/* -*- Mode: js; js-indent-level: 2; -*- */
/*
* Copyright 2014 Mozilla Foundation and contributors
* Licensed under the New BSD license. See LICENSE or:
* http://opensource.org/licenses/BSD-3-Clause
*/
var util = require('./util');
/**
* Determine whether mappingB is after mappingA with respect to generated
* position.
*/
function generatedPositionAfter(mappingA, mappingB) {
// Optimized for most common case
var lineA = mappingA.generatedLine;
var lineB = mappingB.generatedLine;
var columnA = mappingA.generatedColumn;
var columnB = mappingB.generatedColumn;
return lineB > lineA || lineB == lineA && columnB >= columnA ||
util.compareByGeneratedPositionsInflated(mappingA, mappingB) <= 0;
}
/**
* A data structure to provide a sorted view of accumulated mappings in a
* performance conscious manner. It trades a neglibable overhead in general
* case for a large speedup in case of mappings being added in order.
*/
function MappingList() {
this._array = [];
this._sorted = true;
// Serves as infimum
this._last = {generatedLine: -1, generatedColumn: 0};
}
/**
* Iterate through internal items. This method takes the same arguments that
* `Array.prototype.forEach` takes.
*
* NOTE: The order of the mappings is NOT guaranteed.
*/
MappingList.prototype.unsortedForEach =
function MappingList_forEach(aCallback, aThisArg) {
this._array.forEach(aCallback, aThisArg);
};
/**
* Add the given source mapping.
*
* @param Object aMapping
*/
MappingList.prototype.add = function MappingList_add(aMapping) {
if (generatedPositionAfter(this._last, aMapping)) {
this._last = aMapping;
this._array.push(aMapping);
} else {
this._sorted = false;
this._array.push(aMapping);
}
};
/**
* Returns the flat, sorted array of mappings. The mappings are sorted by
* generated position.
*
* WARNING: This method returns internal data without copying, for
* performance. The return value must NOT be mutated, and should be treated as
* an immutable borrow. If you want to take ownership, you must make your own
* copy.
*/
MappingList.prototype.toArray = function MappingList_toArray() {
if (!this._sorted) {
this._array.sort(util.compareByGeneratedPositionsInflated);
this._sorted = true;
}
return this._array;
};
exports.MappingList = MappingList;