git-svn-id: https://ceph.svn.sf.net/svnroot/ceph@960 29311d96-e01e-0410-9327-a35deaab8ce9

diff --git a/ceph/TODO b/ceph/TODO
index 755c36fd4023738901bca9d6044f1259c29e81a2..c3391f691330b559f31e52cb1d0202a94a1231be 100644 (file)
--- a/ceph/TODO
+++ b/ceph/TODO
@@ -1,6 +1,13 @@
 
 == todo
 
+papers to read
+- gribble et al 2000, scalable distributed hash table
+- sagiv blink trees
+- johnson and colbrook's DE and DB-trees (maybe fewer locks?)
+
+
+
 - messenger lookup() and failure() upcalls
 
 - how to get usage feedback to monitor?
@@ -9,6 +16,26 @@
  - no more rank!  make it a uniquish nonce?
 
 
+osd
+- pull out "object" service
+- btree service
+- interject snapshot abstraction.  inbetween?  
+ - how to generalize pg log entries?  
+ - or put snapshotting in apply_operation?
+
+osdc
+- distributed btree thing: Blinker!
+
+mds
+- rewrite mdstore to use osd btree service
+
+journaler
+- should we pad with zeros to avoid splitting individual entries?
+  - make it a g_conf flag?
+  - have to fix reader to skip over zeros (either <4 bytes for size, or zeroed sizes)
+- need to truncate at detected (valid) write_pos to clear out any other partial trailing writes
+
+
 
 monitor
 ?- monitor user lib that handles resending, redirection of mon requests.
@@ -25,13 +52,14 @@ osdmon
 mdsmon
 
 osd/rados
+- pg_num instead of pg_bits
 - flag missing log entries on crash recovery  --> WRNOOP? or WRLOST?
 - consider implications of nvram writeahead logs
 - fix heartbeat wrt new replication
 - mark residual pgs obsolete  ???
 - rdlocks
 - optimize remove wrt recovery pushes
-- pg_bit changes
+- pg_bit/pg_num changes
 - report crashed pgs?
 
 messenger
@@ -74,7 +102,8 @@ bugs/stability
 
 general
 - timer needs cancel sets, schedulers need to cancel outstanding events on shutdown
-  - well, just figure out general timer cancellation strategy that avoids races
+- well, just figure out general timer cancellation strategy that avoids races
+ - use updated Timer as a model?
 
 
 remaining hard problems

diff --git a/ceph/osdc/Blinker.h b/ceph/osdc/Blinker.h
new file mode 100644 (file)
index 0000000..231fe47
--- /dev/null
+++ b/ceph/osdc/Blinker.h
@@ -0,0 +1,91 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- 
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2004-2006 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 __BLINKER_H
+#define __BLINKER_H
+
+class Blinker {
+
+ public:
+
+  class Op {
+    int op;
+    static const int LOOKUP = 1;
+    static const int INSERT = 2;
+    static const int REMOVE = 3;
+    static const int CLEAR = 4;
+    Op(int o) : op(o) {}
+  };
+  
+  class OpLookup : public Op {
+  public:
+    bufferptr key;
+    OpLookup(bufferptr& k) : Op(Op::LOOKUP), key(k) {}
+  };
+
+  class OpInsert : public Op {
+    bufferptr key;
+    bufferlist val;
+    OpInsert(bufferptr& k, bufferlist& v) : Op(Op::INSERT), key(k), val(v) {}
+  };
+
+  class OpRemove : public Op {
+  public:
+    bufferptr key;
+    OpRemove(bufferptr& k) : Op(Op::REMOVE), key(k) {}
+  };
+
+  class OpClear : public Op {
+  public:
+    OpClear() : Op(Op::CLEAR) {}
+  };
+
+
+
+private:
+  Objecter *objecter;
+
+  // in-flight operations.
+
+
+  // cache information about tree structure.
+  
+
+
+public:
+  // public interface
+
+  // simple accessors
+  void lookup(inode_t& inode, bufferptr& key, bufferlist *pval, Context *onfinish);
+
+  // simple modifiers
+  void insert(inode_t& inode, bufferptr& key, bufferlist& val, Context *onack, Context *onsafe);
+  void remove(inode_t& inode, bufferptr& key, Context *onack, Context *onsafe);
+  void clear(inode_t& inode, Context *onack, Context *onsafe);
+
+  // these are dangerous: the table may be large.
+  void listkeys(inode_t& inode, list<bufferptr>* pkeys, Context *onfinish);
+  void listvals(inode_t& inode, list<bufferptr>* pkeys, list<bufferlist>* pvals, Context *onfinish);
+
+  // fetch *at least* key, but also anything else that is convenient. 
+  // include lexical bounds for which this is a complete result.
+  //  (if *start and *end are empty, it's the entire table)
+  void prefetch(inode_t& inode, bufferptr& key, 
+               list<bufferptr>* pkeys, list<bufferlist>* pvals, 
+               bufferptr *start, bufferptr *end,
+               Context *onfinish);
+
+  
+};
+
+#endif