mirror of
https://github.com/NixOS/nix.git
synced 2024-10-30 22:00:57 +00:00
optimize performance
remove loops and function calls, modify arrays in place this makes the whole thing harder to read, and probably only marginally faster.
This commit is contained in:
Valentin Gagarin
parent
59be1e500a
commit
548c904d40
@ -1,9 +1,12 @@
|
||||
// Redirect rules for anchors ensure backwards compatibility of URLs.
|
||||
// This must be done on the client side, as web servers do not see the anchor part of the URL.
|
||||
// redirect rules for anchors ensure backwards compatibility of URLs.
|
||||
// this must be done on the client side, as web servers do not see the anchor part of the URL.
|
||||
|
||||
// Redirections are declared as follows:
|
||||
// Each entry has as key the matched URL path relative to the mdBook document root.
|
||||
// Each entry is a set of key-value pairs, where
|
||||
// redirections are declared as follows:
|
||||
// each entry has as key the matched URL path relative to the mdBook document root.
|
||||
//
|
||||
// IMPORTANT: it must specify the full path with file name and suffix
|
||||
//
|
||||
// each entry is a set of key-value pairs, where
|
||||
// - keys are anchors on to the matched path.
|
||||
// - values are redirection targets relative to the current path.
|
||||
|
||||
@ -332,7 +335,7 @@ var redirects = {
|
||||
"ssec-relnotes-2.2": "release-notes/rl-2.2.html",
|
||||
"ssec-relnotes-2.3": "release-notes/rl-2.3.html"
|
||||
},
|
||||
"language/values": {
|
||||
"language/values.html": {
|
||||
"simple-values": "#primitives",
|
||||
"lists": "#list",
|
||||
"strings": "#string",
|
||||
@ -341,73 +344,79 @@ var redirects = {
|
||||
}
|
||||
};
|
||||
|
||||
// the following code matches the current page's URL against the set of redirects.
|
||||
//
|
||||
// it is written to minimize the latency between page load and redirect.
|
||||
// therefore we avoid function calls, copying data, and unnecessary loops.
|
||||
// IMPORTANT: we use stateful array operations and their order matters!
|
||||
//
|
||||
// matching URLs is more involved than it should be:
|
||||
//
|
||||
// 1. `document.location.pathname` can have an have an arbitrary prefix.
|
||||
//
|
||||
// 2. `path_to_root` is set by mdBook and consists only of `../`s and
|
||||
// determines the depth of `<path>` relative to the prefix:
|
||||
//
|
||||
// `document.location.pathname`
|
||||
// |------------------------------|
|
||||
// /<prefix>/<path>/[<file>[.html]][#<anchor>]
|
||||
// |----|
|
||||
// `path_to_root` has same number of segments
|
||||
//
|
||||
// source: https://phaiax.github.io/mdBook/format/theme/index-hbs.html#data
|
||||
//
|
||||
// 3. the following paths are equivalent:
|
||||
//
|
||||
// /foo/bar/
|
||||
// /foo/bar/index.html
|
||||
// /foo/bar/index
|
||||
//
|
||||
// 4. the following paths are also equivalent:
|
||||
//
|
||||
// /foo/bar/baz
|
||||
// /foo/bar/baz.html
|
||||
//
|
||||
|
||||
function pathsMatch(a, b, path_to_root) {
|
||||
// Do paths `a` and `b` match?
|
||||
//
|
||||
// This is more involved than it should be:
|
||||
//
|
||||
// 1. Path `b` can have an have an arbitrary prefix.
|
||||
//
|
||||
// 2. `path_to_root` consists only of `../`s and determines the depth
|
||||
// of `b` relative to the prefix:
|
||||
//
|
||||
// `document.location.pathname`
|
||||
// |-----------------------------|
|
||||
// <prefix>/<path>/[<file>[.html]][#<anchor>]
|
||||
// |----|
|
||||
// `path_to_root` has same number of segments
|
||||
//
|
||||
// 3. The following paths are equivalent:
|
||||
//
|
||||
// foo/bar/
|
||||
// foo/bar/index.html
|
||||
// foo/bar/index
|
||||
//
|
||||
// 4. The following paths are also equivalent:
|
||||
//
|
||||
// foo/bar/baz
|
||||
// foo/bar/baz.html
|
||||
//
|
||||
// We can use `path_to_root` to discern prefix from path.
|
||||
//
|
||||
// The last element of the following split is always empty.
|
||||
// Example: '../../'.split('/') -> [ '..', '..', '' ]
|
||||
const depth = path_to_root.split('/').length - 1;
|
||||
var segmentsB = b.split('/');
|
||||
// get file name of `b`
|
||||
const fileB = segmentsB.pop(); // mutates `segmentsB`!
|
||||
// get path of `b` without prefix and file name
|
||||
const pathB = segmentsB.slice(segmentsB.length - depth).join('/');
|
||||
var segments = document.location.pathname.split('/');
|
||||
|
||||
var segmentsA = a.split('/');
|
||||
const fileA = segmentsA.pop(); // mutates `segmentsA`!
|
||||
const pathA = segmentsA.join('/')
|
||||
var file = segments.pop();
|
||||
|
||||
function normalize(file) {
|
||||
if (file === '') { return "index.html"; }
|
||||
if (!file.endsWith('.html')) { return file + '.html'; }
|
||||
return file;
|
||||
}
|
||||
// normalize file name
|
||||
if (file === '') { file = "index.html"; }
|
||||
else if (!file.endsWith('.html')) { file = file + '.html'; }
|
||||
|
||||
return pathA === pathB && normalize(fileA) === normalize(fileB);
|
||||
}
|
||||
segments.push(file);
|
||||
|
||||
// The anchor starts with the hash character (`#`),
|
||||
// use `path_to_root` to discern prefix from path.
|
||||
const depth = path_to_root.split('/').length;
|
||||
|
||||
// remove segments containing prefix. the following works because
|
||||
// 1. the original `document.location.pathname` is absolute,
|
||||
// hence first element of `segments` is always empty.
|
||||
// 2. last element of splitting `path_to_root` is also always empty.
|
||||
// 3. last element of `segments` is the file name.
|
||||
//
|
||||
// visual example:
|
||||
//
|
||||
// '/foo/bar/baz.html'.split('/') -> [ '', 'foo', 'bar', 'baz.html' ]
|
||||
// '../'.split('/') -> [ '..', '' ]
|
||||
//
|
||||
// the following operations will then result in
|
||||
//
|
||||
// path = 'bar/baz.html'
|
||||
//
|
||||
segments.splice(0, segments.length - depth);
|
||||
const path = segments.join('/');
|
||||
|
||||
// anchor starts with the hash character (`#`),
|
||||
// but our redirect declarations don't, so we strip it.
|
||||
// Example: document.location.hash -> '#foo'
|
||||
// example: document.location.hash -> '#foo'
|
||||
const anchor = document.location.hash.substring(1);
|
||||
|
||||
for (const [path, redirect] of Object.entries(redirects)) {
|
||||
// The global variable `path_to_root` is set by `mdBook`:
|
||||
//
|
||||
// > This is a path containing exclusively `../`'s that points to the root of the
|
||||
// > book from the current file. Since the original directory structure is
|
||||
// > maintained, it is useful to prepend relative links with this `path_to_root`.
|
||||
//
|
||||
// Source: https://phaiax.github.io/mdBook/format/theme/index-hbs.html#data
|
||||
if (pathsMatch(path, document.location.pathname, path_to_root) && redirect[anchor]) {
|
||||
document.location.href = redirect[anchor];
|
||||
break;
|
||||
const redirect = redirects[path];
|
||||
if (redirect) {
|
||||
const target = redirect[anchor];
|
||||
if (target) {
|
||||
document.location.href = target;
|
||||
}
|
||||
}
|
||||
|
||||
Loading…
Reference in New Issue
Block a user