| 'use strict' |
| |
| const fs = require('fs') |
| const util = require('util') |
| const chmod = util.promisify(fs.chmod) |
| const unlink = util.promisify(fs.unlink) |
| const stat = util.promisify(fs.stat) |
| const move = require('@npmcli/move-file') |
| const pinflight = require('promise-inflight') |
| |
| module.exports = moveFile |
| |
| function moveFile (src, dest) { |
| const isWindows = global.__CACACHE_TEST_FAKE_WINDOWS__ || |
| process.platform === 'win32' |
| |
| // This isn't quite an fs.rename -- the assumption is that |
| // if `dest` already exists, and we get certain errors while |
| // trying to move it, we should just not bother. |
| // |
| // In the case of cache corruption, users will receive an |
| // EINTEGRITY error elsewhere, and can remove the offending |
| // content their own way. |
| // |
| // Note that, as the name suggests, this strictly only supports file moves. |
| return new Promise((resolve, reject) => { |
| fs.link(src, dest, (err) => { |
| if (err) { |
| if (isWindows && err.code === 'EPERM') { |
| // XXX This is a really weird way to handle this situation, as it |
| // results in the src file being deleted even though the dest |
| // might not exist. Since we pretty much always write files to |
| // deterministic locations based on content hash, this is likely |
| // ok (or at worst, just ends in a future cache miss). But it would |
| // be worth investigating at some time in the future if this is |
| // really what we want to do here. |
| return resolve() |
| } else if (err.code === 'EEXIST' || err.code === 'EBUSY') { |
| // file already exists, so whatever |
| return resolve() |
| } else |
| return reject(err) |
| } else |
| return resolve() |
| }) |
| }) |
| .then(() => { |
| // content should never change for any reason, so make it read-only |
| return Promise.all([ |
| unlink(src), |
| !isWindows && chmod(dest, '0444'), |
| ]) |
| }) |
| .catch(() => { |
| return pinflight('cacache-move-file:' + dest, () => { |
| return stat(dest).catch((err) => { |
| if (err.code !== 'ENOENT') { |
| // Something else is wrong here. Bail bail bail |
| throw err |
| } |
| // file doesn't already exist! let's try a rename -> copy fallback |
| // only delete if it successfully copies |
| return move(src, dest) |
| }) |
| }) |
| }) |
| } |