diff options
Diffstat (limited to 'deps/npm/node_modules/tar/lib/get-write-flag.js')
| -rw-r--r-- | deps/npm/node_modules/tar/lib/get-write-flag.js | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/deps/npm/node_modules/tar/lib/get-write-flag.js b/deps/npm/node_modules/tar/lib/get-write-flag.js new file mode 100644 index 0000000000..e869599966 --- /dev/null +++ b/deps/npm/node_modules/tar/lib/get-write-flag.js @@ -0,0 +1,20 @@ +// Get the appropriate flag to use for creating files +// We use fmap on Windows platforms for files less than +// 512kb. This is a fairly low limit, but avoids making +// things slower in some cases. Since most of what this +// library is used for is extracting tarballs of many +// relatively small files in npm packages and the like, +// it can be a big boost on Windows platforms. +// Only supported in Node v12.9.0 and above. +const platform = process.env.__FAKE_PLATFORM__ || process.platform +const isWindows = platform === 'win32' +const fs = global.__FAKE_TESTING_FS__ || require('fs') + +/* istanbul ignore next */ +const { O_CREAT, O_TRUNC, O_WRONLY, UV_FS_O_FILEMAP = 0 } = fs.constants + +const fMapEnabled = isWindows && !!UV_FS_O_FILEMAP +const fMapLimit = 512 * 1024 +const fMapFlag = UV_FS_O_FILEMAP | O_TRUNC | O_CREAT | O_WRONLY +module.exports = !fMapEnabled ? () => 'w' + : size => size < fMapLimit ? fMapFlag : 'w' |