Smart Contract Tour

This is a tour through some of go-ethereum’s source code relating to smart contracts:

Setup

The geth client must be run as a full node for this walkthrough. Full nodes can:

  • Mine real ether
  • Transfer funds between addresses
  • Create contracts and send transactions
  • Explore block history

  1. The command line to set up for this tour is:

    $ geth --syncmode full --cache 64 --maxpeers 12 \
 --rpcapi --wsapi --rinkeby

    Typical output looks like:

    INFO [06-27|13:38:05] Maximum peer count                       ETH=12 LES=0 total=12
INFO [06-27|13:38:05] Starting peer-to-peer node               instance=Geth/v1.8.11-stable-dea1ce05/linux-amd64/go1.10
INFO [06-27|13:38:05] Allocated cache and file handles         database=/home/mslinn/.ethereum/rinkeby/geth/chaindata cache=48 handles=512
INFO [06-27|13:38:05] Writing custom genesis block
INFO [06-27|13:38:05] Persisted trie from memory database      nodes=355 size=51.91kB time=2.318ms gcnodes=0 gcsize=0.00B gctime=0s livenodes=1 livesize=0.00B
INFO [06-27|13:38:05] Initialised chain configuration          config="{ChainID: 4 Homestead: 1 DAO: <nil> DAOSupport: true EIP150: 2 EIP155: 3 EIP158: 3 Byzantium: 1035301 Constantinople: <nil> Engine: clique}"
INFO [06-27|13:38:05] Initialising Ethereum protocol           versions="[63 62]" network=4
INFO [06-27|13:38:05] Loaded most recent local header          number=0 hash=6341fd…67e177 td=1
INFO [06-27|13:38:05] Loaded most recent local full block      number=0 hash=6341fd…67e177 td=1
INFO [06-27|13:38:05] Loaded most recent local fast block      number=0 hash=6341fd…67e177 td=1
INFO [06-27|13:38:05] Regenerated local transaction journal    transactions=0 accounts=0
INFO [06-27|13:38:05] Starting P2P networking
INFO [06-27|13:38:08] UDP listener up                          self=enode://fe9c3c8f29c364be0fc7659e1b6f8e9eb90c8ed7861d0b02474d3b46adff1581cc6f4be61a8769da087449358c24a2642cebd3a6797ce49bdeeca087ceea836c@[::]:30303
INFO [06-27|13:38:08] RLPx listener up                         self=enode://fe9c3c8f29c364be0fc7659e1b6f8e9eb90c8ed7861d0b02474d3b46adff1581cc6f4be61a8769da087449358c24a2642cebd3a6797ce49bdeeca087ceea836c@[::]:30303
INFO [06-27|13:38:08] IPC endpoint opened                      url=/home/mslinn/.ethereum/rinkeby/geth.ipc
INFO [06-27|13:38:18] Block synchronisation started
INFO [06-27|13:38:20] Imported new chain segment               blocks=54 txs=0 mgas=0.000 elapsed=14.861ms mgasps=0.000 number=54 hash=dafe6e…02bf13 cache=0.00B

    Many messages similar to the last one should continuously appear. It typically takes hours for an Ethereum node to fully synchronize with the blockchain.

  2. Start a JavaScript console in another terminal console that connects to the above running geth instance with this incantation:

    $ geth attach ~/.ethereum/rinkeby/geth.ipc

  3. When you are done with this tour, press CTRL-C from the first terminal console to terminate geth. Output generated by geth as it shuts down will look something like:

    INFO [06-27|13:39:03] IPC endpoint closed                      endpoint=/home/mslinn/.ethereum/rinkeby/geth.ipc
INFO [06-27|13:39:03] Writing cached state to disk             block=46376 hash=7efacc…f41d6c root=d4e03e…041271
INFO [06-27|13:39:03] Persisted trie from memory database      nodes=283 size=49.29kB time=9.335ms gcnodes=1617 gcsize=407.84kB gctime=77.473ms livenodes=1 livesize=0.00B
INFO [06-27|13:39:03] Writing cached state to disk             block=46375 hash=83aa1c…be0d26 root=d4e03e…041271
INFO [06-27|13:39:03] Persisted trie from memory database      nodes=0   size=0.00B   time=24µs    gcnodes=0    gcsize=0.00B    gctime=0s       livenodes=1 livesize=0.00B
INFO [06-27|13:39:03] Writing cached state to disk             block=46249 hash=b4cdf5…f24d50 root=d4e03e…041271
INFO [06-27|13:39:03] Persisted trie from memory database      nodes=0   size=0.00B   time=9µs     gcnodes=0    gcsize=0.00B    gctime=0s       livenodes=1 livesize=0.00B
INFO [06-27|13:39:03] Blockchain manager stopped
INFO [06-27|13:39:03] Stopping Ethereum protocol
WARN [06-27|13:39:03] Synchronisation failed, retrying         err="header processing canceled (requested)"
INFO [06-27|13:39:03] Ethereum protocol stopped
INFO [06-27|13:39:03] Transaction pool stopped
INFO [06-27|13:39:03] Database closed                          database=/home/mslinn/.ethereum/rinkeby/geth/chaindata

results matching ""

    No results matching ""