merkle-patricia-tree
Version:
This is an implementation of the modified merkle patricia tree as specified in Ethereum's yellow paper.
289 lines • 13.2 kB
JavaScript
"use strict";
var __extends = (this && this.__extends) || (function () {
var extendStatics = function (d, b) {
extendStatics = Object.setPrototypeOf ||
({ __proto__: [] } instanceof Array && function (d, b) { d.__proto__ = b; }) ||
function (d, b) { for (var p in b) if (Object.prototype.hasOwnProperty.call(b, p)) d[p] = b[p]; };
return extendStatics(d, b);
};
return function (d, b) {
if (typeof b !== "function" && b !== null)
throw new TypeError("Class extends value " + String(b) + " is not a constructor or null");
extendStatics(d, b);
function __() { this.constructor = d; }
d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
};
})();
var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
return new (P || (P = Promise))(function (resolve, reject) {
function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
step((generator = generator.apply(thisArg, _arguments || [])).next());
});
};
var __generator = (this && this.__generator) || function (thisArg, body) {
var _ = { label: 0, sent: function() { if (t[0] & 1) throw t[1]; return t[1]; }, trys: [], ops: [] }, f, y, t, g;
return g = { next: verb(0), "throw": verb(1), "return": verb(2) }, typeof Symbol === "function" && (g[Symbol.iterator] = function() { return this; }), g;
function verb(n) { return function (v) { return step([n, v]); }; }
function step(op) {
if (f) throw new TypeError("Generator is already executing.");
while (_) try {
if (f = 1, y && (t = op[0] & 2 ? y["return"] : op[0] ? y["throw"] || ((t = y["return"]) && t.call(y), 0) : y.next) && !(t = t.call(y, op[1])).done) return t;
if (y = 0, t) op = [op[0] & 2, t.value];
switch (op[0]) {
case 0: case 1: t = op; break;
case 4: _.label++; return { value: op[1], done: false };
case 5: _.label++; y = op[1]; op = [0]; continue;
case 7: op = _.ops.pop(); _.trys.pop(); continue;
default:
if (!(t = _.trys, t = t.length > 0 && t[t.length - 1]) && (op[0] === 6 || op[0] === 2)) { _ = 0; continue; }
if (op[0] === 3 && (!t || (op[1] > t[0] && op[1] < t[3]))) { _.label = op[1]; break; }
if (op[0] === 6 && _.label < t[1]) { _.label = t[1]; t = op; break; }
if (t && _.label < t[2]) { _.label = t[2]; _.ops.push(op); break; }
if (t[2]) _.ops.pop();
_.trys.pop(); continue;
}
op = body.call(thisArg, _);
} catch (e) { op = [6, e]; y = 0; } finally { f = t = 0; }
if (op[0] & 5) throw op[1]; return { value: op[0] ? op[1] : void 0, done: true };
}
};
var __values = (this && this.__values) || function(o) {
var s = typeof Symbol === "function" && Symbol.iterator, m = s && o[s], i = 0;
if (m) return m.call(o);
if (o && typeof o.length === "number") return {
next: function () {
if (o && i >= o.length) o = void 0;
return { value: o && o[i++], done: !o };
}
};
throw new TypeError(s ? "Object is not iterable." : "Symbol.iterator is not defined.");
};
Object.defineProperty(exports, "__esModule", { value: true });
exports.CheckpointDB = void 0;
var db_1 = require("./db");
/**
* DB is a thin wrapper around the underlying levelup db,
* which validates inputs and sets encoding type.
*/
var CheckpointDB = /** @class */ (function (_super) {
__extends(CheckpointDB, _super);
/**
* Initialize a DB instance. If `leveldb` is not provided, DB
* defaults to an [in-memory store](https://github.com/Level/memdown).
* @param leveldb - An abstract-leveldown compliant store
*/
function CheckpointDB(leveldb) {
var _this = _super.call(this, leveldb) || this;
// Roots of trie at the moment of checkpoint
_this.checkpoints = [];
return _this;
}
Object.defineProperty(CheckpointDB.prototype, "isCheckpoint", {
/**
* Is the DB during a checkpoint phase?
*/
get: function () {
return this.checkpoints.length > 0;
},
enumerable: false,
configurable: true
});
/**
* Adds a new checkpoint to the stack
* @param root
*/
CheckpointDB.prototype.checkpoint = function (root) {
this.checkpoints.push({ keyValueMap: new Map(), root: root });
};
/**
* Commits the latest checkpoint
*/
CheckpointDB.prototype.commit = function () {
return __awaiter(this, void 0, void 0, function () {
var keyValueMap, batchOp_1, currentKeyValueMap_1;
return __generator(this, function (_a) {
switch (_a.label) {
case 0:
keyValueMap = this.checkpoints.pop().keyValueMap;
if (!!this.isCheckpoint) return [3 /*break*/, 2];
batchOp_1 = [];
keyValueMap.forEach(function (value, key) {
if (value === null) {
batchOp_1.push({
type: 'del',
key: Buffer.from(key, 'binary'),
});
}
else {
batchOp_1.push({
type: 'put',
key: Buffer.from(key, 'binary'),
value: value,
});
}
});
return [4 /*yield*/, this.batch(batchOp_1)];
case 1:
_a.sent();
return [3 /*break*/, 3];
case 2:
currentKeyValueMap_1 = this.checkpoints[this.checkpoints.length - 1].keyValueMap;
keyValueMap.forEach(function (value, key) { return currentKeyValueMap_1.set(key, value); });
_a.label = 3;
case 3: return [2 /*return*/];
}
});
});
};
/**
* Reverts the latest checkpoint
*/
CheckpointDB.prototype.revert = function () {
return __awaiter(this, void 0, void 0, function () {
var root;
return __generator(this, function (_a) {
root = this.checkpoints.pop().root;
return [2 /*return*/, root];
});
});
};
/**
* Retrieves a raw value from leveldb.
* @param key
* @returns A Promise that resolves to `Buffer` if a value is found or `null` if no value is found.
*/
CheckpointDB.prototype.get = function (key) {
return __awaiter(this, void 0, void 0, function () {
var index, value_1, value;
return __generator(this, function (_a) {
switch (_a.label) {
case 0:
// Lookup the value in our cache. We return the latest checkpointed value (which should be the value on disk)
for (index = this.checkpoints.length - 1; index >= 0; index--) {
value_1 = this.checkpoints[index].keyValueMap.get(key.toString('binary'));
if (value_1 !== undefined) {
return [2 /*return*/, value_1];
}
}
return [4 /*yield*/, _super.prototype.get.call(this, key)];
case 1:
value = _a.sent();
if (this.isCheckpoint) {
// Since we are a checkpoint, put this value in cache, so future `get` calls will not look the key up again from disk.
this.checkpoints[this.checkpoints.length - 1].keyValueMap.set(key.toString('binary'), value);
}
return [2 /*return*/, value];
}
});
});
};
/**
* Writes a value directly to leveldb.
* @param key The key as a `Buffer`
* @param value The value to be stored
*/
CheckpointDB.prototype.put = function (key, val) {
return __awaiter(this, void 0, void 0, function () {
return __generator(this, function (_a) {
switch (_a.label) {
case 0:
if (!this.isCheckpoint) return [3 /*break*/, 1];
// put value in cache
this.checkpoints[this.checkpoints.length - 1].keyValueMap.set(key.toString('binary'), val);
return [3 /*break*/, 3];
case 1: return [4 /*yield*/, _super.prototype.put.call(this, key, val)];
case 2:
_a.sent();
_a.label = 3;
case 3: return [2 /*return*/];
}
});
});
};
/**
* Removes a raw value in the underlying leveldb.
* @param keys
*/
CheckpointDB.prototype.del = function (key) {
return __awaiter(this, void 0, void 0, function () {
return __generator(this, function (_a) {
switch (_a.label) {
case 0:
if (!this.isCheckpoint) return [3 /*break*/, 1];
// delete the value in the current cache
this.checkpoints[this.checkpoints.length - 1].keyValueMap.set(key.toString('binary'), null);
return [3 /*break*/, 3];
case 1:
// delete the value on disk
return [4 /*yield*/, this._leveldb.del(key, db_1.ENCODING_OPTS)];
case 2:
// delete the value on disk
_a.sent();
_a.label = 3;
case 3: return [2 /*return*/];
}
});
});
};
/**
* Performs a batch operation on db.
* @param opStack A stack of levelup operations
*/
CheckpointDB.prototype.batch = function (opStack) {
return __awaiter(this, void 0, void 0, function () {
var opStack_1, opStack_1_1, op, e_1_1;
var e_1, _a;
return __generator(this, function (_b) {
switch (_b.label) {
case 0:
if (!this.isCheckpoint) return [3 /*break*/, 11];
_b.label = 1;
case 1:
_b.trys.push([1, 8, 9, 10]);
opStack_1 = __values(opStack), opStack_1_1 = opStack_1.next();
_b.label = 2;
case 2:
if (!!opStack_1_1.done) return [3 /*break*/, 7];
op = opStack_1_1.value;
if (!(op.type === 'put')) return [3 /*break*/, 4];
return [4 /*yield*/, this.put(op.key, op.value)];
case 3:
_b.sent();
return [3 /*break*/, 6];
case 4:
if (!(op.type === 'del')) return [3 /*break*/, 6];
return [4 /*yield*/, this.del(op.key)];
case 5:
_b.sent();
_b.label = 6;
case 6:
opStack_1_1 = opStack_1.next();
return [3 /*break*/, 2];
case 7: return [3 /*break*/, 10];
case 8:
e_1_1 = _b.sent();
e_1 = { error: e_1_1 };
return [3 /*break*/, 10];
case 9:
try {
if (opStack_1_1 && !opStack_1_1.done && (_a = opStack_1.return)) _a.call(opStack_1);
}
finally { if (e_1) throw e_1.error; }
return [7 /*endfinally*/];
case 10: return [3 /*break*/, 13];
case 11: return [4 /*yield*/, _super.prototype.batch.call(this, opStack)];
case 12:
_b.sent();
_b.label = 13;
case 13: return [2 /*return*/];
}
});
});
};
return CheckpointDB;
}(db_1.DB));
exports.CheckpointDB = CheckpointDB;
//# sourceMappingURL=checkpointDb.js.map