add storage factory (#3922)

api/extensions/storage/google_storage.py

@@ -0,0 +1,56 @@
+import base64
+from collections.abc import Generator
+from contextlib import closing
+
+from flask import Flask
+from google.cloud import storage as GoogleCloudStorage
+
+from extensions.storage.base_storage import BaseStorage
+
+
+class GoogleStorage(BaseStorage):
+    """Implementation for google storage.
+    """
+    def __init__(self, app: Flask):
+        super().__init__(app)
+        app_config = self.app.config
+        self.bucket_name = app_config.get('GOOGLE_STORAGE_BUCKET_NAME')
+        service_account_json = base64.b64decode(app_config.get('GOOGLE_STORAGE_SERVICE_ACCOUNT_JSON_BASE64')).decode(
+            'utf-8')
+        self.client = GoogleCloudStorage.Client().from_service_account_json(service_account_json)
+
+    def save(self, filename, data):
+        bucket = self.client.get_bucket(self.bucket_name)
+        blob = bucket.blob(filename)
+        blob.upload_from_file(data)
+
+    def load_once(self, filename: str) -> bytes:
+        bucket = self.client.get_bucket(self.bucket_name)
+        blob = bucket.get_blob(filename)
+        data = blob.download_as_bytes()
+        return data
+
+    def load_stream(self, filename: str) -> Generator:
+        def generate(filename: str = filename) -> Generator:
+            bucket = self.client.get_bucket(self.bucket_name)
+            blob = bucket.get_blob(filename)
+            with closing(blob.open(mode='rb')) as blob_stream:
+                while chunk := blob_stream.read(4096):
+                    yield chunk
+        return generate()
+
+    def download(self, filename, target_filepath):
+        bucket = self.client.get_bucket(self.bucket_name)
+        blob = bucket.get_blob(filename)
+        with open(target_filepath, "wb") as my_blob:
+            blob_data = blob.download_blob()
+            blob_data.readinto(my_blob)
+
+    def exists(self, filename):
+        bucket = self.client.get_bucket(self.bucket_name)
+        blob = bucket.blob(filename)
+        return blob.exists()
+
+    def delete(self, filename):
+        bucket = self.client.get_bucket(self.bucket_name)
+        bucket.delete_blob(filename)