add rusqlite

display thread should be dedicated to not steal resources from tokio

Cargo.lock

@@ -17,6 +17,18 @@ version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f26201604c87b1e01bd3d98f8d5d9a8fcbb815e8cedb41ffccbeb4bf593a35fe"
 
+[[package]]
+name = "ahash"
+version = "0.8.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e89da841a80418a9b391ebaea17f5c112ffaaa96f621d2c285b5174da76b9011"
+dependencies = [
+ "cfg-if",
+ "once_cell",
+ "version_check",
+ "zerocopy",
+]
+
 [[package]]
 name = "aho-corasick"
 version = "1.1.3"
@@ -587,6 +599,18 @@ dependencies = [
  "zune-inflate",
 ]
 
+[[package]]
+name = "fallible-iterator"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2acce4a10f12dc2fb14a218589d4f1f62ef011b2d0cc4b3cb1bba8e94da14649"
+
+[[package]]
+name = "fallible-streaming-iterator"
+version = "0.1.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7360491ce676a36bf9bb3c56c1aa791658183a54d2744120f27285738d90465a"
+
 [[package]]
 name = "fast-srgb8"
 version = "1.0.0"
@@ -722,6 +746,18 @@ name = "hashbrown"
 version = "0.14.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e5274423e17b7c9fc20b6e7e208532f9b19825d82dfd615708b70edd83df41f1"
+dependencies = [
+ "ahash",
+]
+
+[[package]]
+name = "hashlink"
+version = "0.9.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6ba4ff7128dee98c7dc9794b6a411377e1404dba1c97deb8d1a55297bd25d8af"
+dependencies = [
+ "hashbrown",
+]
 
 [[package]]
 name = "heck"
@@ -997,6 +1033,17 @@ dependencies = [
  "once_cell",
 ]
 
+[[package]]
+name = "libsqlite3-sys"
+version = "0.30.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2e99fb7a497b1e3339bc746195567ed8d3e24945ecd636e3619d20b9de9e9149"
+dependencies = [
+ "cc",
+ "pkg-config",
+ "vcpkg",
+]
+
 [[package]]
 name = "linux-embedded-hal"
 version = "0.4.0"
@@ -1416,6 +1463,7 @@ dependencies = [
  "mime",
  "minijinja",
  "palette",
+ "rusqlite",
  "serde",
  "strum",
  "thiserror",
@@ -1709,6 +1757,20 @@ dependencies = [
  "bytemuck",
 ]
 
+[[package]]
+name = "rusqlite"
+version = "0.32.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7753b721174eb8ff87a9a0e799e2d7bc3749323e773db92e0984debb00019d6e"
+dependencies = [
+ "bitflags 2.6.0",
+ "fallible-iterator",
+ "fallible-streaming-iterator",
+ "hashlink",
+ "libsqlite3-sys",
+ "smallvec",
+]
+
 [[package]]
 name = "rustc-demangle"
 version = "0.1.24"
@@ -2231,6 +2293,12 @@ version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "830b7e5d4d90034032940e4ace0d9a9a057e7a45cd94e6c007832e39edb82f6d"
 
+[[package]]
+name = "vcpkg"
+version = "0.2.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "accd4ea62f7bb7a82fe23066fb0957d48ef677f6eeb8215f372f52e48bb32426"
+
 [[package]]
 name = "version-compare"
 version = "0.2.0"
@@ -2442,6 +2510,26 @@ dependencies = [
  "memchr",
 ]
 
+[[package]]
+name = "zerocopy"
+version = "0.7.35"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1b9b4fd18abc82b8136838da5d50bae7bdea537c574d8dc1a34ed098d6c166f0"
+dependencies = [
+ "zerocopy-derive",
+]
+
+[[package]]
+name = "zerocopy-derive"
+version = "0.7.35"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fa4f8080344d4671fb4e831a13ad1e68092748387dfc4f55e356242fae12ce3e"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "zune-core"
 version = "0.4.12"

Cargo.toml

@@ -16,6 +16,7 @@ linux-embedded-hal = { version = "0.4.0"}
 mime = "0.3.17"
 minijinja = "2.1.0"
 palette = "0.7.6"
+rusqlite = { version = "0.32.1", features = ["bundled"] }
 serde = { version = "1.0.204", features = ["derive"] }
 strum = { version = "0.26.3", features = ["derive"] }
 thiserror = "1.0.63"

src/api.rs

@@ -1,4 +1,4 @@
-use crate::display::EInkPanel;
+use crate::display::{create_display_thread, EInkPanel};
 use crate::dither::{DitherMethod, DitheredImage};
 use crate::eink::Palette;
 use axum::async_trait;
@@ -10,10 +10,10 @@ use image::{ImageReader, RgbImage};
 use std::io::Cursor;
 use std::str;
 use std::str::FromStr;
+use std::sync::mpsc;
 use std::sync::Arc;
+use std::thread::JoinHandle;
 use std::time::Duration;
-use tokio::sync::mpsc::{self, Receiver, Sender};
-use tokio::task::JoinHandle;
 use tracing::{error, info, instrument};
 
 #[derive(thiserror::Error, Debug)]
@@ -24,18 +24,17 @@ pub enum ApiError {
 
 #[derive(Clone)]
 pub struct AppState {
-    display_channel: Sender<DisplaySetCommand>,
+    display_channel: mpsc::Sender<Box<DitheredImage>>,
     display_task: Arc<JoinHandle<()>>,
 }
 
 impl AppState {
     #[must_use]
     pub fn new(disp: Box<dyn EInkPanel + Send>) -> Self {
-        let (tx, rx) = mpsc::channel(2);
+        let (handle, tx) = create_display_thread(disp);
-        let task = tokio::spawn(display_task(rx, disp));
         Self {
             display_channel: tx,
-            display_task: Arc::new(task),
+            display_task: Arc::new(handle),
         }
     }
 }
@@ -65,25 +64,6 @@ where
     }
 }
 
-#[derive(Debug)]
-pub struct DisplaySetCommand {
-    img: Box<DitheredImage>,
-}
-
-#[instrument(skip_all)]
-pub async fn display_task(
-    mut rx: Receiver<DisplaySetCommand>,
-    mut display: Box<dyn EInkPanel + Send>,
-) {
-    while let Some(cmd) = rx.recv().await {
-        info!("Got a display set command");
-        if let Err(e) = display.display(&cmd.img) {
-            error!("Error displaying command {e}");
-        }
-        info!("Done setting display");
-    }
-}
-
 /// API routes for axum
 /// Start with the basics: Send an image, crop it, dither, and upload.
 /// we defer the upload to a separate task.
@@ -163,10 +143,7 @@ async fn set_image(
         let mut dither = img_req.dither_method.get_ditherer();
         dither.dither(&img_req.image, &mut buf);
     }
-    let cmd = DisplaySetCommand { img: Box::new(buf) };
+    ctx.display_channel.send(Box::new(buf))?;
-    ctx.display_channel
-        .send_timeout(cmd, Duration::from_secs(10))
-        .await?;
     Ok(StatusCode::OK)
 }
 

src/display.rs

@@ -1,14 +1,16 @@
+// Manages display hardware
+use crate::dither::DitheredImage;
+use anyhow::Result;
 use epd_waveshare::{epd7in3f::Epd7in3f, prelude::WaveshareDisplay};
+use linux_embedded_hal::gpio_cdev::{Chip, LineRequestFlags};
 use linux_embedded_hal::spidev::SpiModeFlags;
 use linux_embedded_hal::spidev::SpidevOptions;
 use linux_embedded_hal::{CdevPin, Delay, SpidevDevice};
+use std::sync::mpsc;
+use std::thread;
 use tracing::instrument;
-use tracing::{debug, warn};
+use tracing::span;
-
+use tracing::{debug, error, info, warn, Level};
-use anyhow::Result;
-use linux_embedded_hal::gpio_cdev::{Chip, LineRequestFlags};
-
-use crate::dither::DitheredImage;
 
 pub trait EInkPanel {
     fn display(&mut self, buf: &DitheredImage) -> Result<()>;
@@ -88,3 +90,34 @@ impl EInkPanel for FakeEInk {
         Ok(())
     }
 }
+
+/// Create a thread that can take dithered images and display them. This allows the display to be
+/// used in an async context since updating the display can take ~30 seconds.
+#[must_use]
+pub fn create_display_thread(
+    mut display: Box<dyn EInkPanel + Send>,
+) -> (thread::JoinHandle<()>, mpsc::Sender<Box<DitheredImage>>) {
+    let (tx, rx) = mpsc::channel::<Box<DitheredImage>>();
+    let handle = thread::spawn(move || {
+        let span = span!(Level::INFO, "display_thread");
+        let _enter = span.enter();
+        loop {
+            let res = rx.recv();
+            match res {
+                Ok(img) => {
+                    info!("Received an image to display");
+                    if let Err(e) = display.display(&img) {
+                        error!("Error displaying image: {e}");
+                        return;
+                    }
+                    info!("Successfully set display image");
+                }
+                Err(e) => {
+                    error!("Error reading image from channel: {e}");
+                    return;
+                }
+            }
+        }
+    });
+    (handle, tx)
+}

src/main.rs

@@ -1,7 +1,6 @@
 pub mod api;
 pub mod display;
 pub mod dither;
-pub mod errors;
 pub mod eink;
 
 use std::path::PathBuf;
@@ -18,8 +17,10 @@ use tracing::{error, info};
 
 
 /// Application config, including sqlite db path, scan folders, and scheduling.
-#[derive(Deserialize)]
+#[derive(Deserialize, Debug)]
 struct Config {
+    database_path: PathBuf,
+    search_paths: Vec<PathBuf>,
     
 }