foundationdb/bindings/nodejs/lib/locality.js

132 lines
3.7 KiB
JavaScript

/*
* locality.js
*
* This source file is part of the FoundationDB open source project
*
* Copyright 2013-2018 Apple Inc. and the FoundationDB project authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
"use strict";
var buffer = require('./bufferConversion');
var transactional = require('./retryDecorator');
var Database = require('./database');
var LazyIterator = require('./lazyIterator');
var fdb = require('./fdbModule');
var fdbUtil = require('./fdbUtil');
var KEY_SERVERS_PREFIX = buffer.fromByteLiteral('\xff/keyServers/');
var PAST_VERSION_ERROR_CODE = 1007;
function getBoundaryKeysImpl(tr, begin, end, callback) {
function BoundaryFetcher(wantAll) {
this.tr = tr;
this.begin = begin;
this.end = end;
this.lastBegin = undefined;
var fetcher = this;
if(wantAll)
this.streamingMode = fdb.streamingMode.wantAll;
else
this.streamingMode = fdb.streamingMode.iterator;
function iteratorCb(err, res) {
if(err) {
if(err.code === PAST_VERSION_ERROR_CODE && fetcher.begin !== fetcher.lastBegin) {
fetcher.tr = fetcher.tr.db.createTransaction();
readKeys();
}
else {
fetcher.tr.onError(err, function(e) {
if(e)
fetcher.fetchCb(e);
else
readKeys();
});
}
}
else
fetcher.fetchCb();
}
function readKeys() {
fetcher.lastBegin = fetcher.begin;
fetcher.tr.options.setReadSystemKeys();
fetcher.tr.options.setLockAware();
fetcher.tr.snapshot.getRange(fetcher.begin, fetcher.end, {streamingMode: fetcher.streamingMode}).forEachBatch(function(kvs, innerCb) {
fetcher.forEachCb = innerCb;
var keys = kvs.map(function(kv) { return kv.key.slice(13); });
var last = kvs[kvs.length-1].key;
fetcher.begin = Buffer.concat([last, buffer.fromByteLiteral('\x00')], last.length + 1);
fetcher.fetchCb(undefined, keys);
}, iteratorCb);
fetcher.streamingMode = fdb.streamingMode.wantAll;
}
this.fetch = function(cb) {
this.fetchCb = cb;
if(this.read)
this.forEachCb();
else {
this.read = true;
readKeys();
}
};
this.clone = function(wantAll) {
var clone = new BoundaryFetcher(wantAll);
clone.tr = this.tr.db.createTransaction();
clone.begin = this.begin;
clone.end = this.end;
clone.lastBegin = this.lastBegin;
return clone;
};
}
callback(null, new LazyIterator(BoundaryFetcher));
}
function getBoundaryKeys(databaseOrTransaction, begin, end, callback) {
begin = fdbUtil.keyToBuffer(begin);
end = fdbUtil.keyToBuffer(end);
begin = Buffer.concat([KEY_SERVERS_PREFIX, begin], KEY_SERVERS_PREFIX.length + begin.length);
end = Buffer.concat([KEY_SERVERS_PREFIX, end], KEY_SERVERS_PREFIX.length + end.length);
if(databaseOrTransaction instanceof Database) {
getBoundaryKeysImpl(databaseOrTransaction.createTransaction(), begin, end, callback);
}
else {
var tr = databaseOrTransaction.db.createTransaction();
databaseOrTransaction.getReadVersion(function(err, ver) {
tr.setReadVersion(ver);
getBoundaryKeysImpl(tr, begin, end, callback);
});
}
}
var getAddressesForKey = transactional(function (tr, key, cb) {
key = fdbUtil.keyToBuffer(key);
tr.tr.getAddressesForKey(key, cb);
});
module.exports = {getBoundaryKeys: getBoundaryKeys, getAddressesForKey: getAddressesForKey};