119 lines
2.8 KiB
JavaScript
119 lines
2.8 KiB
JavaScript
/**
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* lowlevelup.js - low level levelup
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* Copyright (c) 2014-2015, Fedor Indutny (MIT License)
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* Copyright (c) 2014-2016, Christopher Jeffrey (MIT License).
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* https://github.com/indutny/bcoin
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*/
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var utils = require('./utils');
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var EventEmitter = require('events').EventEmitter;
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/**
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* LowlevelUp
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*
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* Extremely low-level version of levelup.
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* The only levelup feature it provides is
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* error-wrapping. It gives a nice recallable
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* `open()` method and event. It assumes ascii
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* keys and binary values.
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*
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* This avoids pulling in extra deps and
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* lowers memory usage.
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*/
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function LowlevelUp(file, options) {
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var self = this;
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if (!(this instanceof LowlevelUp))
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return new LowlevelUp(file, options);
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EventEmitter.call(this);
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this.loaded = false;
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this.db = new options.db(file);
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// Stay as close to the metal as possible.
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// We want to make calls to C++ directly.
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while (this.db.db && this.db.db.put && this.db.db !== this.db)
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this.db = this.db.db;
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this.binding = this.db;
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if (this.db.binding)
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this.binding = this.db.binding;
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this.binding.open(options, function(err) {
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if (err)
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return self.emit('error', err);
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self.loaded = true;
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self.emit('open');
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});
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}
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utils.inherits(LowlevelUp, EventEmitter);
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LowlevelUp.prototype.open = function open(callback) {
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if (this.loaded)
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return utils.nextTick(callback);
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this.once('open', callback);
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};
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LowlevelUp.prototype.get = function get(key, options, callback) {
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if (typeof options === 'function') {
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callback = options;
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options = {};
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}
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return this.binding.get(key, options, function(err, result) {
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if (err) {
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if (err.notFound || /not\s*found/i.test(err.message)) {
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err.notFound = true;
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err.type = 'NotFoundError';
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}
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return callback(err);
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}
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return callback(null, result);
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});
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};
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LowlevelUp.prototype.close = function close(callback) {
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return this.binding.close(callback);
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};
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LowlevelUp.prototype.put = function put(key, value, options, callback) {
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return this.binding.put(key, value, options, callback);
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};
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LowlevelUp.prototype.del = function del(key, options, callback) {
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return this.binding.del(key, options, callback);
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};
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LowlevelUp.prototype.batch = function batch(ops, options, callback) {
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if (!ops)
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return this.binding.batch();
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return this.binding.batch(ops, options, callback);
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};
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LowlevelUp.prototype.iterator = function iterator(options) {
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return this.db.iterator(options);
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};
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LowlevelUp.prototype.getProperty = function getProperty(name) {
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if (!this.binding.getProperty)
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return null;
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return this.binding.getProperty(name);
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};
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LowlevelUp.prototype.approximateSize = function approximateSize(start, end, callback) {
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return this.binding.approximateSize(start, end, callback);
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};
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/**
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* Expose
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*/
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module.exports = LowlevelUp;
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