'use strict'
|
|
/**
|
* Calculates and returns the chunk size for given file paths and `chunkSize`
|
* option.
|
*
|
* It returns the minimum of the following:
|
*
|
* - Total number of files
|
* - Max allowed chunk size so that command length does not exceed the system
|
* limitation on windows
|
* - User specified chunk size or the default
|
*
|
* Worked example:
|
* **Assumption** - Our max file path length is 100, Hence max allowed chunk
|
* size is 80
|
*
|
* - Case 1: Only 10 files are there, chunk size should be 10 only
|
* - Case 2: There are 100 files and user has overridden the option with
|
* chunk size 40. So chunk size should be 40
|
* - Case 3: There are 100 files and user has overridden the option with
|
* chunk size 100. So chunk size should be 80
|
*
|
* @param {Array<string>} paths The array of file paths
|
* @param {number} idealChunkSize User specified / default chunk size
|
* @returns {number} The chunk size
|
*/
|
module.exports = function calcChunkSize(paths, idealChunkSize) {
|
/* What is the longest file path? */
|
const maxPathLen = paths.reduce(
|
(maxLen, filePath) => Math.max(maxLen, filePath.length),
|
20 // safe initial value
|
)
|
|
/* In the worst case scenario, */
|
/* how many files can we process in a single command? */
|
/* For windows systems, command length is limited to 8192 */
|
const maxAllowedChunkSize = Math.floor(8000 / maxPathLen)
|
|
/* Configured chunk size / default - idealChunkSize */
|
return Math.min(paths.length, maxAllowedChunkSize, idealChunkSize)
|
}
|
