From 245832235d46ff6f8975dc8a19df83d2aa27a4aa Mon Sep 17 00:00:00 2001
From: nolash <dev@holbrook.no>
Date: Tue, 1 Jun 2021 11:37:32 +0200
Subject: [PATCH] Add hexdir handler, test

---
 chainqueue/fs/dir.py | 104 +++++++++++++++++++++++++++++++++++++++++++
 tests/test_hexdir.py |  68 ++++++++++++++++++++++++++++
 2 files changed, 172 insertions(+)
 create mode 100644 chainqueue/fs/dir.py
 create mode 100644 tests/test_hexdir.py

diff --git a/chainqueue/fs/dir.py b/chainqueue/fs/dir.py
new file mode 100644
index 0000000..37c8fa4
--- /dev/null
+++ b/chainqueue/fs/dir.py
@@ -0,0 +1,104 @@
+# standard imports
+import os
+import stat
+import logging
+
+# external imports
+from hexathon import valid as valid_hex
+
+logg = logging.getLogger(__name__)
+
+
+class HexDir:
+
+    def __init__(self, root_path, key_length, levels=2, prefix_length=0):
+        self.path = root_path
+        self.key_length = key_length
+        self.prefix_length = prefix_length
+        self.__levels = levels + 2
+        fi = None
+        try:
+            fi = os.stat(self.path)
+            self.__verify_directory()
+        except FileNotFoundError:
+            HexDir.__setup_directory(self.path)
+        if not stat.S_ISDIR(fi.st_mode):
+            raise ValueError('{} is not a directory'.format(self.path))
+        self.master_file = os.path.join(self.path, 'master')
+
+
+    @property
+    def levels(self):
+        return self.__levels - 2
+
+
+    def add(self, key, content, prefix=b''):
+        l = len(key)
+        if l != self.key_length:
+            raise ValueError('expected key length {}, got {}'.format(self.key_length, l))
+        l = len(prefix)
+        if l != self.prefix_length:
+            raise ValueError('expected prefix length {}, got {}'.format(self.prefix_length, l))
+        if not isinstance(content, bytes):
+            raise ValueError('content must be bytes, got {}'.format(type(content).__name__))
+        if prefix != None and not isinstance(prefix, bytes):
+            raise ValueError('prefix must be bytes, got {}'.format(type(content).__name__))
+        key_hex = key.hex()
+        entry_path = self.to_filepath(key_hex)
+
+        os.makedirs(os.path.dirname(entry_path), exist_ok=True)
+        f = open(entry_path, 'wb')
+        f.write(content)
+        f.close()
+
+        f = open(self.master_file, 'ab')
+        if prefix != None:
+            f.write(prefix)
+        f.write(key)
+        f.close()
+
+        logg.info('created new entry {} in {}'.format(key_hex, entry_path)) 
+
+
+    def set_prefix(self, idx, prefix):
+        l = len(prefix)
+        if l != self.prefix_length:
+            raise ValueError('expected prefix length {}, got {}'.format(self.prefix_length, l))
+        if not isinstance(prefix, bytes):
+            raise ValueError('prefix must be bytes, got {}'.format(type(content).__name__))
+        cursor = idx * (self.prefix_length + self.key_length)
+        f = open(self.master_file, 'rb+')
+        f.seek(cursor)
+        f.write(prefix)
+        f.close()
+
+
+    def to_subpath(self, hx):
+        lead = ''
+        for i in range(0, self.__levels, 2):
+            lead += hx[i:i+2] + '/'
+        return lead.upper()
+
+
+    def to_dirpath(self, hx):
+        sub_path = self.to_subpath(hx)
+        return os.path.join(self.path, sub_path)
+
+
+    def to_filepath(self, hx):
+        dir_path = self.to_dirpath(hx)
+        file_path = os.path.join(dir_path, hx.upper())
+        return file_path
+
+
+    def __verify_directory(self):
+        return True
+
+
+    @staticmethod
+    def __prepare_directory(path):
+        os.makedirs(path, exist_ok=True)
+        state_file = os.path.join(path, 'master')
+        f = open(state_file, 'w')
+        f.close()
+
diff --git a/tests/test_hexdir.py b/tests/test_hexdir.py
new file mode 100644
index 0000000..e507d14
--- /dev/null
+++ b/tests/test_hexdir.py
@@ -0,0 +1,68 @@
+# standard imports
+import unittest
+import tempfile
+import shutil
+import logging
+import os
+
+# local imports
+from chainqueue.fs.dir import HexDir
+
+logging.basicConfig(level=logging.DEBUG)
+logg = logging.getLogger()
+
+
+class HexDirTest(unittest.TestCase):
+
+    def setUp(self):
+        self.dir = tempfile.mkdtemp() 
+        self.hexdir = HexDir(self.dir, 4, 3, 2)
+        logg.debug('setup hexdir root {}'.format(self.dir))
+      
+
+    def tearDown(self):
+        shutil.rmtree(self.dir)
+        logg.debug('cleaned hexdir root {}'.format(self.dir))
+
+
+    def test_path(self):
+        content = b'cdef'
+        prefix = b'ab'
+        label = b'\xde\xad\xbe\xef'
+        self.hexdir.add(label, content, prefix=prefix)
+        file_path = os.path.join(self.dir, 'DE', 'AD', 'BE', label.hex().upper())
+        
+        f = open(file_path, 'rb')
+        r = f.read()
+        f.close()
+        self.assertEqual(content, r)
+
+        f = open(self.hexdir.master_file, 'rb')
+        r = f.read()
+        f.close()
+        self.assertEqual(prefix + label, r)
+
+
+    def test_size(self):
+        content = b'cdef'
+        prefix = b'ab'
+        label = b'\xde\xad\xbe\xef'
+        with self.assertRaises(ValueError):
+            self.hexdir.add(label, content, prefix=b'a')
+
+
+    def test_edit(self):
+        self.hexdir.add(b'\xde\xad\xbe\xef', b'foo', b'ab')
+        self.hexdir.add(b'\xbe\xef\xfe\xed', b'bar', b'cd')
+        self.hexdir.add(b'\x01\x02\x03\x04', b'baz', b'ef')
+        self.hexdir.set_prefix(1, b'ff')
+
+        f = open(self.hexdir.master_file, 'rb')
+        f.seek(6)
+        r = f.read(2)
+        f.close()
+        self.assertEqual(b'ff', r)
+
+
+if __name__ == '__main__':
+    unittest.main()