Convert dirns to the templatized nstbl class

d5460024 · Silas Boyd-Wickizer · eb852be9 · d5460024 · d5460024
--- a/include/dirns.hh
+++ b/include/dirns.hh
 #pragma once

-u64 namehash(const strbuf<DIRSIZ>&);
-
-#define NINS      251
-
-// Prevent potentially non-scalable bucket groupings
-static_assert(NINS != NHASH, "Bad NINS choice");
-
-class dirns : public rcu_freed
-{
-  typedef xns<strbuf<DIRSIZ>, u32, namehash> ins;
-
-public:
-  dirns() : rcu_freed("dirns") {
-    for (int i = 0; i < NINS; i++)
-      a_[i].store(nullptr);
-  }
-
-  ~dirns() {
-    for (int i = 0; i < NINS; i++)
-      if (a_[i].load() != nullptr) {
-        delete a_[i].load();
-        a_[i].store(nullptr);
-      }
-  }
-
-  bool remove(const strbuf<DIRSIZ>& name, const u32* vp = nullptr) {
-    u32 i = ah(name);
-    if (a_[i].load() != nullptr)
-      return a_[i].load()->remove(name, vp);
-    return false;
-  }
-
-  int insert(const strbuf<DIRSIZ>& name, const u32& inum) {
-    ins* ns;
-    u32 i;
-
-    i = ah(name);
+#include "nstbl.hh"

-  retry:
-    if (a_[i].load() == nullptr) {
-      ns = new ins(false);
-      if (!cmpxch(&a_[i], (decltype(ns)) nullptr, ns)) {
-        delete ns;
-        goto retry;
-      }
-    } else {
-      ns = a_[i];
-    }
-    
-    return ns->insert(name, inum);
-  }
-
-  u32 lookup(const strbuf<DIRSIZ>& name) const {
-    ins* ns;
-    u32 i;
-
-    i = ah(name);
-    ns = a_[i].load();
-    if (ns != nullptr)
-      return ns->lookup(name);
-    return 0;
-  }
-
-  template<class CB>
-  void enumerate(CB cb) const {
-    // XXX(sbw) not the same semantics as xns::enumerate.
-    // This continues if cb returns true.
-    for (int i = 0; i < NINS; i++) {
-      ins* ns = a_[i].load();
-      if (ns != nullptr)
-        ns->enumerate(cb);
-    }
-  }
-
-  virtual void do_gc(void) {
-    delete this;
-  }
-
-  NEW_DELETE_OPS(dirns);
-
-private:
-  std::atomic<ins*> a_[NINS];
-
-  u32 ah(const strbuf<DIRSIZ>& name) const {
-    u64 h = namehash(name);
-    return h % NINS;
-  }
-};
+u64 namehash(const strbuf<DIRSIZ>&);
+class dirns : public nstbl<strbuf<DIRSIZ>, u32, namehash> {};
--- a/include/nstbl.hh
+++ b/include/nstbl.hh
+#pragma once
+
+#define NINS      251
+
+// Prevent potentially non-scalable bucket groupings
+static_assert(NINS != NHASH, "Bad NINS choice");
+
+template<class K, class V, u64 (*HF)(const K&)>
+class nstbl : public rcu_freed
+{
+  typedef xns<K, V, HF> ins;
+
+public:
+  nstbl() : rcu_freed("nstbl") {
+    for (int i = 0; i < NINS; i++)
+      a_[i].store(nullptr);
+  }
+
+  ~nstbl() {
+    for (int i = 0; i < NINS; i++)
+      if (a_[i].load() != nullptr) {
+        delete a_[i].load();
+        a_[i].store(nullptr);
+      }
+  }
+
+  bool remove(const K& key, const V* vp = nullptr) {
+    u32 i = ah(key);
+    if (a_[i].load() != nullptr)
+      return a_[i].load()->remove(key, vp);
+    return false;
+  }
+
+  int insert(const K& key, const V& val) {
+    ins* ns;
+    u32 i;
+
+    i = ah(key);
+
+  retry:
+    if (a_[i].load() == nullptr) {
+      ns = new ins(false);
+      if (!cmpxch(&a_[i], (decltype(ns)) nullptr, ns)) {
+        delete ns;
+        goto retry;
+      }
+    } else {
+      ns = a_[i];
+    }
+    
+    return ns->insert(key, val);
+  }
+
+  V lookup(const K& key) const {
+    ins* ns;
+    u32 i;
+
+    i = ah(key);
+    ns = a_[i].load();
+    if (ns != nullptr)
+      return ns->lookup(key);
+    return 0;
+  }
+
+  template<class CB>
+  void enumerate(CB cb) const {
+    // XXX(sbw) not the same semantics as xns::enumerate.
+    // This continues if cb returns true.
+    for (int i = 0; i < NINS; i++) {
+      ins* ns = a_[i].load();
+      if (ns != nullptr)
+        ns->enumerate(cb);
+    }
+  }
+
+  virtual void do_gc(void) {
+    delete this;
+  }
+
+  NEW_DELETE_OPS(nstbl);
+
+private:
+  std::atomic<ins*> a_[NINS];
+
+  u32 ah(const K& key) const {
+    u64 h = HF(key);
+    return h % NINS;
+  }
+};