X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=src%2Fceph%2Fsrc%2Finclude%2FCompatSet.h;fp=src%2Fceph%2Fsrc%2Finclude%2FCompatSet.h;h=83a1349d8420250c2fb02321175c9fe73ca0eab8;hb=812ff6ca9fcd3e629e49d4328905f33eee8ca3f5;hp=0000000000000000000000000000000000000000;hpb=15280273faafb77777eab341909a3f495cf248d9;p=stor4nfv.git

diff --git a/src/ceph/src/include/CompatSet.h b/src/ceph/src/include/CompatSet.h
new file mode 100644
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+++ b/src/ceph/src/include/CompatSet.h
@@ -0,0 +1,267 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- 
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2009 Sage Weil <sage@newdream.net>
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software 
+ * Foundation.  See file COPYING.
+ * 
+ */
+
+#ifndef CEPH_COMPATSET_H
+#define CEPH_COMPATSET_H
+#include "include/buffer.h"
+#include "common/Formatter.h"
+
+struct CompatSet {
+
+  struct Feature {
+    uint64_t id;
+    string name;
+
+    Feature(uint64_t _id, const string& _name) : id(_id), name(_name) {}
+  };
+
+  class FeatureSet {
+    uint64_t mask;
+    map <uint64_t,string> names;
+
+  public:
+    friend struct CompatSet;
+    friend class CephCompatSet_AllSet_Test;
+    friend class CephCompatSet_other_Test;
+    friend class CephCompatSet_merge_Test;
+    friend ostream& operator<<(ostream& out, const CompatSet::FeatureSet& fs);
+    friend ostream& operator<<(ostream& out, const CompatSet& compat);
+    FeatureSet() : mask(1), names() {}
+    void insert(const Feature& f) {
+      assert(f.id > 0);
+      assert(f.id < 64);
+      mask |= ((uint64_t)1<<f.id);
+      names[f.id] = f.name;
+    }
+
+    bool contains(const Feature& f) const {
+      return names.count(f.id);
+    }
+    bool contains(uint64_t f) const {
+      return names.count(f);
+    }
+    /**
+     * Getter instead of using name[] to be const safe
+     */
+    std::string get_name(uint64_t const f) const {
+      std::map<uint64_t, std::string>::const_iterator i = names.find(f);
+      assert(i != names.end());
+      return i->second;
+    }
+
+    void remove(uint64_t f) {
+      if (names.count(f)) {
+	names.erase(f);
+	mask &= ~((uint64_t)1<<f);
+      }
+    }
+    void remove(const Feature& f) {
+      remove(f.id);
+    }
+
+    void encode(bufferlist& bl) const {
+      /* See below, mask always has the lowest bit set in memory, but
+       * unset in the encoding */
+      ::encode(mask & (~(uint64_t)1), bl);
+      ::encode(names, bl);
+    }
+
+    void decode(bufferlist::iterator& bl) {
+      ::decode(mask, bl);
+      ::decode(names, bl);
+      /**
+       * Previously, there was a bug where insert did
+       * mask |= f.id rather than mask |= (1 << f.id).
+       * In FeatureSets from those version, mask always
+       * has the lowest bit set.  Since then, masks always
+       * have the lowest bit unset.
+       *
+       * When we encounter such a FeatureSet, we have to
+       * reconstruct the mask from the names map.
+       */
+      if (mask & 1) {
+	mask = 1;
+	map<uint64_t, string> temp_names;
+	temp_names.swap(names);
+	for (map<uint64_t, string>::iterator i = temp_names.begin();
+	     i != temp_names.end();
+	     ++i) {
+	  insert(Feature(i->first, i->second));
+	}
+      } else {
+	mask |= 1;
+      }
+    }
+
+    void dump(Formatter *f) const {
+      for (map<uint64_t,string>::const_iterator p = names.begin();
+	   p != names.end();
+	   ++p) {
+	char s[18];
+	snprintf(s, sizeof(s), "feature_%lld", (unsigned long long)p->first);
+	f->dump_string(s, p->second);
+      }
+    }
+  };
+
+  // These features have no impact on the read / write status
+  FeatureSet compat;
+  // If any of these features are missing, read is possible ( as long
+  // as no incompat feature is missing ) but it is not possible to write
+  FeatureSet ro_compat;
+  // If any of these features are missing, read or write is not possible
+  FeatureSet incompat;
+
+  CompatSet(FeatureSet& _compat, FeatureSet& _ro_compat, FeatureSet& _incompat) :
+    compat(_compat), ro_compat(_ro_compat), incompat(_incompat) {}
+
+  CompatSet() : compat(), ro_compat(), incompat() { }
+
+
+  /* does this filesystem implementation have the
+     features required to read the other? */
+  bool readable(CompatSet const& other) const {
+    return !((other.incompat.mask ^ incompat.mask) & other.incompat.mask);
+  }
+
+  /* does this filesystem implementation have the
+     features required to write the other? */
+  bool writeable(CompatSet const& other) const {
+    return readable(other) &&
+      !((other.ro_compat.mask ^ ro_compat.mask) & other.ro_compat.mask);
+  }
+
+  /* Compare this CompatSet to another.
+   * CAREFULLY NOTE: This operation is NOT commutative.
+   * a > b DOES NOT imply that b < a.
+   * If returns:
+   * 0: The CompatSets have the same feature set.
+   * 1: This CompatSet's features are a strict superset of the other's.
+   * -1: This CompatSet is missing at least one feature
+   *     described in the other. It may still have more features, though.
+   */
+  int compare(const CompatSet& other) {
+    if ((other.compat.mask == compat.mask) &&
+	(other.ro_compat.mask == ro_compat.mask) &&
+	(other.incompat.mask == incompat.mask)) return 0;
+    //okay, they're not the same
+
+    //if we're writeable we have a superset of theirs on incompat and ro_compat
+    if (writeable(other) && !((other.compat.mask ^ compat.mask)
+			      & other.compat.mask)) return 1;
+    //if we make it here, we weren't writeable or had a difference compat set
+    return -1;
+  }
+
+  /* Get the features supported by other CompatSet but not this one,
+   * as a CompatSet.
+   */
+  CompatSet unsupported(CompatSet& other) {
+    CompatSet diff;
+    uint64_t other_compat =
+      ((other.compat.mask ^ compat.mask) & other.compat.mask);
+    uint64_t other_ro_compat =
+      ((other.ro_compat.mask ^ ro_compat.mask) & other.ro_compat.mask);
+    uint64_t other_incompat =
+      ((other.incompat.mask ^ incompat.mask) & other.incompat.mask);
+    for (int id = 1; id < 64; ++id) {
+      uint64_t mask = (uint64_t)1 << id;
+      if (mask & other_compat) {
+	diff.compat.insert( Feature(id, other.compat.names[id]));
+      }
+      if (mask & other_ro_compat) {
+	diff.ro_compat.insert(Feature(id, other.ro_compat.names[id]));
+      }
+      if (mask & other_incompat) {
+	diff.incompat.insert( Feature(id, other.incompat.names[id]));
+      }
+    }
+    return diff;
+  }
+  
+  /* Merge features supported by other CompatSet into this one.
+   * Return: true if some features were merged
+   */
+  bool merge(CompatSet const & other) {
+    uint64_t other_compat =
+      ((other.compat.mask ^ compat.mask) & other.compat.mask);
+    uint64_t other_ro_compat =
+      ((other.ro_compat.mask ^ ro_compat.mask) & other.ro_compat.mask);
+    uint64_t other_incompat =
+      ((other.incompat.mask ^ incompat.mask) & other.incompat.mask);
+    if (!other_compat && !other_ro_compat && !other_incompat)
+      return false;
+    for (int id = 1; id < 64; ++id) {
+      uint64_t mask = (uint64_t)1 << id;
+      if (mask & other_compat) {
+	compat.insert( Feature(id, other.compat.get_name(id)));
+      }
+      if (mask & other_ro_compat) {
+	ro_compat.insert(Feature(id, other.ro_compat.get_name(id)));
+      }
+      if (mask & other_incompat) {
+	incompat.insert( Feature(id, other.incompat.get_name(id)));
+      }
+    }
+    return true;
+  }
+
+  void encode(bufferlist& bl) const {
+    compat.encode(bl);
+    ro_compat.encode(bl);
+    incompat.encode(bl);
+  }
+  
+  void decode(bufferlist::iterator& bl) {
+    compat.decode(bl);
+    ro_compat.decode(bl);
+    incompat.decode(bl);
+  }
+
+  void dump(Formatter *f) const {
+    f->open_object_section("compat");
+    compat.dump(f);
+    f->close_section();
+    f->open_object_section("ro_compat");
+    ro_compat.dump(f);
+    f->close_section();
+    f->open_object_section("incompat");
+    incompat.dump(f);
+    f->close_section();
+  }
+
+  static void generate_test_instances(list<CompatSet*>& o) {
+    o.push_back(new CompatSet);
+    o.push_back(new CompatSet);
+    o.back()->compat.insert(Feature(1, "one"));
+    o.back()->compat.insert(Feature(2, "two"));
+    o.back()->ro_compat.insert(Feature(4, "four"));
+    o.back()->incompat.insert(Feature(3, "three"));
+  }
+};
+WRITE_CLASS_ENCODER(CompatSet)
+
+inline ostream& operator<<(ostream& out, const CompatSet::FeatureSet& fs)
+{
+  return out << fs.names;
+}
+
+inline ostream& operator<<(ostream& out, const CompatSet& compat)
+{
+  return out << "compat=" << compat.compat
+	     << ",rocompat=" << compat.ro_compat
+	     << ",incompat=" << compat.incompat;
+}
+
+#endif