Move changelog to separate file.

changelog.rst

@@ -0,0 +1,142 @@
+ChangeLog
+=========
+
+IMPORTANT: version 1.2 changes script hash indexing in the database,
+so you will need to rebuild your databases from scratch.  Running this
+version will refuse to open the DB and not corrupt it, so you can
+revert to 1.1.x if you wish.  The initial synchronisation process
+should be around 10-15% faster than 1.1, owing to this change and
+Justin Arthur's optimisations from 1.1.1.
+
+Version 1.2.1
+-------------
+
+- remove IRC support.  Most coins had empty IRC channels.  Those that
+  don't have peers populated.
+- use estimatesmartfee RPC call if available (SomberNight)
+- new/updated coins: Emercoin (Sergii Vakula), Bitcoin Gold (erasmospunk),
+  Monacoin testnet (Wakiyama P), sibcoin (53r63rn4r), Komodo and Monaize
+  (cipig), Hush (Duke Leto)
+- doc updates (fr3aker)
+- issues fixed: `#302`_
+
+Version 1.2
+-----------
+
+- separate P2PKH from P2PK entries in the history and UTXO databases.
+  These were previously amalgamated by address as that is what
+  electrum-server used to do.  However Electrum didn't handle P2PK
+  spends correctly and now the protocol admits subscriptions by script
+  hash there is no need to have these merged any more.
+
+For Bitcoin (BitcoinSegwit/mainnet) you can download a leveldb database
+synced up to block 490153 using this bittorrent magnet
+`link (~24GB) <magnet:?xt=urn:btih:caa804f48a319b061be3884ac011656c27121a6f&dn=electrumx_1.2_btc_leveldb_490153>`_.
+
+Version 1.1.2
+-------------
+
+- PEER_DISCOVERY environment variable is now tri-state (fixes
+  `#287`_).  Please check your setting as its meaning has changed
+  slightly.
+- fix listunspent protocol methods to remove in-mempool spends (fixes
+  `#277`_).
+- improved environment variable handling
+- EMC2 update (cipig), Monacoin update (cryptocoin-junkey),
+  Canada Ecoin (koad)
+- typo fixes, Bitcoin testnet peers updates (SomberNight)
+
+Version 1.1.1
+-------------
+
+- various refactorings, improvement of env var handling
+- update docs to match
+- various optimizations mainly affecting initial sync (Justin Arthur)
+- Dash fixes (cipig)
+- Add ALLOW_ROOT option (Luke Childs)
+- Add BitZeny support, update Monacoin (cryptocoin-junkey)
+
+Version 1.1
+-----------
+
+See the changelogs below for recent changes.  The most important is
+that for mainnet bitcoin **NET** must now be *mainnet* and you must
+choose a **COIN** from *BitcoinCash* and *BitcoinSegwit*.  Similarly
+for testnets.  These coins will likely diverge further in future so
+it's best they become separate coins now.
+
+- no longer persist peers, rediscover on restart
+- onion peers only reported if can connect; hard-coded exception removed
+- small fix for blockchain.transaction.broadcast
+
+Version 1.1pre2
+---------------
+
+- peerdisc: handle protocol 1.1 server replies
+- issue `#251`_: fix protocol version reported in server.peers.subscribe
+- fix handling of failed transaction broadcast
+- fix typos (SomberNight)
+- doc and test updates
+- dash: return errors in JSON error field for protocol 1.1
+
+Version 1.1pre1
+---------------
+
+Many changes, mostly to prepare for support of Electrum protocol 1.1
+which the next Electrum client release will use.
+
+*NOTE*: the **COIN** environment variable is now mandatory, and if you
+were running for any bitcoin flavour (Cash, Segwit, mainnet or
+testnet) you will need to update your **COIN** and **NET** environment
+variable settings as the old ones will no longer work.
+
+- implement protocol version 1.1 and update protocol documentation
+- rework lib/coins.py for the various bitcoin flavours
+- show protocol version in "sessions" ElectrumX RPC call
+- permit **HOST** envvar to be a comma-separated list
+- daemon abstraction refactoring (erasmospunk)
+- permit alternative event loop policies (based on suggestion / work
+  of JustinTArthur)
+- misc configuration updates (SubPar)
+- add Neblio support (neblioteam) and Bitbay (anoxxxy)
+- HOWTO.rst update for running on privileged port (EagleTM)
+- issues closed: exclude test dirs from installation (`#223`_).
+
+Version 1.0.17
+--------------
+
+- fix #227 introduced in 1.0.16
+
+Version 1.0.16
+--------------
+
+- updated server lists for post-fork.  If you are on the Segwit chain
+  you should have NET be "bitcoin-segwit", and if on the Bitcoin Cash chain
+  continue to use "mainnet".
+- binding address fix for multi-homed machines (mmouse)
+- listen to IPv4 and IPv6 local interfaces
+- add Fujicoin (fujicoin), Crown (Extreemist), RegTest (RCasatta),
+  Monacoin (cryptocoin-junkey)
+- bug fixes and updates (Kefkius, mmouse, thesamesam, cryptocoin-junkey,
+  jtarthur)
+
+Version 1.0.15
+--------------
+
+- split server networks faster if a fork is detected
+- minor speedup
+- add Vertcoin support (erasmospunk)
+- update Faircoin (thokon00)
+
+
+**Neil Booth**  kyuupichan@gmail.com  https://github.com/kyuupichan
+
+1BWwXJH3q6PRsizBkSGm2Uw4Sz1urZ5sCj
+
+LKaFk4KkVpw9pYoUpbckQSKKgCVC4oj78b
+
+.. _#223: https://github.com/kyuupichan/electrumx/issues/223
+.. _#251: https://github.com/kyuupichan/electrumx/issues/251
+.. _#277: https://github.com/kyuupichan/electrumx/issues/277
+.. _#287: https://github.com/kyuupichan/electrumx/issues/287
+.. _#302: https://github.com/kyuupichan/electrumx/issues/287

features.rst

@@ -24,3 +24,48 @@ Features
   for any reason.
 - Peer discovery protocol removes need for IRC
 - Coin abstraction makes compatible altcoin and testnet support easy.
+
+Implementation
+==============
+
+ElectrumX does not do any pruning or throwing away of history.  I want
+to retain this property for as long as it is feasible, and it appears
+efficiently achievable for the forseeable future with plain Python.
+
+The following all play a part in making ElectrumX very efficient as a
+Python blockchain indexer:
+
+- aggressive caching and batching of DB writes
+- more compact and efficient representation of UTXOs, address index,
+  and history.  Electrum Server stores full transaction hash and
+  height for each UTXO, and does the same in its pruned history.  In
+  contrast ElectrumX just stores the transaction number in the linear
+  history of transactions.  For at least another 5 years this
+  transaction number will fit in a 4-byte integer, and when necessary
+  expanding to 5 or 6 bytes is trivial.  ElectrumX can determine block
+  height from a simple binary search of tx counts stored on disk.
+  ElectrumX stores historical transaction hashes in a linear array on
+  disk.
+- placing static append-only metadata indexable by position on disk
+  rather than in levelDB.  It would be nice to do this for histories
+  but I cannot think of a way.
+- avoiding unnecessary or redundant computations, such as converting
+  address hashes to human-readable ASCII strings with expensive bignum
+  arithmetic, and then back again.
+- better choice of Python data structures giving lower memory usage as
+  well as faster traversal
+- leveraging asyncio for asynchronous prefetch of blocks to mostly
+  eliminate CPU idling.  As a Python program ElectrumX is unavoidably
+  single-threaded in its essence; we must keep that CPU core busy.
+
+Python's :mod:`asyncio` means ElectrumX has no (direct) use for threads
+and associated complications.
+
+Roadmap
+=======
+
+- offloading more work of wallet synchronization to the client
+- supporting better client privacy
+- wallet server engine
+- new features such as possibly adding label server functionality
+- potentially move some functionality to C or C++

index.rst

@@ -30,6 +30,7 @@ available .
 .. toctree::
 
    features
+   changelog
    HOWTO
    ENVIRONMENT
    PROTOCOL