fix(decrypt): prevent extra clones while decrypting chunks

src/decrypt.rs

@@ -14,7 +14,7 @@ use std::io::Cursor;
 use std::sync::Arc;
 use xor_name::XorName;
 
-pub fn decrypt(src_hashes: Vec<XorName>, encrypted_chunks: Vec<EncryptedChunk>) -> Result<Bytes> {
+pub fn decrypt(src_hashes: Vec<XorName>, encrypted_chunks: &[&EncryptedChunk]) -> Result<Bytes> {
     let src_hashes = Arc::new(src_hashes);
     let num_chunks = encrypted_chunks.len();
     let cpus = num_cpus::get();

src/lib.rs

@@ -426,12 +426,9 @@ pub fn encrypt(bytes: Bytes) -> Result<(DataMap, Vec<EncryptedChunk>)> {
 /// Decrypts what is expected to be the full set of chunks covered by the data map.
 pub fn decrypt_full_set(data_map: &DataMap, chunks: &[EncryptedChunk]) -> Result<Bytes> {
     let src_hashes = extract_hashes(data_map);
-    let sorted_chunks = chunks
-        .iter()
-        .sorted_by_key(|c| c.index)
-        .cloned() // should not be needed, something is wrong here, the docs for sorted_by_key says it will return owned items...!
-        .collect_vec();
-    decrypt::decrypt(src_hashes, sorted_chunks)
+    let mut sorted_chunks = Vec::with_capacity(chunks.len());
+    sorted_chunks.extend(chunks.iter().sorted_by_key(|c| c.index));
+    decrypt::decrypt(src_hashes, &sorted_chunks)
 }
 
 /// Decrypts a range, used when seeking.
@@ -444,12 +441,10 @@ pub fn decrypt_range(
     len: usize,
 ) -> Result<Bytes> {
     let src_hashes = extract_hashes(data_map);
-    let encrypted_chunks = chunks
-        .iter()
-        .sorted_by_key(|c| c.index)
-        .cloned()
-        .collect_vec();
-    let mut bytes = decrypt::decrypt(src_hashes, encrypted_chunks)?;
+    let mut sorted_chunks = Vec::with_capacity(chunks.len());
+    sorted_chunks.extend(chunks.iter().sorted_by_key(|c| c.index));
+
+    let mut bytes = decrypt::decrypt(src_hashes, &sorted_chunks)?;
 
     if relative_pos >= bytes.len() {
         return Ok(Bytes::new());