services: guix-publish: Add zstd compression by default.

That way, the default config with (advertises? #t) and without a cache
will offer zstd-compressed substitutes, which should lead to much higher
throughput than gzip.

* gnu/services/base.scm (default-compression): When
'guix-publish-configuration-cache' returns true, use higher level
compression ratios.  Add "zstd".
* doc/guix.texi (Base Services): Mention zstd.

diff --git a/doc/guix.texi b/doc/guix.texi
index da18b45..bada446 100644 (file)
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -15646,7 +15646,7 @@ This allows neighboring Guix devices with discovery on (see
 @code{guix-configuration} above) to discover this @command{guix publish}
 instance and to automatically download substitutes from it.
 
-@item @code{compression} (default: @code{'(("gzip" 3))})
+@item @code{compression} (default: @code{'(("gzip" 3) ("zstd" 3))})
 This is a list of compression method/level tuple used when compressing
 substitutes.  For example, to compress all substitutes with @emph{both} lzip
 at level 7 and gzip at level 9, write:

diff --git a/gnu/services/base.scm b/gnu/services/base.scm
index a8214ae..24b3ea7 100644 (file)
--- a/gnu/services/base.scm
+++ b/gnu/services/base.scm
@@ -1816,7 +1816,11 @@ proxy of 'guix-daemon'...~%")
 raise a deprecation warning if the 'compression-level' field was used."
   (match (%guix-publish-configuration-compression-level config)
     (#f
-     '(("gzip" 3)))
+     ;; Default to low compression levels when there's no cache so that users
+     ;; get good bandwidth by default.
+     (if (guix-publish-configuration-cache config)
+         '(("gzip" 5) ("zstd" 19))
+         '(("gzip" 3) ("zstd" 3))))               ;zstd compresses faster
     (level
      (warn-about-deprecation 'compression-level properties
                              #:replacement 'compression)