perf: rewrite batch download_zip to stream via temp file instead of RAM

- Replace in-memory Cursor<Vec<u8>> with async_zip + NamedTempFile (O(256KB) RAM)
- Stream ZIP to client via ReaderStream instead of materializing entire archive
- Replace N+1 BFS folder traversal with 2 bulk ltree queries
- Remove dead zip_service field and with_zip_service() from BatchOperationService
- Remove synchronous zip crate dependency (only async_zip remains)
- Eliminates ~2.5GB RAM spike per 2GB batch download
This commit is contained in:
Dionisio
2026-02-25 23:12:19 +01:00
parent 23474b9681
commit 5f883aa0f8
5 changed files with 176 additions and 347 deletions
+143 -134
View File
@@ -1,6 +1,12 @@
use async_zip::base::write::ZipFileWriter;
use async_zip::{Compression, ZipEntryBuilder};
use futures::io::AsyncWriteExt as FuturesWriteExt;
use futures::{Future, StreamExt, future::join_all};
use std::collections::HashMap;
use std::sync::Arc;
use tempfile::NamedTempFile;
use thiserror::Error;
use tokio::io::BufWriter;
use tokio::sync::Semaphore;
use tracing::info;
@@ -9,7 +15,6 @@ use crate::application::dtos::folder_dto::{FolderDto, MoveFolderDto};
use crate::application::ports::file_ports::{FileManagementUseCase, FileRetrievalUseCase};
use crate::application::ports::inbound::FolderUseCase;
use crate::application::ports::trash_ports::TrashUseCase;
use crate::application::ports::zip_ports::ZipPort;
use crate::application::services::folder_service::FolderService;
use crate::common::config::AppConfig;
use crate::common::errors::DomainError;
@@ -65,7 +70,6 @@ pub struct BatchOperationService {
file_management: Arc<dyn FileManagementUseCase>,
folder_service: Arc<FolderService>,
trash_service: Option<Arc<dyn TrashUseCase>>,
zip_service: Option<Arc<dyn ZipPort>>,
config: AppConfig,
semaphore: Arc<Semaphore>,
}
@@ -86,7 +90,6 @@ impl BatchOperationService {
file_management,
folder_service,
trash_service: None,
zip_service: None,
config,
semaphore: Arc::new(Semaphore::new(max_concurrency)),
}
@@ -112,12 +115,6 @@ impl BatchOperationService {
self
}
/// Set the optional zip service (enables batch download)
pub fn with_zip_service(mut self, zip_service: Arc<dyn ZipPort>) -> Self {
self.zip_service = Some(zip_service);
self
}
/// Copies multiple files in parallel
pub async fn copy_files(
&self,
@@ -675,17 +672,16 @@ impl BatchOperationService {
Ok(result)
}
/// Downloads multiple files/folders as a single ZIP archive
/// Downloads multiple files/folders as a single ZIP archive.
///
/// Writes the archive to a temporary file so RAM usage is O(buffer_size)
/// regardless of total archive size. The caller streams the resulting
/// `NamedTempFile` to the client; the OS deletes it on drop.
pub async fn download_zip(
&self,
file_ids: Vec<String>,
folder_ids: Vec<String>,
) -> Result<Vec<u8>, BatchOperationError> {
use std::io::{Cursor, Write};
use zip::{ZipWriter, write::SimpleFileOptions};
let zip_service = self.zip_service.as_ref();
) -> Result<NamedTempFile, BatchOperationError> {
info!(
"Starting batch download: {} files, {} folders",
file_ids.len(),
@@ -693,163 +689,176 @@ impl BatchOperationService {
);
let start_time = std::time::Instant::now();
let buf = Cursor::new(Vec::new());
let mut zip = ZipWriter::new(buf);
let options = SimpleFileOptions::default()
.compression_method(zip::CompressionMethod::Deflated)
.unix_permissions(0o644);
// ── Open temp file + async ZIP writer (all writes go to disk) ────
let temp = NamedTempFile::new()
.map_err(|e| BatchOperationError::Internal(format!("temp file error: {}", e)))?;
let tokio_file = tokio::fs::File::create(temp.path())
.await
.map_err(|e| BatchOperationError::Internal(format!("temp file open: {}", e)))?;
let buf_writer = BufWriter::with_capacity(256 * 1024, tokio_file);
let mut zip = ZipFileWriter::with_tokio(buf_writer);
// Add individual files at the root of the ZIP
// ── Add individual files at the root of the ZIP ──────────────────
for file_id in &file_ids {
match self.file_retrieval.get_file(file_id).await {
Ok(file_dto) => match self.file_retrieval.get_file_stream(file_id).await {
Ok(stream) => {
let mut stream = std::pin::Pin::from(stream);
if let Err(e) = zip.start_file(&file_dto.name, options) {
info!("Could not start zip entry for {}: {}", file_dto.name, e);
continue;
}
while let Some(chunk) = stream.next().await {
match chunk {
Ok(bytes) => {
if let Err(e) = zip.write_all(&bytes) {
info!(
"Could not write zip chunk for {}: {}",
file_dto.name, e
);
break;
}
}
Err(e) => {
info!("Stream error for {}: {}", file_dto.name, e);
break;
}
}
}
Ok(file_dto) => {
if let Err(e) = self
.add_file_entry_streamed(&mut zip, file_id, &file_dto.name)
.await
{
info!("Could not add file {} to ZIP: {}", file_dto.name, e);
}
Err(e) => {
info!("Could not stream file content {}: {}", file_id, e);
}
},
}
Err(e) => {
info!("Could not get file metadata {}: {}", file_id, e);
}
}
}
// Add folders as sub-trees using the existing ZipPort if available
// Otherwise fall back to manual folder traversal
if let Some(zip_svc) = zip_service {
// For each folder, create a separate zip and merge its contents
// Actually, we need to build the tree ourselves for a single zip
// Use manual approach for consistency within one archive
for folder_id in &folder_ids {
match self.folder_service.get_folder(folder_id).await {
Ok(folder) => {
self.add_folder_to_zip(&mut zip, folder_id, &folder.name, &options)
.await;
}
Err(e) => {
info!("Could not get folder {}: {}", folder_id, e);
// ── Add folders as sub-trees (bulk subtree queries, not N+1) ─────
for folder_id in &folder_ids {
match self.folder_service.get_folder(folder_id).await {
Ok(root_folder) => {
if let Err(e) = self
.add_folder_subtree_to_zip(&mut zip, folder_id, &root_folder)
.await
{
info!("Could not add folder {} to ZIP: {}", root_folder.name, e);
}
}
}
// Suppress unused variable warning
let _ = zip_svc;
} else {
for folder_id in &folder_ids {
match self.folder_service.get_folder(folder_id).await {
Ok(folder) => {
self.add_folder_to_zip(&mut zip, folder_id, &folder.name, &options)
.await;
}
Err(e) => {
info!("Could not get folder {}: {}", folder_id, e);
}
Err(e) => {
info!("Could not get folder {}: {}", folder_id, e);
}
}
}
let mut zip_buf = zip
.finish()
.map_err(|e| BatchOperationError::Internal(format!("ZIP finalize error: {}", e)))?;
// ── Finalize ─────────────────────────────────────────────────────
let mut compat_writer = zip.close().await.map_err(|e| {
BatchOperationError::Internal(format!("ZIP finalize error: {}", e))
})?;
compat_writer.close().await.map_err(|e| {
BatchOperationError::Internal(format!("ZIP flush error: {}", e))
})?;
use std::io::Read;
let mut bytes = Vec::new();
zip_buf
.read_to_end(&mut bytes)
.map_err(|e| BatchOperationError::Internal(format!("ZIP read error: {}", e)))?;
let file_size = temp
.as_file()
.metadata()
.map(|m| m.len())
.unwrap_or(0);
info!(
"Batch download ZIP created: {} bytes in {}ms",
bytes.len(),
file_size,
start_time.elapsed().as_millis()
);
Ok(bytes)
Ok(temp)
}
/// Recursively add a folder and its contents to a ZipWriter
async fn add_folder_to_zip(
/// Streams a single file into an async ZIP entry (~64 KB peak RAM per file).
async fn add_file_entry_streamed(
&self,
zip: &mut zip::ZipWriter<std::io::Cursor<Vec<u8>>>,
folder_id: &str,
path: &str,
options: &zip::write::SimpleFileOptions,
) {
use std::io::Write;
zip: &mut ZipFileWriter<tokio_util::compat::Compat<BufWriter<tokio::fs::File>>>,
file_id: &str,
entry_name: &str,
) -> Result<(), BatchOperationError> {
let entry = ZipEntryBuilder::new(entry_name.to_string().into(), Compression::Deflate);
let mut writer = zip
.write_entry_stream(entry)
.await
.map_err(|e| BatchOperationError::Internal(format!("zip entry start: {}", e)))?;
struct PendingFolder {
id: String,
path: String,
let stream = self
.file_retrieval
.get_file_stream(file_id)
.await
.map_err(|e| BatchOperationError::Domain(e))?;
let mut stream = std::pin::Pin::from(stream);
while let Some(chunk) = stream.next().await {
let bytes = chunk.map_err(|e| {
BatchOperationError::Internal(format!("stream read: {}", e))
})?;
writer.write_all(&bytes).await.map_err(|e| {
BatchOperationError::Internal(format!("zip chunk write: {}", e))
})?;
}
let mut queue = vec![PendingFolder {
id: folder_id.to_string(),
path: path.to_string(),
}];
writer.close().await.map_err(|e| {
BatchOperationError::Internal(format!("zip entry close: {}", e))
})?;
Ok(())
}
let mut visited = std::collections::HashSet::new();
/// Adds an entire folder subtree to the ZIP using 2 bulk SQL queries
/// (ltree `<@`) instead of N+1 per-folder traversal.
async fn add_folder_subtree_to_zip(
&self,
zip: &mut ZipFileWriter<tokio_util::compat::Compat<BufWriter<tokio::fs::File>>>,
folder_id: &str,
root_folder: &FolderDto,
) -> Result<(), BatchOperationError> {
// Bulk-fetch entire subtree (2 queries total)
let all_folders = self
.folder_service
.list_subtree_folders(folder_id)
.await
.map_err(BatchOperationError::Domain)?;
while let Some(current) = queue.pop() {
if visited.contains(&current.id) {
continue;
let all_files = self
.file_retrieval
.list_files_in_subtree(folder_id)
.await
.map_err(BatchOperationError::Domain)?;
// Group files by folder_id
let mut files_by_folder: HashMap<String, Vec<FileDto>> =
HashMap::with_capacity(all_folders.len());
for file in all_files {
let fid = file.folder_id.clone().unwrap_or_default();
files_by_folder.entry(fid).or_default().push(file);
}
// Build path mapping: folder_id → ZIP-relative path
let root_path = root_folder.path.trim_end_matches('/');
let folder_zip_path = |db_path: &str| -> String {
let db_path = db_path.trim_end_matches('/');
if db_path == root_path {
root_folder.name.clone()
} else {
let suffix = db_path
.strip_prefix(root_path)
.unwrap_or(db_path)
.trim_start_matches('/');
format!("{}/{}", root_folder.name, suffix)
}
visited.insert(current.id.clone());
};
let dir_path = format!("{}/", current.path);
let _ = zip.add_directory(&dir_path, *options);
// Write folder + file entries (folders are sorted by path from DB)
for folder in &all_folders {
let zip_dir = format!("{}/", folder_zip_path(&folder.path));
// Add files via streaming (constant ~64 KB memory per file)
if let Ok(files) = self.file_retrieval.list_files(Some(&current.id)).await {
// Directory entry (Stored, zero-length body)
let dir_entry = ZipEntryBuilder::new(zip_dir.clone().into(), Compression::Stored);
if let Err(e) = zip.write_entry_whole(dir_entry, &[]).await {
info!("Could not add folder entry {}: {}", zip_dir, e);
}
// Stream files belonging to this folder
if let Some(files) = files_by_folder.get(&folder.id) {
for file in files {
let file_path = format!("{}{}", dir_path, file.name);
if let Ok(stream) = self.file_retrieval.get_file_stream(&file.id).await {
let mut stream = std::pin::Pin::from(stream);
if zip.start_file(&file_path, *options).is_ok() {
while let Some(chunk) = stream.next().await {
match chunk {
Ok(bytes) => {
let _ = zip.write_all(&bytes);
}
Err(_) => break,
}
}
}
let file_path = format!("{}{}", zip_dir, file.name);
if let Err(e) = self
.add_file_entry_streamed(zip, &file.id, &file_path)
.await
{
info!("Could not add file {} to ZIP: {}", file.name, e);
}
}
}
// Enqueue subfolders
if let Ok(subfolders) = self.folder_service.list_folders(Some(&current.id)).await {
for sub in subfolders {
queue.push(PendingFolder {
id: sub.id.clone(),
path: format!("{}/{}", current.path, sub.name),
});
}
}
}
Ok(())
}
/// Generic batch operation for any type of async function