Add a Config class to simplify adding configuration settings

The typical use is to inherit Config and add Setting<T> members:

  class MyClass : private Config
  {
    Setting<int> foo{this, 123, "foo", "the number of foos to use"};
    Setting<std::string> bar{this, "blabla", "bar", "the name of the bar"};

    MyClass() : Config(readConfigFile("/etc/my-app.conf"))
    {
      std::cout << foo << "\n"; // will print 123 unless overriden
    }
  };

Currently, this is used by Store and its subclasses for store
parameters. You now get a warning if you specify a non-existant store
parameter in a store URI.

1 files changed, 4 insertions, 5 deletions

diff --git a/src/libstore/local-fs-store.cc b/src/libstore/local-fs-store.cc
index 57e1b8a09fe6..bf247903c9db 100644
--- a/src/libstore/local-fs-store.cc
+++ b/src/libstore/local-fs-store.cc
@@ -9,9 +9,6 @@ namespace nix {
 
 LocalFSStore::LocalFSStore(const Params & params)
     : Store(params)
-    , rootDir(get(params, "root"))
-    , stateDir(canonPath(get(params, "state", rootDir != "" ? rootDir + "/nix/var/nix" : settings.nixStateDir)))
-    , logDir(canonPath(get(params, "log", rootDir != "" ? rootDir + "/nix/var/log/nix" : settings.nixLogDir)))
 {
 }
 
@@ -88,6 +85,8 @@ void LocalFSStore::narFromPath(const Path & path, Sink & sink)
 
 const string LocalFSStore::drvsLogDir = "drvs";
 
+
+
 std::shared_ptr<std::string> LocalFSStore::getBuildLog(const Path & path_)
 {
     auto path(path_);
@@ -110,8 +109,8 @@ std::shared_ptr<std::string> LocalFSStore::getBuildLog(const Path & path_)
 
         Path logPath =
             j == 0
-            ? (format("%1%/%2%/%3%/%4%") % logDir % drvsLogDir % string(baseName, 0, 2) % string(baseName, 2)).str()
-            : (format("%1%/%2%/%3%") % logDir % drvsLogDir % baseName).str();
+            ? fmt("%s/%s/%s/%s", logDir, drvsLogDir, string(baseName, 0, 2), string(baseName, 2))
+            : fmt("%s/%s/%s", logDir, drvsLogDir, baseName);
         Path logBz2Path = logPath + ".bz2";
 
         if (pathExists(logPath))