarios due to character limitations on platforms like SMS. ### Short Link Generation 1. **Hash Algorithm**: Generates short links using a hashing method, which may lead to hash collisions. - A function is provided that combines the original URL and a user ID, hashes it using SHA-256, and then encodes it in base58 to create a shorter link. 2. **ID Generator**: Uses the Snowflake algorithm to generate unique IDs. ### Redirection - Short links typically use 302 redirects. Using 301 redirects can lead to caching issues in browsers, which affects the tracking of short link usage. ### Reference The document concludes with a note on the design considerations for short links.

Currently, most scenarios use long connections, which have led to the creation of short links for various purposes (such as character limits on SMS platforms).

Short Link Generation#

Generated through hash algorithms

Generated through an identifier

Both methods can ultimately reduce length using base algorithms.

Hash Algorithm Generation#

Possible hash collisions

// 1.hash
func GenerateShortenUrl(initUrl, userID string) string {
  // Encrypted with 256
	urlSHA256 := sha256f(initUrl + userID)
	genNum := new(big.Int).SetBytes(urlSHA256).Uint64()
  // Base 58 does not include misleading letters o,O,I,l and +,/
  // Reduces character length
	return base58Encoded([]byte(fmt.Sprintf("%d", genNum)))[0:8]
}

func sha256f(input string) []byte {
	hashed := sha256.Sum256([]byte(input))
	return hashed[:]
}

func base58Encoded(input []byte) string {
	encoded, err := base58.BitcoinEncoding.Encode(input)
	if err != nil {
		fmt.Println(err.Error())
		os.Exit(1)
	}
	return string(encoded)
}

Identifier Generation#

Generated ID through the Snowflake algorithm.

Redirection#

Generally redirected using 302, while 301 permanent redirection will leave a cache in the browser, making it impossible to track statistics through short link access.

Reference#

Discussion on Short Link Design