[improvement][aur] optimizations to speed up zst packages building

CHANGELOG.md

@@ -14,6 +14,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
     - improved how missing dependencies are checked when installing a new package ( the old way was not identifying some missing dependencies of **anbox-git** ). It is possible to use the old algorithm by setting **simple_checking** to **true** in **~/.config/bauh/arch.yml**. More information at [README](https://github.com/vinifmor/bauh/#aur--arch-).
     - checking architecture dependencies (x86_64, i686)
     - architecture dependencies are displayed on the info window as well
+    - optimizations to speed up zst packages building
 - Web:
     - separate temp build folder for standard and root users
 - UI:

README.md

@@ -154,7 +154,7 @@ db_updater:
     then a copy of **/etc/makepkg.conf** will be generated at **~/.config/bauh/arch/makepkg.conf** defining MAKEFLAGS to work with
     the number of your machine processors (**-j${nproc}**).
 
-    b) same as previous, but related to **COMPRESSXZ** definition ( if '--threads=0' is not defined )
+    b) same as previous, but related to **COMPRESSXZ** and **COMPRESSZST** definitions ( if '--threads=0' is not defined )
     
     c) **ccache** will be added to **BUILDENV** if it is installed on the system and already not defined 
 

bauh/gems/arch/worker.py

@@ -76,6 +76,7 @@ class ArchCompilationOptimizer(Thread):
         super(ArchCompilationOptimizer, self).__init__(daemon=True)
         self.logger = logger
         self.re_compress_xz = re.compile(r'#?\s*COMPRESSXZ\s*=\s*.+')
+        self.re_compress_zst = re.compile(r'#?\s*COMPRESSZST\s*=\s*.+')
         self.re_build_env = re.compile(r'\s+BUILDENV\s*=.+')
         self.re_ccache = re.compile(r'!?ccache')
 
@@ -127,6 +128,19 @@ class ArchCompilationOptimizer(Thread):
             else:
                 optimizations.append('COMPRESSXZ=(xz -c -z - --threads=0)')
 
+            compress_zst = self.re_compress_zst.findall(custom_makepkg or global_makepkg)
+
+            if compress_zst:
+                not_eligible = [f for f in compress_zst if not f.startswith('#') and '--threads' in f]
+
+                if not not_eligible:
+                    custom_makepkg = self.re_compress_zst.sub('', custom_makepkg or global_makepkg)
+                    optimizations.append('COMPRESSZST=(zstd -c -z -q - --threads=0)')
+                else:
+                    self.logger.warning("It seems '{}' COMPRESSZST is already customized".format(GLOBAL_MAKEPKG))
+            else:
+                optimizations.append('COMPRESSZST=(zstd -c -z -q - --threads=0)')
+
             build_envs = self.re_build_env.findall(custom_makepkg or global_makepkg)
 
             if build_envs: