From: Brian Warner Date: Wed, 28 Mar 2007 18:31:31 +0000 (-0700) Subject: document a proposed IDecoder interface, still pretty bare-bones X-Git-Url: https://git.rkrishnan.org/?a=commitdiff_plain;h=dc25f327a3a33968621f7f3cf8e57cc3566298e6;p=tahoe-lafs%2Ftahoe-lafs.git document a proposed IDecoder interface, still pretty bare-bones --- diff --git a/src/allmydata/interfaces.py b/src/allmydata/interfaces.py index 38ac1308..fc7965f7 100644 --- a/src/allmydata/interfaces.py +++ b/src/allmydata/interfaces.py @@ -314,7 +314,7 @@ class IEncoder(Interface): 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(). + must be called before start(). """ def start(): @@ -325,6 +325,39 @@ class IEncoder(Interface): I return a Deferred that fires with the root hash. """ +class IDecoder(Interface): + """I take a list of shareholders and some setup information, then + download, validate, decode, and decrypt data from them, writing the + results to an output file. + + I do not locate the shareholders, that is left to the IDownloader. I must + be given a dict of RemoteReferences to storage buckets that are ready to + send data. + """ + + def setup(outfile): + """I take a file-like object (providing write and close) to which all + the plaintext data will be written. + + TODO: producer/consumer . Maybe write() should return a Deferred that + indicates when it will accept more data? But probably having the + IDecoder be a producer is easier to glue to IConsumer pieces. + """ + + def set_shareholders(shareholders): + """I take a dictionary that maps share identifiers (small integers) + to RemoteReferences that provide RIBucketReader. This must be called + before start().""" + + def start(): + """I start the download. This process involves retrieving data and + hash chains from the shareholders, using the hashes to validate the + data, decoding the shares into segments, decrypting the segments, + then writing the resulting plaintext to the output file. + + I return a Deferred that will fire (with self) when the download is + complete. + """ class IDownloadTarget(Interface): def open():