11cb0ef41Sopenharmony_ci// Get the appropriate flag to use for creating files
21cb0ef41Sopenharmony_ci// We use fmap on Windows platforms for files less than
31cb0ef41Sopenharmony_ci// 512kb.  This is a fairly low limit, but avoids making
41cb0ef41Sopenharmony_ci// things slower in some cases.  Since most of what this
51cb0ef41Sopenharmony_ci// library is used for is extracting tarballs of many
61cb0ef41Sopenharmony_ci// relatively small files in npm packages and the like,
71cb0ef41Sopenharmony_ci// it can be a big boost on Windows platforms.
81cb0ef41Sopenharmony_ci// Only supported in Node v12.9.0 and above.
91cb0ef41Sopenharmony_ciconst platform = process.env.__FAKE_PLATFORM__ || process.platform
101cb0ef41Sopenharmony_ciconst isWindows = platform === 'win32'
111cb0ef41Sopenharmony_ciconst fs = global.__FAKE_TESTING_FS__ || require('fs')
121cb0ef41Sopenharmony_ci
131cb0ef41Sopenharmony_ci/* istanbul ignore next */
141cb0ef41Sopenharmony_ciconst { O_CREAT, O_TRUNC, O_WRONLY, UV_FS_O_FILEMAP = 0 } = fs.constants
151cb0ef41Sopenharmony_ci
161cb0ef41Sopenharmony_ciconst fMapEnabled = isWindows && !!UV_FS_O_FILEMAP
171cb0ef41Sopenharmony_ciconst fMapLimit = 512 * 1024
181cb0ef41Sopenharmony_ciconst fMapFlag = UV_FS_O_FILEMAP | O_TRUNC | O_CREAT | O_WRONLY
191cb0ef41Sopenharmony_cimodule.exports = !fMapEnabled ? () => 'w'
201cb0ef41Sopenharmony_ci  : size => size < fMapLimit ? fMapFlag : 'w'
21