Added live-object store and simple indexing.

[didex.git] / didex / values.py

diff --git a/didex/values.py b/didex/values.py
new file mode 100644 (file)
index 0000000..0e7bddc
--- /dev/null
+++ b/didex/values.py
@@ -0,0 +1,102 @@
+import threading
+from . import store, lib
+from .store import storedesc
+
+class cursor(lib.closable):
+    def __init__(self, bk, st):
+        self.bk = bk
+        self.st = st
+
+    def close(self):
+        self.bk.close()
+
+    def __iter__(self):
+        return self
+
+    def __next__(self):
+        k, id = next(self.bk)
+        return k, self.st.get(id)
+
+    def skip(self, n=1):
+        self.bk.skip(n)
+
+class base(storedesc):
+    def __init__(self, store, indextype, name, datatype, default):
+        self.store = store
+        self.indextype = indextype
+        self.name = name
+        self.typ = datatype
+        self.default = default
+        self.idx = None
+        self.lk = threading.Lock()
+        self.mattr = "__idx_%s_new" % name
+        self.iattr = "__idx_%s_cur" % name
+
+    def index(self):
+        with self.lk:
+            if self.idx is None:
+                self.idx = self.indextype(self.store.db(), self.name, self.typ)
+            return self.idx
+
+    def __get__(self, obj, cls):
+        if obj is None: return self
+        return getattr(obj, self.mattr, self.default)
+
+    def __set__(self, obj, val):
+        setattr(obj, self.mattr, val)
+
+    def __delete__(self, obj):
+        delattr(obj, self.mattr)
+
+    def get(self, **kwargs):
+        return cursor(self.index().get(**kwargs), self.store)
+
+class simple(base):
+    def __init__(self, store, indextype, name, datatype, default=None):
+        super().__init__(store, indextype, name, datatype, default)
+
+    def register(self, id, obj, tx):
+        val = self.__get__(obj, None)
+        self.index().put(val, id, tx=tx)
+        tx.postcommit(lambda: setattr(obj, self.iattr, val))
+
+    def unregister(self, id, obj, tx):
+        self.index().remove(getattr(obj, self.iattr), id, tx=tx)
+        tx.postcommit(lambda: delattr(obj, self.iattr))
+
+    def update(self, id, obj, tx):
+        val = self.__get__(obj, None)
+        ival = getattr(obj, self.iattr)
+        if val != ival:
+            idx = self.index()
+            idx.remove(ival, id, tx=tx)
+            idx.put(val, id, tx=tx)
+            tx.postcommit(lambda: setattr(obj, self.iattr, val))
+
+class multi(base):
+    def __init__(self, store, indextype, name, datatype):
+        super().__init__(store, indextype, name, datatype, ())
+
+    def register(self, id, obj, tx):
+        vals = frozenset(self.__get__(obj, None))
+        idx = self.index()
+        for val in vals:
+            idx.put(val, id, tx=tx)
+        tx.postcommit(lambda: setattr(obj, self.iattr, vals))
+
+    def unregister(self, id, obj, tx):
+        idx = self.index()
+        for val in getattr(obj, self.iattr):
+            idx.remove(val, id, tx=tx)
+        tx.postcommit(lambda: delattr(obj, self.iattr))
+
+    def update(self, id, obj, tx):
+        vals = frozenset(self.__get__(obj, None))
+        ivals = getattr(obj, self.iattr)
+        if vals != ivals:
+            idx = self.index()
+            for val in ivals - vals:
+                idx.remove(val, id, tx=tx)
+            for val in vals - ivals:
+                idx.put(val, id, tx=tx)
+            tx.postcommit(lambda: setattr(obj, self.iattr, vals))