store reference to manager in all txns; add origin_information()

5 files changed, 49 insertions, 23 deletions

diff --git a/dns/masterfile.py b/dns/masterfile.py
index 30553b5..66bb6a3 100644
--- a/dns/masterfile.py
+++ b/dns/masterfile.py
@@ -42,19 +42,15 @@ class Reader:
 
     """Read a DNS master file into a transaction."""
 
-    def __init__(self, tok, origin, rdclass, relativize, txn,
-                 allow_include=False):
-        if isinstance(origin, str):
-            origin = dns.name.from_text(origin)
+    def __init__(self, tok, rdclass, txn, allow_include=False):
         self.tok = tok
-        self.current_origin = origin
-        self.relativize = relativize
+        (self.zone_origin, self.relativize) = txn.manager.origin_information()
+        self.current_origin = self.zone_origin
         self.last_ttl = 0
         self.last_ttl_known = False
         self.default_ttl = 0
         self.default_ttl_known = False
         self.last_name = self.current_origin
-        self.zone_origin = origin
         self.zone_rdclass = rdclass
         self.txn = txn
         self.saved_state = []
diff --git a/dns/transaction.py b/dns/transaction.py
index aec0662..eae2920 100644
--- a/dns/transaction.py
+++ b/dns/transaction.py
@@ -20,13 +20,30 @@ class TransactionManager:
     def writer(self, replacement=False):
         """Begin a writable transaction.
 
-        *replacement*, a `bool`.  If `True`, the content of the
+        *replacement*, a ``bool``.  If `True`, the content of the
         transaction completely replaces any prior content.  If False,
         the default, then the content of the transaction updates the
         existing content.
         """
         raise NotImplementedError  # pragma: no cover
 
+    def origin_information(self):
+        """Returns an (origin: ``dns.name.Name``, relativize: ``bool``) tuple
+        giving the absolute name of the default origin for any
+        relative domain names, and whether names should be relativized
+        to that origin.
+
+        If the returned name is `None`, then no origin information is
+        available.
+
+        This information is used by code working with transactions to
+        allow it to coordinate relativization.  The transaction code
+        itself takes what it gets (i.e. does not change name
+        relativity).
+
+        """
+        raise NotImplementedError  # pragma: no cover
+
 
 class DeleteNotExact(dns.exception.DNSException):
     """Existing data did not match data specified by an exact delete."""
@@ -42,7 +59,8 @@ class AlreadyEnded(dns.exception.DNSException):
 
 class Transaction:
 
-    def __init__(self, replacement=False, read_only=False):
+    def __init__(self, manager, replacement=False, read_only=False):
+        self.manager = manager
         self.replacement = replacement
         self.read_only = read_only
         self._ended = False
diff --git a/dns/versioned.py b/dns/versioned.py
index e070c1a..99c30e4 100644
--- a/dns/versioned.py
+++ b/dns/versioned.py
@@ -234,7 +234,7 @@ class Zone(dns.zone.Zone):
                     raise KeyError('serial not found')
             else:
                 version = self._versions[-1]
-            txn = Transaction(False, self, version)
+            txn = Transaction(self, False, version)
             self._readers.add(txn)
             return txn
 
@@ -252,7 +252,7 @@ class Zone(dns.zone.Zone):
                     # give up the lock, so that we hold the lock as
                     # short a time as possible.  This is why we call
                     # _setup_version() below.
-                    self._write_txn = Transaction(replacement, self)
+                    self._write_txn = Transaction(self, replacement)
                     # give up our exclusive right to make a Transaction
                     self._write_event = None
                     break
@@ -403,12 +403,15 @@ class Zone(dns.zone.Zone):
 
 class Transaction(dns.transaction.Transaction):
 
-    def __init__(self, replacement, zone, version=None):
+    def __init__(self, zone, replacement, version=None):
         read_only = version is not None
-        super().__init__(replacement, read_only)
-        self.zone = zone
+        super().__init__(zone, replacement, read_only)
         self.version = version
 
+    @property
+    def zone(self):
+        return self.manager
+
     def _setup_version(self):
         assert self.version is None
         self.version = WritableVersion(self.zone, self.replacement)
diff --git a/dns/zone.py b/dns/zone.py
index e85603b..11c4c33 100644
--- a/dns/zone.py
+++ b/dns/zone.py
@@ -643,10 +643,13 @@ class Zone(dns.transaction.TransactionManager):
             raise NoNS
 
     def reader(self):
-        return Transaction(False, True, self)
+        return Transaction(self, False, True)
 
     def writer(self, replacement=False):
-        return Transaction(replacement, False, self)
+        return Transaction(self, replacement, False)
+
+    def origin_information(self):
+        return (self.origin, self.relativize)
 
 
 class Transaction(dns.transaction.Transaction):
@@ -654,11 +657,14 @@ class Transaction(dns.transaction.Transaction):
     _deleted_rdataset = dns.rdataset.Rdataset(dns.rdataclass.ANY,
                                               dns.rdatatype.ANY)
 
-    def __init__(self, replacement, read_only, zone):
-        super().__init__(replacement, read_only)
-        self.zone = zone
+    def __init__(self, zone, replacement, read_only):
+        super().__init__(zone, replacement, read_only)
         self.rdatasets = {}
 
+    @property
+    def zone(self):
+        return self.manager
+
     def _get_rdataset(self, name, rdclass, rdtype, covers):
         if rdclass != self.zone.rdclass:
             raise ValueError(f'class {rdclass} != ' +
@@ -805,7 +811,7 @@ def from_text(text, origin=None, rdclass=dns.rdataclass.IN,
     zone = zone_factory(origin, rdclass, relativize=relativize)
     with zone.writer(True) as txn:
         tok = dns.tokenizer.Tokenizer(text, filename, idna_codec=idna_codec)
-        reader = dns.masterfile.Reader(tok, origin, rdclass, relativize, txn,
+        reader = dns.masterfile.Reader(tok, rdclass, txn,
                                        allow_include=allow_include)
         try:
             reader.read()
diff --git a/tests/test_transaction.py b/tests/test_transaction.py
index 3dcaba0..bf7b130 100644
--- a/tests/test_transaction.py
+++ b/tests/test_transaction.py
@@ -18,14 +18,17 @@ class DB(dns.transaction.TransactionManager):
         self.rdatasets = {}
 
     def reader(self):
-        return Transaction(False, True, self)
+        return Transaction(self, False, True)
 
     def writer(self, replacement=False):
-        return Transaction(replacement, False, self)
+        return Transaction(self, replacement, False)
+
+    def origin_information(self):
+        return (None, True)
 
 
 class Transaction(dns.transaction.Transaction):
-    def __init__(self, replacement, read_only, db):
+    def __init__(self, db, replacement, read_only):
         super().__init__(replacement)
         self.db = db
         self.rdatasets = {}