Always use SHA1 hashes for pieces.

Only affects non-sha1 files like source files.
Also added a unit test for it.
Also added a unit test for the previous piece boundaries bug.

diff --git a/apt_p2p/Hash.py b/apt_p2p/Hash.py
index 9fe1947815789c3c7ef9678be889e4a2c2697463..bf23e9635e546825f7a439cbee83a001af42c132 100644 (file)
--- a/apt_p2p/Hash.py
+++ b/apt_p2p/Hash.py
@@ -65,8 +65,7 @@ class HashObject:
         self.fileHasher = None
         self.pieceHasher = None
         self.fileHash = digest
-        self.pieceHash = [pieces[x:x+self.ORDER[self.hashTypeNum]['length']]
-                          for x in xrange(0, len(pieces), self.ORDER[self.hashTypeNum]['length'])]
+        self.pieceHash = [pieces[x:x+20] for x in xrange(0, len(pieces), 20)]
         self.size = size
         self.fileHex = None
         self.fileNormHash = None
@@ -84,7 +83,11 @@ class HashObject:
             self.result = None
             self.done = False
             self.fileHasher = self._new()
-            self.pieceHasher = None
+            if self.ORDER[self.hashTypeNum]['name'] == 'sha1':
+                self.pieceHasher = None
+            else:
+                self.pieceHasher = self._newSHA1()
+                self.pieceSize = 0
             self.fileHash = None
             self.pieceHash = []
             self.size = 0
@@ -101,6 +104,15 @@ class HashObject:
             func = getattr(hashlib, self.ORDER[self.hashTypeNum]['hashlib_func'])
             return func()
 
+    def _newSHA1(self):
+        """Create a new SHA1 hashing object."""
+        if sys.version_info < (2, 5):
+            import sha
+            return sha.new()
+        else:
+            import hashlib
+            return hashlib.sha1()
+
     def update(self, data):
         """Add more data to the file hasher."""
         if self.result is None:
@@ -118,7 +130,7 @@ class HashObject:
 
                 # Save the first piece digest and initialize a new piece hasher
                 self.pieceHash.append(self.fileHasher.digest())
-                self.pieceHasher = self._new()
+                self.pieceHasher = self._newSHA1()
 
             if self.pieceHasher:
                 # Loop in case the data contains multiple pieces
@@ -126,7 +138,7 @@ class HashObject:
                     # Save the piece hash and start a new one
                     self.pieceHasher.update(data[:(PIECE_SIZE - self.pieceSize)])
                     self.pieceHash.append(self.pieceHasher.digest())
-                    self.pieceHasher = self._new()
+                    self.pieceHasher = self._newSHA1()
                     
                     # Don't forget to hash the data normally
                     self.fileHasher.update(data[:(PIECE_SIZE - self.pieceSize)])
@@ -261,7 +273,7 @@ class TestHashObject(unittest.TestCase):
     timeout = 5
     if sys.version_info < (2, 4):
         skip = "skippingme"
-    
+
     def test_failure(self):
         """Tests that the hash object fails when treated badly."""
         h = HashObject()
@@ -271,7 +283,20 @@ class TestHashObject(unittest.TestCase):
         self.failUnlessRaises(HashError, h.update, 'gfgf')
     
     def test_pieces(self):
-        """Tests the hashing of large files into pieces."""
+        """Tests updating of pieces a little at a time."""
+        h = HashObject()
+        h.new(True)
+        for i in xrange(120*1024):
+            h.update('1234567890')
+        pieces = h.pieceDigests()
+        self.failUnless(h.digest() == '1(j\xd2q\x0b\n\x91\xd2\x13\x90\x15\xa3E\xcc\xb0\x8d.\xc3\xc5')
+        self.failUnless(len(pieces) == 3)
+        self.failUnless(pieces[0] == ',G \xd8\xbbPl\xf1\xa3\xa0\x0cW\n\xe6\xe6a\xc9\x95/\xe5')
+        self.failUnless(pieces[1] == '\xf6V\xeb/\xa8\xad[\x07Z\xf9\x87\xa4\xf5w\xdf\xe1|\x00\x8e\x93')
+        self.failUnless(pieces[2] == 'M[\xbf\xee\xaa+\x19\xbaV\xf699\r\x17o\xcb\x8e\xcfP\x19')
+
+    def test_pieces_at_once(self):
+        """Tests the updating of multiple pieces at once."""
         h = HashObject()
         h.new()
         h.update('1234567890'*120*1024)
@@ -281,9 +306,21 @@ class TestHashObject(unittest.TestCase):
         self.failUnless(pieces[0] == ',G \xd8\xbbPl\xf1\xa3\xa0\x0cW\n\xe6\xe6a\xc9\x95/\xe5')
         self.failUnless(pieces[1] == '\xf6V\xeb/\xa8\xad[\x07Z\xf9\x87\xa4\xf5w\xdf\xe1|\x00\x8e\x93')
         self.failUnless(pieces[2] == 'M[\xbf\xee\xaa+\x19\xbaV\xf699\r\x17o\xcb\x8e\xcfP\x19')
+        
+    def test_pieces_boundaries(self):
+        """Tests the updating exactly to piece boundaries."""
+        h = HashObject()
         h.new(True)
-        for i in xrange(120*1024):
-            h.update('1234567890')
+        h.update('1234567890'*52428)
+        h.update('12345678')
+        assert h.size % PIECE_SIZE == 0
+        h.update('90')
+        h.update('1234567890'*52428)
+        h.update('123456')
+        assert h.size % PIECE_SIZE == 0
+        h.update('7890')
+        h.update('1234567890'*18022)
+        assert h.size == 10*120*1024
         pieces = h.pieceDigests()
         self.failUnless(h.digest() == '1(j\xd2q\x0b\n\x91\xd2\x13\x90\x15\xa3E\xcc\xb0\x8d.\xc3\xc5')
         self.failUnless(len(pieces) == 3)
@@ -291,6 +328,23 @@ class TestHashObject(unittest.TestCase):
         self.failUnless(pieces[1] == '\xf6V\xeb/\xa8\xad[\x07Z\xf9\x87\xa4\xf5w\xdf\xe1|\x00\x8e\x93')
         self.failUnless(pieces[2] == 'M[\xbf\xee\xaa+\x19\xbaV\xf699\r\x17o\xcb\x8e\xcfP\x19')
         
+    def test_pieces_other_hashes(self):
+        """Tests updating of pieces a little at a time."""
+        h = HashObject()
+        for hashType in h.ORDER:
+            if hashType['name'] != 'sha1':
+                h.hashTypeNum = h.ORDER.index(hashType)
+                break
+        assert h.ORDER[h.hashTypeNum]['name'] != 'sha1'
+        h.new(True)
+        for i in xrange(120*1024):
+            h.update('1234567890')
+        pieces = h.pieceDigests()
+        self.failUnless(len(pieces) == 3)
+        self.failUnless(pieces[0] == ',G \xd8\xbbPl\xf1\xa3\xa0\x0cW\n\xe6\xe6a\xc9\x95/\xe5')
+        self.failUnless(pieces[1] == '\xf6V\xeb/\xa8\xad[\x07Z\xf9\x87\xa4\xf5w\xdf\xe1|\x00\x8e\x93')
+        self.failUnless(pieces[2] == 'M[\xbf\xee\xaa+\x19\xbaV\xf699\r\x17o\xcb\x8e\xcfP\x19')
+
     def test_sha1(self):
         """Test hashing using the SHA1 hash."""
         h = HashObject()