enable mod_module_files lint

src/service/media.rs

@@ -0,0 +1,228 @@
+mod data;
+use std::io::Cursor;
+
+pub use data::Data;
+
+use crate::{services, Result};
+use image::imageops::FilterType;
+
+use tokio::{
+    fs::File,
+    io::{AsyncReadExt, AsyncWriteExt, BufReader},
+};
+
+pub struct FileMeta {
+    pub content_disposition: Option<String>,
+    pub content_type: Option<String>,
+    pub file: Vec<u8>,
+}
+
+pub struct Service {
+    pub db: &'static dyn Data,
+}
+
+impl Service {
+    /// Uploads a file.
+    pub async fn create(
+        &self,
+        mxc: String,
+        content_disposition: Option<&str>,
+        content_type: Option<&str>,
+        file: &[u8],
+    ) -> Result<()> {
+        // Width, Height = 0 if it's not a thumbnail
+        let key = self
+            .db
+            .create_file_metadata(mxc, 0, 0, content_disposition, content_type)?;
+
+        let path = services().globals.get_media_file(&key);
+        let mut f = File::create(path).await?;
+        f.write_all(file).await?;
+        Ok(())
+    }
+
+    /// Uploads or replaces a file thumbnail.
+    #[allow(clippy::too_many_arguments)]
+    pub async fn upload_thumbnail(
+        &self,
+        mxc: String,
+        content_disposition: Option<&str>,
+        content_type: Option<&str>,
+        width: u32,
+        height: u32,
+        file: &[u8],
+    ) -> Result<()> {
+        let key =
+            self.db
+                .create_file_metadata(mxc, width, height, content_disposition, content_type)?;
+
+        let path = services().globals.get_media_file(&key);
+        let mut f = File::create(path).await?;
+        f.write_all(file).await?;
+
+        Ok(())
+    }
+
+    /// Downloads a file.
+    pub async fn get(&self, mxc: String) -> Result<Option<FileMeta>> {
+        if let Ok((content_disposition, content_type, key)) =
+            self.db.search_file_metadata(mxc, 0, 0)
+        {
+            let path = services().globals.get_media_file(&key);
+            let mut file = Vec::new();
+            BufReader::new(File::open(path).await?)
+                .read_to_end(&mut file)
+                .await?;
+
+            Ok(Some(FileMeta {
+                content_disposition,
+                content_type,
+                file,
+            }))
+        } else {
+            Ok(None)
+        }
+    }
+
+    /// Returns width, height of the thumbnail and whether it should be cropped. Returns None when
+    /// the server should send the original file.
+    pub fn thumbnail_properties(&self, width: u32, height: u32) -> Option<(u32, u32, bool)> {
+        match (width, height) {
+            (0..=32, 0..=32) => Some((32, 32, true)),
+            (0..=96, 0..=96) => Some((96, 96, true)),
+            (0..=320, 0..=240) => Some((320, 240, false)),
+            (0..=640, 0..=480) => Some((640, 480, false)),
+            (0..=800, 0..=600) => Some((800, 600, false)),
+            _ => None,
+        }
+    }
+
+    /// Downloads a file's thumbnail.
+    ///
+    /// Here's an example on how it works:
+    ///
+    /// - Client requests an image with width=567, height=567
+    /// - Server rounds that up to (800, 600), so it doesn't have to save too many thumbnails
+    /// - Server rounds that up again to (958, 600) to fix the aspect ratio (only for width,height>96)
+    /// - Server creates the thumbnail and sends it to the user
+    ///
+    /// For width,height <= 96 the server uses another thumbnailing algorithm which crops the image afterwards.
+    pub async fn get_thumbnail(
+        &self,
+        mxc: String,
+        width: u32,
+        height: u32,
+    ) -> Result<Option<FileMeta>> {
+        let (width, height, crop) = self
+            .thumbnail_properties(width, height)
+            .unwrap_or((0, 0, false)); // 0, 0 because that's the original file
+
+        if let Ok((content_disposition, content_type, key)) =
+            self.db.search_file_metadata(mxc.clone(), width, height)
+        {
+            // Using saved thumbnail
+            let path = services().globals.get_media_file(&key);
+            let mut file = Vec::new();
+            File::open(path).await?.read_to_end(&mut file).await?;
+
+            Ok(Some(FileMeta {
+                content_disposition,
+                content_type,
+                file: file.to_vec(),
+            }))
+        } else if let Ok((content_disposition, content_type, key)) =
+            self.db.search_file_metadata(mxc.clone(), 0, 0)
+        {
+            // Generate a thumbnail
+            let path = services().globals.get_media_file(&key);
+            let mut file = Vec::new();
+            File::open(path).await?.read_to_end(&mut file).await?;
+
+            if let Ok(image) = image::load_from_memory(&file) {
+                let original_width = image.width();
+                let original_height = image.height();
+                if width > original_width || height > original_height {
+                    return Ok(Some(FileMeta {
+                        content_disposition,
+                        content_type,
+                        file: file.to_vec(),
+                    }));
+                }
+
+                let thumbnail = if crop {
+                    image.resize_to_fill(width, height, FilterType::CatmullRom)
+                } else {
+                    let (exact_width, exact_height) = {
+                        // Copied from image::dynimage::resize_dimensions
+                        let ratio = u64::from(original_width) * u64::from(height);
+                        let nratio = u64::from(width) * u64::from(original_height);
+
+                        let use_width = nratio <= ratio;
+                        let intermediate = if use_width {
+                            u64::from(original_height) * u64::from(width)
+                                / u64::from(original_width)
+                        } else {
+                            u64::from(original_width) * u64::from(height)
+                                / u64::from(original_height)
+                        };
+                        if use_width {
+                            if intermediate <= u64::from(::std::u32::MAX) {
+                                (width, intermediate as u32)
+                            } else {
+                                (
+                                    (u64::from(width) * u64::from(::std::u32::MAX) / intermediate)
+                                        as u32,
+                                    ::std::u32::MAX,
+                                )
+                            }
+                        } else if intermediate <= u64::from(::std::u32::MAX) {
+                            (intermediate as u32, height)
+                        } else {
+                            (
+                                ::std::u32::MAX,
+                                (u64::from(height) * u64::from(::std::u32::MAX) / intermediate)
+                                    as u32,
+                            )
+                        }
+                    };
+
+                    image.thumbnail_exact(exact_width, exact_height)
+                };
+
+                let mut thumbnail_bytes = Vec::new();
+                thumbnail.write_to(
+                    &mut Cursor::new(&mut thumbnail_bytes),
+                    image::ImageOutputFormat::Png,
+                )?;
+
+                // Save thumbnail in database so we don't have to generate it again next time
+                let thumbnail_key = self.db.create_file_metadata(
+                    mxc,
+                    width,
+                    height,
+                    content_disposition.as_deref(),
+                    content_type.as_deref(),
+                )?;
+
+                let path = services().globals.get_media_file(&thumbnail_key);
+                let mut f = File::create(path).await?;
+                f.write_all(&thumbnail_bytes).await?;
+
+                Ok(Some(FileMeta {
+                    content_disposition,
+                    content_type,
+                    file: thumbnail_bytes.to_vec(),
+                }))
+            } else {
+                // Couldn't parse file to generate thumbnail, send original
+                Ok(Some(FileMeta {
+                    content_disposition,
+                    content_type,
+                    file: file.to_vec(),
+                }))
+            }
+        } else {
+            Ok(None)
+        }
+    }
+}