55 lines
1.6 KiB
JavaScript
55 lines
1.6 KiB
JavaScript
var Level = require("level");
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var nThen = require('nthen');
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var getIndex = function(db, cName, cb) {
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db.get(cName+'=>index', function(e, out){
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if (e) {
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if (e.notFound) {
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cb(-1);
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} else {
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throw e;
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}
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return;
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}
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cb(parseInt(out));
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});
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};
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var insert = function (db, channelName, content, cb) {
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var index;
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nThen(function (waitFor) {
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getIndex(db, channelName, waitFor(function (i) { index = i+1; }));
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}).nThen(function (waitFor) {
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db.put(channelName+'=>'+index, content, waitFor(function (e) { if (e) { throw e; } }));
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}).nThen(function (waitFor) {
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db.put(channelName+'=>index', ''+index, waitFor(function (e) { if (e) { throw e; } }));
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}).nThen(cb);
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};
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var getMessages = function (db, channelName, msgHandler) {
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var index;
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nThen(function (waitFor) {
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getIndex(db, channelName, waitFor(function (i) { index = i; }));
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}).nThen(function (waitFor) {
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var again = function (i) {
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db.get(channelName + '=>' + i, waitFor(function (e, out) {
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if (e) { throw e; }
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msgHandler(out);
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if (i < index) { again(i+1); }
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}));
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};
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again(0);
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});
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};
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module.exports.create = function (conf, cb) {
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var db = Level(conf.levelPath || './test.level.db');
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cb({
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message: function (channelName, content, cb) {
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insert(db, channelName, content, cb);
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},
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getMessages: function (channelName, msgHandler) {
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getMessages(db, channelName, msgHandler);
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}
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});
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};
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