从 geth 事务跟踪中提取发出的事件(日志)(debug_traceCall)
Extracting emitted events (logs) from geth transaction trace (debug_traceCall)
使用 debug_traceCall 时,我得到了执行期间所有操作码和状态更改的低级 EVM 跟踪。这个太详细了。当我使用默认 callTracer
时,我可以获得更好的调用树。但是,无论哪种方式,我似乎都无法从跟踪中提取发出的事件。我可以在跟踪中看到它们(LOG*
操作码)但是没有简单的方法将它们实际解析为“可读”的东西(连同值和原始地址)必须有一种获取日志的方法 - 任何想法?
例如。这是 Etherscan 显示的内容 https://etherscan.io/tx-decoder?tx=0x3e3ad35fda1fddd9e154b3860b50371a1acd2fdb4f27f897e234846522bde732(请参阅已发出的事件部分)
所以我自己想到了这一点 - 我为 geth 创建了一个自定义 JavaScript 跟踪器,它在第三个参数中传递给 geth 到 debug_traceCall(参见 API 提供的参考 link):
{
data: [],
fault: function (log) {
},
step: function (log) {
var topicCount = (log.op.toString().match(/LOG(\d)/) || [])[1];
if (topicCount) {
var res = {
address: log.contract.getAddress(),
data: log.memory.slice(parseInt(log.stack.peek(0)), parseInt(log.stack.peek(0)) + parseInt(log.stack.peek(1))),
};
for (var i = 0; i < topicCount; i++)
res['topic' + i.toString()] = log.stack.peek(i + 2);
this.data.push(res);
}
},
result: function () {
return this.data;
}
}
此跟踪程序由 geth 为跟踪中的每个操作执行。它的主要作用:
- 检查这是否是
LOG0
、LOG1
、LOG2
、LOG3
或 LOG4
EVM 操作码之一
- 从当前合约中提取合约地址
- 提取默认
topic0
和后续主题(如果有)
- 从内存中提取额外的事件数据(注意:stack[0]是偏移量,stack[1]是数据大小)
将跟踪器传递给 geth 如下所示:
res = await ethersProvider.send('debug_traceCall', [{
from: tx.from,
to: tx.to,
gas: BigNumber.from(tx.gas)._hex.replace('0x0', '0x'),
gasPrice: BigNumber.from(tx.gasPrice)._hex.replace('0x0', '0x'),
value: BigNumber.from(tx.value)._hex.replace('0x0', '0x'),
data: tx.input
}, "latest", {
tracer: "{\n" +
" data: [],\n" +
" fault: function (log) {\n" +
" },\n" +
" step: function (log) {\n" +
" var topicCount = (log.op.toString().match(/LOG(\d)/) || [])[1];\n" +
" if (topicCount) {\n" +
" var res = {\n" +
" address: log.contract.getAddress(),\n" +
" data: log.memory.slice(parseInt(log.stack.peek(0)), parseInt(log.stack.peek(0)) + parseInt(log.stack.peek(1))),\n" +
" };\n" +
" for (var i = 0; i < topicCount; i++)\n" +
" res['topic' + i.toString()] = log.stack.peek(i + 2);\n" +
" this.data.push(res);\n" +
" }\n" +
" },\n" +
" result: function () {\n" +
" return this.data;\n" +
" }\n" +
"}",
enableMemory: true,
enableReturnData: true,
disableStorage: true
}])
使用 debug_traceCall 时,我得到了执行期间所有操作码和状态更改的低级 EVM 跟踪。这个太详细了。当我使用默认 callTracer
时,我可以获得更好的调用树。但是,无论哪种方式,我似乎都无法从跟踪中提取发出的事件。我可以在跟踪中看到它们(LOG*
操作码)但是没有简单的方法将它们实际解析为“可读”的东西(连同值和原始地址)必须有一种获取日志的方法 - 任何想法?
例如。这是 Etherscan 显示的内容 https://etherscan.io/tx-decoder?tx=0x3e3ad35fda1fddd9e154b3860b50371a1acd2fdb4f27f897e234846522bde732(请参阅已发出的事件部分)
所以我自己想到了这一点 - 我为 geth 创建了一个自定义 JavaScript 跟踪器,它在第三个参数中传递给 geth 到 debug_traceCall(参见 API 提供的参考 link):
{
data: [],
fault: function (log) {
},
step: function (log) {
var topicCount = (log.op.toString().match(/LOG(\d)/) || [])[1];
if (topicCount) {
var res = {
address: log.contract.getAddress(),
data: log.memory.slice(parseInt(log.stack.peek(0)), parseInt(log.stack.peek(0)) + parseInt(log.stack.peek(1))),
};
for (var i = 0; i < topicCount; i++)
res['topic' + i.toString()] = log.stack.peek(i + 2);
this.data.push(res);
}
},
result: function () {
return this.data;
}
}
此跟踪程序由 geth 为跟踪中的每个操作执行。它的主要作用:
- 检查这是否是
LOG0
、LOG1
、LOG2
、LOG3
或LOG4
EVM 操作码之一 - 从当前合约中提取合约地址
- 提取默认
topic0
和后续主题(如果有) - 从内存中提取额外的事件数据(注意:stack[0]是偏移量,stack[1]是数据大小)
将跟踪器传递给 geth 如下所示:
res = await ethersProvider.send('debug_traceCall', [{
from: tx.from,
to: tx.to,
gas: BigNumber.from(tx.gas)._hex.replace('0x0', '0x'),
gasPrice: BigNumber.from(tx.gasPrice)._hex.replace('0x0', '0x'),
value: BigNumber.from(tx.value)._hex.replace('0x0', '0x'),
data: tx.input
}, "latest", {
tracer: "{\n" +
" data: [],\n" +
" fault: function (log) {\n" +
" },\n" +
" step: function (log) {\n" +
" var topicCount = (log.op.toString().match(/LOG(\d)/) || [])[1];\n" +
" if (topicCount) {\n" +
" var res = {\n" +
" address: log.contract.getAddress(),\n" +
" data: log.memory.slice(parseInt(log.stack.peek(0)), parseInt(log.stack.peek(0)) + parseInt(log.stack.peek(1))),\n" +
" };\n" +
" for (var i = 0; i < topicCount; i++)\n" +
" res['topic' + i.toString()] = log.stack.peek(i + 2);\n" +
" this.data.push(res);\n" +
" }\n" +
" },\n" +
" result: function () {\n" +
" return this.data;\n" +
" }\n" +
"}",
enableMemory: true,
enableReturnData: true,
disableStorage: true
}])