[v14.x Backport] lib: add throws option to fs.f/l/statSync #36921
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For consumers that aren't interested in *why* a `statSync` call failed, allocating and throwing an exception is an unnecessary expense. This PR adds an option that will cause it to return `undefined` in such cases instead. As a motivating example, the JavaScript & TypeScript language service shared between Visual Studio and Visual Studio Code is stuck with synchronous file IO for architectural and backward-compatibility reasons. It frequently needs to speculatively check for the existence of files and directories that may not exist (and cares about file vs directory, so `existsSync` is insufficient), but ignores file system entries it can't access, regardless of the reason. Benchmarking the language service is difficult because it's so hard to get good coverage of both code bases and user behaviors, but, as a representative metric, we measured batch compilation of a few hundred popular projects (by star count) from GitHub and found that, on average, we saved about 1-2% of total compilation time. We speculate that the savings could be even more significant in interactive (language service or watch mode) scenarios, where the same (non-existent) files need to be polled over and over again. It's not a huge improvement, but it's a very small change and it will affect a lot of users (and CI runs). For reference, our measurements were against `v12.x` (3637a06 at the time) on an Ubuntu Server desktop with an SSD. PR-URL: nodejs#33716 Reviewed-By: Denys Otrishko <[email protected]> Reviewed-By: Joyee Cheung <[email protected]>
PR-URL: nodejs#36882 Reviewed-By: Antoine du Hamel <[email protected]> Reviewed-By: James M Snell <[email protected]>
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For consumers that aren't interested in *why* a `statSync` call failed, allocating and throwing an exception is an unnecessary expense. This PR adds an option that will cause it to return `undefined` in such cases instead. As a motivating example, the JavaScript & TypeScript language service shared between Visual Studio and Visual Studio Code is stuck with synchronous file IO for architectural and backward-compatibility reasons. It frequently needs to speculatively check for the existence of files and directories that may not exist (and cares about file vs directory, so `existsSync` is insufficient), but ignores file system entries it can't access, regardless of the reason. Benchmarking the language service is difficult because it's so hard to get good coverage of both code bases and user behaviors, but, as a representative metric, we measured batch compilation of a few hundred popular projects (by star count) from GitHub and found that, on average, we saved about 1-2% of total compilation time. We speculate that the savings could be even more significant in interactive (language service or watch mode) scenarios, where the same (non-existent) files need to be polled over and over again. It's not a huge improvement, but it's a very small change and it will affect a lot of users (and CI runs). For reference, our measurements were against `v12.x` (3637a06 at the time) on an Ubuntu Server desktop with an SSD. PR-URL: #33716 Backport-PR-URL: #36921 Reviewed-By: Denys Otrishko <[email protected]> Reviewed-By: Joyee Cheung <[email protected]>
targos
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PR-URL: #36882 Backport-PR-URL: #36921 Reviewed-By: Antoine du Hamel <[email protected]> Reviewed-By: James M Snell <[email protected]>
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Backport of #33716 and #36882.
Note that #36882 hasn't been released to v15.x for two weeks; however it's a doc-only change, IMHO it would make sense two backport the two PRs at the same time in the next v14.x minor release.