crush: introduce a helper class for dumping crush tree.

Signed-off-by: Mykola Golub <mgolub@mirantis.com>

diff --git a/src/crush/CrushTreeDumper.h b/src/crush/CrushTreeDumper.h
new file mode 100644 (file)
index 0000000..812b4ed
--- /dev/null
+++ b/src/crush/CrushTreeDumper.h
@@ -0,0 +1,178 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph distributed storage system
+ *
+ * Copyright (C) 2015 Mirantis Inc
+ *
+ * Author: Mykola Golub <mgolub@mirantis.com>
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2.1 of the License, or (at your option) any later version.
+ *
+ */
+
+#ifndef CRUSH_TREE_DUMPER_H
+#define CRUSH_TREE_DUMPER_H
+
+#include "CrushWrapper.h"
+
+/**
+ * CrushTreeDumper:
+ * A helper class and functions to dump a crush tree.
+ *
+ * Example:
+ *
+ *  class SimpleDumper : public CrushTreeDumper::Dumper<ostream> {
+ *  public:
+ *    SimpleDumper(const CrushWrapper *crush) :
+ *      CrushTreeDumper::Dumper<ostream>(crush) {}
+ *  protected:
+ *    virtual void dump_item(const CrushTreeDumper::Item &qi, ostream *out) {
+ *      *out << qi.id;
+ *      for (int k = 0; k < qi.depth; k++)
+ *        *out << "-";
+ *      if (qi.is_bucket())
+ *        *out << crush->get_item_name(qi.id)
+ *      else
+ *        *out << "osd." << qi.id;
+ *      *out << "\n";
+ *    }
+ *  };
+ *
+ *  SimpleDumper(crush).dump(out);
+ *
+ */
+
+namespace CrushTreeDumper {
+
+  struct Item {
+    int id;
+    int depth;
+    float weight;
+    list<int> children;
+
+    Item() : id(0), depth(0), weight(0) {}
+    Item(int i, int d, float w) : id(i), depth(d), weight(w) {}
+
+    bool is_bucket() const { return id < 0; }
+  };
+
+  template <typename F>
+  class Dumper : public list<Item> {
+  public:
+    Dumper(const CrushWrapper *crush_) : crush(crush_) {
+      crush->find_roots(roots);
+      root = roots.begin();
+    }
+
+    virtual ~Dumper() {}
+
+    virtual void reset() {
+      root = roots.begin();
+      touched.clear();
+      clear();
+    }
+
+    bool next(Item &qi) {
+      if (empty()) {
+       if (root == roots.end())
+         return false;
+       push_back(Item(*root, 0, crush->get_bucket_weightf(*root)));
+       root++;
+      }
+
+      qi = front();
+      pop_front();
+      touched.insert(qi.id);
+
+      if (qi.is_bucket()) {
+       // queue bucket contents...
+       int s = crush->get_bucket_size(qi.id);
+       for (int k = s - 1; k >= 0; k--) {
+         int id = crush->get_bucket_item(qi.id, k);
+         qi.children.push_back(id);
+         push_front(Item(id, qi.depth + 1,
+                         crush->get_bucket_item_weightf(qi.id, k)));
+       }
+      }
+      return true;
+    }
+
+    void dump(F *f) {
+      reset();
+      Item qi;
+      while (next(qi))
+       dump_item(qi, f);
+    }
+
+    bool is_touched(int id) const { return touched.count(id) > 0; }
+
+  protected:
+    virtual void dump_item(const Item &qi, F *f) = 0;
+
+  protected:
+    const CrushWrapper *crush;
+
+  private:
+    set<int> touched;
+    set<int> roots;
+    set<int>::iterator root;
+  };
+
+  inline void dump_item_fields(const CrushWrapper *crush,
+                              const Item &qi, Formatter *f) {
+    f->dump_int("id", qi.id);
+    if (qi.is_bucket()) {
+      int type = crush->get_bucket_type(qi.id);
+      f->dump_string("name", crush->get_item_name(qi.id));
+      f->dump_string("type", crush->get_type_name(type));
+      f->dump_int("type_id", type);
+    } else {
+      f->dump_stream("name") << "osd." << qi.id;
+      f->dump_string("type", crush->get_type_name(0));
+      f->dump_int("type_id", 0);
+      f->dump_float("crush_weight", qi.weight);
+      f->dump_unsigned("depth", qi.depth);
+    }
+  }
+
+  inline void dump_bucket_children(const CrushWrapper *crush,
+                                  const Item &qi, Formatter *f) {
+    if (!qi.is_bucket())
+      return;
+
+    f->open_array_section("children");
+    for (list<int>::const_iterator i = qi.children.begin();
+        i != qi.children.end();
+        i++) {
+      f->dump_int("child", *i);
+    }
+    f->close_section();
+  }
+
+  class FormattingDumper : public Dumper<Formatter> {
+  public:
+    FormattingDumper(const CrushWrapper *crush) : Dumper<Formatter>(crush) {}
+
+  protected:
+    virtual void dump_item(const Item &qi, Formatter *f) {
+      f->open_object_section("item");
+      dump_item_fields(qi, f);
+      dump_bucket_children(qi, f);
+    }
+
+    virtual void dump_item_fields(const Item &qi, Formatter *f) {
+      CrushTreeDumper::dump_item_fields(crush, qi, f);
+    }
+
+    virtual void dump_bucket_children(const Item &qi, Formatter *f) {
+      CrushTreeDumper::dump_bucket_children(crush, qi, f);
+    }
+  };
+
+}
+
+#endif

diff --git a/src/crush/CrushWrapper.h b/src/crush/CrushWrapper.h
index b17f9a14f14f4b81420a943a3ad4016f6ef92091..5e5330591e5d8c30ae3d7b5323b1029b25a81b3f 100644 (file)
--- a/src/crush/CrushWrapper.h
+++ b/src/crush/CrushWrapper.h
@@ -890,6 +890,11 @@ public:
     if (IS_ERR(b)) return PTR_ERR(b);
     return crush_get_bucket_item_weight(b, pos);
   }
+  float get_bucket_item_weightf(int id, int pos) const {
+    const crush_bucket *b = get_bucket(id);
+    if (IS_ERR(b)) return 0;
+    return (float)crush_get_bucket_item_weight(b, pos) / (float)0x10000;
+  }
 
   /* modifiers */
   int add_bucket(int bucketno, int alg, int hash, int type, int size,

diff --git a/src/crush/Makefile.am b/src/crush/Makefile.am
index 3d2f45b80e60f40bf08b3f7b32da8824cbc14e3c..bae9c886faa4aaf37519640cc027d6c07e1bfda0 100644 (file)
--- a/src/crush/Makefile.am
+++ b/src/crush/Makefile.am
@@ -11,6 +11,7 @@ noinst_LTLIBRARIES += libcrush.la
 noinst_HEADERS += \
        crush/CrushCompiler.h \
        crush/CrushTester.h \
+       crush/CrushTreeDumper.h \
        crush/CrushWrapper.h \
        crush/CrushWrapper.i \
        crush/builder.h \