github.com/codingfuture/orig-energi3@v0.8.4/swarm/storage/feed/doc.go (about)

     1  // Copyright 2018 The Energi Core Authors
     2  // Copyright 2018 The go-ethereum Authors
     3  // This file is part of the Energi Core library.
     4  //
     5  // The Energi Core library is free software: you can redistribute it and/or modify
     6  // it under the terms of the GNU Lesser General Public License as published by
     7  // the Free Software Foundation, either version 3 of the License, or
     8  // (at your option) any later version.
     9  //
    10  // The Energi Core library is distributed in the hope that it will be useful,
    11  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    12  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    13  // GNU Lesser General Public License for more details.
    14  //
    15  // You should have received a copy of the GNU Lesser General Public License
    16  // along with the Energi Core library. If not, see <http://www.gnu.org/licenses/>.
    17  
    18  /*
    19  Package feeds defines Swarm Feeds.
    20  
    21  Swarm Feeds allows a user to build an update feed about a particular topic
    22  without resorting to ENS on each update.
    23  The update scheme is built on swarm chunks with chunk keys following
    24  a predictable, versionable pattern.
    25  
    26  A Feed is tied to a unique identifier that is deterministically generated out of
    27  the chosen topic.
    28  
    29  A Feed is defined as the series of updates of a specific user about a particular topic
    30  
    31  Actual data updates are also made in the form of swarm chunks. The keys
    32  of the updates are the hash of a concatenation of properties as follows:
    33  
    34  updateAddr = H(Feed, Epoch ID)
    35  where H is the SHA3 hash function
    36  Feed is the combination of Topic and the user address
    37  Epoch ID is a time slot. See the lookup package for more information.
    38  
    39  A user looking up a the latest update in a Feed only needs to know the Topic
    40  and the other user's address.
    41  
    42  The Feed Update data is:
    43  updatedata = Feed|Epoch|data
    44  
    45  The full update data that goes in the chunk payload is:
    46  updatedata|sign(updatedata)
    47  
    48  Structure Summary:
    49  
    50  Request: Feed Update with signature
    51  	Update: headers + data
    52  		Header: Protocol version and reserved for future use placeholders
    53  		ID: Information about how to locate a specific update
    54  			Feed: Represents a user's series of publications about a specific Topic
    55  				Topic: Item that the updates are about
    56  				User: User who updates the Feed
    57  			Epoch: time slot where the update is stored
    58  
    59  */
    60  package feed