CMakeLists.txt

@@ -212,6 +212,7 @@ set(TILE_SRCS
     # "tile/rpc/server.cc"
     "tile/util/config.cc"
     "tile/util/ini_file_config.cc"
+    "tile/util/layered_config.cc"
 )
 
 if((NOT TILE_HAVE_GETIFADDRS) OR (NOT TILE_HAVE_FREEIFADDRS))

tile/util/config.h

@@ -109,13 +109,14 @@ protected:
   };
 
   virtual bool GetRaw(const Slice &key, std::string *value) const = 0;
-  virtual void SetRaw(const Slice &key, const Slice &value) = 0;
+  virtual bool SetRaw(const Slice &key, const Slice &value) = 0;
   virtual void RemoveRaw(const Slice &key) = 0;
   virtual Keys Enumerate(const Slice &range) const = 0;
   void SetRawWithEvent(const Slice &key, const std::string &value);
   virtual ~Config();
 
   friend class std::default_delete<Config>;
+  friend class LayeredConfig;
 
 private:
   mutable Mutex mutex_;

tile/util/ini_file_config.cc

@@ -35,8 +35,9 @@ bool IniFileConfig::GetRaw(const Slice &key, std::string *value) const {
     return false;
   }
 }
-void IniFileConfig::SetRaw(const Slice &key, const Slice &value) {
+bool IniFileConfig::SetRaw(const Slice &key, const Slice &value) {
   map_[key] = value;
+  return true;
 }
 
 void IniFileConfig::RemoveRaw(const Slice &key) {

tile/util/ini_file_config.h

@@ -21,7 +21,7 @@ public:
 
 protected:
   bool GetRaw(const Slice &key, std::string *value) const override;
-  void SetRaw(const Slice &key, const Slice &value) override;
+  bool SetRaw(const Slice &key, const Slice &value) override;
   void RemoveRaw(const Slice &key) override;
   Keys Enumerate(const Slice &range) const override;
 

tile/util/layerd_config.h

@@ -1,25 +0,0 @@
-#ifndef TILE_UTIL_LAYERD_CONFIG_H
-#define TILE_UTIL_LAYERD_CONFIG_H
-
-#pragma once
-
-#include "tile/util/config.h"
-
-namespace tile {
-namespace util {
-class LayerdConfig : public Config {
-public:
-protected:
-  struct ConfigItem {
-    Config::Ptr cfg;
-    // 1 < 2 < 3 < 4 ...
-    int priority;
-    // can remove or set new?
-    bool writeable;
-    std::string label;
-  };
-};
-} // namespace util
-} // namespace tile
-
-#endif // TILE_UTIL_LAYERD_CONFIG_H

tile/util/layered_config.cc

@@ -0,0 +1,129 @@
+#include "tile/util/layered_config.h"
+
+namespace tile {
+namespace util {
+
+LayeredConfig::LayeredConfig() {}
+LayeredConfig::~LayeredConfig() {}
+
+void LayeredConfig::Add(Config::Ptr cfg) { Add(cfg, highest(), false); }
+
+void LayeredConfig::Add(Config::Ptr cfg, int priority) {
+  Add(cfg, priority, false);
+}
+
+void LayeredConfig::Add(Config::Ptr cfg, const std::string &label) {
+  Add(cfg, label, highest(), false);
+}
+
+void LayeredConfig::Add(Config::Ptr cfg, const std::string &label,
+                        int priority) {
+  Add(cfg, label, priority, false);
+}
+
+void LayeredConfig::Add(Config::Ptr cfg, const std::string &label,
+                        bool writeable) {
+  Add(cfg, label, highest(), writeable);
+}
+
+void LayeredConfig::Add(Config::Ptr cfg, const std::string &label, int priority,
+                        bool writeable) {
+  Config::ScopedLock lock(*this);
+  ConfigItem item;
+  item.cfg = cfg;
+  item.priority = priority;
+  item.writeable = writeable;
+  item.label = label;
+  auto it = configs_.begin();
+  while (it != configs_.end() && it->priority < priority) {
+    ++it;
+  }
+  configs_.insert(it, item);
+}
+
+void LayeredConfig::Add(Config::Ptr cfg, int priority, bool writeable) {
+  Add(cfg, std::string(), priority, writeable);
+}
+void LayeredConfig::AddWriteable(Config::Ptr cfg, int priority) {
+  Add(cfg, priority, true);
+}
+
+Config::Ptr LayeredConfig::Find(const Slice &label) const {
+  Config::ScopedLock lock(*this);
+
+  for (const auto &conf : configs_) {
+    if (conf.label == label) {
+      return conf.cfg;
+    }
+  }
+  return 0;
+}
+
+void LayeredConfig::RemoveConfig(Config::Ptr cfg) {
+  Config::ScopedLock lock(*this);
+  for (auto it = configs_.begin(); it != configs_.end();) {
+    if (it->cfg == cfg) {
+      it = configs_.erase(it);
+    } else {
+      ++it;
+    }
+  }
+}
+
+bool LayeredConfig::GetRaw(const Slice &key, std::string *value) const {
+  for (const auto &conf : configs_) {
+    if (conf.cfg->GetRaw(key, value)) {
+      return true;
+    }
+  }
+  return false;
+}
+
+bool LayeredConfig::SetRaw(const Slice &key, const Slice &value) {
+  for (const auto &conf : configs_) {
+    if (conf.writeable && conf.cfg->SetRaw(key, value)) {
+      return true;
+    }
+  }
+  return false;
+}
+
+Config::Keys LayeredConfig::Enumerate(const Slice &key) const {
+  Config::Keys keys;
+  std::set<Slice> key_set;
+  for (const auto &conf : configs_) {
+    auto conf_keys = conf.cfg->Enumerate(key);
+    for (const auto &k : conf_keys) {
+      if (key_set.insert(k).second) {
+        keys.push_back(k);
+      }
+    }
+  }
+  return keys;
+}
+
+void LayeredConfig::RemoveRaw(const std::string &key) {
+  for (auto &conf : configs_) {
+    if (conf.writeable) {
+      conf.cfg->RemoveRaw(key);
+    }
+  }
+}
+
+int LayeredConfig::lowest() const {
+  if (configs_.empty()) {
+    return 0;
+  } else {
+    return configs_.front().priority - 1;
+  }
+}
+int LayeredConfig::highest() const {
+  if (configs_.empty()) {
+    return 0;
+  } else {
+    return configs_.back().priority + 1;
+  }
+}
+
+} // namespace util
+} // namespace tile

tile/util/layered_config.h

@@ -0,0 +1,57 @@
+#ifndef TILE_UTIL_LAYERD_CONFIG_H
+#define TILE_UTIL_LAYERD_CONFIG_H
+
+#pragma once
+
+#include "tile/util/config.h"
+#include <list>
+
+namespace tile {
+namespace util {
+class LayeredConfig : public Config {
+public:
+  using Ptr = RefPtr<LayeredConfig>;
+  LayeredConfig();
+  LayeredConfig(const LayeredConfig &) = delete;
+  LayeredConfig &operator=(const LayeredConfig &) = delete;
+
+  void Add(Config::Ptr cfg);
+  void Add(Config::Ptr cfg, int priority);
+  void Add(Config::Ptr cfg, const std::string &label);
+  void Add(Config::Ptr cfg, const std::string &label, int priority);
+  void Add(Config::Ptr cfg, const std::string &label, bool writeable);
+  void Add(Config::Ptr cfg, const std::string &label, int priority,
+           bool writeable);
+  void Add(Config::Ptr cfg, int priority, bool writeable);
+  void AddWriteable(Config::Ptr cfg, int priority);
+  Config::Ptr Find(const Slice &label) const;
+  void RemoveConfig(Config::Ptr cfg);
+
+protected:
+  struct ConfigItem {
+    Config::Ptr cfg;
+    // ... > -2 > -1 > 0 > 1 > 2 > 3 > 4 ...
+    int priority;
+    // can remove or set new?
+    bool writeable;
+    std::string label;
+  };
+
+  bool GetRaw(const Slice &key, std::string *value) const override;
+  bool SetRaw(const Slice &key, const Slice &value) override;
+  Config::Keys Enumerate(const Slice &key) const override;
+  void RemoveRaw(const std::string &key);
+
+  int lowest() const;
+  int highest() const;
+
+  ~LayeredConfig();
+
+private:
+  using ConfigList = std::list<ConfigItem>;
+  ConfigList configs_;
+};
+} // namespace util
+} // namespace tile
+
+#endif // TILE_UTIL_LAYERD_CONFIG_H