Linearize

Construct a linear, no-fork, best version of the Bitcoin blockchain.

Step 1: Download hash list

$ ./linearize-hashes.py linearize.cfg > hashlist.txt

Required configuration file settings for linearize-hashes:

  • RPC: datadir (Required if rpcuser and rpcpassword are not specified)
  • RPC: rpcuser, rpcpassword (Required if datadir is not specified)

Optional config file setting for linearize-hashes:

  • RPC: host (Default: 127.0.0.1)
  • RPC: port (Default: 8332)
  • Blockchain: min_height, max_height
  • rev_hash_bytes: If true, the written block hash list will be byte-reversed. (In other words, the hash returned by getblockhash will have its bytes reversed.) False by default. Intended for generation of standalone hash lists but safe to use with linearize-data.py, which will output the same data no matter which byte format is chosen.

The linearize-hashes script requires a connection, local or remote, to a JSON-RPC server. Running bitcoind or bitcoin-qt -server will be sufficient.

Step 2: Copy local block data

$ ./linearize-data.py linearize.cfg

Required configuration file settings:

  • output_file: The file that will contain the final blockchain. or
  • output: Output directory for linearized blocks/blkNNNNN.dat output.

Optional config file setting for linearize-data:

  • debug_output: Some printouts may not always be desired. If true, such output will be printed.
  • file_timestamp: Set each file's last-accessed and last-modified times, respectively, to the current time and to the timestamp of the most recent block written to the script's blockchain.
  • genesis: The hash of the genesis block in the blockchain.
  • input: bitcoind blocks/ directory containing blkNNNNN.dat
  • hashlist: text file containing list of block hashes created by linearize-hashes.py.
  • max_out_sz: Maximum size for files created by the output_file option. (Default: 1000*1000*1000 bytes)
  • netmagic: Network magic number.
  • out_of_order_cache_sz: If out-of-order blocks are being read, the block can be written to a cache so that the blockchain doesn't have to be sought again. This option specifies the cache size. (Default: 100*1000*1000 bytes)
  • rev_hash_bytes: If true, the block hash list written by linearize-hashes.py will be byte-reversed when read by linearize-data.py. See the linearize-hashes entry for more information.
  • split_timestamp: Split blockchain files when a new month is first seen, in addition to reaching a maximum file size (max_out_sz).