From 65c9eed1c61bf121ff2f034aad3dc48a67a8454c Mon Sep 17 00:00:00 2001
From: Elliott Slaughter <slaughter@cs.stanford.edu>
Date: Thu, 19 Oct 2023 12:17:09 -0700
Subject: [PATCH 1/2] Add a FileDataSource that fetches archive files from
 local disk.

---
 src/file_data.rs | 68 ++++++++++++++++++++++++++++++++++++++++++++++++
 src/lib.rs       |  2 ++
 2 files changed, 70 insertions(+)
 create mode 100644 src/file_data.rs

diff --git a/src/file_data.rs b/src/file_data.rs
new file mode 100644
index 0000000..376c38b
--- /dev/null
+++ b/src/file_data.rs
@@ -0,0 +1,68 @@
+use std::fs::File;
+use std::path::{Path, PathBuf};
+
+use serde::Deserialize;
+
+use crate::data::{
+    DataSource, DataSourceInfo, EntryID, SlotMetaTile, SlotTile, SummaryTile, TileID,
+};
+use crate::http::schema::TileRequestRef;
+
+pub struct FileDataSource {
+    pub basedir: PathBuf,
+}
+
+impl FileDataSource {
+    pub fn new(basedir: impl AsRef<Path>) -> Self {
+        Self {
+            basedir: basedir.as_ref().to_owned(),
+        }
+    }
+
+    fn read_file<T>(&self, path: impl AsRef<Path>) -> T
+    where
+        T: for<'a> Deserialize<'a>,
+    {
+        let f = File::open(path).expect("opening file failed");
+        let f = zstd::Decoder::new(f).expect("zstd decompression failed");
+        let result = ciborium::from_reader(f).expect("cbor decoding failed");
+        result
+    }
+}
+
+impl DataSource for FileDataSource {
+    fn fetch_info(&self) -> DataSourceInfo {
+        let mut path = self.basedir.clone();
+        path.push("info");
+        self.read_file::<DataSourceInfo>(&path)
+    }
+
+    fn fetch_summary_tile(&self, entry_id: &EntryID, tile_id: TileID, _full: bool) -> SummaryTile {
+        let req = TileRequestRef { entry_id, tile_id };
+        let mut path = self.basedir.clone();
+        path.push("summary_tile");
+        path.push(&req.to_slug());
+        self.read_file::<SummaryTile>(&path)
+    }
+
+    fn fetch_slot_tile(&self, entry_id: &EntryID, tile_id: TileID, _full: bool) -> SlotTile {
+        let req = TileRequestRef { entry_id, tile_id };
+        let mut path = self.basedir.clone();
+        path.push("slot_tile");
+        path.push(&req.to_slug());
+        self.read_file::<SlotTile>(&path)
+    }
+
+    fn fetch_slot_meta_tile(
+        &self,
+        entry_id: &EntryID,
+        tile_id: TileID,
+        _full: bool,
+    ) -> SlotMetaTile {
+        let req = TileRequestRef { entry_id, tile_id };
+        let mut path = self.basedir.clone();
+        path.push("slot_meta_tile");
+        path.push(&req.to_slug());
+        self.read_file::<SlotMetaTile>(&path)
+    }
+}
diff --git a/src/lib.rs b/src/lib.rs
index f9fbec0..fb87ed2 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -5,6 +5,8 @@ pub mod app;
 pub mod archive_data;
 pub mod data;
 pub mod deferred_data;
+#[cfg(not(target_arch = "wasm32"))]
+pub mod file_data;
 pub mod http;
 #[cfg(not(target_arch = "wasm32"))]
 pub mod parallel_data;

From 3676bc9e9ee596cdaf2dca2fe5a5388d1ce11dd9 Mon Sep 17 00:00:00 2001
From: Elliott Slaughter <slaughter@cs.stanford.edu>
Date: Thu, 19 Oct 2023 13:54:51 -0700
Subject: [PATCH 2/2] Clean up.

---
 src/file_data.rs | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/src/file_data.rs b/src/file_data.rs
index 376c38b..af680b2 100644
--- a/src/file_data.rs
+++ b/src/file_data.rs
@@ -25,30 +25,26 @@ impl FileDataSource {
     {
         let f = File::open(path).expect("opening file failed");
         let f = zstd::Decoder::new(f).expect("zstd decompression failed");
-        let result = ciborium::from_reader(f).expect("cbor decoding failed");
-        result
+        ciborium::from_reader(f).expect("cbor decoding failed")
     }
 }
 
 impl DataSource for FileDataSource {
     fn fetch_info(&self) -> DataSourceInfo {
-        let mut path = self.basedir.clone();
-        path.push("info");
+        let path = self.basedir.join("info");
         self.read_file::<DataSourceInfo>(&path)
     }
 
     fn fetch_summary_tile(&self, entry_id: &EntryID, tile_id: TileID, _full: bool) -> SummaryTile {
         let req = TileRequestRef { entry_id, tile_id };
-        let mut path = self.basedir.clone();
-        path.push("summary_tile");
+        let mut path = self.basedir.join("summary_tile");
         path.push(&req.to_slug());
         self.read_file::<SummaryTile>(&path)
     }
 
     fn fetch_slot_tile(&self, entry_id: &EntryID, tile_id: TileID, _full: bool) -> SlotTile {
         let req = TileRequestRef { entry_id, tile_id };
-        let mut path = self.basedir.clone();
-        path.push("slot_tile");
+        let mut path = self.basedir.join("slot_tile");
         path.push(&req.to_slug());
         self.read_file::<SlotTile>(&path)
     }
@@ -60,8 +56,7 @@ impl DataSource for FileDataSource {
         _full: bool,
     ) -> SlotMetaTile {
         let req = TileRequestRef { entry_id, tile_id };
-        let mut path = self.basedir.clone();
-        path.push("slot_meta_tile");
+        let mut path = self.basedir.join("slot_meta_tile");
         path.push(&req.to_slug());
         self.read_file::<SlotMetaTile>(&path)
     }