using sqlite3 + blake as backup hash algo

backup.py

@@ -0,0 +1,69 @@
+from imohash.imohash import hashfile as _imohash
+import hashlib
+import hashlib
+import multiprocessing
+import os
+import psutil
+import sqlite3
+# https://stackoverflow.com/a/17782753
+def file_hash(path, block_size=4096*8):
+    '''
+    Block size directly depends on the block size of your filesystem
+    to avoid performances issues
+    Here I have blocks of 4096 octets (Default NTFS)
+    '''
+    _hash = hashlib.blake2b()
+    if os.path.getsize(path) < psutil.virtual_memory().available:
+        split = False
+    else:
+        split = True
+    with open(path,'rb') as f:
+        if split:
+            for chunk in iter(lambda: f.read(block_size), b''):
+                _hash.update(chunk)
+        else:
+            bytes = f.read()
+            _hash.update(bytes)
+    return path,_hash.digest()
+
+def hashify(top):
+    old_dir = os.getcwd()
+    os.chdir(top)
+    ret = []
+    imo_hashes = set()
+    for root,dirs,files in os.walk('.'):
+        try:
+            for file in files:
+                filepath = os.path.join(root,file)
+                imohash = _imohash(filepath)
+                real_hash = None
+                if imohash in imo_hashes:
+                    real_hash = file_hash(filepath)
+                print(file)
+                ret.append(
+                    (
+                        filepath,
+                        imohash,
+                        real_hash
+                    )
+                )
+        except PermissionError:
+            print('Access denied:',root)
+        except Exception as e:
+            print(e,file)
+    os.chdir(old_dir)
+    return ret
+def __init_database__(path):
+    con = sqlite3.connect(path)
+    cur = con.cursor()
+    cur.execute('CREATE TABLE IF NOT EXISTS `paths` (`path` TEXT, `imohash` BLOB, `blake` BLOB, UNIQUE(`path`, `imohash`, `blake`));')
+    con.commit()
+    return con
+def backup(top,db_path):
+    paths = hashify(top)
+    con = __init_database__(db_path)
+    cur = con.cursor()
+    cur.executemany('INSERT OR IGNORE INTO `paths` VALUES (?,?,?);',paths)
+    con.commit()
+if __name__ == "__main__":
+    backup(os.path.expandvars('%userprofile%'),'test.db')