Working

app.py

@@ -1,12 +1,13 @@
 #!/usr/bin/env python
 
 from flask import Flask, redirect, request, render_template, send_from_directory, session
+import io
 import json
 import os
 from os.path import join
 import sqlite3
 import uuid
-from typing import Optional
+import tarfile
 from . import db, config, scanner, calibration
 
 app = Flask(__name__)
@@ -269,6 +270,53 @@ def validate_calibration():
     return redirect('/')
 
 
+@app.route('/download-object/<id>')
+def download_object(id: int):
+    conn = db.get()
+    object = db.Object.get_from_id(id, conn).full(conn)
+
+    def generate():
+        for acquisition_index, acquisition in enumerate(object.acquisitions):
+            acquisition_dir = join(config.OBJECT_DIR, str(object.id), str(acquisition.id))
+
+            # Send each image
+            for image in os.listdir(acquisition_dir):
+
+                # Generate tar header for file
+                image_path = join(acquisition_dir, image)
+                bytes = io.BytesIO()
+                stat = os.stat(image_path)
+
+                # Create dummy tar to extract tar header for file
+                with tarfile.open(fileobj=bytes, mode='w') as buffer:
+                    tar_info = tarfile.TarInfo(image_path)
+                    tar_info.name = f'object/{acquisition_index}/{image}'
+                    tar_info.size = stat.st_size
+                    buffer.addfile(tar_info)
+
+                # Yield header
+                value = bytes.getvalue()
+                yield value[:512]
+
+                # Yield file content, by chunks of 4MiB
+                chunk_size = 4_194_304
+                bytes_len = 0
+
+                with open(image_path, 'rb') as file:
+                    while True:
+                        bytes = file.read(chunk_size)
+
+                        if len(bytes) == 0:
+                            break
+
+                        bytes_len += len(bytes)
+                        yield bytes
+
+                    yield b'\x00' * (512 - bytes_len % 512)
+
+    return app.response_class(generate(), mimetype='application/x-tar')
+
+
 @app.route('/static/<path:path>')
 def send_static(path):
     return send_from_directory('static', path)

templates/object.html

@@ -4,6 +4,7 @@
 <section class="section">
     <div class="container content">
         <h1 class="title">{{ object.name }}</h1>
+        <a href="/download-object/{{ object.id }}">Télécharger les données de l'objet</a>
         {% if object.acquisitions %}
             <div class="fixed-grid has-6-cols">
                 <div class="grid">