Change input syntax and add cache storage handler

- input syntax changed to <subcommand> <options...>
- Added clear-cache subcommand
- CacheStorage now handles the caching of files

Signed-off-by: trivernis <trivernis@protonmail.com>

src/format/chromium_pdf/mod.rs

@@ -8,7 +8,7 @@ use crate::references::configuration::keys::{
     PDF_PAGE_SCALE, PDF_PAGE_WIDTH,
 };
 use crate::references::configuration::Configuration;
-use crate::utils::downloads::get_cached_path;
+use crate::utils::caching::CacheStorage;
 use headless_chrome::protocol::page::PrintToPdfOptions;
 use headless_chrome::{Browser, LaunchOptionsBuilder, Tab};
 use std::fs;
@@ -22,8 +22,9 @@ pub mod result;
 
 /// Renders the document to pdf and returns the resulting bytes
 pub fn render_to_pdf(document: Document) -> PdfRenderingResult<Vec<u8>> {
+    let cache = CacheStorage::new();
     let mut file_path = PathBuf::from(format!("tmp-document.html"));
-    file_path = get_cached_path(file_path).with_extension("html");
+    file_path = cache.get_file_path(&file_path);
     let mut mathjax = false;
 
     if let Some(entry) = document.config.get_entry(INCLUDE_MATHJAX) {

src/main.rs

@@ -6,16 +6,38 @@ use snekdown::elements::Document;
 use snekdown::format::html::html_writer::HTMLWriter;
 use snekdown::format::html::to_html::ToHtml;
 use snekdown::parser::ParserOptions;
+use snekdown::utils::caching::CacheStorage;
 use snekdown::Parser;
 use std::fs::{File, OpenOptions};
 use std::io::{BufWriter, Write};
 use std::path::PathBuf;
+use std::process::exit;
 use std::sync::mpsc::channel;
 use std::time::{Duration, Instant};
 use structopt::StructOpt;
 
 #[derive(StructOpt, Debug)]
 struct Opt {
+    #[structopt(subcommand)]
+    sub_command: SubCommand,
+}
+
+#[derive(StructOpt, Debug)]
+#[structopt()]
+enum SubCommand {
+    /// Watch the document and its imports and render on change.
+    Watch(RenderOptions),
+
+    /// Parse and render the document.
+    Render(RenderOptions),
+
+    /// Clears the cache directory
+    ClearCache,
+}
+
+#[derive(StructOpt, Debug)]
+#[structopt()]
+struct RenderOptions {
     /// Path to the input file
     #[structopt(parse(from_os_str))]
     input: PathBuf,
@@ -31,19 +53,6 @@ struct Opt {
     /// Don't use the cache
     #[structopt(long)]
     no_cache: bool,
-
-    #[structopt(subcommand)]
-    sub_command: Option<SubCommand>,
-}
-
-#[derive(StructOpt, Debug)]
-#[structopt()]
-enum SubCommand {
-    /// Watch the document and its imports and render on change.
-    Watch,
-
-    /// Default. Parse and render the document.
-    Render,
 }
 
 fn main() {
@@ -68,19 +77,16 @@ fn main() {
             )
         })
         .init();
-    if !opt.input.exists() {
-        log::error!(
-            "The input file {} could not be found",
-            opt.input.to_str().unwrap()
-        );
-        return;
-    }
 
     match &opt.sub_command {
-        Some(SubCommand::Render) | None => {
+        SubCommand::Render(opt) => {
             let _ = render(&opt);
         }
-        Some(SubCommand::Watch) => watch(&opt),
+        SubCommand::Watch(opt) => watch(&opt),
+        SubCommand::ClearCache => {
+            let cache = CacheStorage::new();
+            cache.clear().expect("Failed to clear cache");
+        }
     };
 }
 
@@ -95,7 +101,7 @@ fn get_level_style(level: Level) -> colored::Color {
 }
 
 /// Watches a file with all of its imports and renders on change
-fn watch(opt: &Opt) {
+fn watch(opt: &RenderOptions) {
     let parser = render(opt);
     let (tx, rx) = channel();
     let mut watcher = watcher(tx, Duration::from_millis(250)).unwrap();
@@ -112,7 +118,15 @@ fn watch(opt: &Opt) {
 }
 
 /// Renders the document to the output path
-fn render(opt: &Opt) -> Parser {
+fn render(opt: &RenderOptions) -> Parser {
+    if !opt.input.exists() {
+        log::error!(
+            "The input file {} could not be found",
+            opt.input.to_str().unwrap()
+        );
+
+        exit(1)
+    }
     let start = Instant::now();
 
     let mut parser = Parser::with_defaults(
@@ -142,7 +156,7 @@ fn render(opt: &Opt) -> Parser {
 }
 
 #[cfg(not(feature = "pdf"))]
-fn render_format(opt: &Opt, document: Document, writer: BufWriter<File>) {
+fn render_format(opt: &RenderOptions, document: Document, writer: BufWriter<File>) {
     match opt.format.as_str() {
         "html" => render_html(document, writer),
         _ => log::error!("Unknown format {}", opt.format),
@@ -150,7 +164,7 @@ fn render_format(opt: &Opt, document: Document, writer: BufWriter<File>) {
 }
 
 #[cfg(feature = "pdf")]
-fn render_format(opt: &Opt, document: Document, writer: BufWriter<File>) {
+fn render_format(opt: &RenderOptions, document: Document, writer: BufWriter<File>) {
     match opt.format.as_str() {
         "html" => render_html(document, writer),
         "pdf" => render_pdf(document, writer),

src/utils/caching.rs

@@ -0,0 +1,63 @@
+use platform_dirs::{AppDirs, AppUI};
+use std::collections::hash_map::DefaultHasher;
+use std::fs;
+use std::hash::{Hash, Hasher};
+use std::io;
+use std::path::PathBuf;
+
+#[derive(Clone, Debug)]
+pub struct CacheStorage {
+    location: PathBuf,
+}
+
+impl CacheStorage {
+    pub fn new() -> Self {
+        lazy_static::lazy_static! {
+            static ref APP_DIRS: AppDirs = AppDirs::new(Some("snekdown"), AppUI::CommandLine).unwrap();
+        }
+
+        Self {
+            location: APP_DIRS.cache_dir.clone(),
+        }
+    }
+
+    /// Returns the cache path for a given file
+    pub fn get_file_path(&self, path: &PathBuf) -> PathBuf {
+        let mut hasher = DefaultHasher::new();
+        path.hash(&mut hasher);
+        let mut file_name = PathBuf::from(format!("{:x}", hasher.finish()));
+
+        if let Some(extension) = path.extension() {
+            file_name.set_extension(extension);
+        }
+
+        return self.location.join(PathBuf::from(file_name));
+    }
+
+    /// Returns if the given file exists in the cache
+    pub fn has_file(&self, path: &PathBuf) -> bool {
+        let cache_path = self.get_file_path(path);
+
+        cache_path.exists()
+    }
+
+    /// Writes into the corresponding cache file
+    pub fn read(&self, path: &PathBuf) -> io::Result<Vec<u8>> {
+        let cache_path = self.get_file_path(path);
+
+        fs::read(cache_path)
+    }
+
+    /// Reads the corresponding cache file
+    pub fn write<R: AsRef<[u8]>>(&self, path: &PathBuf, contents: R) -> io::Result<()> {
+        let cache_path = self.get_file_path(path);
+
+        fs::write(cache_path, contents)
+    }
+
+    /// Clears the cache directory by deleting and recreating it
+    pub fn clear(&self) -> io::Result<()> {
+        fs::remove_dir_all(&self.location)?;
+        fs::create_dir(&self.location)
+    }
+}

src/utils/downloads.rs

@@ -1,10 +1,7 @@
+use crate::utils::caching::CacheStorage;
 use indicatif::{ProgressBar, ProgressStyle};
-use platform_dirs::{AppDirs, AppUI};
 use rayon::prelude::*;
-use std::collections::hash_map::DefaultHasher;
-use std::fs;
 use std::fs::read;
-use std::hash::{Hash, Hasher};
 use std::path::PathBuf;
 use std::sync::{Arc, Mutex};
 
@@ -60,6 +57,7 @@ pub struct PendingDownload {
     pub(crate) path: String,
     pub(crate) data: Option<Vec<u8>>,
     pub(crate) use_cache: bool,
+    cache: CacheStorage,
 }
 
 impl PendingDownload {
@@ -68,6 +66,7 @@ impl PendingDownload {
             path,
             data: None,
             use_cache: true,
+            cache: CacheStorage::new(),
         }
     }
 
@@ -98,22 +97,18 @@ impl PendingDownload {
     /// Stores the data to a cache file to retrieve it later
     fn store_to_cache(&self, data: &Vec<u8>) {
         if self.use_cache {
-            let cache_file = get_cached_path(PathBuf::from(&self.path));
-            log::debug!("Writing to cache {} -> {:?}", self.path, cache_file);
-            fs::write(&cache_file, data.clone()).unwrap_or_else(|_| {
-                log::warn!(
-                    "Failed to write file to cache: {} -> {:?}",
-                    self.path,
-                    cache_file
-                )
-            });
+            let path = PathBuf::from(&self.path);
+            self.cache
+                .write(&path, data.clone())
+                .unwrap_or_else(|_| log::warn!("Failed to write file to cache: {}", self.path));
         }
     }
 
     fn read_from_cache(&self) -> Option<Vec<u8>> {
-        let cache_path = get_cached_path(PathBuf::from(&self.path));
-        if cache_path.exists() && self.use_cache {
-            read(cache_path).ok()
+        let path = PathBuf::from(&self.path);
+
+        if self.cache.has_file(&path) && self.use_cache {
+            self.cache.read(&path).ok()
         } else {
             None
         }
@@ -128,19 +123,3 @@ impl PendingDownload {
             .map(|b| b.to_vec())
     }
 }
-
-pub fn get_cached_path(path: PathBuf) -> PathBuf {
-    lazy_static::lazy_static! {
-        static ref APP_DIRS: AppDirs = AppDirs::new(Some("snekdown"), AppUI::CommandLine).unwrap();
-    }
-    let mut hasher = DefaultHasher::new();
-    path.hash(&mut hasher);
-    let file_name = PathBuf::from(format!("{:x}", hasher.finish()));
-
-    if !APP_DIRS.cache_dir.is_dir() {
-        fs::create_dir(&APP_DIRS.cache_dir)
-            .unwrap_or_else(|_| log::warn!("Failed to create cache dir {:?}", APP_DIRS.cache_dir))
-    }
-
-    APP_DIRS.cache_dir.join(file_name)
-}

src/utils/mod.rs

@@ -1,3 +1,4 @@
+pub mod caching;
 pub mod downloads;
 pub mod macros;
 pub mod parsing;