[bug#56759] [PATCH 18/20] gnu: ruby-anystyle: Initialize dictionary files.

[Philip McGrath <philip@philipmcgrath.com>]

For the GDBM and Marshal dictionary adapters to be useful with their
default settings, we must initialize their data files during the package
build: upstream would initialize them lazily, but that doesn't work with
an immutable installation directory (at least, not without more complex
patches). Otherwise, we would always end up rebuilding the dictionary at
startup, which is “slow” and “not recommended”.

* gnu/packages/patches/ruby-anystyle-fix-dictionary-populate.patch: New
patch.
* gnu/local.mk (dist_patch_DATA): Add it.
* gnu/packages/ruby.scm (ruby-anystyle)[patches]: Use it.
[arguments]<#:phases>: Add 'populate-dictionaries' phase.
---
 gnu/local.mk                                  |  1 +
 ...uby-anystyle-fix-dictionary-populate.patch | 94 +++++++++++++++++++
 gnu/packages/ruby.scm                         | 31 +++++-
 3 files changed, 125 insertions(+), 1 deletion(-)
 create mode 100644 gnu/packages/patches/ruby-anystyle-fix-dictionary-populate.patch

diff --git a/gnu/local.mk b/gnu/local.mk
index 54ac9f2f9f..cb7bd1dc23 100644
--- a/gnu/local.mk
+++ b/gnu/local.mk
@@ -1775,6 +1775,7 @@ dist_patch_DATA =						\
   %D%/packages/patches/rocm-opencl-runtime-4.3-noclinfo.patch \
   %D%/packages/patches/rocm-opencl-runtime-4.3-noopencl.patch \
   %D%/packages/patches/ruby-anystyle-data-immutable-install.patch	\
+  %D%/packages/patches/ruby-anystyle-fix-dictionary-populate.patch	\
   %D%/packages/patches/ruby-latex-decode-fix-test.patch		\
   %D%/packages/patches/ruby-mustache-1.1.1-fix-race-condition-tests.patch \
   %D%/packages/patches/ruby-sanitize-system-libxml.patch	\
diff --git a/gnu/packages/patches/ruby-anystyle-fix-dictionary-populate.patch b/gnu/packages/patches/ruby-anystyle-fix-dictionary-populate.patch
new file mode 100644
index 0000000000..b2e0498e8d
--- /dev/null
+++ b/gnu/packages/patches/ruby-anystyle-fix-dictionary-populate.patch
@@ -0,0 +1,94 @@
+From fae622c8b77feebac66a538d76e4211de8bd8eb3 Mon Sep 17 00:00:00 2001
+From: Philip McGrath <philip@philipmcgrath.com>
+Date: Sun, 24 Jul 2022 21:50:44 -0400
+Subject: [PATCH] fix saving `AnyStyle::Dictionary` after `populate!`
+
+Some of these fixes are more generally applicable.
+
+A more robust solution might find data files using
+e.g. `Gem.find_files()`.
+---
+ lib/anystyle/dictionary/gdbm.rb    |  6 ++++++
+ lib/anystyle/dictionary/marshal.rb | 31 ++++++++++++++++++++++++------
+ 2 files changed, 31 insertions(+), 6 deletions(-)
+
+diff --git a/lib/anystyle/dictionary/gdbm.rb b/lib/anystyle/dictionary/gdbm.rb
+index 754903c..c814df2 100644
+--- a/lib/anystyle/dictionary/gdbm.rb
++++ b/lib/anystyle/dictionary/gdbm.rb
+@@ -1,5 +1,6 @@
+ module AnyStyle
+   require 'gdbm'
++  require 'fileutils'
+ 
+   class Dictionary
+     class GDBM < Dictionary
+@@ -17,8 +18,13 @@ module AnyStyle
+ 
+       def open
+         close
++        FileUtils.mkdir_p(File.dirname(options[:path]))
+         @db = ::GDBM.new(*options.values_at(:path, :mode, :flags))
+         self
++      rescue Errno::EACCES
++        # GDBM.new tries this if :flags is nil, but not necessarily otherwise
++        @db = ::GDBM.new(options[:path],options[:mode],::GDBM::READER)
++        self
+       ensure
+         populate! if empty?
+       end
+diff --git a/lib/anystyle/dictionary/marshal.rb b/lib/anystyle/dictionary/marshal.rb
+index 761ca36..b9529d0 100644
+--- a/lib/anystyle/dictionary/marshal.rb
++++ b/lib/anystyle/dictionary/marshal.rb
+@@ -1,4 +1,6 @@
+ module AnyStyle
++  require 'fileutils'
++  require 'tempfile'
+   class Dictionary
+     class Marshal < Dictionary
+       @defaults = {
+@@ -10,17 +12,34 @@ module AnyStyle
+       end
+ 
+       def open
+-        if File.exists?(options[:path])
+-          @db = ::Marshal.load(File.open(options[:path]))
+-        else
+-          @db = {}
++        File.open(options[:path]) do |file|
++          @db = ::Marshal.load(file)
+         end
+         self
++      rescue Errno::ENOENT
++        @db = {}
++        self
+       ensure
+         if empty?
+           populate!
+-          if File.writable?(options[:path])
+-            ::Marshal.dump(db, File.open(options[:path], 'wb'))
++          tmp = nil
++          begin
++            FileUtils.mkdir_p(File.dirname(options[:path]))
++            tmp = Tempfile.create(File.basename(options[:path]),
++                                  File.dirname(options[:path]),
++                                  mode: File::Constants::BINARY)
++            pth = tmp.path()
++            ::Marshal.dump(db, tmp)
++            tmp.close()
++            File.rename(tmp.path, options[:path]) # will overwrite if exists
++            tmp = nil
++          rescue SystemCallError => e
++            warn(e.message)
++          ensure
++            if tmp then
++              tmp.close()
++              tmp.unlink()
++            end
+           end
+         end
+       end
+-- 
+2.32.0
+
diff --git a/gnu/packages/ruby.scm b/gnu/packages/ruby.scm
index 32ba09d283..608b1ebe89 100644
--- a/gnu/packages/ruby.scm
+++ b/gnu/packages/ruby.scm
@@ -13514,6 +13514,9 @@ (define-public ruby-anystyle
                      (substitute* "spec/anystyle/parser_spec.rb"
                        (("language: 'en'," orig)
                         (string-append "# " orig " # no lanugage_detector")))))
+                (patches
+                 (search-patches
+                  "ruby-anystyle-fix-dictionary-populate.patch"))
                 (file-name (git-file-name name version))))
       (build-system ruby-build-system)
       (propagated-inputs
@@ -13543,7 +13546,33 @@ (define-public ruby-anystyle
               (lambda args
                 (substitute* "anystyle.gemspec"
                   (("`git ls-files spec`")
-                   "`find spec -type f | sort`")))))))
+                   "`find spec -type f | sort`"))))
+            (add-after 'wrap 'populate-dictionaries
+              (lambda args
+                ;; We must initiallize these files here, or they will never be
+                ;; usable with the default settings. A more flexible approach
+                ;; might use something like `Gem.find_files()` or
+                ;; XDG_DATA_DIRS.
+                (with-output-to-file "initialize-dictionaries.rb"
+                  (lambda ()
+                    (display "
+require 'anystyle/dictionary' # must come before 'anystyle/data'
+require 'anystyle/data'
+[:marshal, :gdbm].each do |adapter|
+  AnyStyle::Dictionary.create({adapter: adapter}).open().close()
+end
+")))
+                (let* ((old-gems (getenv "GEM_PATH"))
+                       (new-gems (string-append #$output
+                                                "/lib/ruby/vendor_ruby:"
+                                                old-gems)))
+                  (dynamic-wind
+                    (lambda ()
+                      (setenv "GEM_PATH" new-gems))
+                    (lambda ()
+                      (invoke "ruby" "initialize-dictionaries.rb"))
+                    (lambda ()
+                      (setenv "GEM_PATH" old-gems)))))))))
       (home-page "https://anystyle.io")
       (synopsis "Fast and smart citation reference parsing (Ruby library)")
       (description
-- 
2.32.0