From 893b784fced0ce16c1c4808f0565bdf5342d080f Mon Sep 17 00:00:00 2001
From: Lee Smet <lee.smet@hotmail.com>
Date: Tue, 22 Dec 2020 10:43:40 +0100
Subject: [PATCH] Close #11: Add cmd to verify file existence

Signed-off-by: Lee Smet <lee.smet@hotmail.com>
---
 src/etcd.rs      | 17 +++++++++--------
 src/main.rs      | 43 +++++++++++++++++++++++++++++++++++++++++--
 src/test_etcd.rs |  2 +-
 3 files changed, 51 insertions(+), 11 deletions(-)

diff --git a/src/etcd.rs b/src/etcd.rs
index 55eeda5..e3980be 100644
--- a/src/etcd.rs
+++ b/src/etcd.rs
@@ -64,15 +64,16 @@ impl Etcd {
     }
 
     /// loads the metadata for a given path and prefix
-    pub async fn load_meta(&self, path: &PathBuf) -> Result<MetaData, String> {
+    pub async fn load_meta(&self, path: &PathBuf) -> Result<Option<MetaData>, String> {
         let key = self.build_key(path)?;
-        Ok(toml::from_slice(
-            &self
-                .read_value(&key)
-                .await?
-                .ok_or("no meta found for path".to_string())?,
-        )
-        .map_err(|e| e.to_string())?)
+        Ok(if let Some(value) = self.read_value(&key).await? {
+            Some(
+                toml::from_slice(&value)
+                    .map_err(|e| format!("could not decode metadata: {}", e))?,
+            )
+        } else {
+            None
+        })
     }
 
     // helper functions to read and write a value
diff --git a/src/main.rs b/src/main.rs
index 051a111..253cbd0 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -78,6 +78,17 @@ enum Cmd {
         #[structopt(name = "file", long, short, parse(from_os_str))]
         file: std::path::PathBuf,
     },
+    /// Check if a file exists in the backend
+    ///
+    /// Checks if a valid metadata entry is available for the path. If it is, the hex of the file
+    /// checksum is printed, as well as the resolved path
+    Check {
+        /// Path of the file to check.
+        ///
+        /// The original path which was used to store the file.
+        #[structopt(name = "file", long, short, parse(from_os_str))]
+        file: std::path::PathBuf,
+    },
 }
 
 fn main() -> Result<(), String> {
@@ -148,7 +159,11 @@ fn main() -> Result<(), String> {
                 cluster.save_meta(&file, &metadata).compat().await?;
             }
             Cmd::Retrieve { ref file } => {
-                let metadata = cluster.load_meta(file).compat().await?;
+                let metadata = cluster
+                    .load_meta(file)
+                    .compat()
+                    .await?
+                    .ok_or("no metadata found for file")?;
                 let decoded = recover_data(&metadata).await?;
 
                 let encryptor = AESGCM::new(metadata.encryption().key().clone());
@@ -169,12 +184,36 @@ fn main() -> Result<(), String> {
                 out.write_all(&original).map_err(|e| e.to_string())?;
             }
             Cmd::Rebuild { ref file } => {
-                let metadata = cluster.load_meta(file).compat().await?;
+                let metadata = cluster
+                    .load_meta(file)
+                    .compat()
+                    .await?
+                    .ok_or("no metadata found for file")?;
                 let decoded = recover_data(&metadata).await?;
 
                 let metadata = store_data(decoded, metadata.checksum().clone(), &cfg).await?;
                 cluster.save_meta(&file, &metadata).compat().await?;
             }
+            Cmd::Check { ref file } => {
+                match cluster.load_meta(file).compat().await? {
+                    Some(metadata) => {
+                        let file = canonicalize_path(&file)?;
+                        // strip the virtual_root, if one is set
+                        let actual_path = if let Some(ref virtual_root) = cfg.virtual_root() {
+                            file.strip_prefix(virtual_root)
+                                .map_err(|e| format!("could not strip path prefix: {}", e))?
+                        } else {
+                            file.as_path()
+                        };
+                        println!(
+                            "{}\t{}",
+                            hex::encode(metadata.checksum()),
+                            actual_path.to_string_lossy()
+                        );
+                    }
+                    None => std::process::exit(1),
+                };
+            }
         };
 
         Ok(())
diff --git a/src/test_etcd.rs b/src/test_etcd.rs
index 04204d9..329c36a 100644
--- a/src/test_etcd.rs
+++ b/src/test_etcd.rs
@@ -59,7 +59,7 @@ fn main() {
         let rec = cluster.load_meta(&path).compat().await.unwrap();
 
         log::info!("comparing data");
-        assert_eq!(&rec, &data);
+        assert_eq!(&rec.unwrap(), &data);
         log::info!("compared data");
     });
 }