在以太坊实战【地址监控一】中已经找到了一种用JsonRPC的方式可以对地址进行监控，继续细节实现。

数据解析

块数据

通过RPC接口可以取到块数据，直接返回的是json格式，具体格式如下：

• number: QUANTITY - the block number. null when its pending block.
• hash: DATA, 32 Bytes - hash of the block. null when its pending block.
• parentHash: DATA, 32 Bytes - hash of the parent block.
• nonce: DATA, 8 Bytes - hash of the generated proof-of-work. null when its pending block.
• sha3Uncles: DATA, 32 Bytes - SHA3 of the uncles data in the block.
• logsBloom: DATA, 256 Bytes - the bloom filter for the logs of the block. null when its pending block.
• transactionsRoot: DATA, 32 Bytes - the root of the transaction trie of the block.
• stateRoot: DATA, 32 Bytes - the root of the final state trie of the block.
• receiptsRoot: DATA, 32 Bytes - the root of the receipts trie of the block.
• miner: DATA, 20 Bytes - the address of the beneficiary to whom the mining rewards were given.
• difficulty: QUANTITY - integer of the difficulty for this block.
• totalDifficulty: QUANTITY - integer of the total difficulty of the chain until this block.
• extraData: DATA - the "extra data" field of this block.
• size: QUANTITY - integer the size of this block in bytes.
• gasLimit: QUANTITY - the maximum gas allowed in this block.
• gasUsed: QUANTITY - the total used gas by all transactions in this block.
• timestamp: QUANTITY - the unix timestamp for when the block was collated.
• transactions: Array - Array of transaction objects, or 32 Bytes transaction hashes depending on the last given parameter.
• uncles: Array - Array of uncle hashes.

地址监控可能有用的字段有：

• number：用来判断下一块，记录处理块位置
• transactions：交易列表，需要通过这个交易列表判断是否要我们要处理的交易，还有交易的变化情况

交易数据

• hash: DATA, 32 Bytes - hash of the transaction.
• nonce: QUANTITY - the number of transactions made by the sender prior to this one.
• blockHash: DATA, 32 Bytes - hash of the block where this transaction was in. null when its pending.
• blockNumber: QUANTITY - block number where this transaction was in. null when its pending.
• transactionIndex: QUANTITY - integer of the transactions index position in the block. null when its pending.
• from: DATA, 20 Bytes - address of the sender.
• to: DATA, 20 Bytes - address of the receiver. null when its a contract creation transaction.
• value: QUANTITY - value transferred in Wei.
• gasPrice: QUANTITY - gas price provided by the sender in Wei.
• gas: QUANTITY - gas provided by the sender.
• input: DATA - the data send along with the transaction.
• * 测试数据中还出现了v、r、s字段，暂时不明白意义

v、r、s的内容可以参考这个贴子 2018.03.23

地址监控可能有用的字段有：

• from：用来判断是否监控地址
• to：用来判断是否监控地址
• value：如果是监控地址时，这是Wei的进出数量

实现

通过JsonRPC调用的接口取到了数据，数据结构基本都清晰了，进一步就是怎么完整解析出变化地址，并与监控地址比较，如果是监控地址则进一步处理变化信息。

class EthAddrWatcher:
    def addWatchAddresses(self, setAddrWatch):

    def removeWatchAddresses(self, setAddrWatch):

    def onAddressChanged(self):
    # 地址交易变化

    def run(self, noBlockStart):
    # 从指定块处理到最新块
    # 监控新块变化

完整代码由于还在测试期间，先不列出来了，大体结构就这样，也可以编译成命令行形式直接执行对指定地址的监控。

为了测试代码，用监控代码从创世区块开始跑起，发现在区块高度4万多才开始有交易数据，零星的一两笔持续了很长时间，只到区块高度300多万才有几十上百笔交易，能感受到以太坊成、住、坏、空的过程也是件很有意思的事情！

onBlock number: 46147(0xb443),transactions num:1
...
onBlock number: 4000985(0x3d0cd9),transactions num:320
onBlock number: 4000986(0x3d0cda),transactions num:108
onBlock number: 4000987(0x3d0cdb),transactions num:64
onBlock number: 4000988(0x3d0cdc),transactions num:134
onBlock number: 4000989(0x3d0cdd),transactions num:60

做这个过程中找到有位区块链先行者在2016年写的文章，他还留了以太坊地址，用程序代码跑了一下这个地址：0x893608751d68d046e85802926673cdf2f57f7cb8，发现这人进帐不少啊！佩服！

问题

eth_blockNumber返回0

POST url:http://192.168.0.122:8545,data:{"jsonrpc":"2.0","method":"eth_blockNumber","params":[],"id":1}
{"jsonrpc":"2.0","id":1,"result":"0x0"}

这个调用一直返回0，查了下原因说是同步过程中状态没更新，不管什么原因，这个用不了其它就没法执行了！

既然是同步问题，刚好有个eth_syncing接口，调用这个查询同步状态，如下：

POST url:http://192.168.0.122:8545,data:{"jsonrpc":"2.0","method":"eth_syncing","params":[],"id":2}
{"jsonrpc":"2.0","id":2,"result":{"currentBlock":"0x508255","highestBlock":"0x508296","knownStates":"0xffab46","pulledStates":"0xff7352","startingBlock":"0x50821f"}}

这个地方注意rpc文档里的例子是curl -X POST --data '{"jsonrpc":"2.0","method":"eth_isSyncing","params":[],"id":1}'，这个method方法不对

我们正常是会有一个全节点在同步的，因为现有线上的节点基本都不会对外开放rpc接口调用了，那就用eth_syncing这个接口取得的currentBlock来进行当前块判断，当然这个接口调用也有可能返回失败，失败则用eth_blockNumber的结果。

geth配置

开启RPC调用，为安全起见，只需要指定eth模块，可绑定IP地址和端口等，如下：

geth.exe --datadir "YOURETHDATADIR" --rpc --rpcaddr "YOURIP" --nodiscover --rpcapi "eth" console

参考

https://ethereum.gitbooks.io/frontier-guide/content/rpc.html#eth_getfilterchanges

https://github.com/ethereum/go-ethereum/issues/14338

http://www.yaozihao.cn/2017/07/07/geth%E5%91%BD%E4%BB%A4%E9%80%89%E9%A1%B9%E4%BB%8B%E7%BB%8D/

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