From: Brian Warner <warner@allmydata.com>
Date: Wed, 28 Mar 2007 18:24:53 +0000 (-0700)
Subject: document IEncoder, add Encoder.set_landlords()
X-Git-Url: https://git.rkrishnan.org/Site/Content/Exhibitors/banana.xhtml?a=commitdiff_plain;h=c4f09833f5a853f3bee01247b2d401742881fdde;p=tahoe-lafs%2Ftahoe-lafs.git

document IEncoder, add Encoder.set_landlords()
---

diff --git a/src/allmydata/encode_new.py b/src/allmydata/encode_new.py
index bf734f1a..88ca52af 100644
--- a/src/allmydata/encode_new.py
+++ b/src/allmydata/encode_new.py
@@ -1,11 +1,13 @@
 # -*- test-case-name: allmydata.test.test_encode -*-
 
+from zope.interface import implements
 from twisted.internet import defer
 from allmydata.chunk import HashTree, roundup_pow2
 from allmydata.Crypto.Cipher import AES
 import sha
 from allmydata.util import mathutil
 from allmydata.codec import CRSEncoder
+from allmydata.interfaces import IEncoder
 
 def hash(data):
     return sha.new(data).digest()
@@ -76,6 +78,7 @@ TiB=1024*GiB
 PiB=1024*TiB
 
 class Encoder(object):
+    implements(IEncoder)
 
     def setup(self, infile):
         self.infile = infile
@@ -169,6 +172,9 @@ class Encoder(object):
         #    return self.send(shareid, "write", subshare, offset)
         return self.send(shareid, "put_subshare", segment_num, subshare)
 
+    def set_landlords(self, landlords):
+        self.landlords = landlords.copy()
+
     def send(self, shareid, methname, *args, **kwargs):
         ll = self.landlords[shareid]
         return ll.callRemote(methname, *args, **kwargs)
diff --git a/src/allmydata/interfaces.py b/src/allmydata/interfaces.py
index 63bb6c53..38ac1308 100644
--- a/src/allmydata/interfaces.py
+++ b/src/allmydata/interfaces.py
@@ -283,6 +283,49 @@ class ICodecDecoder(Interface):
         call.
         """
 
+class IEncoder(Interface):
+    """I take a sequence of plaintext bytes and a list of shareholders, then
+    encrypt, encode, hash, and deliver shares to those shareholders. I will
+    compute all the necessary Merkle hash trees that are necessary to
+    validate the data that eventually comes back from the shareholders. I
+    provide the root hash of the hash tree, and the encoding parameters, both
+    of which must be included in the URI.
+
+    I do not choose shareholders, that is left to the IUploader. I must be
+    given a dict of RemoteReferences to storage buckets that are ready and
+    willing to receive data.
+    """
+
+    def setup(infile):
+        """I take a file-like object (providing seek, tell, and read) from
+        which all the plaintext data that is to be uploaded can be read. I
+        will seek to the beginning of the file before reading any data.
+        setup() must be called before making any other calls, in particular
+        before calling get_reservation_size().
+        """
+
+    def get_reservation_size():
+        """I return the size of the data that will be stored on each
+        shareholder. It is useful to determine this size before asking
+        potential shareholders whether they will grant a lease or not, since
+        their answers will depend upon how much space we need.
+        """
+
+    def set_shareholders(shareholders):
+        """I take a dictionary that maps share identifiers (small integers,
+        starting at 0) to RemoteReferences that provide RIBucketWriter. This
+        mus be called before start().
+        """
+
+    def start():
+        """I start the upload. This process involves reading data from the
+        input file, encrypting it, encoding the pieces, uploading the shares
+        to the shareholders, then sending the hash trees.
+
+        I return a Deferred that fires with the root hash.
+        """
+
+
 class IDownloadTarget(Interface):
     def open():
         """Called before any calls to write() or close()."""