envio/src/ReorgDetection.res.js

A latency and sync speed optimized, developer friendly blockchain data indexer.

// Generated by ReScript, PLEASE EDIT WITH CARE
'use strict';

var Belt_Array = require("rescript/lib/js/belt_Array.js");
var Belt_Option = require("rescript/lib/js/belt_Option.js");

function reorgDetectedToLogParams(reorgDetected, shouldRollbackOnReorg) {
  var scannedBlock = reorgDetected.scannedBlock;
  return {
          msg: "Blockchain reorg detected. " + (
            shouldRollbackOnReorg ? "Initiating indexer rollback" : "NOT initiating indexer rollback due to configuration"
          ) + ".",
          blockNumber: scannedBlock.blockNumber,
          indexedBlockHash: scannedBlock.blockHash,
          receivedBlockHash: reorgDetected.receivedBlock.blockHash
        };
}

function make(chainReorgCheckpoints, maxReorgDepth, shouldRollbackOnReorg) {
  var dataByBlockNumber = {};
  Belt_Array.forEach(chainReorgCheckpoints, (function (block) {
          dataByBlockNumber[block.block_number] = {
            blockHash: block.block_hash,
            blockNumber: block.block_number
          };
        }));
  return {
          shouldRollbackOnReorg: shouldRollbackOnReorg,
          maxReorgDepth: maxReorgDepth,
          dataByBlockNumber: dataByBlockNumber
        };
}

function getDataByBlockNumberCopyInThreshold(param, currentBlockHeight) {
  var dataByBlockNumber = param.dataByBlockNumber;
  var ascBlockNumberKeys = Object.keys(dataByBlockNumber);
  var thresholdBlockNumber = currentBlockHeight - param.maxReorgDepth | 0;
  var copy = {};
  for(var idx = 0 ,idx_finish = ascBlockNumberKeys.length; idx < idx_finish; ++idx){
    var blockNumberKey = ascBlockNumberKeys[idx];
    var scannedBlock = dataByBlockNumber[blockNumberKey];
    var isInReorgThreshold = scannedBlock.blockNumber >= thresholdBlockNumber;
    if (isInReorgThreshold) {
      copy[blockNumberKey] = scannedBlock;
    }
    
  }
  return copy;
}

function registerReorgGuard(self, reorgGuard, currentBlockHeight) {
  var maxReorgDepth = self.maxReorgDepth;
  var shouldRollbackOnReorg = self.shouldRollbackOnReorg;
  var dataByBlockNumberCopyInThreshold = getDataByBlockNumberCopyInThreshold(self, currentBlockHeight);
  var prevRangeLastBlock = reorgGuard.prevRangeLastBlock;
  var rangeLastBlock = reorgGuard.rangeLastBlock;
  var scannedBlock = dataByBlockNumberCopyInThreshold[String(rangeLastBlock.blockNumber)];
  var maybeReorgDetected;
  var exit = 0;
  if (scannedBlock !== undefined && scannedBlock.blockHash !== rangeLastBlock.blockHash) {
    maybeReorgDetected = {
      scannedBlock: scannedBlock,
      receivedBlock: rangeLastBlock
    };
  } else {
    exit = 1;
  }
  if (exit === 1) {
    if (prevRangeLastBlock !== undefined) {
      var scannedBlock$1 = dataByBlockNumberCopyInThreshold[String(prevRangeLastBlock.blockNumber)];
      maybeReorgDetected = scannedBlock$1 !== undefined && scannedBlock$1.blockHash !== prevRangeLastBlock.blockHash ? ({
            scannedBlock: scannedBlock$1,
            receivedBlock: prevRangeLastBlock
          }) : undefined;
    } else {
      maybeReorgDetected = undefined;
    }
  }
  if (maybeReorgDetected !== undefined) {
    return [
            shouldRollbackOnReorg ? self : make([], maxReorgDepth, shouldRollbackOnReorg),
            {
              TAG: "ReorgDetected",
              _0: maybeReorgDetected
            }
          ];
  } else {
    dataByBlockNumberCopyInThreshold[String(rangeLastBlock.blockNumber)] = rangeLastBlock;
    if (prevRangeLastBlock !== undefined) {
      dataByBlockNumberCopyInThreshold[String(prevRangeLastBlock.blockNumber)] = prevRangeLastBlock;
    }
    return [
            {
              shouldRollbackOnReorg: shouldRollbackOnReorg,
              maxReorgDepth: maxReorgDepth,
              dataByBlockNumber: dataByBlockNumberCopyInThreshold
            },
            "NoReorg"
          ];
  }
}

function getLatestValidScannedBlock(reorgDetection, blockNumbersAndHashes) {
  var verifiedDataByBlockNumber = {};
  for(var idx = 0 ,idx_finish = blockNumbersAndHashes.length; idx < idx_finish; ++idx){
    var blockData = blockNumbersAndHashes[idx];
    verifiedDataByBlockNumber[String(blockData.blockNumber)] = blockData;
  }
  var ascBlockNumberKeys = Object.keys(verifiedDataByBlockNumber);
  var getPrevScannedBlockNumber = function (idx) {
    return Belt_Option.map(Belt_Array.get(ascBlockNumberKeys, idx - 1 | 0), (function (key) {
                  return verifiedDataByBlockNumber[key].blockNumber;
                }));
  };
  var _idx = 0;
  while(true) {
    var idx$1 = _idx;
    var blockNumberKey = Belt_Array.get(ascBlockNumberKeys, idx$1);
    if (blockNumberKey === undefined) {
      return getPrevScannedBlockNumber(idx$1);
    }
    var scannedBlock = reorgDetection.dataByBlockNumber[blockNumberKey];
    if (scannedBlock === undefined) {
      return getPrevScannedBlockNumber(idx$1);
    }
    if (verifiedDataByBlockNumber[blockNumberKey].blockHash !== scannedBlock.blockHash) {
      return getPrevScannedBlockNumber(idx$1);
    }
    _idx = idx$1 + 1 | 0;
    continue ;
  };
}

function rollbackToValidBlockNumber(param, blockNumber) {
  var dataByBlockNumber = param.dataByBlockNumber;
  var ascBlockNumberKeys = Object.keys(dataByBlockNumber);
  var newDataByBlockNumber = {};
  var loop = function (_idx) {
    while(true) {
      var idx = _idx;
      var blockNumberKey = Belt_Array.get(ascBlockNumberKeys, idx);
      if (blockNumberKey === undefined) {
        return ;
      }
      var scannedBlock = dataByBlockNumber[blockNumberKey];
      var shouldKeep = scannedBlock.blockNumber <= blockNumber;
      if (!shouldKeep) {
        return ;
      }
      newDataByBlockNumber[blockNumberKey] = scannedBlock;
      _idx = idx + 1 | 0;
      continue ;
    };
  };
  loop(0);
  return {
          shouldRollbackOnReorg: param.shouldRollbackOnReorg,
          maxReorgDepth: param.maxReorgDepth,
          dataByBlockNumber: newDataByBlockNumber
        };
}

function getThresholdBlockNumbersBelowBlock(self, blockNumber, currentBlockHeight) {
  var arr = [];
  var ascBlockNumberKeys = Object.keys(self.dataByBlockNumber);
  var thresholdBlockNumber = currentBlockHeight - self.maxReorgDepth | 0;
  for(var idx = 0 ,idx_finish = ascBlockNumberKeys.length; idx < idx_finish; ++idx){
    var blockNumberKey = ascBlockNumberKeys[idx];
    var scannedBlock = self.dataByBlockNumber[blockNumberKey];
    var isInReorgThreshold = scannedBlock.blockNumber >= thresholdBlockNumber;
    if (isInReorgThreshold && scannedBlock.blockNumber < blockNumber) {
      arr.push(scannedBlock.blockNumber);
    }
    
  }
  return arr;
}

function getHashByBlockNumber(reorgDetection, blockNumber) {
  var v = reorgDetection.dataByBlockNumber[blockNumber];
  if (v !== undefined) {
    return v.blockHash;
  } else {
    return null;
  }
}

exports.reorgDetectedToLogParams = reorgDetectedToLogParams;
exports.make = make;
exports.getDataByBlockNumberCopyInThreshold = getDataByBlockNumberCopyInThreshold;
exports.registerReorgGuard = registerReorgGuard;
exports.getLatestValidScannedBlock = getLatestValidScannedBlock;
exports.rollbackToValidBlockNumber = rollbackToValidBlockNumber;
exports.getThresholdBlockNumbersBelowBlock = getThresholdBlockNumbersBelowBlock;
exports.getHashByBlockNumber = getHashByBlockNumber;
/* No side effect */