Press n or j to go to the next uncovered block, b, p or k for the previous block.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 | 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 34x 34x 34x 34x 34x 34x 34x 34x 34x 34x 34x 34x 34x 2x 2x 2x 34x 22x 34x 10x 10x 32x 32x 32x 32x 32x 32x 34x 80x 80x 76x 76x 80x 34x 34x 34x 34x 34x 34x 90x 90x 90x 90x 90x 12x 90x 60x 78x 18x 18x 90x 90x 90x 90x 90x 90x 90x 90x 90x 90x 10x 10x 10x 90x 10x 10x 10x 70x 70x 90x 90x 34x 34x 34x 34x 34x 34x 34x 34x 34x 80x 10x 10x 10x 70x 70x 80x 14x 14x 80x 22x 22x 22x 80x 34x 3x 3x 3x 3x 3x | /**
* @license Apache-2.0
*
* Copyright (c) 2018 The Stdlib 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';
// MODULES //
var logger = require( 'debug' );
// VARIABLES //
var debug = logger( 'inmap-async:limit' );
// MAIN //
/**
* Invokes a function once for each element in a collection, limiting the number of concurrently pending functions, and updates a collection in-place.
*
* @private
* @param {Collection} collection - input collection
* @param {Options} opts - function options
* @param {*} [opts.thisArg] - execution context
* @param {PositiveInteger} [opts.limit] - maximum number of pending function invocations
* @param {Function} fcn - function to invoke
* @param {Callback} done - function to invoke upon completion or upon encountering an error
* @returns {void}
*/
function limit( collection, opts, fcn, done ) {
var maxIndex;
var count;
var flg;
var lim;
var len;
var idx;
var i;
len = collection.length;
debug( 'Collection length: %d', len );
if ( len === 0 ) {
debug( 'Finished processing a collection.' );
return done();
}
if ( len < opts.limit ) {
lim = len;
} else {
lim = opts.limit;
}
debug( 'Concurrency limit: %d', lim );
debug( 'Number of arguments: %d', fcn.length );
maxIndex = len - 1;
count = 0;
idx = -1;
for ( i = 0; i < lim; i++ ) {
// This guard is necessary to protect against synchronous functions which exhaust all collection elements...
if ( idx < maxIndex ) {
next(); // eslint-disable-line node/callback-return
}
}
/**
* Callback to invoke a provided function for the next element in a collection.
*
* @private
*/
function next() {
var j;
idx += 1;
j = idx;
debug( 'Collection element %d: %s.', j, JSON.stringify( collection[ j ] ) );
if ( fcn.length === 2 ) {
fcn.call( opts.thisArg, collection[ j ], cb );
} else if ( fcn.length === 3 ) {
fcn.call( opts.thisArg, collection[ j ], j, cb );
} else {
fcn.call( opts.thisArg, collection[ j ], j, collection, cb );
}
/**
* Callback invoked once a provided function finishes processing a collection element.
*
* @private
* @param {*} [error] - error
* @param {*} [result] - result
* @returns {void}
*/
function cb( error, result ) {
if ( flg ) {
// Prevent further processing of collection elements:
return;
}
if ( error ) {
flg = true;
return clbk( error );
}
collection[ j ] = result;
clbk();
}
}
/**
* Callback invoked once ready to process the next collection element.
*
* @private
* @param {*} [error] - error
* @returns {void}
*/
function clbk( error ) {
if ( error ) {
debug( 'Encountered an error: %s', error.message );
return done( error );
}
count += 1;
debug( 'Processed %d of %d collection elements.', count, len );
if ( idx < maxIndex ) {
return next();
}
if ( count === len ) {
debug( 'Finished processing a collection.' );
return done();
}
}
}
// EXPORTS //
module.exports = limit;
|