envio/src/ReorgDetection.res.mjs

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

// Generated by ReScript, PLEASE EDIT WITH CARE

import * as Stdlib_Option from "@rescript/runtime/lib/es6/Stdlib_Option.js";

function reorgDetectedToLogParams(reorgDetected, shouldRollbackOnReorg) {
  let 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) {
  let dataByBlockNumber = {};
  chainReorgCheckpoints.forEach(block => {
    dataByBlockNumber[block.block_number] = {
      blockHash: block.block_hash,
      blockNumber: block.block_number
    };
  });
  return {
    shouldRollbackOnReorg: shouldRollbackOnReorg,
    maxReorgDepth: maxReorgDepth,
    dataByBlockNumber: dataByBlockNumber
  };
}

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

function registerReorgGuard(self, blockHashes, knownHeight) {
  let maxReorgDepth = self.maxReorgDepth;
  let shouldRollbackOnReorg = self.shouldRollbackOnReorg;
  let dataByBlockNumberCopyInThreshold = getDataByBlockNumberCopyInThreshold(self, knownHeight);
  let thresholdBlockNumber = knownHeight - maxReorgDepth | 0;
  let maybeReorgDetected;
  let idx = 0;
  while (maybeReorgDetected === undefined && idx < blockHashes.length) {
    let receivedBlock = blockHashes[idx];
    if (receivedBlock.blockNumber >= thresholdBlockNumber) {
      let key = receivedBlock.blockNumber.toString();
      let scannedBlock = dataByBlockNumberCopyInThreshold[key];
      if (scannedBlock !== undefined && scannedBlock.blockHash !== receivedBlock.blockHash) {
        maybeReorgDetected = {
          scannedBlock: scannedBlock,
          receivedBlock: receivedBlock
        };
      } else {
        dataByBlockNumberCopyInThreshold[key] = receivedBlock;
      }
    }
    idx = idx + 1 | 0;
  };
  let reorgDetected = maybeReorgDetected;
  if (reorgDetected !== undefined) {
    return [
      shouldRollbackOnReorg ? self : make([], maxReorgDepth, shouldRollbackOnReorg),
      {
        TAG: "ReorgDetected",
        _0: reorgDetected
      }
    ];
  } else {
    return [
      {
        shouldRollbackOnReorg: shouldRollbackOnReorg,
        maxReorgDepth: maxReorgDepth,
        dataByBlockNumber: dataByBlockNumberCopyInThreshold
      },
      "NoReorg"
    ];
  }
}

function getLatestValidScannedBlock(reorgDetection, blockNumbersAndHashes) {
  let verifiedDataByBlockNumber = {};
  for (let idx = 0, idx_finish = blockNumbersAndHashes.length; idx < idx_finish; ++idx) {
    let blockData = blockNumbersAndHashes[idx];
    verifiedDataByBlockNumber[blockData.blockNumber.toString()] = blockData;
  }
  let ascBlockNumberKeys = Object.keys(verifiedDataByBlockNumber);
  let getPrevScannedBlockNumber = idx => Stdlib_Option.map(ascBlockNumberKeys[idx - 1 | 0], key => verifiedDataByBlockNumber[key].blockNumber);
  let _idx = 0;
  while (true) {
    let idx$1 = _idx;
    let blockNumberKey = ascBlockNumberKeys[idx$1];
    if (blockNumberKey === undefined) {
      return getPrevScannedBlockNumber(idx$1);
    }
    let 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) {
  let dataByBlockNumber = param.dataByBlockNumber;
  let ascBlockNumberKeys = Object.keys(dataByBlockNumber);
  let newDataByBlockNumber = {};
  let loop = _idx => {
    while (true) {
      let idx = _idx;
      let blockNumberKey = ascBlockNumberKeys[idx];
      if (blockNumberKey === undefined) {
        return;
      }
      let scannedBlock = dataByBlockNumber[blockNumberKey];
      let 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, knownHeight) {
  let arr = [];
  let ascBlockNumberKeys = Object.keys(self.dataByBlockNumber);
  let thresholdBlockNumber = knownHeight - self.maxReorgDepth | 0;
  for (let idx = 0, idx_finish = ascBlockNumberKeys.length; idx < idx_finish; ++idx) {
    let blockNumberKey = ascBlockNumberKeys[idx];
    let scannedBlock = self.dataByBlockNumber[blockNumberKey];
    let isInReorgThreshold = scannedBlock.blockNumber >= thresholdBlockNumber;
    if (isInReorgThreshold && scannedBlock.blockNumber < blockNumber) {
      arr.push(scannedBlock.blockNumber);
    }
  }
  return arr;
}

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

export {
  reorgDetectedToLogParams,
  make,
  getDataByBlockNumberCopyInThreshold,
  registerReorgGuard,
  getLatestValidScannedBlock,
  rollbackToValidBlockNumber,
  getThresholdBlockNumbersBelowBlock,
  getHashByBlockNumber,
}
/* No side effect */