make cache optional

README.md

@@ -38,11 +38,15 @@ port = 3000 # port to listen on
 title = "bingus-blog" # title of the website
 description = "blazingly fast markdown blog software written in rust memory safe" # description of the website
 posts_dir = "posts" # where posts are stored
-#cache_file = "..." # file to serialize the cache into on shutdown, and
-                    # to deserialize from on startup. uncomment to enable
 markdown_access = true # allow users to see the raw markdown of a post
 
-[render] # rendering-specific settings
+[cache] # cache settings
+enable = true # save metadata and rendered posts into RAM
+              # highly recommended, only turn off if asolutely necessary
+#persistence = "..." # file to save the cache to on shutdown, and
+                     # to load from on startup. uncomment to enable
+
+[render] # post rendering settings
 syntect.load_defaults = false # include default syntect themes
 syntect.themes_dir = "themes" # directory to include themes from
 syntect.theme = "Catppuccin Mocha" # theme file name (without `.tmTheme`)

src/config.rs

@@ -10,13 +10,14 @@ use tokio::io::{AsyncReadExt, AsyncWriteExt};
 use tracing::{error, info};
 
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq, Hash)]
+#[serde(default)]
 pub struct SyntectConfig {
     pub load_defaults: bool,
     pub themes_dir: Option<PathBuf>,
     pub theme: Option<String>,
 }
 
-#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq, Hash)]
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq, Hash, Default)]
 #[serde(default)]
 pub struct RenderConfig {
     pub syntect: SyntectConfig,
@@ -30,6 +31,13 @@ pub struct PrecompressionConfig {
     pub watch: bool,
 }
 
+#[derive(Serialize, Deserialize, Debug, Clone)]
+#[serde(default)]
+pub struct CacheConfig {
+    pub enable: bool,
+    pub persistence: Option<PathBuf>,
+}
+
 #[derive(Serialize, Deserialize, Debug, Clone)]
 #[serde(default)]
 pub struct Config {
@@ -41,7 +49,7 @@ pub struct Config {
     pub render: RenderConfig,
     #[cfg(feature = "precompression")]
     pub precompression: PrecompressionConfig,
-    pub cache_file: Option<PathBuf>,
+    pub cache: CacheConfig,
     pub markdown_access: bool,
 }
 
@@ -56,20 +64,18 @@ impl Default for Config {
             posts_dir: "posts".into(),
             #[cfg(feature = "precompression")]
             precompression: Default::default(),
-            cache_file: None,
+            cache: Default::default(),
             markdown_access: true,
         }
     }
 }
 
-impl Default for RenderConfig {
+impl Default for SyntectConfig {
     fn default() -> Self {
         Self {
-            syntect: SyntectConfig {
             load_defaults: false,
             themes_dir: Some("themes".into()),
             theme: Some("Catppuccin Mocha".into()),
-            },
         }
     }
 }
@@ -84,6 +90,15 @@ impl Default for PrecompressionConfig {
     }
 }
 
+impl Default for CacheConfig {
+    fn default() -> Self {
+        Self {
+            enable: true,
+            persistence: None,
+        }
+    }
+}
+
 pub async fn load() -> Result<Config> {
     let config_file = env::var(format!("{}_CONFIG", env!("CARGO_BIN_NAME")))
         .unwrap_or(String::from("config.toml"));

src/main.rs

@@ -189,7 +189,8 @@ async fn main() -> eyre::Result<()> {
         }
     }
 
-    let posts = if let Some(path) = config.cache_file.as_ref()
+    let posts = if config.cache.enable {
+        if let Some(path) = config.cache.persistence.as_ref()
             && tokio::fs::try_exists(&path)
                 .await
                 .with_context(|| format!("failed to check if {} exists", path.display()))?
@@ -221,6 +222,13 @@ async fn main() -> eyre::Result<()> {
                     PostManager::new(config.posts_dir.clone(), config.render.clone())
                 }
             }
+        } else {
+            PostManager::new_with_cache(
+                config.posts_dir.clone(),
+                config.render.clone(),
+                Default::default(),
+            )
+        }
     } else {
         PostManager::new(config.posts_dir.clone(), config.render.clone())
     };
@@ -321,8 +329,12 @@ async fn main() -> eyre::Result<()> {
             warn!("couldn't unwrap Arc over AppState, more than one strong reference exists for Arc. cloning instead");
             AppState::clone(state.as_ref())
         });
-        if let Some(path) = config.cache_file.as_ref() {
-            let cache = posts.into_cache();
+        if config.cache.enable
+            && let Some(path) = config.cache.persistence.as_ref()
+        {
+            let cache = posts
+                .into_cache()
+                .unwrap_or_else(|| unreachable!("cache should always exist in this state"));
             let mut serialized = bitcode::serialize(&cache).context("failed to serialize cache")?;
             let mut cache_file = tokio::fs::File::create(path)
                 .await

src/post/mod.rs

@@ -75,7 +75,7 @@ pub enum RenderStats {
 #[derive(Clone)]
 pub struct PostManager {
     dir: PathBuf,
-    cache: Cache,
+    cache: Option<Cache>,
     config: RenderConfig,
 }
 
@@ -83,13 +83,17 @@ impl PostManager {
     pub fn new(dir: PathBuf, config: RenderConfig) -> PostManager {
         PostManager {
             dir,
-            cache: Default::default(),
+            cache: None,
             config,
         }
     }
 
     pub fn new_with_cache(dir: PathBuf, config: RenderConfig, cache: Cache) -> PostManager {
-        PostManager { dir, cache, config }
+        PostManager {
+            dir,
+            cache: Some(cache),
+            config,
+        }
     }
 
     async fn parse_and_render(
@@ -125,7 +129,8 @@ impl PostManager {
         .render()?;
         let rendering = before_render.elapsed();
 
-        self.cache
+        if let Some(cache) = self.cache.as_ref() {
+            cache
                 .insert(
                     name.to_string(),
                     metadata.clone(),
@@ -137,7 +142,8 @@ impl PostManager {
                     &self.config,
                 )
                 .await
-            .unwrap_or_else(|err| warn!("failed to insert {:?} into cache", err.0));
+                .unwrap_or_else(|err| warn!("failed to insert {:?} into cache", err.0))
+        };
 
         Ok((metadata, post, (parsing, rendering)))
     }
@@ -166,7 +172,9 @@ impl PostManager {
                     .to_string_lossy()
                     .to_string();
 
-                if let Some(hit) = self.cache.lookup_metadata(&name, mtime).await {
+                if let Some(cache) = self.cache.as_ref()
+                    && let Some(hit) = cache.lookup_metadata(&name, mtime).await
+                {
                     posts.push(hit)
                 } else if let Ok((metadata, ..)) = self.parse_and_render(name, path).await {
                     posts.push(metadata);
@@ -194,7 +202,9 @@ impl PostManager {
             Ok(value) => value,
             Err(err) => match err.kind() {
                 io::ErrorKind::NotFound => {
-                    self.cache.remove(name).await;
+                    if let Some(cache) = self.cache.as_ref() {
+                        cache.remove(name).await;
+                    }
                     return Err(PostError::NotFound(name.to_string()));
                 }
                 _ => return Err(PostError::IoError(err)),
@@ -206,7 +216,9 @@ impl PostManager {
             .unwrap()
             .as_secs();
 
-        if let Some(hit) = self.cache.lookup(name, mtime, &self.config).await {
+        if let Some(cache) = self.cache.as_ref()
+            && let Some(hit) = cache.lookup(name, mtime, &self.config).await
+        {
             Ok((
                 hit.metadata,
                 hit.rendered,
@@ -222,7 +234,7 @@ impl PostManager {
         }
     }
 
-    pub fn into_cache(self) -> Cache {
+    pub fn into_cache(self) -> Option<Cache> {
         self.cache
     }
 }