fix(decrypt): prevent extra clones while decrypting chunks

maidsafe · Dec 18, 2023 · a557f96 · a557f96
1 parent 377c072
commit a557f96
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Showing 2 changed files with 10 additions and 36 deletions.
diff --git a/src/decrypt.rs b/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();
@@ -23,30 +23,19 @@ pub fn decrypt(src_hashes: Vec<XorName>, encrypted_chunks: Vec<EncryptedChunk>)
     let raw_chunks: Vec<(usize, Bytes)> = encrypted_chunks
         .chunks(batch_size)
         .par_bridge()
-        .map(|batch| DecryptionBatch {
-            jobs: batch
-                .iter()
-                .map(|c| DecryptionJob {
-                    index: c.index,
-                    encrypted_content: c.content.clone(),
-                    src_hashes: src_hashes.clone(),
-                })
-                .collect_vec(),
-        })
         .map(|batch| {
             batch
-                .jobs
                 .par_iter()
                 .map(|c| {
                     Ok::<(usize, Bytes), Error>((
                         c.index,
-                        decrypt_chunk(c.index, c.encrypted_content.clone(), c.src_hashes.as_ref())?,
+                        decrypt_chunk(c.index, c.content.clone(), src_hashes.as_ref())?,
                     ))
                 })
+                .flatten()
                 .collect::<Vec<_>>()
         })
         .flatten()
-        .flatten()
         .collect();
 
     if num_chunks > raw_chunks.len() {
@@ -66,16 +55,6 @@ pub fn decrypt(src_hashes: Vec<XorName>, encrypted_chunks: Vec<EncryptedChunk>)
     Ok(raw_data)
 }
 
-struct DecryptionBatch {
-    jobs: Vec<DecryptionJob>,
-}
-
-struct DecryptionJob {
-    index: usize,
-    encrypted_content: Bytes,
-    src_hashes: Arc<Vec<XorName>>,
-}
-
 pub(crate) fn decrypt_chunk(
     chunk_number: usize,
     content: Bytes,

diff --git a/src/lib.rs b/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());