From d74a8117d758aa66664f514710f49f1de65ba719 Mon Sep 17 00:00:00 2001
From: Bill Thiede <git@xinu.tv>
Date: Mon, 17 Feb 2020 17:50:43 -0800
Subject: [PATCH] Refactor thumbnail generation.

---
 src/library.rs | 75 ++++++++++++++++++++++++++------------------------
 src/web.rs     |  1 +
 2 files changed, 40 insertions(+), 36 deletions(-)

diff --git a/src/library.rs b/src/library.rs
index 40c52d8..afefd54 100644
--- a/src/library.rs
+++ b/src/library.rs
@@ -6,6 +6,8 @@ use std::path::PathBuf;
 use std::sync::Arc;
 
 use google_photoslibrary1 as photos;
+use image::imageops::FilterType;
+use image::ImageFormat;
 use log::error;
 use log::info;
 use log::warn;
@@ -16,7 +18,7 @@ use rocksdb::IteratorMode;
 use rocksdb::DB;
 
 // Used to ensure DB is invalidated after schema changes.
-const LIBRARY_GENERATION: &'static str = "2";
+const LIBRARY_GENERATION: &'static str = "5";
 
 #[derive(Clone)]
 pub struct Library {
@@ -143,36 +145,35 @@ impl Library {
     fn generational_key(generation: &str, key: &str) -> String {
         format!("{}/{}", generation, key)
     }
-    pub fn thumbnail(&self, media_items_id: &str, dimensions: (u32, u32)) -> Option<Vec<u8>> {
-        fn generate_thumbnail(
-            lib: &Library,
-            media_items_id: &str,
-            dimensions: (u32, u32),
-        ) -> Result<Vec<u8>, io::Error> {
-            let (w, h) = dimensions;
-            match lib.original(&media_items_id) {
-                None => {
-                    warn!("Couldn't find original {}", &media_items_id);
-                    Err(io::Error::new(
-                        io::ErrorKind::NotFound,
-                        format!("{}", media_items_id),
-                    ))
-                }
-                Some(path) => {
-                    let orig_img = image::io::Reader::open(&path)?
-                        .with_guessed_format()?
-                        .decode()
-                        .map_err(|e| io::Error::new(io::ErrorKind::Other, e))?;
-                    // TODO (wathiede) resize..fill
-                    let img =
-                        orig_img.resize_to_fill(w, h, image::imageops::FilterType::CatmullRom);
-                    let mut buf = Vec::new();
-                    img.write_to(&mut buf, image::ImageFormat::Jpeg)
-                        .map_err(|e| io::Error::new(io::ErrorKind::Other, e))?;
-                    Ok(buf)
-                }
+    pub fn generate_thumbnail(
+        &self,
+        media_items_id: &str,
+        dimensions: (u32, u32),
+        filter: FilterType,
+    ) -> Result<Vec<u8>, io::Error> {
+        let (w, h) = dimensions;
+        match self.original(&media_items_id) {
+            None => {
+                warn!("Couldn't find original {}", &media_items_id);
+                Err(io::Error::new(
+                    io::ErrorKind::NotFound,
+                    format!("{}", media_items_id),
+                ))
+            }
+            Some(path) => {
+                let orig_img = image::io::Reader::open(&path)?
+                    .with_guessed_format()?
+                    .decode()
+                    .map_err(|e| io::Error::new(io::ErrorKind::Other, e))?;
+                let img = orig_img.resize_to_fill(w, h, filter);
+                let mut buf = Vec::new();
+                img.write_to(&mut buf, ImageFormat::Jpeg)
+                    .map_err(|e| io::Error::new(io::ErrorKind::Other, e))?;
+                Ok(buf)
             }
         }
+    }
+    pub fn thumbnail(&self, media_items_id: &str, dimensions: (u32, u32)) -> Option<Vec<u8>> {
         fn cache_key(media_items_id: &str, dimensions: (u32, u32)) -> String {
             let (w, h) = dimensions;
             Library::generational_key(
@@ -191,13 +192,15 @@ impl Library {
             // Cache miss, fill cache and return.
             Ok(None) => {
                 info!("cache MISS {}", key);
-                let bytes = match generate_thumbnail(self, media_items_id, dimensions) {
-                    Ok(bytes) => bytes,
-                    Err(e) => {
-                        error!("Failed to generate thumbnail for {}: {}", media_items_id, e);
-                        return None;
-                    }
-                };
+                let bytes =
+                    match self.generate_thumbnail(media_items_id, dimensions, FilterType::Lanczos3)
+                    {
+                        Ok(bytes) => bytes,
+                        Err(e) => {
+                            error!("Failed to generate thumbnail for {}: {}", media_items_id, e);
+                            return None;
+                        }
+                    };
                 match db.put(key.as_bytes(), &bytes) {
                     Ok(_) => Some(bytes),
                     Err(e) => {
diff --git a/src/web.rs b/src/web.rs
index d1a93f8..fed5daf 100644
--- a/src/web.rs
+++ b/src/web.rs
@@ -80,6 +80,7 @@ fn image(
     media_items_id: String,
     params: ImageParams,
 ) -> Result<impl warp::Reply, warp::Rejection> {
+    // TODO(wathiede): add caching headers.
     match lib.thumbnail(
         &media_items_id,
         (params.w.unwrap_or(0), params.h.unwrap_or(0)),