add svg size extraction (#4741)

### Description

parse the size info from SVGs

crates/turbopack-image/Cargo.toml

@@ -25,6 +25,8 @@ image = { workspace = true, default-features = false, features = [
 ] }
 indexmap = { workspace = true }
 mime = { workspace = true }
+once_cell = { workspace = true }
+regex = { workspace = true }
 serde = { workspace = true }
 serde_with = { workspace = true }
 turbo-tasks = { workspace = true }

crates/turbopack-image/src/process/SVG_LICENSE

@@ -0,0 +1,9 @@
+The MIT License (MIT)
+
+Copyright © 2017 Aditya Yadav, http://netroy.in
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

crates/turbopack-image/src/process.rs → crates/turbopack-image/src/process/mod.rs

@@ -1,3 +1,5 @@
+pub mod svg;
+
 use std::{io::Cursor, str::FromStr};
 
 use anyhow::{bail, Context, Result};
@@ -21,6 +23,8 @@ use turbopack_core::{
     issue::{Issue, IssueVc},
 };
 
+use self::svg::calculate;
+
 /// Small placeholder version of the image.
 #[derive(PartialEq, Eq, Serialize, Deserialize, TraceRawVcs, ValueDebugFormat)]
 pub struct BlurPlaceholder {
@@ -246,7 +250,22 @@ pub async fn get_meta_data(
       bail!("Input image not found");
     };
     let bytes = content.content().to_bytes()?;
-    let Some((image, format)) = load_image(ident, &bytes, ident.path().await?.extension()) else {
+    let path = ident.path().await?;
+    let extension = path.extension();
+    if extension == Some("svg") {
+        let content = std::str::from_utf8(&bytes).context("Input image is not valid utf-8")?;
+        let (width, height) =
+            calculate(content).context("Failed to parse svg source code for image dimensions")?;
+        return Ok(ImageMetaData {
+            width,
+            height,
+            mime_type: Some(mime::IMAGE_SVG),
+            blur_placeholder: None,
+            placeholder_for_future_extensions: (),
+        }
+        .cell());
+    }
+    let Some((image, format)) = load_image(ident, &bytes, extension) else {
         return Ok(ImageMetaData::default().cell());
     };
     let (width, height) = image.dimensions();

crates/turbopack-image/src/process/svg.rs

@@ -0,0 +1,162 @@
+// Ported from https://github.com/image-size/image-size/blob/94e9c1ee913b71222d7583dc904ac0116ae00834/lib/types/svg.ts
+// see SVG_LICENSE for license info
+
+use std::collections::HashMap;
+
+use anyhow::{anyhow, bail, Result};
+use once_cell::sync::Lazy;
+use regex::Regex;
+
+const INCH_CM: f64 = 2.54;
+static UNITS: Lazy<HashMap<&str, f64>> = Lazy::new(|| {
+    HashMap::from([
+        ("in", 96.0),
+        ("cm", 96.0 / INCH_CM),
+        ("em", 16.0),
+        ("ex", 8.0),
+        ("m", 96.0 / INCH_CM * 100.0),
+        ("mm", 96.0 / INCH_CM / 10.0),
+        ("pc", 96.0 / 72.0 / 12.0),
+        ("pt", 96.0 / 72.0),
+        ("px", 1.0),
+        ("", 1.0),
+    ])
+});
+
+static UNIT_REGEX: Lazy<Regex> =
+    Lazy::new(|| Regex::new(r"^([0-9.]+(?:e\d+)?)((?:in|cm|em|ex|m|mm|pc|pt|px)?)$").unwrap());
+
+static ROOT_REGEX: Lazy<Regex> =
+    Lazy::new(|| Regex::new(r#"<svg\s([^>"']|"[^"]*"|'[^']*')*>"#).unwrap());
+static WIDTH_REGEX: Lazy<Regex> = Lazy::new(|| Regex::new(r#"\swidth=['"]([^%]+?)['"]"#).unwrap());
+static HEIGHT_REGEX: Lazy<Regex> =
+    Lazy::new(|| Regex::new(r#"\sheight=['"]([^%]+?)['"]"#).unwrap());
+static VIEW_BOX_REGEX: Lazy<Regex> =
+    Lazy::new(|| Regex::new(r#"\sviewBox=['"](.+?)['"]"#).unwrap());
+static VIEW_BOX_CONTENT_REGEX: Lazy<Regex> =
+    Lazy::new(|| Regex::new(r#"^\s*(\w+)\s+(\w+)\s+(\w+)\s+(\w+)\s*$"#).unwrap());
+
+fn parse_length(len: &str) -> Result<f64> {
+    let captures = UNIT_REGEX
+        .captures(len)
+        .ok_or_else(|| anyhow!("Unknown syntax for length, expected value with unit ({len})"))?;
+    let val = captures[1].parse::<f64>()?;
+    let unit = &captures[2];
+    let unit_scale = UNITS
+        .get(unit)
+        .ok_or_else(|| anyhow!("Unknown unit {unit}"))?;
+    Ok(val * unit_scale)
+}
+
+fn parse_viewbox(viewbox: &str) -> Result<(f64, f64)> {
+    let captures = VIEW_BOX_CONTENT_REGEX
+        .captures(viewbox)
+        .ok_or_else(|| anyhow!("Unknown syntax for viewBox ({viewbox})"))?;
+    let width = parse_length(&captures[3])?;
+    let height = parse_length(&captures[4])?;
+    Ok((width, height))
+}
+
+fn calculate_by_viewbox(
+    view_box: (f64, f64),
+    width: Option<Result<f64>>,
+    height: Option<Result<f64>>,
+) -> Result<(u32, u32)> {
+    let ratio = view_box.0 / view_box.1;
+    if let Some(width) = width {
+        let width = width?.round() as u32;
+        let height = (width as f64 / ratio).round() as u32;
+        return Ok((width, height));
+    }
+    if let Some(height) = height {
+        let height = height?.round() as u32;
+        let width = (height as f64 * ratio).round() as u32;
+        return Ok((width, height));
+    }
+    Ok((view_box.0.round() as u32, view_box.1.round() as u32))
+}
+
+pub fn calculate(content: &str) -> Result<(u32, u32)> {
+    let Some(root) = ROOT_REGEX.find(&content) else {
+        bail!("Source code does not contain a <svg> root element");
+    };
+    let root = root.as_str();
+    let width = WIDTH_REGEX.captures(root).map(|c| parse_length(&c[1]));
+    let height = HEIGHT_REGEX.captures(root).map(|c| parse_length(&c[1]));
+    let viewbox = VIEW_BOX_REGEX.captures(root).map(|c| parse_viewbox(&c[1]));
+    if let Some(width) = width {
+        if let Some(height) = height {
+            Ok((width?.round() as u32, height?.round() as u32))
+        } else {
+            bail!("SVG source code contains only a width attribute but not height attribute");
+        }
+    } else if let Some(viewbox) = viewbox {
+        calculate_by_viewbox(viewbox?, width, height)
+    } else {
+        bail!("SVG source code does not contain width and height or viewBox attribute");
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use anyhow::Result;
+
+    use super::calculate;
+
+    #[test]
+    fn test_calculate() {
+        let svg1 = r#"<svg width="100" height="50"></svg>"#;
+        assert_eq!(calculate(svg1).unwrap(), (100, 50));
+
+        let svg2 = r#"<svg width="100" height="50" viewBox="0 0 200 100"></svg>"#;
+        assert_eq!(calculate(svg2).unwrap(), (100, 50));
+
+        let svg3 = r#"<svg viewBox="0 0 200 100"></svg>"#;
+        assert_eq!(calculate(svg3).unwrap(), (200, 100));
+
+        let svg4 = r#"<svg width="100px" height="50px"></svg>"#;
+        assert_eq!(calculate(svg4).unwrap(), (100, 50));
+
+        let svg5 = r#"<svg width="100" height="50" viewBox="0 0 200 100"></svg>"#;
+        assert_eq!(calculate(svg5).unwrap(), (100, 50));
+
+        let svg6 = r#"<svg></svg>"#;
+        assert!(calculate(svg6).is_err());
+
+        let svg7 = r#"<svg width="100"></svg>"#;
+        assert!(calculate(svg7).is_err());
+
+        let svg8 = r#"<svg height="50"></svg>"#;
+        assert!(calculate(svg8).is_err());
+
+        let svg9 = r#"<svg viewBox="0 0 200"></svg>"#;
+        assert!(calculate(svg9).is_err());
+
+        let svg10 = r#"<svg width="100" height="invalid"></svg>"#;
+        assert!(calculate(svg10).is_err());
+    }
+
+    #[test]
+    fn test_calculate_with_units() -> Result<()> {
+        let svg = r#"<svg width="2cm" height="50mm"></svg>"#;
+        let result = calculate(svg)?;
+        assert_eq!(result, (76, 189));
+        Ok(())
+    }
+
+    #[test]
+    fn test_calculate_with_em() -> Result<()> {
+        let svg = r#"<svg width="20em" height="10em"></svg>"#;
+        let result = calculate(svg)?;
+        assert_eq!(result, (320, 160));
+        Ok(())
+    }
+
+    #[test]
+    fn test_calculate_with_ex() -> Result<()> {
+        let svg = r#"<svg width="20ex" height="10ex"></svg>"#;
+        let result = calculate(svg)?;
+        assert_eq!(result, (160, 80));
+        Ok(())
+    }
+}