137 lines
2.9 KiB
JavaScript
137 lines
2.9 KiB
JavaScript
/**
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* ldb.js - database backend for bcoin
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* Copyright (c) 2014-2015, Fedor Indutny (MIT License)
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* Copyright (c) 2014-2017, Christopher Jeffrey (MIT License).
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* https://github.com/bcoin-org/bcoin
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*/
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'use strict';
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var assert = require('assert');
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var LowlevelUp = require('./lowlevelup');
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var backends = require('./backends');
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/**
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* Create a database.
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* @alias module:db.LDB
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* @param {Object} options
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* @param {Boolean} options.compression
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* @param {Number} options.cacheSize
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* @param {Number} options.writeBufferSize
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* @param {Number} options.maxOpenFiles
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* @param {Boolean} options.sync
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* @param {Number} options.mapSize
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* @param {Boolean} options.writeMap
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* @param {String} options.db - Database backend (`"leveldb"` by default).
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* @param {String} options.name - Database name.
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* @param {String} options.location - Database location (overrides `name`).
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* @returns {LowlevelUp}
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*/
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function LDB(options) {
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var target = LDB.getTarget(options);
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var cacheSize = options.cacheSize;
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if (!cacheSize)
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cacheSize = 16 << 20;
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return new LowlevelUp(target.location, {
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// Generic
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createIfMissing: options.createIfMissing !== false,
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errorIfExists: options.errorIfExists === true,
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// LevelDB
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compression: options.compression === true,
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cacheSize: cacheSize / 2 | 0,
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writeBufferSize: cacheSize / 4 | 0,
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maxOpenFiles: options.maxFiles || 64,
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paranoidChecks: false,
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memory: false,
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// LMDB
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sync: options.sync || false,
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mapSize: options.mapSize || 256 * (1024 << 20),
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writeMap: options.writeMap || false,
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noSubdir: options.noSubdir !== false,
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// Browser
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bufferKeys: options.bufferKeys,
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db: target.db
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});
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}
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/**
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* Get database name and extension based on options.
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* @param {String} db
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* @returns {Object}
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*/
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LDB.getBackend = function getBackend(db) {
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var name, ext;
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if (!db)
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db = 'memory';
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switch (db) {
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case 'ldb':
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case 'leveldb':
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case 'leveldown':
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name = 'leveldown';
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ext = 'ldb';
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break;
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case 'rdb':
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case 'rocksdb':
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case 'rocksdown':
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name = 'rocksdown';
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ext = 'rdb';
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break;
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case 'mdb':
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case 'lmdb':
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name = 'lmdb';
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ext = 'mdb';
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break;
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case 'mem':
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case 'memory':
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case 'rbt':
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name = 'memory';
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ext = 'mem';
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break;
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default:
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name = db;
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ext = 'db';
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break;
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}
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return { name: name, ext: ext };
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};
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/**
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* Get target backend and location.
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* @param {Object} options
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* @returns {Object}
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*/
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LDB.getTarget = function getTarget(options) {
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var backend = LDB.getBackend(options.db);
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var location = options.location;
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var db = backends.get(backend.name);
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if (typeof location !== 'string') {
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assert(backend.name === 'memory', 'Location required.');
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location = 'memory';
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}
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return {
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db: db,
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backend: backend.name,
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location: location + '.' + backend.ext
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};
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};
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/*
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* Expose
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*/
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module.exports = LDB;
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