From 9ac6ec868aaa4412a01ae4b70bf3b2c6d67276e2 Mon Sep 17 00:00:00 2001
From: Wolfgang Bumiller <w.bumiller@proxmox.com>
Date: Fri, 22 Feb 2019 10:35:40 +0100
Subject: [PATCH] backup/chunk_store: split insert_chunk

The protocol handler will receive chunk data plus a hash
pre-calculated by the client. It will verify the hash before
sending it up to the datastore in order to respond to the
client with an error on a mismatch, so there's no need to
recalculate the hash another time.

Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
---
 src/backup/chunk_store.rs | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/src/backup/chunk_store.rs b/src/backup/chunk_store.rs
index 9a95e8ca..b5c32903 100644
--- a/src/backup/chunk_store.rs
+++ b/src/backup/chunk_store.rs
@@ -298,24 +298,30 @@ impl ChunkStore {
     pub fn insert_chunk(&self, chunk: &[u8]) -> Result<(bool, [u8; 32], u64), Error> {
 
         // fixme: use Sha512/256 when available
-        let mut hasher = sha::Sha256::new();
-        hasher.update(chunk);
+        let digest = sha::sha256(chunk);
+        let (new, csize) = self.insert_chunk_noverify(&digest, chunk)?;
+        Ok((new, digest, csize))
+    }
 
-        let digest = hasher.finish();
+    pub fn insert_chunk_noverify(
+        &self,
+        digest: &[u8; 32],
+        chunk: &[u8],
+    ) -> Result<(bool, u64), Error> {
 
         //println!("DIGEST {}", tools::digest_to_hex(&digest));
 
         let mut chunk_path = self.chunk_dir.clone();
-        let prefix = digest_to_prefix(&digest);
+        let prefix = digest_to_prefix(digest);
         chunk_path.push(&prefix);
-        let digest_str = tools::digest_to_hex(&digest);
+        let digest_str = tools::digest_to_hex(digest);
         chunk_path.push(&digest_str);
 
         let lock = self.mutex.lock();
 
         if let Ok(metadata) = std::fs::metadata(&chunk_path) {
             if metadata.is_file() {
-                return Ok((true, digest, metadata.len()));
+                return Ok((true, metadata.len()));
             } else {
                 bail!("Got unexpected file type on store '{}' for chunk {}", self.name, digest_str);
             }
@@ -351,7 +357,7 @@ impl ChunkStore {
 
         drop(lock);
 
-        Ok((false, digest, compressed_size))
+        Ok((false, compressed_size))
     }
 
     pub fn relative_path(&self, path: &Path) -> PathBuf {