From 49b9c584d4d74ec1d0daf428a485210565935bd3 Mon Sep 17 00:00:00 2001
From: Iain Lane <iain.lane@canonical.com>
Date: Tue, 20 Sep 2016 16:59:25 +0100
Subject: [PATCH] ubuntu: Don't reference all packages, just the ones we need
 (langpacks)

---
 source/backends/ubuntu/ubupkg.d      | 16 +++++++++++-----
 source/backends/ubuntu/ubupkgindex.d | 25 +++++++++++++++++--------
 2 files changed, 28 insertions(+), 13 deletions(-)

diff --git a/source/backends/ubuntu/ubupkg.d b/source/backends/ubuntu/ubupkg.d
index 77dc81f2..d69f3ba6 100644
--- a/source/backends/ubuntu/ubupkg.d
+++ b/source/backends/ubuntu/ubupkg.d
@@ -39,12 +39,12 @@ extern (C) char *bindtextdomain (const char *domainname, const char *dirName) no
 
 class UbuntuPackage : DebPackage
 {
-    this (string pname, string pver, string parch, string globalTmpDir, ref Array!Package allPackages)
+    this (string pname, string pver, string parch, string globalTmpDir, ref Array!Package langpacks)
     {
         this.globalTmpDir = globalTmpDir;
         this.langpackDir = buildPath (globalTmpDir, "langpacks");
         this.localeDir = buildPath (langpackDir, "locales");
-        this.allPackages = allPackages;
+        this.langpacks = langpacks;
         super (pname, pver, parch);
     }
 
@@ -78,7 +78,7 @@ private:
     string langpackDir;
     string localeDir;
     string[] langpackLocales;
-    Array!Package allPackages;
+    Array!Package langpacks;
 
     private void extractLangpacks ()
     {
@@ -97,8 +97,8 @@ private:
 
             langpackDir.mkdirRecurse ();
 
-            foreach (pkg; allPackages) {
-                if (!pkg.name.startsWith ("language-pack") || pkg.name in extracted)
+            foreach (ref pkg; langpacks) {
+                if (pkg.name in extracted)
                     continue;
 
                 auto upkg = to!UbuntuPackage (pkg);
@@ -109,6 +109,9 @@ private:
                 extracted[pkg.name] = true;
             }
 
+            // get back the memory
+            langpacks.clear;
+
             auto supportedd = buildPath (langpackDir, "var", "lib", "locales", "supported.d");
 
             localeDir.mkdirRecurse ();
@@ -133,6 +136,9 @@ private:
                             scope (exit) wait (pid);
                     }
             }
+        } else {
+            // we don't need it; we've already extracted the langpacks
+            langpacks.clear;
         }
 
         if (langpackLocales is null)
diff --git a/source/backends/ubuntu/ubupkgindex.d b/source/backends/ubuntu/ubupkgindex.d
index 278714eb..c7a4b628 100644
--- a/source/backends/ubuntu/ubupkgindex.d
+++ b/source/backends/ubuntu/ubupkgindex.d
@@ -30,34 +30,43 @@ class UbuntuPackageIndex : DebianPackageIndex
 {
 
 private:
-    Array!Package allPackages;
+    Array!Package langpacks;
 
 public:
     this (string dir)
     {
         /*
          * UbuntuPackage needs to extract the langpacks, so we give it an array
-         * of all packages. We don't do this here, as you migh think makes
-         * sense, because it is a very expensive operation and we want to avoid
-         * doing it if it's not necessary (when no packages being processed are
-         * using langpacks).
+         * of langpacks. There is a small overhead when computing this array
+         * which might be unnecessary if no processed packages are using
+         * langpacks, but otherwise we need to keep a reference to all packages
+         * around, which is very expensive.
          */
-        allPackages = make!(Array!Package);
+        langpacks = make!(Array!Package);
         super (dir);
     }
 
     override
     DebPackage newPackage (string name, string ver, string arch)
     {
-        return new UbuntuPackage (name, ver, arch, tmpDir, allPackages);
+        return new UbuntuPackage (name, ver, arch, tmpDir, langpacks);
     }
 
     override
     Package[] packagesFor (string suite, string section, string arch)
     {
+        import std.string : startsWith;
+
         auto pkgs = super.packagesFor (suite, section, arch);
+        auto pkgslangpacks = appender!(Package[]);
+
+        foreach (ref pkg; pkgs) {
+                if (pkg.name.startsWith ("language-pack-"))
+                    pkgslangpacks ~= pkg;
+        }
+
+        langpacks ~= pkgslangpacks.data;
 
-        allPackages ~= pkgs;
         return pkgs;
     }
 }