Add source cache types

This adds a module for source cache handling.

Signed-off-by: Matthias Beyer <mail@beyermatthias.de>

1 files changed, 81 insertions, 0 deletions

diff --git a/src/source/mod.rs b/src/source/mod.rs
new file mode 100644
index 0000000..e88fd60
--- /dev/null
+++ b/src/source/mod.rs
@@ -0,0 +1,81 @@
+use std::path::PathBuf;
+
+use anyhow::Result;
+use anyhow::Error;
+
+use crate::package::Package;
+use crate::package::PackageName;
+use crate::package::PackageVersion;
+use crate::package::Source;
+
+pub struct SourceCache {
+    root: PathBuf,
+}
+
+impl SourceCache {
+    pub fn new(root: PathBuf) -> Self {
+        SourceCache { root }
+    }
+
+    pub fn source_for(&self, p: &Package) -> SourceEntry {
+        SourceEntry::for_package(self.root.clone(), p)
+    }
+}
+
+pub struct SourceEntry {
+    cache_root: PathBuf,
+    package_name: PackageName,
+    package_version: PackageVersion,
+    package_source: Source,
+    package_source_path: PathBuf,
+}
+
+impl SourceEntry {
+
+    fn for_package(cache_root: PathBuf, package: &Package) -> Self {
+        let package_source_path = cache_root.join(format!("{}-{}.source", package.name(), package.version()));
+
+        SourceEntry {
+            cache_root,
+            package_name: package.name().clone(),
+            package_version: package.version().clone(),
+            package_source: package.source().clone(),
+            package_source_path
+        }
+    }
+
+    pub fn exists(&self) -> bool {
+        self.package_source_path.exists()
+    }
+
+    pub fn path(&self) -> &PathBuf {
+        &self.package_source_path
+    }
+
+    pub async fn verify_hash(&self) -> Result<bool> {
+        use tokio::io::AsyncReadExt;
+
+        let mut buf = vec![];
+        tokio::fs::OpenOptions::new()
+            .create(false)
+            .create_new(false)
+            .read(true)
+            .open(&self.package_source_path)
+            .await?
+            .read_to_end(&mut buf)
+            .await?;
+
+        self.package_source.hash().matches_hash_of(&buf)
+    }
+
+    pub async fn open(&self) -> Result<tokio::fs::File> {
+        tokio::fs::OpenOptions::new()
+            .create(false)
+            .create_new(false)
+            .read(true)
+            .open(&self.package_source_path)
+            .await
+            .map_err(Error::from)
+    }
+
+}