Use real singletons, remove older code. Be consistent in initializing and finalizing db objects api.py

pisi/api.py

@@ -111,12 +111,12 @@ def init(database = True, write = True,
     ctx.database = database
     if database:
         shelve.init_dbenv(write=write)
-        ctx.repodb = pisi.db.repodb.init()
+        ctx.repodb = pisi.db.repodb.RepoDB()
-        ctx.installdb = pisi.db.installdb.init()
+        ctx.installdb = pisi.db.installdb.InstallDB()
         ctx.filesdb = pisi.db.filesdb.FilesDB()
         ctx.componentdb = pisi.db.componentdb.ComponentDB()
-        ctx.packagedb = packagedb.init_db()
+        ctx.packagedb = pisi.db.packagedb.PackageDB()
-        ctx.sourcedb = pisi.db.sourcedb.init()
+        ctx.sourcedb = pisi.db.sourcedb.SourceDB()
     else:
         ctx.repodb = None
         ctx.installdb = None
@@ -134,9 +134,12 @@ def finalize():
         if ctx.log:
             ctx.loghandler.flush()
             ctx.log.removeHandler(ctx.loghandler)
-
+        if ctx.repodb != None:
-        pisi.db.repodb.finalize()
+            ctx.repodb.close()
-        pisi.db.installdb.finalize()
+            ctx.repodb = None
+        if ctx.installdb != None:
+            ctx.installdb.close()
+            ctx.installdb = None
         if ctx.filesdb != None:
             ctx.filesdb.close()
             ctx.filesdb = None
@@ -144,10 +147,10 @@ def finalize():
             ctx.componentdb.close()
             ctx.componentdb = None
         if ctx.packagedb:
-            packagedb.finalize_db()
+            ctx.packagedb.close()
             ctx.packagedb = None
-        if ctx.sourcedb:
+        if ctx.sourcedb != None:
-            pisi.db.sourcedb.finalize()
+            ctx.sourcedb.close()
             ctx.sourcedb = None
         if ctx.dbenv:
             ctx.dbenv.close()

pisi/db/installdb.py

@@ -24,12 +24,12 @@ _ = __trans.ugettext
 # PiSi
 import pisi
 import pisi.context as ctx
+import pisi.oo
 import pisi.db.lockeddbshelve as dbshelve
 from pisi.files import Files
 import pisi.util as util
 from pisi.util import join_path
 
-
 class InstallDBError(pisi.Error):
     pass
 
@@ -70,7 +70,8 @@ class InstallInfo:
 
 
 class InstallDB:
-
+    __metaclass__ = pisi.oo.Singleton
+    
     def __init__(self):
         self.d = dbshelve.LockedDBShelf('install')
         self.dp = dbshelve.LockedDBShelf('configpending')
@@ -198,20 +199,4 @@ class InstallDB:
         def proc(txn):
             if self.d.has_key(pkg, txn):
                 self.d.delete(pkg, txn)
-        self.d.txn_proc(proc, txn)
+        self.d.txn_proc(proc, txn)
-
-db = None
-
-def init():
-    global db
-    if db:
-        return db
-
-    db = InstallDB()
-    return db
-
-def finalize():
-    global db
-    if db:
-        db.close()
-        db = None

pisi/db/packagedb.py

@@ -28,6 +28,7 @@ _ = __trans.ugettext
 import pisi
 import pisi.util as util
 import pisi.context as ctx
+import pisi.oo
 import pisi.db.itembyrepodb as itembyrepodb
 
 
@@ -42,6 +43,7 @@ class NotfoundError(pisi.Error):
 class PackageDB(object):
     """PackageDB class provides an interface to the package database
     using shelf objects"""
+    __metaclass__ = pisi.oo.Singleton
 
     def __init__(self):
         self.d = itembyrepodb.ItemByRepoDB('package')
@@ -152,21 +154,9 @@ class PackageDB(object):
             self.dr.remove_repo(repo, txn=txn)
         self.d.txn_proc(proc, txn)
 
-pkgdb = None
-
 def remove_tracking_package(name, txn = None):
     # remove the guy from the tracking databases
     if pkgdb.has_package(name, itembyrepodb.installed, txn=txn):
         pkgdb.remove_package(name, itembyrepodb.installed, txn=txn)
     if pkgdb.has_package(name, itembyrepodb.thirdparty, txn=txn):
         pkgdb.remove_package(name, itembyrepodb.thirdparty, txn=txn)
-
-def init_db():
-    global pkgdb
-    pkgdb = PackageDB()
-    return pkgdb
-
-def finalize_db():
-    global pkgdb
-    if pkgdb:
-        pkgdb.close()

pisi/db/repodb.py

@@ -18,6 +18,7 @@ import pisi
 import pisi.db.lockeddbshelve as shelve
 import pisi.context as ctx
 import pisi.db.packagedb as packagedb
+import pisi.oo
 
 class Error(pisi.Error):
     pass
@@ -35,7 +36,8 @@ class Repo:
 
 class RepoDB(object):
     """RepoDB maps repo ids to repository information"""
-
+    __metaclass__ = pisi.oo.Singleton
+    
     def __init__(self, txn = None):
         self.d = shelve.LockedDBShelf("repo")
         def proc(txn):
@@ -104,22 +106,4 @@ class RepoDB(object):
             ctx.packagedb.remove_repo(name, txn=txn)
             ctx.sourcedb.remove_repo(name, txn=txn)
             ctx.componentdb.remove_repo(name, txn=txn)
-        self.d.txn_proc(proc, txn)
+        self.d.txn_proc(proc, txn)
-
-db = None
-
-def init():
-    global db
-
-    if db:
-        return db
-
-    db = RepoDB()
-    return db
-
-def finalize():
-    global db
-
-    if db:
-        db.close()
-        db = None

pisi/db/sourcedb.py

@@ -27,11 +27,13 @@ _ = __trans.ugettext
 import pisi.context as ctx
 import pisi.db.repodb
 import pisi.db.itembyrepodb as itembyrepodb
+import pisi.oo
 
 class NotfoundError(pisi.Error):
     pass
 
 class SourceDB(object):
+    __metaclass__ = pisi.oo.Singleton
 
     def __init__(self):
         self.d = itembyrepodb.ItemByRepoDB('source')
@@ -81,7 +83,6 @@ class SourceDB(object):
             for pkg in spec.packages:
                 self.dpkgtosrc.remove_item_repo(pkg.name, repo, txn)
             ctx.componentdb.remove_spec(spec.source.partOf, spec.source.name, repo, txn)
-
         self.d.txn_proc(proc, txn)
 
     def remove_repo(self, repo, txn = None):
@@ -89,19 +90,3 @@ class SourceDB(object):
             self.d.remove_repo(repo, txn=txn)
             self.dpkgtosrc.remove_repo(repo, txn=txn)
         self.d.txn_proc(proc, txn)
-
-sourcedb = None
-
-def init():
-    global sourcedb
-    if sourcedb:
-        return sourcedb
-
-    sourcedb = SourceDB()
-    return sourcedb
-
-def finalize():
-    global sourcedb
-    if sourcedb:
-        sourcedb.close()
-        sourcedb = None

pisi/oo.py

@@ -37,3 +37,13 @@ class Struct:
 
     def __init__(self, **entries):
         self.__dict__.update(entries)
+        
+class Singleton(type):
+    def __init__(cls, name, bases, dic):
+        super(Singleton, cls).__init__(name, bases, dic)
+        cls.instance = None
+    
+    def __call__(cls, *args, **kwargs):
+        if not cls.instance:
+            cls.instance = super(Singleton, cls).__call__(*args, **kwargs)
+        return cls.instance