`insecureHash` function in langchainjs source code.

In this article, we will review insecureHash function in langchainjs source code. we will look at: 

1. insecureHash function definition

2. Where is insecureHash invoked?

insecureHash function definition

you will find the below code in langchainjs/langchain-core/src/utils/js-sha1hash.ts

export const insecureHash = (message) => {
  return new Sha1(true).update(message)["hex"]();
};

sha1 function is defined in the same file at line 24:

function Sha1(sharedMemory) {
  if (sharedMemory) {
    blocks[0] =
      blocks[16] =
      blocks[1] =
      blocks[2] =
      blocks[3] =
      blocks[4] =

Learn more about sha1.

Where is insecureHash invoked?

I found that insecureHash is imported in a file named cache_backed.ts as shown below:

import { insecureHash } from "@langchain/core/utils/hash";

At line 155 in cache_backed.ts, you will find that insecureHash is invoked as shown below:

 const encoderBackedStore = new EncoderBackedStore<
      string,
      number[],
      Uint8Array
    >({
      store: documentEmbeddingStore,
      keyEncoder: (key) => (options?.namespace ?? "") + insecureHash(key),

There are 14 references to insecureHash function in the langchainjs codebase.

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Hey, my name is Ramu Narasinga. I study codebase architecture in large open-source projects.

Email: ramu.narasinga@gmail.com

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References:

1. https://github.com/langchain-ai/langchainjs/blob/main/langchain/src/embeddings/cache_backed.ts#L1

2. https://github.com/langchain-ai/langchainjs/blob/main/langchain/src/embeddings/cache_backed.ts#L155

3. https://github.com/langchain-ai/langchainjs/blob/main/langchain-core/src/utils/js-sha1/hash.ts#L415

4. https://github.com/langchain-ai/langchainjs/blob/main/langchain-core/src/utils/js-sha1/hash.ts#L24