download.pl: add jsDelivr mirror for GitHub

jsDelivr has CDN servers in Mainland China (as well as rest of the world)
so it can be used to accelerate downloading.

jsDelivr uses the following URL for GitHub files:
https://cdn.jsdelivr.net/gh/{username}/{repo}@{revision}/path/to/file

For compatibility, the script will replace the 2nd '/' with '@' when
pushing the jsDelivr URL to mirrors.

Signed-off-by: DENG Qingfang <dengqf6@mail2.sysu.edu.cn>

diff --git a/scripts/download.pl b/scripts/download.pl
index c14ec07e448d6799e16a78b8f772f998a8206e81..2b1ffde51e3df9e89d23cca9af32f71e644ff3af 100755 (executable)
--- a/scripts/download.pl
+++ b/scripts/download.pl
@@ -267,9 +267,13 @@ foreach my $mirror (@ARGV) {
                push @mirrors, "https://mirrors.tuna.tsinghua.edu.cn/apache/$1";
                push @mirrors, "https://mirrors.ustc.edu.cn/apache/$1";
        } elsif ($mirror =~ /^\@GITHUB\/(.+)$/) {
+               my $dir = $1;
+               my $i = 0;
+               # replace the 2nd '/' with '@' for jsDelivr mirror
+               push @mirrors, "https://cdn.jsdelivr.net/gh/". $dir =~ s{\/}{++$i == 2 ? '@' : $&}ger;
                # give github a few more tries (different mirrors)
                for (1 .. 5) {
-                       push @mirrors, "https://raw.githubusercontent.com/$1";
+                       push @mirrors, "https://raw.githubusercontent.com/$dir";
                }
        } elsif ($mirror =~ /^\@GNU\/(.+)$/) {
                push @mirrors, "https://mirror.csclub.uwaterloo.ca/gnu/$1";