refactor cache

Signed-off-by: Frank Villaro-Dixon <frank@villaro-dixon.eu>

Cargo.lock

@@ -37,6 +37,8 @@ dependencies = [
  "serde",
  "serde_json",
  "tokio",
+ "tower",
+ "tower-http",
  "tracing",
  "tracing-subscriber",
 ]
@@ -385,6 +387,12 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "futures-sink"
+version = "0.3.30"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9fb8e00e87438d937621c1c6269e53f536c14d3fbd6a042bb24879e57d474fb5"
+
 [[package]]
 name = "futures-task"
 version = "0.3.30"
@@ -522,6 +530,12 @@ dependencies = [
  "pin-project-lite",
 ]
 
+[[package]]
+name = "http-range-header"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3ce4ef31cda248bbdb6e6820603b82dfcd9e833db65a43e997a0ccec777d11fe"
+
 [[package]]
 name = "httparse"
 version = "1.8.0"
@@ -658,6 +672,16 @@ version = "0.3.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6877bb514081ee2a7ff5ef9de3281f14a4dd4bceac4c09388074a6b5df8a139a"
 
+[[package]]
+name = "mime_guess"
+version = "2.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4192263c238a5f0d0c6bfd21f336a313a4ce1c450542449ca191bb657b4642ef"
+dependencies = [
+ "mime",
+ "unicase",
+]
+
 [[package]]
 name = "minimal-lexical"
 version = "0.2.1"
@@ -1231,6 +1255,19 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "tokio-util"
+version = "0.7.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5419f34732d9eb6ee4c3578b7989078579b7f039cbbb9ca2c4da015749371e15"
+dependencies = [
+ "bytes",
+ "futures-core",
+ "futures-sink",
+ "pin-project-lite",
+ "tokio",
+]
+
 [[package]]
 name = "tower"
 version = "0.4.13"
@@ -1247,6 +1284,31 @@ dependencies = [
  "tracing",
 ]
 
+[[package]]
+name = "tower-http"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e9cd434a998747dd2c4276bc96ee2e0c7a2eadf3cae88e52be55a05fa9053f5"
+dependencies = [
+ "bitflags 2.5.0",
+ "bytes",
+ "futures-util",
+ "http",
+ "http-body",
+ "http-body-util",
+ "http-range-header",
+ "httpdate",
+ "mime",
+ "mime_guess",
+ "percent-encoding",
+ "pin-project-lite",
+ "tokio",
+ "tokio-util",
+ "tower-layer",
+ "tower-service",
+ "tracing",
+]
+
 [[package]]
 name = "tower-layer"
 version = "0.3.2"

Cargo.toml

@@ -14,5 +14,7 @@ moka = { version = "0.12.5", features = ["future"] }
 serde = { version = "1.0.197", features = ["derive"] }
 serde_json = "1.0.115"
 tokio = { version = "1.37.0", features = ["full"] }
+tower = "0.4.13"
+tower-http = { version = "0.5.2", features = ["fs"]}
 tracing = "0.1.40"
 tracing-subscriber = "0.3.18"

Dockerfile

@@ -17,7 +17,7 @@ RUN cargo build --release --bin api-server
 
 # We do not need the Rust toolchain to run the binary!
 FROM debian:bookworm-slim AS runtime
-RUN apt update && apt install -y libgdal-dev
+RUN apt update && apt install -y gdal-bin
 WORKDIR /app
 COPY --from=builder /app/target/release/api-server /usr/local/bin
 ENTRYPOINT ["/usr/local/bin/api-server"]

src/dem.rs

@@ -1,50 +1,83 @@
 use std::sync::Arc;
-use std::env;
 
 use gdal::errors::GdalError;
 use gdal::Dataset;
 
-use tracing::{info, debug_span, debug};
+use tracing::{debug, debug_span, info};
 
 use moka::future::Cache;
 
-pub struct MyDataset{pub ds: Dataset}
+pub struct MyDataset {
+    pub ds: Dataset,
+}
 unsafe impl Send for MyDataset {}
 unsafe impl Sync for MyDataset {}
 
-pub type DSC = Cache<String, Arc<MyDataset>>;
+pub struct DatasetRepository {
-pub fn new_cache(max_elems: u64) -> DSC {
+    cache: Cache<String, Arc<MyDataset>>,
-    Cache::builder()
+    basedir: String,
-        // Up to 10,000 entries.
-        .max_capacity(max_elems)
-        // Create the cache.
-        .build()
 }
 
-pub async fn elevation_from_coordinates(dsc: DSC, lat: f64, lon: f64) -> f64 {
+unsafe impl Send for DatasetRepository {}
+unsafe impl Sync for DatasetRepository {}
+impl DatasetRepository {
+    pub fn new(basedir: String) -> Self {
+        let c = Cache::builder()
+            .max_capacity(100)
+            // Create the cache.
+            .build();
+
+        DatasetRepository { cache: c, basedir }
+    }
+
+    async fn get(&self, filename: String) -> Arc<MyDataset> {
+        let full_filename = format!("{}/{filename}", self.basedir);
+
+        if !self.cache.contains_key(&full_filename) {
+            info!("Will open {full_filename} because not in cache!");
+            let ds = Arc::new(MyDataset {
+                ds: Dataset::open(full_filename.clone()).unwrap(),
+            });
+            self.cache.insert(full_filename.clone(), ds).await;
+        }
+
+        match self.cache.get(&full_filename).await {
+            Some(dataset_arc) => dataset_arc,
+            None => panic!("foo")
+        }
+
+    }
+
+}
+
+impl Clone for DatasetRepository {
+    fn clone(&self) -> Self {
+        Self {
+            basedir: self.basedir.clone(),
+            cache: self.cache.clone(),
+        }
+    }
+}
+
+
+pub async fn elevation_from_coordinates(dr: DatasetRepository, lat: f64, lon: f64) -> f64 {
     let span = debug_span!("req", lat=%lat, lon=%lon);
     let _guard = span.enter();
 
     let filename = get_filename_from_latlon(lat, lon);
     debug!(filename, "filename");
 
-
+    let ds = &dr.get(filename).await.ds;
-    if !dsc.contains_key(&filename) {
-        info!("Will open {filename} because not in cache!");
-        let ds = Arc::new(MyDataset{ds:Dataset::open(filename.clone()).unwrap()});
-        dsc.insert(filename.clone(), ds).await;
-    }
-
-    let ds = &dsc.get(&filename).await.unwrap().ds;
 
     let (px, py) = geo_to_pixel(ds, lat, lon).unwrap();
 
     let raster_band = ds.rasterband(1).unwrap();
-    let raster_value = raster_band.read_as::<f64>((px, py), (1, 1), (1, 1), None).unwrap();
+    let raster_value = raster_band
+        .read_as::<f64>((px, py), (1, 1), (1, 1), None)
+        .unwrap();
     raster_value.data[0]
 }
 
-
 fn get_filename_from_latlon(lat: f64, lon: f64) -> String {
     // Calculate the rounded values for latitude and longitude
     let rounded_lat = lat.floor();
@@ -58,16 +91,13 @@ fn get_filename_from_latlon(lat: f64, lon: f64) -> String {
     let lat_prefix = if rounded_lat >= 0.0 { "N" } else { "S" };
     let lon_prefix = if rounded_lon >= 0.0 { "E" } else { "W" };
 
-
-    let filename_prefix = env::var("DEM_LOCATION").unwrap_or("/data".to_string());
     // Construct the filename
     let filename = format!(
-        "{filename_prefix}/Copernicus_DSM_30_{}{}_00_{}{}_00_DEM.tif",
+        "Copernicus_DSM_30_{}{}_00_{}{}_00_DEM.tif",
         lat_prefix, lat_deg, lon_prefix, lon_deg
     );
 
     filename
-
 }
 
 fn geo_to_pixel(dataset: &Dataset, lat: f64, lon: f64) -> Result<(isize, isize), GdalError> {

src/main.rs

@@ -1,47 +1,64 @@
-
 mod dem;
 
-
-use std::env;
-use axum_macros::debug_handler;
 use axum::{
-    extract::{Path, State}, routing::{get}, Router
+    extract::{Path, State},
+    routing::get,
+    Router,
 };
-use dem::{DSC, new_cache};
+use axum_macros::debug_handler;
+use std::env;
+
+use tower_http::services::ServeDir;
+
+use dem::DatasetRepository;
 
 use tracing::info;
 
 
+const DEFAULT_DATA_DIR: &str = "/data";
+const DEFAULT_PORT: &str = "3000";
 
-#[tokio::main(flavor = "current_thread")]
+//#[tokio::main(flavor = "current_thread")]
+#[tokio::main]
 async fn main() {
     // initialize tracing
     tracing_subscriber::fmt::init();
 
 
-    let cache = new_cache(1000);
+    let config = load_config().unwrap();
+    let cache = DatasetRepository::new(config.basedir);
+
+    let serve_dir = ServeDir::new("assets");
 
     // build our application with a route
     let app = Router::new()
         .route("/elevation/:lat/:lon", get(get_elevation))
+        .nest_service("/", serve_dir)
         .with_state(cache);
 
-
+    let host = format!("[::]:{}", config.port);
-    let port = env::var("HTTP_PORT").unwrap_or("3000".to_string());
-    let host = format!("[::]:{port}");
     info!("Will start server on {host}");
 
-
     let listener = tokio::net::TcpListener::bind(host).await.unwrap();
     axum::serve(listener, app).await.unwrap();
 }
 
-
 #[debug_handler]
-async fn get_elevation(State(shared): State<DSC>, Path((lat, lon)): Path<(f64, f64)>) -> String{
+async fn get_elevation(State(dsr): State<DatasetRepository>, Path((lat, lon)): Path<(f64, f64)>) -> String {
-
+    let ele = dem::elevation_from_coordinates(dsr, lat, lon);
-    let ele = dem::elevation_from_coordinates(shared, lat, lon);
     let myele = ele.await;
     format!("{myele}")
 }
 
+
+fn load_config() -> Result<Config, env::VarError> {
+    Ok(Config {
+        basedir: env::var("DEM_LOCATION").unwrap_or_else(|_| DEFAULT_DATA_DIR.to_string()),
+        port: env::var("HTTP_PORT").unwrap_or_else(|_| DEFAULT_PORT.to_string()),
+    })
+}
+
+struct Config {
+    basedir: String,
+    port: String,
+}