From 876055ee7be3bc1f05cdff4f3cb070cbe3b0e6a7 Mon Sep 17 00:00:00 2001
From: Jonathas-Conceicao <jonathas.conceicao@ossystems.com.br>
Date: Wed, 9 Jun 2021 18:31:40 -0300
Subject: [PATCH] Add support for archiving raw-delta object

Signed-off-by: Jonathas-Conceicao <jonathas.conceicao@ossystems.com.br>
---
 uhu/core/_object.py |  8 ++++++++
 uhu/core/delta.py   | 33 +++++++++++++++++++++++++++++++++
 uhu/core/modes.py   | 20 ++++++++++++++++++++
 3 files changed, 61 insertions(+)
 create mode 100644 uhu/core/delta.py

diff --git a/uhu/core/_object.py b/uhu/core/_object.py
index 5d52beb..4bddfbb 100644
--- a/uhu/core/_object.py
+++ b/uhu/core/_object.py
@@ -9,6 +9,7 @@
 
 from ._options import Options
 from .compression import compression_to_metadata
+from .delta import validate_delta
 from .install_condition import InstallCondition
 from .validators import validate_options
 
@@ -64,6 +65,7 @@ def __init__(cls, classname, bases, methods):
 
 class BaseObject(metaclass=ObjectType):
     mode = None
+    using_delta = False
     allow_compression = False
     allow_install_condition = False
     options = []
@@ -93,6 +95,7 @@ def to_metadata(self, callback=None):
         metadata['mode'] = self.mode
         metadata.update(self._metadata_install_condition(metadata))
         metadata.update(self._metadata_compression())
+        metadata.update(self._metadata_delta())
         return metadata
 
     def _metadata_install_condition(self, metadata):
@@ -105,6 +108,11 @@ def _metadata_compression(self):
             return {}
         return compression_to_metadata(self.filename)
 
+    def _metadata_delta(self):
+        if not self.using_delta:
+            return {}
+        return validate_delta(self.filename)
+
     def to_upload(self):
         return {
             'filename': self['filename'],
diff --git a/uhu/core/delta.py b/uhu/core/delta.py
new file mode 100644
index 0000000..c3f9f94
--- /dev/null
+++ b/uhu/core/delta.py
@@ -0,0 +1,33 @@
+# Copyright (C) 2021 O.S. Systems Software LTDA.
+# SPDX-License-Identifier: GPL-2.0
+
+ARCHIVERS = {
+    # Bita format: https://github.com/oll3/bita
+    'bita': {
+        'signature': b'BITA1\0',
+    },
+}
+
+
+MAX_ARCHIVER_SIGNATURE_SIZE = max(
+    [len(archiver['signature']) for archiver in ARCHIVERS.values()]
+)
+
+
+def get_archiver_format(fn):
+    """Returns the delta archiver backend for a given file.
+    """
+    with open(fn, 'rb') as fp:
+        header = fp.read(MAX_ARCHIVER_SIGNATURE_SIZE)
+    for fmt, archiver in ARCHIVERS.items():
+        signature = archiver['signature']
+        if signature == header[:len(signature)]:
+            return fmt
+    return None
+
+
+def validate_delta(filename):
+    if get_archiver_format(filename) is None:
+        err = '"{}" doesn\'t match a known format type'
+        raise ValueError(err.format(filename))
+    return {}
diff --git a/uhu/core/modes.py b/uhu/core/modes.py
index 5cad348..9b06d3a 100644
--- a/uhu/core/modes.py
+++ b/uhu/core/modes.py
@@ -209,3 +209,23 @@ class ZephyrObject(BaseObject):
     required_options = [
         'filename',
     ]
+
+
+class RawDeltaObject(BaseObject):
+    mode = 'raw-delta'
+    using_delta = True
+    allow_compression = False
+    allow_install_condition = False
+    target_types = ['device']
+    options = [
+        'filename',
+        'sha256sum',
+        'size',
+        'target-type',
+        'target',
+    ]
+    required_options = [
+        'filename',
+        'target-type',
+        'target',
+    ]