/* -*- 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
|
*/
|
|
const util = require("./util");
|
|
/**
|
* Determine whether mappingB is after mappingA with respect to generated
|
* position.
|
*/
|
function generatedPositionAfter(mappingA, mappingB) {
|
// Optimized for most common case
|
const lineA = mappingA.generatedLine;
|
const lineB = mappingB.generatedLine;
|
const columnA = mappingA.generatedColumn;
|
const 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 negligible overhead in general
|
* case for a large speedup in case of mappings being added in order.
|
*/
|
class MappingList {
|
constructor() {
|
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.
|
*/
|
unsortedForEach(aCallback, aThisArg) {
|
this._array.forEach(aCallback, aThisArg);
|
}
|
|
/**
|
* Add the given source mapping.
|
*
|
* @param Object aMapping
|
*/
|
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.
|
*/
|
toArray() {
|
if (!this._sorted) {
|
this._array.sort(util.compareByGeneratedPositionsInflated);
|
this._sorted = true;
|
}
|
return this._array;
|
}
|
}
|
|
exports.MappingList = MappingList;
|
