pm: use native binding to query packages ...

* Also queries if the packages have been installed via libapt-pkg
* Automatically corrects APT/dpkg issues when detected
* Caches query results obtained from libapt-pkg to speed up the query
  process

Author: liushuyu

acbs/pm.py

@@ -47,10 +47,12 @@ def fix_pm_states(escaped: List[str]):
     count = 0
     while count < 3:
         try:
+            subprocess.check_call(['dpkg', '--configure', '-a'])
             subprocess.check_call(['apt-get', 'install', '-yf'])
-            command = ['apt-get', 'install', '-y']
-            command.extend(escaped)
-            subprocess.check_call(command)
+            if escaped:
+                command = ['apt-get', 'install', '-y']
+                command.extend(escaped)
+                subprocess.check_call(command)
             return
         except subprocess.CalledProcessError:
             count += 1
@@ -63,6 +65,25 @@ def check_if_installed(name: str) -> bool:
     cached = installed_cache.get(name)
     if cached is not None:
         return cached
+    if use_native_bindings:
+        logging.debug('... using libapt-pkg')
+        result = apt_check_if_available(name)
+        if result == 0:
+            installed_cache[name] = True
+            return True
+        elif result == 1:
+            installed_cache[name] = False
+            available_cache[name] = True
+            return False
+        elif result == 2:
+            installed_cache[name] = False
+            available_cache[name] = False
+            return False
+        elif result == -4:
+            fix_pm_states([])
+            return check_if_installed(name)
+        else:
+            raise RuntimeError(f'libapt-pkg binding returned error: {result}')
     try:
         subprocess.check_output(['dpkg', '-s', name], stderr=subprocess.STDOUT)
         installed_cache[name] = True

src/miniapt-query.cc

@@ -39,13 +39,17 @@ int check_available(const char *name)
     APT::CacheSetHelper helper(true, GlobalError::NOTICE);
     const char *list[2] = {name, NULL};
     APT::PackageList pkgset = APT::PackageList::FromCommandLine(cachefile, list, helper);
+    // returns 0: installed; 1: not installed, available; 2: not installed, not available
     for (APT::PackageList::const_iterator Pkg = pkgset.begin(); Pkg != pkgset.end(); ++Pkg)
     {
+        if (Pkg->CurrentVer != 0) {
+            return 0;
+        }
         if (depCache->GetCandidateVersion(Pkg)) {
             if (depCache->MarkInstall(Pkg, true, 0, true)) {
                 return 1;
             }
         }
     }
-    return 0;
+    return 2;
 }