Maximum useful, minimum dependency

inary/db/filesdb.py

 # -*- coding: utf-8 -*-
 #
-# Copyright (C) 2016 - 2018, Suleyman POYRAZ (Zaryob)
+# Copyright (C) 2005 - 2007, TUBITAK/UEKAE
 #
 # This program is free software; you can redistribute it and/or modify it under
 # the terms of the GNU General Public License as published by the Free
@@ -12,30 +12,36 @@
 
 import os
 import re
+import shelve
 import hashlib
 
+import inary
+import inary.context as ctx
+import inary.db.lazydb as lazydb
+
 import gettext
 __trans = gettext.translation('inary', fallback=True)
 _ = __trans.gettext
 
-import inary
-import inary.context as ctx
+# FIXME:
+# We could traverse through files.xml files of the packages to find the path and
+# the package - a linear search - as some well known package managers do. But the current 
+# file conflict mechanism of inary prevents this and needs a fast has_file function. 
+# So currently filesdb is the only db and we cant still get rid of rebuild-db :/
+
+class FilesDB(lazydb.LazyDB):
 
-class FilesDB():
     def __init__(self):
-        try:
-            import plyvel
-        except ImportError:
-            raise ImportError(_("LevelDB not found! Please install LevelDB and plyvel!"))
-        self.files_ldb_path = os.path.join(ctx.config.info_dir(), ctx.const.files_ldb)
-        self.filesdb = plyvel.DB(self.files_ldb_path, create_if_missing=True)
-        if not [f for f in os.listdir(self.files_ldb_path) if f.endswith('.ldb')]:
-            if ctx.scom: self.destroy()
-            self.create_filesdb()
+        self.filesdb = {}
+        self.__check_filesdb()
 
     def __del__(self):
         self.close()
 
+    def has_file(self, path):
+        if key in self.filesdb:
+            return True
+
     def create_filesdb(self):
         ctx.ui.info(inary.util.colorize(_('Creating files database...'), 'blue'))
         installdb = inary.db.installdb.InstallDB()
@@ -47,36 +53,60 @@ class FilesDB():
         ctx.ui.info(inary.util.colorize(_('Added files database...'), 'blue'))
 
     def get_file(self, path):
-        return self.filesdb.get(hashlib.md5(path.encode('utf-8')).digest()), path
+        key=hashlib.md5(path.encode('utf-8')).hexdigest()
+        return self.filesdb.get(key), path
 
     def search_file(self, term):
-        pkg, path = self.get_file(term)
-        if pkg:
+        if self.has_file(term):
+            pkg, path = self.get_file(term)
             return [(pkg,[path])]
 
         installdb = inary.db.installdb.InstallDB()
         found = []
         for pkg in installdb.list_installed():
             files_xml = open(os.path.join(installdb.package_path(pkg), ctx.const.files_xml)).read()
-            paths = re.compile('<Path>(.*?{}.*?)</Path>'.format(re.escape(term)), re.I).findall(files_xml)
+            paths = re.compile('<Path>(.*?%s.*?)</Path>' % re.escape(term), re.I).findall(files_xml)
             if paths:
                 found.append((pkg, paths))
         return found
 
     def add_files(self, pkg, files):
+
+        self.__check_filesdb()
+        ctx.ui.info(inary.util.colorize(_('* Adding \'{}\' to db... '), 'purple').format(pkg), noln=True)
         for f in files.list:
-            key=bytes(hashlib.md5(f.path.encode('utf-8')).digest())
-            value= bytes(pkg.encode('utf-8'))
-            self.filesdb.put(key=key, value=value)
+            key=hashlib.md5(f.path.encode('utf-8')).hexdigest()
+            self.filesdb[key] = pkg
 
     def remove_files(self, files):
         for f in files:
-            self.filesdb.delete(bytes(hashlib.md5(f.path.encode('utf-8')).digest()))
+            key=bytes(hashlib.md5(f.path.encode('utf-8')).hexdigest())
+            if hashlib.md5(key).hexdigest() in self.filesdb:
+                del self.filesdb[key]
 
     def destroy(self):
-        ctx.ui.info(inary.util.colorize(_('Cleaning files database folder... '), 'green'), noln=True)
-        for f in os.listdir(self.files_ldb_path): os.unlink(os.path.join(self.files_ldb_path, f))
-        ctx.ui.info(inary.util.colorize(_('done.'), 'green'))
+        files_db = os.path.join(ctx.config.info_dir(), ctx.const.files_db)
+        if os.path.exists(files_db):
+            os.unlink(files_db)
 
     def close(self):
-        if not self.filesdb.closed: self.filesdb.close()
+        if isinstance(self.filesdb, shelve.DbfilenameShelf):
+            self.filesdb.close()
+
+    def __check_filesdb(self):
+        ctx.ui.info(_("Checking filesdb..."))
+        if isinstance(self.filesdb, shelve.DbfilenameShelf):
+            return
+
+        files_db = os.path.join(ctx.config.info_dir(), ctx.const.files_db)
+
+        if not os.path.exists(files_db):
+            flag = "n"
+        elif os.access(files_db, os.W_OK):
+            flag = "w"
+        else:
+            flag = "r"
+
+        self.filesdb = shelve.open(files_db, flag)
+        if flag == "n":
+            self.create_filesdb()