[PATCH v11 09/11] qcow2_format.py: collect fields to dump in JSON format

[Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>]

As __dict__ is being extended with class members we do not want to
print, add the to_dict() method to classes that returns a dictionary
with desired fields and their values. Extend it in subclass when
necessary to print the final dictionary in the JSON output which
follows.

Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
---
 tests/qemu-iotests/qcow2_format.py | 38 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/tests/qemu-iotests/qcow2_format.py b/tests/qemu-iotests/qcow2_format.py
index 2921a27..19d29b8 100644
--- a/tests/qemu-iotests/qcow2_format.py
+++ b/tests/qemu-iotests/qcow2_format.py
@@ -119,6 +119,9 @@ class Qcow2Struct(metaclass=Qcow2StructMeta):
 
             print('{:<25} {}'.format(f[2], value_str))
 
+    def to_dict(self):
+        return dict((f[2], self.__dict__[f[2]]) for f in self.fields)
+
 
 class Qcow2BitmapExt(Qcow2Struct):
 
@@ -152,6 +155,11 @@ class Qcow2BitmapExt(Qcow2Struct):
             print()
             entry.dump()
 
+    def to_dict(self):
+        fields_dict = super().to_dict()
+        fields_dict.update(bitmap_directory=self.bitmap_directory)
+        return fields_dict
+
 
 class Qcow2BitmapDirEntry(Qcow2Struct):
 
@@ -190,6 +198,13 @@ class Qcow2BitmapDirEntry(Qcow2Struct):
         super(Qcow2BitmapDirEntry, self).dump()
         self.bitmap_table.dump()
 
+    def to_dict(self):
+        fields_dict = super().to_dict()
+        fields_dict.update(bitmap_table=self.bitmap_table)
+        bmp_name = dict(name=self.name)
+        bme_dict = {**bmp_name, **fields_dict}
+        return bme_dict
+
 
 class Qcow2BitmapTableEntry:
 
@@ -205,6 +220,9 @@ class Qcow2BitmapTableEntry:
         else:
             self.type = 'all-zeroes'
 
+    def to_dict(self):
+        return dict(type=self.type, offset=self.offset)
+
 
 class Qcow2BitmapTable:
 
@@ -226,6 +244,9 @@ class Qcow2BitmapTable:
         for i, entry in bitmap_table:
             print(f'{i:<14} {entry.type:<15} {entry.offset:<24} {size}')
 
+    def to_dict(self):
+        return dict(entries=self.entries)
+
 
 QCOW2_EXT_MAGIC_BITMAPS = 0x23852875
 
@@ -241,6 +262,9 @@ class QcowHeaderExtension(Qcow2Struct):
             0x44415441: 'Data file'
         }
 
+        def to_dict(self):
+            return self.mapping.get(self.value, "<unknown>")
+
     fields = (
         ('u32', Magic, 'magic'),
         ('u32', '{}', 'length')
@@ -303,6 +327,17 @@ class QcowHeaderExtension(Qcow2Struct):
         else:
             self.obj.dump()
 
+    def to_dict(self):
+        fields_dict = super().to_dict()
+        ext_name = dict(name=self.Magic(self.magic))
+        he_dict = {**ext_name, **fields_dict}
+        if self.obj is not None:
+            he_dict.update(data=self.obj)
+        else:
+            he_dict.update(data_str=self.data_str)
+
+        return he_dict
+
     @classmethod
     def create(cls, magic, data):
         return QcowHeaderExtension(magic, len(data), data)
@@ -405,3 +440,6 @@ class QcowHeader(Qcow2Struct):
             print('Header extension:')
             ex.dump()
             print()
+
+    def to_dict(self):
+        return super().to_dict()
-- 
1.8.3.1