What is correct way to import rust dependencies?

Anki Development
1

I am implementing image-occlusion for Anki ecosystem (more in this branch GitHub - krmanik/anki at image-occlusion).

I need to get base64, width and height of image. I have added this Cargo.toml file in rslib

base64 = "0.13.0"
imagesize = "0.9"

Imported the dependencies

use base64::{encode};
use imagesize::size;

anki/metadata.rs at 72a251e2b34e1669da9cc08d043c81b4cd77a15d · krmanik/anki · GitHub

but getting errors.

error[E0432]: unresolved import `base64`
 --> rslib/src/image_occlusion/metadata.rs:4:5
  |
4 | use base64::{encode};
  |     ^^^^^^ use of undeclared crate or module `base64`

error[E0432]: unresolved import `imagesize`
 --> rslib/src/image_occlusion/metadata.rs:5:5
  |
5 | use imagesize::size;
  |     ^^^^^^^^^ use of undeclared crate or module `imagesize`

I have tested by creating a new cargo project where I get the result without errors. So, what is correct way to import the dependencies in above code?

use std::{fs, fs::File, io::Read, path::Path};

use base64::encode;
use imagesize::size;

fn main() {
    let img = "image.png";
    let data = get_base64(img);
    fs::write("base64.txt", data).expect("Unable to write file");

    let (width, height) = match size(img) {
        Ok(dim) => {(dim.width, dim.height)},
        Err(why) => {panic!("Error! {}", why)}
    };
    println!("{}, {}", width.to_string(), height.to_string());
}

fn get_base64(path: &str) -> String {
    let ext = Path::new(&path).extension().unwrap().to_str().unwrap();
    let mut file = File::open(path).unwrap();
    let mut vec = Vec::new();
    let _ = file.read_to_end(&mut vec);
    let base64 = encode(vec);
    return format!("data:image/{};base64,{}", ext, base64.replace("\r\n", ""));
}
3 Likes
2

It needs to add in rslib/BUILD.bazel

rust_library(
  deps = [
  ..
  ..
        "//rslib/cargo:base64",
]

I have generated the file using cargo raze which generated 340 files, so I think it is not the next step.

3

See cargo/README.md. I think rslib/BUILD.bazel is not mentioned there, but is still required to be updated before running update.py.

1 Like
4

Thanks, According the Readme, I need to create a issues for adding base64 = "0.13.0". I have removed imagesize and used js to get width and height, so that only one dependencies need to add now.

5

Is it necessary? Perhaps it would be possible to have the endpoint return raw bytes, and then convert them to base64 on the js end, using something like javascript - ArrayBuffer to base64 encoded string - Stack Overflow?

Looking forward to seeing what you come up with here :slight_smile:

1 Like
6

Thanks it works.

I have changed the rust code to this

    pub fn get_image_bytes(&mut self, path: &str) -> Result<ImageBytes> {
        let mut image_bytes = ImageBytes {
            ..Default::default()
        };

        let bytes = std::fs::read(path)?;
        image_bytes.data = bytes;

        Ok(image_bytes)
    }

and get base64 data in ts

    let b64encoded = protobuf.util.base64.encode(bytes.data, 0, bytes.data.length);
    let bs64 = "data:image/png;base64," + b64encoded;
7

As an aside, you can write that more succinctly as:

pub fn get_image_bytes(&self, path: &str) -> Result<ImageBytes> {
  Ok(ImageBytes {
    data: std::fs::read(path)?
   })
}
2 Likes