Candeia•6mo ago

Read source code content

Is there a way to read the current source code of the a given a file URL (using import.meta.url) without re-downloading it? I know that inside $DENO_DIR or cache directories there are the content of the already downloaded files, but I suppose they are content-addressable somehow (sha1, maybe?). I have a code that generates a schema based on types definitions but currently I need to download them all again because I can't leverage the deno cache.

4 Replies

Candeia•6mo ago

wondering if is a good idea to try: https://deno.land/x/deno_cache@0.6.3/mod.ts

Deno AI Helper•6mo ago

I wasn't able to find the answer to your question in the official Deno documentation. However, based on your message, I can provide some general advice. In Deno, import.meta.url gives you the URL of the current module. To read the current source code of the module without re-downloading it, you could theoretically use Deno's built-in functions to read from the local file system, assuming you have the necessary permissions. Here's a general approach you might consider:

const currentModuleUrl = new URL(import.meta.url);
if (currentModuleUrl.protocol === "file:") {
  const currentModulePath = currentModuleUrl.pathname;
  const sourceCode = await Deno.readTextFile(currentModulePath);
  console.log(sourceCode);
}

const currentModuleUrl = new URL(import.meta.url);
if (currentModuleUrl.protocol === "file:") {
  const currentModulePath = currentModuleUrl.pathname;
  const sourceCode = await Deno.readTextFile(currentModulePath);
  console.log(sourceCode);
}

This code snippet checks if the module URL's protocol is file:, which means it's a local file. It then reads the file content directly from the file system without re-downloading it. Please note that this advice is not based on the Deno documentation, and I would advise you to double-check the accuracy of this advice. If the file URL is not a local file but a remote resource, you would indeed need to access the cached version, which might not be straightforward as it could be content-addressed in Deno's cache. For that scenario, there isn't a documented API in Deno to directly access cached files by their original URLs. You might need to look into the structure of the $DENO_DIR to understand how files are cached and addressed.

Helpful Links: File system APIs | Deno Docs Integrity Checking & Lock Files | Deno Docs Using Web Platform APIs | Deno Docs Deno 1.8 Release Notes

Leokuma•6mo ago

Yes, I believe you can use that to get the source file from Deno's cache if available

Candeia•6mo ago

how about when running in deno deploy?