From: Zooko O'Whielacronx <zooko@zooko.com>
Date: Thu, 3 Jan 2008 05:12:15 +0000 (-0700)
Subject: refactor constructing URI objects from strings and add human-encoding of WriteableSSK... 
X-Git-Tag: allmydata-tahoe-0.7.0~47
X-Git-Url: https://git.rkrishnan.org/quickstart.html?a=commitdiff_plain;h=eae499539d2058ebe8c8728eb507982412c9d606;p=tahoe-lafs%2Ftahoe-lafs.git

refactor constructing URI objects from strings and add human-encoding of WriteableSSKFileURI
---

diff --git a/src/allmydata/uri.py b/src/allmydata/uri.py
index 46921cd2..0433d908 100644
--- a/src/allmydata/uri.py
+++ b/src/allmydata/uri.py
@@ -18,7 +18,7 @@ ZBASE32STR_256bits = "%s{51}%s" % (ZBASE32CHAR, ZBASE32CHAR_1bits)
 COLON="(:|%3A)"
 
 # Writeable SSK bits
-WSSKBITS= "%s%s%s" % (ZBASE32STR_128bits, COLON, ZBASE32STR_256bits)
+WSSKBITS= "(%s)%s(%s)" % (ZBASE32STR_128bits, COLON, ZBASE32STR_256bits)
 
 # URIs (soon to be renamed "caps") are always allowed to come with a leading
 # "http://127.0.0.1:8123/uri/" that will be ignored.
@@ -59,7 +59,8 @@ class CHKFileURI(_BaseURI):
                                 % name)
         self.storage_index = hashutil.storage_index_chk_hash(self.key)
 
-    def init_from_string(self, uri):
+    @classmethod
+    def init_from_string(cls, uri):
         assert uri.startswith("URI:CHK:"), uri
         d = {}
         (header_uri, header_chk,
@@ -68,22 +69,24 @@ class CHKFileURI(_BaseURI):
         assert header_uri == "URI"
         assert header_chk == "CHK"
 
-        self.key = idlib.a2b(key_s)
-        assert isinstance(self.key, str)
-        assert len(self.key) == 16 # AES-128
+        key = idlib.a2b(key_s)
+        assert isinstance(key, str)
+        assert len(key) == 16 # AES-128
 
-        self.storage_index = hashutil.storage_index_chk_hash(self.key)
-        assert isinstance(self.storage_index, str)
-        assert len(self.storage_index) == 16 # sha256 hash truncated to 128
+        storage_index = hashutil.storage_index_chk_hash(key)
+        assert isinstance(storage_index, str)
+        assert len(storage_index) == 16 # sha256 hash truncated to 128
 
-        self.uri_extension_hash = idlib.a2b(uri_extension_hash_s)
-        assert isinstance(self.uri_extension_hash, str)
-        assert len(self.uri_extension_hash) == 32 # sha56 hash
+        uri_extension_hash = idlib.a2b(uri_extension_hash_s)
+        assert isinstance(uri_extension_hash, str)
+        assert len(uri_extension_hash) == 32 # sha256 hash
 
-        self.needed_shares = int(needed_shares_s)
-        self.total_shares = int(total_shares_s)
-        self.size = int(size_s)
-        return self
+        needed_shares = int(needed_shares_s)
+        total_shares = int(total_shares_s)
+        size = int(size_s)
+        return cls(key=key, uri_extension_hash=uri_extension_hash,
+                   needed_shares=needed_shares, total_shares=total_shares,
+                   size=size)
 
     def to_string(self):
         assert isinstance(self.needed_shares, int)
@@ -131,7 +134,8 @@ class CHKFileVerifierURI(_BaseURI):
         self.total_shares = total_shares
         self.size = size
 
-    def init_from_string(self, uri):
+    @classmethod
+    def init_from_string(cls, uri):
         assert uri.startswith("URI:CHK-Verifier:"), uri
         d = {}
         (header_uri, header_chk,
@@ -140,18 +144,23 @@ class CHKFileVerifierURI(_BaseURI):
         assert header_uri == "URI"
         assert header_chk == "CHK-Verifier"
 
-        self.storage_index = idlib.a2b(storage_index_s)
-        assert isinstance(self.storage_index, str)
-        assert len(self.storage_index) == 16 # sha256 hash truncated to 128
+        storage_index = idlib.a2b(storage_index_s)
+        assert isinstance(storage_index, str)
+        assert len(storage_index) == 16 # sha256 hash truncated to 128
 
-        self.uri_extension_hash = idlib.a2b(uri_extension_hash_s)
-        assert isinstance(self.uri_extension_hash, str)
-        assert len(self.uri_extension_hash) == 32 # sha56 hash
+        uri_extension_hash = idlib.a2b(uri_extension_hash_s)
+        assert isinstance(uri_extension_hash, str)
+        assert len(uri_extension_hash) == 32 # sha256 hash
 
-        self.needed_shares = int(needed_shares_s)
-        self.total_shares = int(total_shares_s)
-        self.size = int(size_s)
-        return self
+        needed_shares = int(needed_shares_s)
+        total_shares = int(total_shares_s)
+        size = int(size_s)
+
+        return cls(storage_index=storage_index,
+                   uri_extension_hash=uri_extension_hash,
+                   needed_shares=needed_shares,
+                   total_shares=total_shares,
+                   size=size)
 
     def to_string(self):
         assert isinstance(self.needed_shares, int)
@@ -173,11 +182,11 @@ class LiteralFileURI(_BaseURI):
         if data is not None:
             self.data = data
 
-    def init_from_string(self, uri):
+    @classmethod
+    def init_from_string(cls, uri):
         assert uri.startswith("URI:LIT:")
         data_s = uri[len("URI:LIT:"):]
-        self.data = idlib.a2b(data_s)
-        return self
+        return cls(idlib.a2b(data_s))
 
     def to_string(self):
         return "URI:LIT:%s" % idlib.b2a(self.data)
@@ -199,22 +208,28 @@ class LiteralFileURI(_BaseURI):
 class WriteableSSKFileURI(_BaseURI):
     implements(IURI, IMutableFileURI)
 
-    def __init__(self, *args, **kwargs):
-        if not args and not kwargs:
-            return
-        self.populate(*args, **kwargs)
-
-    def populate(self, writekey, fingerprint):
+    def __init__(self, writekey, fingerprint):
         self.writekey = writekey
         self.readkey = hashutil.ssk_readkey_hash(writekey)
         self.storage_index = hashutil.ssk_storage_index_hash(self.readkey)
         self.fingerprint = fingerprint
 
-    def init_from_string(self, uri):
+    @classmethod
+    def init_from_human_encoding(cls, uri):
+        mo = WriteableSSKFileURI_RE.search(uri)
+        assert mo
+        return cls(idlib.a2b(mo.group(5)), idlib.a2b(mo.group(7)))
+
+    @classmethod
+    def init_from_string(cls, uri):
         assert uri.startswith("URI:SSK:"), uri
         (header_uri, header_ssk, writekey_s, fingerprint_s) = uri.split(":")
-        self.populate(idlib.a2b(writekey_s), idlib.a2b(fingerprint_s))
-        return self
+        return cls(idlib.a2b(writekey_s), idlib.a2b(fingerprint_s))
+
+    def to_human_encoding(self):
+        assert isinstance(self.writekey, str)
+        assert isinstance(self.fingerprint, str)
+        return "http://127.0.0.1:8123/uri/URI:SSK:%s:%s" % (idlib.b2a(self.writekey), idlib.b2a(self.fingerprint))
 
     def to_string(self):
         assert isinstance(self.writekey, str)
@@ -240,21 +255,16 @@ class WriteableSSKFileURI(_BaseURI):
 class ReadonlySSKFileURI(_BaseURI):
     implements(IURI, IMutableFileURI)
 
-    def __init__(self, *args, **kwargs):
-        if not args and not kwargs:
-            return
-        self.populate(*args, **kwargs)
-
-    def populate(self, readkey, fingerprint):
+    def __init__(self, readkey, fingerprint):
         self.readkey = readkey
         self.storage_index = hashutil.ssk_storage_index_hash(self.readkey)
         self.fingerprint = fingerprint
 
-    def init_from_string(self, uri):
+    @classmethod
+    def init_from_string(cls, uri):
         assert uri.startswith("URI:SSK-RO:"), uri
         (header_uri, header_ssk, readkey_s, fingerprint_s) = uri.split(":")
-        self.populate(idlib.a2b(readkey_s), idlib.a2b(fingerprint_s))
-        return self
+        return cls(idlib.a2b(readkey_s), idlib.a2b(fingerprint_s))
 
     def to_string(self):
         assert isinstance(self.readkey, str)
@@ -280,21 +290,16 @@ class ReadonlySSKFileURI(_BaseURI):
 class SSKVerifierURI(_BaseURI):
     implements(IVerifierURI)
 
-    def __init__(self, *args, **kwargs):
-        if not args and not kwargs:
-            return
-        self.populate(*args, **kwargs)
-
-    def populate(self, storage_index, fingerprint):
+    def __init__(self, storage_index, fingerprint):
         self.storage_index = storage_index
         self.fingerprint = fingerprint
 
-    def init_from_string(self, uri):
+    @classmethod
+    def init_from_string(cls, uri):
         assert uri.startswith("URI:SSK-Verifier:"), uri
         (header_uri, header_ssk,
          storage_index_s, fingerprint_s) = uri.split(":")
-        self.populate(idlib.a2b(storage_index_s), idlib.a2b(fingerprint_s))
-        return self
+        return cls(idlib.a2b(storage_index_s), idlib.a2b(fingerprint_s))
 
     def to_string(self):
         assert isinstance(self.storage_index, str)
@@ -329,13 +334,12 @@ class NewDirectoryURI(_NewDirectoryBaseURI):
             assert not filenode_uri.is_readonly()
         _NewDirectoryBaseURI.__init__(self, filenode_uri)
 
-    def init_from_string(self, uri):
+    @classmethod
+    def init_from_string(cls, uri):
         assert uri.startswith("URI:DIR2:")
         (header_uri, header_dir2, bits) = uri.split(":", 2)
-        fn = WriteableSSKFileURI()
-        fn.init_from_string("URI:SSK:" + bits)
-        self._filenode_uri = fn
-        return self
+        fn = WriteableSSKFileURI.init_from_string("URI:SSK:" + bits)
+        return cls(fn)
 
     def to_string(self):
         assert isinstance(self._filenode_uri, WriteableSSKFileURI)
@@ -356,13 +360,12 @@ class ReadonlyNewDirectoryURI(_NewDirectoryBaseURI):
             assert filenode_uri.is_readonly()
         _NewDirectoryBaseURI.__init__(self, filenode_uri)
 
-    def init_from_string(self, uri):
+    @classmethod
+    def init_from_string(cls, uri):
         assert uri.startswith("URI:DIR2-RO:")
         (header_uri, header_dir2, bits) = uri.split(":", 2)
-        fn = ReadonlySSKFileURI()
-        fn.init_from_string("URI:SSK-RO:" + bits)
-        self._filenode_uri = fn
-        return self
+        fn = ReadonlySSKFileURI.init_from_string("URI:SSK-RO:" + bits)
+        return cls(fn)
 
     def to_string(self):
         assert isinstance(self._filenode_uri, ReadonlySSKFileURI)
@@ -384,13 +387,12 @@ class NewDirectoryURIVerifier(_BaseURI):
             filenode_uri = IVerifierURI(filenode_uri)
         self._filenode_uri = filenode_uri
 
-    def init_from_string(self, uri):
+    @classmethod
+    def init_from_string(cls, uri):
         assert uri.startswith("URI:DIR2-Verifier:")
         (header_uri, header_dir2, bits) = uri.split(":", 2)
-        fn = SSKVerifierURI()
-        fn.init_from_string("URI:SSK-Verifier:" + bits)
-        self._filenode_uri = fn
-        return self
+        fv = SSKVerifierURI.init_from_string("URI:SSK-Verifier:" + bits)
+        return cls(fv)
 
     def to_string(self):
         assert isinstance(self._filenode_uri, SSKVerifierURI)
@@ -403,27 +405,25 @@ class NewDirectoryURIVerifier(_BaseURI):
 
 
 
-
-
 def from_string(s):
     if s.startswith("URI:CHK:"):
-        return CHKFileURI().init_from_string(s)
+        return CHKFileURI.init_from_string(s)
     elif s.startswith("URI:CHK-Verifier:"):
-        return CHKFileVerifierURI().init_from_string(s)
+        return CHKFileVerifierURI.init_from_string(s)
     elif s.startswith("URI:LIT:"):
-        return LiteralFileURI().init_from_string(s)
+        return LiteralFileURI.init_from_string(s)
     elif s.startswith("URI:SSK:"):
-        return WriteableSSKFileURI().init_from_string(s)
+        return WriteableSSKFileURI.init_from_string(s)
     elif s.startswith("URI:SSK-RO:"):
-        return ReadonlySSKFileURI().init_from_string(s)
+        return ReadonlySSKFileURI.init_from_string(s)
     elif s.startswith("URI:SSK-Verifier:"):
-        return SSKVerifierURI().init_from_string(s)
+        return SSKVerifierURI.init_from_string(s)
     elif s.startswith("URI:DIR2:"):
-        return NewDirectoryURI().init_from_string(s)
+        return NewDirectoryURI.init_from_string(s)
     elif s.startswith("URI:DIR2-RO:"):
-        return ReadonlyNewDirectoryURI().init_from_string(s)
+        return ReadonlyNewDirectoryURI.init_from_string(s)
     elif s.startswith("URI:DIR2-Verifier:"):
-        return NewDirectoryURIVerifier().init_from_string(s)
+        return NewDirectoryURIVerifier.init_from_string(s)
     else:
         raise TypeError("unknown URI type: %s.." % s[:12])