Files
llmx/codex-rs/utils/image/src/lib.rs
jif-oai aea7610c76 feat: image resizing (#5446)
Add image resizing on the client side to reduce load on the API
2025-10-27 16:58:10 +00:00

253 lines
8.4 KiB
Rust

use std::num::NonZeroUsize;
use std::path::Path;
use std::sync::LazyLock;
use crate::error::ImageProcessingError;
use base64::Engine;
use base64::engine::general_purpose::STANDARD as BASE64_STANDARD;
use codex_utils_cache::BlockingLruCache;
use codex_utils_cache::sha1_digest;
use image::ColorType;
use image::DynamicImage;
use image::GenericImageView;
use image::ImageEncoder;
use image::ImageFormat;
use image::codecs::jpeg::JpegEncoder;
use image::codecs::png::PngEncoder;
use image::imageops::FilterType;
/// Maximum width used when resizing images before uploading.
pub const MAX_WIDTH: u32 = 2048;
/// Maximum height used when resizing images before uploading.
pub const MAX_HEIGHT: u32 = 768;
pub mod error;
#[derive(Debug, Clone)]
pub struct EncodedImage {
pub bytes: Vec<u8>,
pub mime: String,
pub width: u32,
pub height: u32,
}
impl EncodedImage {
pub fn into_data_url(self) -> String {
let encoded = BASE64_STANDARD.encode(&self.bytes);
format!("data:{};base64,{}", self.mime, encoded)
}
}
static IMAGE_CACHE: LazyLock<BlockingLruCache<[u8; 20], EncodedImage>> =
LazyLock::new(|| BlockingLruCache::new(NonZeroUsize::new(32).unwrap_or(NonZeroUsize::MIN)));
pub fn load_and_resize_to_fit(path: &Path) -> Result<EncodedImage, ImageProcessingError> {
let path_buf = path.to_path_buf();
let file_bytes = read_file_bytes(path, &path_buf)?;
let key = sha1_digest(&file_bytes);
IMAGE_CACHE.get_or_try_insert_with(key, move || {
let format = match image::guess_format(&file_bytes) {
Ok(ImageFormat::Png) => Some(ImageFormat::Png),
Ok(ImageFormat::Jpeg) => Some(ImageFormat::Jpeg),
_ => None,
};
let dynamic = image::load_from_memory(&file_bytes).map_err(|source| {
ImageProcessingError::Decode {
path: path_buf.clone(),
source,
}
})?;
let (width, height) = dynamic.dimensions();
let encoded = if width <= MAX_WIDTH && height <= MAX_HEIGHT {
if let Some(format) = format {
let mime = format_to_mime(format);
EncodedImage {
bytes: file_bytes,
mime,
width,
height,
}
} else {
let (bytes, output_format) = encode_image(&dynamic, ImageFormat::Png)?;
let mime = format_to_mime(output_format);
EncodedImage {
bytes,
mime,
width,
height,
}
}
} else {
let resized = dynamic.resize(MAX_WIDTH, MAX_HEIGHT, FilterType::Triangle);
let target_format = format.unwrap_or(ImageFormat::Png);
let (bytes, output_format) = encode_image(&resized, target_format)?;
let mime = format_to_mime(output_format);
EncodedImage {
bytes,
mime,
width: resized.width(),
height: resized.height(),
}
};
Ok(encoded)
})
}
fn read_file_bytes(path: &Path, path_for_error: &Path) -> Result<Vec<u8>, ImageProcessingError> {
match tokio::runtime::Handle::try_current() {
// If we're inside a Tokio runtime, avoid block_on (it panics on worker threads).
// Use block_in_place and do a standard blocking read safely.
Ok(_) => tokio::task::block_in_place(|| std::fs::read(path)).map_err(|source| {
ImageProcessingError::Read {
path: path_for_error.to_path_buf(),
source,
}
}),
// Outside a runtime, just read synchronously.
Err(_) => std::fs::read(path).map_err(|source| ImageProcessingError::Read {
path: path_for_error.to_path_buf(),
source,
}),
}
}
fn encode_image(
image: &DynamicImage,
preferred_format: ImageFormat,
) -> Result<(Vec<u8>, ImageFormat), ImageProcessingError> {
let target_format = match preferred_format {
ImageFormat::Jpeg => ImageFormat::Jpeg,
_ => ImageFormat::Png,
};
let mut buffer = Vec::new();
match target_format {
ImageFormat::Png => {
let rgba = image.to_rgba8();
let encoder = PngEncoder::new(&mut buffer);
encoder
.write_image(
rgba.as_raw(),
image.width(),
image.height(),
ColorType::Rgba8.into(),
)
.map_err(|source| ImageProcessingError::Encode {
format: target_format,
source,
})?;
}
ImageFormat::Jpeg => {
let mut encoder = JpegEncoder::new_with_quality(&mut buffer, 85);
encoder
.encode_image(image)
.map_err(|source| ImageProcessingError::Encode {
format: target_format,
source,
})?;
}
_ => unreachable!("unsupported target_format should have been handled earlier"),
}
Ok((buffer, target_format))
}
fn format_to_mime(format: ImageFormat) -> String {
match format {
ImageFormat::Jpeg => "image/jpeg".to_string(),
_ => "image/png".to_string(),
}
}
#[cfg(test)]
mod tests {
use super::*;
use image::GenericImageView;
use image::ImageBuffer;
use image::Rgba;
use tempfile::NamedTempFile;
#[tokio::test(flavor = "multi_thread")]
async fn returns_original_image_when_within_bounds() {
let temp_file = NamedTempFile::new().expect("temp file");
let image = ImageBuffer::from_pixel(64, 32, Rgba([10u8, 20, 30, 255]));
image
.save_with_format(temp_file.path(), ImageFormat::Png)
.expect("write png to temp file");
let original_bytes = std::fs::read(temp_file.path()).expect("read written image");
let encoded = load_and_resize_to_fit(temp_file.path()).expect("process image");
assert_eq!(encoded.width, 64);
assert_eq!(encoded.height, 32);
assert_eq!(encoded.mime, "image/png");
assert_eq!(encoded.bytes, original_bytes);
}
#[tokio::test(flavor = "multi_thread")]
async fn downscales_large_image() {
let temp_file = NamedTempFile::new().expect("temp file");
let image = ImageBuffer::from_pixel(4096, 2048, Rgba([200u8, 10, 10, 255]));
image
.save_with_format(temp_file.path(), ImageFormat::Png)
.expect("write png to temp file");
let processed = load_and_resize_to_fit(temp_file.path()).expect("process image");
assert!(processed.width <= MAX_WIDTH);
assert!(processed.height <= MAX_HEIGHT);
let loaded =
image::load_from_memory(&processed.bytes).expect("read resized bytes back into image");
assert_eq!(loaded.dimensions(), (processed.width, processed.height));
}
#[tokio::test(flavor = "multi_thread")]
async fn fails_cleanly_for_invalid_images() {
let temp_file = NamedTempFile::new().expect("temp file");
std::fs::write(temp_file.path(), b"not an image").expect("write bytes");
let err = load_and_resize_to_fit(temp_file.path()).expect_err("invalid image should fail");
match err {
ImageProcessingError::Decode { .. } => {}
_ => panic!("unexpected error variant"),
}
}
#[tokio::test(flavor = "multi_thread")]
async fn reprocesses_updated_file_contents() {
{
IMAGE_CACHE.clear();
}
let temp_file = NamedTempFile::new().expect("temp file");
let first_image = ImageBuffer::from_pixel(32, 16, Rgba([20u8, 120, 220, 255]));
first_image
.save_with_format(temp_file.path(), ImageFormat::Png)
.expect("write initial image");
let first = load_and_resize_to_fit(temp_file.path()).expect("process first image");
let second_image = ImageBuffer::from_pixel(96, 48, Rgba([50u8, 60, 70, 255]));
second_image
.save_with_format(temp_file.path(), ImageFormat::Png)
.expect("write updated image");
let second = load_and_resize_to_fit(temp_file.path()).expect("process updated image");
assert_eq!(first.width, 32);
assert_eq!(first.height, 16);
assert_eq!(second.width, 96);
assert_eq!(second.height, 48);
assert_ne!(second.bytes, first.bytes);
}
}