storage: wrap buckets in a local proxy

This will make it easier to change RIBucketWriter in the future to reduce the wire
protocol to just open/write(offset,data)/close, and do all the structuring on the
client end. The ultimate goal is to store each bucket in a single file, to reduce
the considerable filesystem-quantization/inode overhead on the storage servers.

src/allmydata/download.py

@@ -7,7 +7,7 @@ from twisted.application import service
 
 from allmydata.util import idlib, mathutil, hashutil
 from allmydata.util.assertutil import _assert
-from allmydata import codec, hashtree
+from allmydata import codec, hashtree, storageserver
 from allmydata.Crypto.Cipher import AES
 from allmydata.uri import unpack_uri, unpack_extension
 from allmydata.interfaces import IDownloadTarget, IDownloader
@@ -109,7 +109,7 @@ class ValidatedBucket:
         # of the share hash tree to validate it from our share hash up to the
         # hashroot.
         if not self._share_hash:
-            d1 = self.bucket.callRemote('get_share_hashes')
+            d1 = self.bucket.get_share_hashes()
         else:
             d1 = defer.succeed(None)
 
@@ -117,12 +117,12 @@ class ValidatedBucket:
         # validate the requested block up to the share hash
         needed = self.block_hash_tree.needed_hashes(blocknum)
         if needed:
-            # TODO: get fewer hashes, callRemote('get_block_hashes', needed)
-            d2 = self.bucket.callRemote('get_block_hashes')
+            # TODO: get fewer hashes, use get_block_hashes(needed)
+            d2 = self.bucket.get_block_hashes()
         else:
             d2 = defer.succeed([])
 
-        d3 = self.bucket.callRemote('get_block', blocknum)
+        d3 = self.bucket.get_block(blocknum)
 
         d = defer.gatherResults([d1, d2, d3])
         d.addCallback(self._got_data, blocknum)
@@ -321,8 +321,9 @@ class FileDownloader:
     def _got_response(self, buckets, connection):
         _assert(isinstance(buckets, dict), buckets) # soon foolscap will check this for us with its DictOf schema constraint
         for sharenum, bucket in buckets.iteritems():
-            self.add_share_bucket(sharenum, bucket)
-            self._uri_extension_sources.append(bucket)
+            b = storageserver.ReadBucketProxy(bucket)
+            self.add_share_bucket(sharenum, b)
+            self._uri_extension_sources.append(b)
 
     def add_share_bucket(self, sharenum, bucket):
         # this is split out for the benefit of test_encode.py
@@ -379,7 +380,8 @@ class FileDownloader:
                                       "%s" % name)
         bucket = sources[0]
         sources = sources[1:]
-        d = bucket.callRemote(methname, *args)
+        #d = bucket.callRemote(methname, *args)
+        d = getattr(bucket, methname)(*args)
         d.addCallback(validatorfunc, bucket)
         def _bad(f):
             log.msg("%s from vbucket %s failed: %s" % (name, bucket, f)) # WEIRD

src/allmydata/encode.py

@@ -9,7 +9,7 @@ from allmydata.Crypto.Cipher import AES
 from allmydata.util import mathutil, hashutil
 from allmydata.util.assertutil import _assert
 from allmydata.codec import CRSEncoder
-from allmydata.interfaces import IEncoder
+from allmydata.interfaces import IEncoder, IStorageBucketWriter
 
 """
 
@@ -158,6 +158,7 @@ class Encoder(object):
         for k in landlords:
             # it would be nice to:
             #assert RIBucketWriter.providedBy(landlords[k])
+            assert IStorageBucketWriter(landlords[k])
             pass
         self.landlords = landlords.copy()
 
@@ -307,7 +308,7 @@ class Encoder(object):
         if shareid not in self.landlords:
             return defer.succeed(None)
         sh = self.landlords[shareid]
-        d = sh.callRemote("put_block", segment_num, subshare)
+        d = sh.put_block(segment_num, subshare)
         d.addErrback(self._remove_shareholder, shareid,
                      "segnum=%d" % segment_num)
         return d
@@ -356,7 +357,7 @@ class Encoder(object):
         if shareid not in self.landlords:
             return defer.succeed(None)
         sh = self.landlords[shareid]
-        d = sh.callRemote("put_plaintext_hashes", all_hashes)
+        d = sh.put_plaintext_hashes(all_hashes)
         d.addErrback(self._remove_shareholder, shareid, "put_plaintext_hashes")
         return d
 
@@ -374,7 +375,7 @@ class Encoder(object):
         if shareid not in self.landlords:
             return defer.succeed(None)
         sh = self.landlords[shareid]
-        d = sh.callRemote("put_crypttext_hashes", all_hashes)
+        d = sh.put_crypttext_hashes(all_hashes)
         d.addErrback(self._remove_shareholder, shareid, "put_crypttext_hashes")
         return d
 
@@ -397,7 +398,7 @@ class Encoder(object):
         if shareid not in self.landlords:
             return defer.succeed(None)
         sh = self.landlords[shareid]
-        d = sh.callRemote("put_block_hashes", all_hashes)
+        d = sh.put_block_hashes(all_hashes)
         d.addErrback(self._remove_shareholder, shareid, "put_block_hashes")
         return d
 
@@ -427,7 +428,7 @@ class Encoder(object):
         if shareid not in self.landlords:
             return defer.succeed(None)
         sh = self.landlords[shareid]
-        d = sh.callRemote("put_share_hashes", needed_hashes)
+        d = sh.put_share_hashes(needed_hashes)
         d.addErrback(self._remove_shareholder, shareid, "put_share_hashes")
         return d
 
@@ -442,7 +443,7 @@ class Encoder(object):
 
     def send_uri_extension(self, shareid, uri_extension):
         sh = self.landlords[shareid]
-        d = sh.callRemote("put_uri_extension", uri_extension)
+        d = sh.put_uri_extension(uri_extension)
         d.addErrback(self._remove_shareholder, shareid, "put_uri_extension")
         return d
 
@@ -450,7 +451,7 @@ class Encoder(object):
         log.msg("%s: closing shareholders" % self)
         dl = []
         for shareid in self.landlords:
-            d = self.landlords[shareid].callRemote("close")
+            d = self.landlords[shareid].close()
             d.addErrback(self._remove_shareholder, shareid, "close")
             dl.append(d)
         return self._gather_responses(dl)

src/allmydata/interfaces.py

@@ -119,6 +119,42 @@ class RIStorageServer(RemoteInterface):
     def get_buckets(storage_index=StorageIndex):
         return DictOf(int, RIBucketReader, maxKeys=MAX_BUCKETS)
 
+
+class IStorageBucketWriter(Interface):
+    def put_block(segmentnum, data):
+        pass
+
+    def put_plaintext_hashes(hashes):
+        pass
+    def put_crypttext_hashes(hashes):
+        pass
+    def put_block_hashes(blockhashes):
+        pass
+    def put_share_hashes(sharehashes):
+        pass
+    def put_uri_extension(data):
+        pass
+    def close():
+        pass
+
+class IStorageBucketReader(Interface):
+
+    def get_block(blocknum):
+        pass
+
+    def get_plaintext_hashes():
+        pass
+    def get_crypttext_hashes():
+        pass
+    def get_block_hashes():
+        pass
+    def get_share_hashes():
+        pass
+    def get_uri_extension():
+        pass
+
+
+
 # hm, we need a solution for forward references in schemas
 from foolscap.schema import Any
 RIMutableDirectoryNode_ = Any() # TODO: how can we avoid this?

src/allmydata/storageserver.py

@@ -5,7 +5,7 @@ from twisted.application import service
 
 from zope.interface import implements
 from allmydata.interfaces import RIStorageServer, RIBucketWriter, \
-     RIBucketReader
+     RIBucketReader, IStorageBucketWriter, IStorageBucketReader
 from allmydata import interfaces
 from allmydata.util import bencode, fileutil, idlib
 from allmydata.util.assertutil import precondition
@@ -203,3 +203,44 @@ class StorageServer(service.MultiService, Referenceable):
             pass
 
         return bucketreaders
+
+class WriteBucketProxy:
+    implements(IStorageBucketWriter)
+    def __init__(self, rref):
+        self._rref = rref
+
+    def put_block(self, segmentnum, data):
+        return self._rref.callRemote("put_block", segmentnum, data)
+
+    def put_plaintext_hashes(self, hashes):
+        return self._rref.callRemote("put_plaintext_hashes", hashes)
+    def put_crypttext_hashes(self, hashes):
+        return self._rref.callRemote("put_crypttext_hashes", hashes)
+    def put_block_hashes(self, blockhashes):
+        return self._rref.callRemote("put_block_hashes", blockhashes)
+    def put_share_hashes(self, sharehashes):
+        return self._rref.callRemote("put_share_hashes", sharehashes)
+    def put_uri_extension(self, data):
+        return self._rref.callRemote("put_uri_extension", data)
+    def close(self):
+        return self._rref.callRemote("close")
+
+class ReadBucketProxy:
+    implements(IStorageBucketReader)
+    def __init__(self, rref):
+        self._rref = rref
+
+    def get_block(self, blocknum):
+        return self._rref.callRemote("get_block", blocknum)
+
+    def get_plaintext_hashes(self):
+        return self._rref.callRemote("get_plaintext_hashes")
+    def get_crypttext_hashes(self):
+        return self._rref.callRemote("get_crypttext_hashes")
+    def get_block_hashes(self):
+        return self._rref.callRemote("get_block_hashes")
+    def get_share_hashes(self):
+        return self._rref.callRemote("get_share_hashes")
+    def get_uri_extension(self):
+        return self._rref.callRemote("get_uri_extension")
+

src/allmydata/test/test_encode.py

@@ -1,4 +1,5 @@
 
+from zope.interface import implements
 from twisted.trial import unittest
 from twisted.internet import defer
 from twisted.python.failure import Failure
@@ -7,6 +8,7 @@ from allmydata import encode, download, hashtree
 from allmydata.util import hashutil
 from allmydata.uri import pack_uri
 from allmydata.Crypto.Cipher import AES
+from allmydata.interfaces import IStorageBucketWriter, IStorageBucketReader
 from cStringIO import StringIO
 
 class FakePeer:
@@ -48,6 +50,7 @@ def flip_bit(good): # flips the last bit
     return good[:-1] + chr(ord(good[-1]) ^ 0x01)
 
 class FakeBucketWriter:
+    implements(IStorageBucketWriter, IStorageBucketReader)
     # these are used for both reading and writing
     def __init__(self, mode="good"):
         self.mode = mode
@@ -59,90 +62,123 @@ class FakeBucketWriter:
         self.closed = False
 
     def callRemote(self, methname, *args, **kwargs):
+        # this allows FakeBucketWriter to be used either as an
+        # IStorageBucketWriter or as the remote reference that it wraps. This
+        # should be cleaned up eventually when we change RIBucketWriter to
+        # have just write(offset, data) and close()
         def _call():
             meth = getattr(self, methname)
             return meth(*args, **kwargs)
-        return defer.maybeDeferred(_call)
+        d = eventual.fireEventually()
+        d.addCallback(lambda res: _call())
+        return d
 
     def put_block(self, segmentnum, data):
-        assert not self.closed
-        assert segmentnum not in self.blocks
-        if self.mode == "lost" and segmentnum >= 1:
-            raise LostPeerError("I'm going away now")
-        self.blocks[segmentnum] = data
+        def _try():
+            assert not self.closed
+            assert segmentnum not in self.blocks
+            if self.mode == "lost" and segmentnum >= 1:
+                raise LostPeerError("I'm going away now")
+            self.blocks[segmentnum] = data
+        return defer.maybeDeferred(_try)
 
     def put_plaintext_hashes(self, hashes):
-        assert not self.closed
-        assert self.plaintext_hashes is None
-        self.plaintext_hashes = hashes
+        def _try():
+            assert not self.closed
+            assert self.plaintext_hashes is None
+            self.plaintext_hashes = hashes
+        return defer.maybeDeferred(_try)
 
     def put_crypttext_hashes(self, hashes):
-        assert not self.closed
-        assert self.crypttext_hashes is None
-        self.crypttext_hashes = hashes
+        def _try():
+            assert not self.closed
+            assert self.crypttext_hashes is None
+            self.crypttext_hashes = hashes
+        return defer.maybeDeferred(_try)
 
     def put_block_hashes(self, blockhashes):
-        assert not self.closed
-        assert self.block_hashes is None
-        self.block_hashes = blockhashes
+        def _try():
+            assert not self.closed
+            assert self.block_hashes is None
+            self.block_hashes = blockhashes
+        return defer.maybeDeferred(_try)
         
     def put_share_hashes(self, sharehashes):
-        assert not self.closed
-        assert self.share_hashes is None
-        self.share_hashes = sharehashes
+        def _try():
+            assert not self.closed
+            assert self.share_hashes is None
+            self.share_hashes = sharehashes
+        return defer.maybeDeferred(_try)
 
     def put_uri_extension(self, uri_extension):
-        assert not self.closed
-        self.uri_extension = uri_extension
+        def _try():
+            assert not self.closed
+            self.uri_extension = uri_extension
+        return defer.maybeDeferred(_try)
 
     def close(self):
-        assert not self.closed
-        self.closed = True
+        def _try():
+            assert not self.closed
+            self.closed = True
+        return defer.maybeDeferred(_try)
 
     def get_block(self, blocknum):
-        assert isinstance(blocknum, (int, long))
-        if self.mode == "bad block":
-            return flip_bit(self.blocks[blocknum])
-        return self.blocks[blocknum]
+        def _try():
+            assert isinstance(blocknum, (int, long))
+            if self.mode == "bad block":
+                return flip_bit(self.blocks[blocknum])
+            return self.blocks[blocknum]
+        return defer.maybeDeferred(_try)
 
     def get_plaintext_hashes(self):
-        hashes = self.plaintext_hashes[:]
-        if self.mode == "bad plaintext hashroot":
-            hashes[0] = flip_bit(hashes[0])
-        if self.mode == "bad plaintext hash":
-            hashes[1] = flip_bit(hashes[1])
-        return hashes
+        def _try():
+            hashes = self.plaintext_hashes[:]
+            if self.mode == "bad plaintext hashroot":
+                hashes[0] = flip_bit(hashes[0])
+            if self.mode == "bad plaintext hash":
+                hashes[1] = flip_bit(hashes[1])
+            return hashes
+        return defer.maybeDeferred(_try)
 
     def get_crypttext_hashes(self):
-        hashes = self.crypttext_hashes[:]
-        if self.mode == "bad crypttext hashroot":
-            hashes[0] = flip_bit(hashes[0])
-        if self.mode == "bad crypttext hash":
-            hashes[1] = flip_bit(hashes[1])
-        return hashes
+        def _try():
+            hashes = self.crypttext_hashes[:]
+            if self.mode == "bad crypttext hashroot":
+                hashes[0] = flip_bit(hashes[0])
+            if self.mode == "bad crypttext hash":
+                hashes[1] = flip_bit(hashes[1])
+            return hashes
+        return defer.maybeDeferred(_try)
 
     def get_block_hashes(self):
-        if self.mode == "bad blockhash":
-            hashes = self.block_hashes[:]
-            hashes[1] = flip_bit(hashes[1])
-            return hashes
-        return self.block_hashes
+        def _try():
+            if self.mode == "bad blockhash":
+                hashes = self.block_hashes[:]
+                hashes[1] = flip_bit(hashes[1])
+                return hashes
+            return self.block_hashes
+        return defer.maybeDeferred(_try)
+
     def get_share_hashes(self):
-        if self.mode == "bad sharehash":
-            hashes = self.share_hashes[:]
-            hashes[1] = (hashes[1][0], flip_bit(hashes[1][1]))
-            return hashes
-        if self.mode == "missing sharehash":
-            # one sneaky attack would be to pretend we don't know our own
-            # sharehash, which could manage to frame someone else.
-            # download.py is supposed to guard against this case.
-            return []
-        return self.share_hashes
+        def _try():
+            if self.mode == "bad sharehash":
+                hashes = self.share_hashes[:]
+                hashes[1] = (hashes[1][0], flip_bit(hashes[1][1]))
+                return hashes
+            if self.mode == "missing sharehash":
+                # one sneaky attack would be to pretend we don't know our own
+                # sharehash, which could manage to frame someone else.
+                # download.py is supposed to guard against this case.
+                return []
+            return self.share_hashes
+        return defer.maybeDeferred(_try)
 
     def get_uri_extension(self):
-        if self.mode == "bad uri_extension":
-            return flip_bit(self.uri_extension)
-        return self.uri_extension
+        def _try():
+            if self.mode == "bad uri_extension":
+                return flip_bit(self.uri_extension)
+            return self.uri_extension
+        return defer.maybeDeferred(_try)
 
 
 def make_data(length):

src/allmydata/upload.py

@@ -5,7 +5,7 @@ from twisted.application import service
 from foolscap import Referenceable
 
 from allmydata.util import idlib, hashutil
-from allmydata import encode
+from allmydata import encode, storageserver
 from allmydata.uri import pack_uri
 from allmydata.interfaces import IUploadable, IUploader
 from allmydata.Crypto.Cipher import AES
@@ -53,8 +53,10 @@ class PeerTracker:
         
     def _got_reply(self, (alreadygot, buckets)):
         #log.msg("%s._got_reply(%s)" % (self, (alreadygot, buckets)))
-        self.buckets.update(buckets)
-        return (alreadygot, set(buckets.keys()))
+        b = dict( [ (sharenum, storageserver.WriteBucketProxy(rref))
+                    for sharenum, rref in buckets.iteritems() ] )
+        self.buckets.update(b)
+        return (alreadygot, set(b.keys()))
 
 class FileUploader: