Linearize

Construct a linear, no-fork, best version of the Bitcoin blockchain. The scripts run using Python 3 but are compatible with Python 2.

Warning

Do not use -txindex=1 in this script.

Step 1:

Fix max_height in linearize.cfg

Step 1.1: Download hash list

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

Required configuration file linearize.cfg 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 linearize.cfg setting for linearize-hashes:

• RPC: host (Default: 127.0.0.1)
• RPC: port (Default: 34229)
• 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 1.2:

Change absolute location in linearize.cfg

input=/home/{USERNAME}/.sugarchain/blocks
output_file=/home/{USERNAME}/Desktop/bootstrap.dat

Step 1.3: Check outputs

$ head -1 hashlist.txt # genesis
  7d5eaec2dbb75f99feadfa524c78b7cabc1d8c8204f79d4f3a83381b811b0adc
$ wc -l hashlist.txt # 6500000+1 (add genesis)
  6500001 hashlist.txt
$ tail -n 1 hashlist.txt
  0ced7787d86e613c2e0aa02a297cde45a6626a53f4217f5d30af4357eeed3429

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).

Step 3: PGP signing on bootstrap release

$ cd ~/Desktop # move to output directory
$ zip -X bootstrap.dat.zip bootstrap.dat # zip into bootstrap.dat.zip
$ sha256sum bootstrap.dat.zip > SHA256SUMS
$ gpg --digest-algo sha256 --clearsign SHA256SUMS # PGP signing
$ rm SHA256SUMS && cat SHA256SUMS.asc # rename to asc
... # release

• Release following files at https://github.com/sugarchain-project/bootstrap/releases
  • bootstrap.dat.zip
  • SHA256SUMS.asc