hypha: move components into separate crates

controller/src/image/cache.rs

@@ -0,0 +1,69 @@
+use crate::image::{ImageInfo, Result};
+use log::debug;
+use oci_spec::image::{ImageConfiguration, ImageManifest};
+use std::fs;
+use std::path::{Path, PathBuf};
+
+pub struct ImageCache {
+    cache_dir: PathBuf,
+}
+
+impl ImageCache {
+    pub fn new(cache_dir: &Path) -> Result<ImageCache> {
+        Ok(ImageCache {
+            cache_dir: cache_dir.to_path_buf(),
+        })
+    }
+
+    pub fn recall(&self, digest: &str) -> Result<Option<ImageInfo>> {
+        let mut squashfs_path = self.cache_dir.clone();
+        let mut config_path = self.cache_dir.clone();
+        let mut manifest_path = self.cache_dir.clone();
+        squashfs_path.push(format!("{}.squashfs", digest));
+        manifest_path.push(format!("{}.manifest.json", digest));
+        config_path.push(format!("{}.config.json", digest));
+        Ok(
+            if squashfs_path.exists() && manifest_path.exists() && config_path.exists() {
+                let squashfs_metadata = fs::metadata(&squashfs_path)?;
+                let manifest_metadata = fs::metadata(&manifest_path)?;
+                let config_metadata = fs::metadata(&config_path)?;
+                if squashfs_metadata.is_file()
+                    && manifest_metadata.is_file()
+                    && config_metadata.is_file()
+                {
+                    let manifest_text = fs::read_to_string(&manifest_path)?;
+                    let manifest: ImageManifest = serde_json::from_str(&manifest_text)?;
+                    let config_text = fs::read_to_string(&config_path)?;
+                    let config: ImageConfiguration = serde_json::from_str(&config_text)?;
+                    debug!("cache hit digest={}", digest);
+                    Some(ImageInfo::new(squashfs_path.clone(), manifest, config)?)
+                } else {
+                    None
+                }
+            } else {
+                debug!("cache miss digest={}", digest);
+                None
+            },
+        )
+    }
+
+    pub fn store(&self, digest: &str, info: &ImageInfo) -> Result<ImageInfo> {
+        debug!("cache store digest={}", digest);
+        let mut squashfs_path = self.cache_dir.clone();
+        let mut manifest_path = self.cache_dir.clone();
+        let mut config_path = self.cache_dir.clone();
+        squashfs_path.push(format!("{}.squashfs", digest));
+        manifest_path.push(format!("{}.manifest.json", digest));
+        config_path.push(format!("{}.config.json", digest));
+        fs::copy(&info.image_squashfs, &squashfs_path)?;
+        let manifest_text = serde_json::to_string_pretty(&info.manifest)?;
+        fs::write(&manifest_path, manifest_text)?;
+        let config_text = serde_json::to_string_pretty(&info.config)?;
+        fs::write(&config_path, config_text)?;
+        ImageInfo::new(
+            squashfs_path.clone(),
+            info.manifest.clone(),
+            info.config.clone(),
+        )
+    }
+}