cls_replica_log: add the actual class

This class can be applied to any object, and will keep track of
the bounds, matching times, and matching sets of in-progress items.
We're about to add a cls_replica_log_client that will provide a friendly
user interface and provide more documentation.

Signed-off-by: Greg Farnum <greg@inktank.com>

2 files changed, 159 insertions, 0 deletions

diff --git a/src/Makefile.am b/src/Makefile.am
index df61ca6d780..b497d6605b4 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -581,6 +581,14 @@ libcls_statelog_la_LDFLAGS = ${AM_LDFLAGS} -version-info 1:0:0 -export-symbols-r
 
 radoslib_LTLIBRARIES += libcls_statelog.la
 
+# replica log class
+libcls_replica_log_la_SOURCES = cls/replica_log/cls_replica_log.cc
+libcls_replica_log_la_CFLAGS = ${AM_CFLAGS}
+libcls_replica_log_la_CXXFLAGS= ${AM_CXXFLAGS}
+libcls_replica_log_la_LIBADD = $(PTHREAD_LIBS) $(EXTRALIBS)
+libcls_replica_log_la_LDFLAGS = ${AM_LDFLAGS} -version-info 1:0:0 -export-symbols-regex '.*__cls_.*'
+
+radoslib_LTLIBRARIES += libcls_replica_log.la
 
 if WITH_RADOSGW
 # rgw: rados gateway
diff --git a/src/cls/replica_log/cls_replica_log.cc b/src/cls/replica_log/cls_replica_log.cc
new file mode 100644
index 00000000000..1083b8adc38
--- /dev/null
+++ b/src/cls/replica_log/cls_replica_log.cc
@@ -0,0 +1,151 @@
+/*
+ * Ceph - scalable distributed file system
+ *
+ * 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.
+ * 
+ * Copyright Inktank 2013
+ */
+
+#include "objclass/objclass.h"
+#include "global/global_context.h"
+
+#include "cls_replica_log_types.h"
+#include "cls_replica_log_ops.h"
+
+CLS_VER(1, 0)
+CLS_NAME(replica_log)
+
+cls_handle_t h_class;
+cls_method_handle_t h_replica_log_set;
+cls_method_handle_t h_replica_log_delete;
+cls_method_handle_t h_replica_log_get;
+
+static const string replica_log_prefix = "rl_";
+static const string replica_log_bounds = replica_log_prefix + "bounds";
+
+static int get_bounds(cls_method_context_t hctx, cls_replica_log_bound& bound)
+{
+  bufferlist bounds_bl;
+  int rc = cls_cxx_map_get_val(hctx, replica_log_bounds, &bounds_bl);
+  if (rc < 0) {
+    return rc;
+  }
+
+  try {
+    bufferlist::iterator bounds_bl_i = bounds_bl.begin();
+    ::decode(bound, bounds_bl_i);
+  } catch (buffer::error& err) {
+    bound = cls_replica_log_bound();
+    CLS_LOG(0, "ERROR: get_bounds(): failed to decode on-disk bounds object");
+    return -EIO;
+  }
+
+  return 0;
+}
+
+static int write_bounds(cls_method_context_t hctx,
+                        const cls_replica_log_bound& bound)
+{
+  bufferlist bounds_bl;
+  ::encode(bound, bounds_bl);
+  return cls_cxx_map_set_val(hctx, replica_log_bounds, &bounds_bl);
+}
+
+static int cls_replica_log_set(cls_method_context_t hctx,
+                               bufferlist *in, bufferlist *out)
+{
+  bufferlist::iterator in_iter = in->begin();
+
+  cls_replica_log_set_marker_op op;
+  try {
+    ::decode(op, in_iter);
+  } catch (buffer::error& err) {
+    CLS_LOG(0, "ERROR: cls_replica_log_set(): failed to decode op");
+    return -EINVAL;
+  }
+
+  cls_replica_log_bound bound;
+  int rc = get_bounds(hctx, bound);
+  if (rc < 0 && rc != -ENOENT) {
+    return rc;
+  }
+
+  rc = bound.update_marker(op.marker);
+  if (rc < 0) {
+    return rc;
+  }
+
+  return write_bounds(hctx, bound);
+}
+
+static int cls_replica_log_delete(cls_method_context_t hctx,
+                                  bufferlist *in, bufferlist *out)
+{
+  bufferlist::iterator in_iter = in->begin();
+
+  cls_replica_log_delete_marker_op op;
+  try {
+    ::decode(op, in_iter);
+  } catch (buffer::error& err) {
+    CLS_LOG(0, "ERROR: cls_replica_log_delete(): failed to decode op");
+    return -EINVAL;
+  }
+
+  cls_replica_log_bound bound;
+  int rc = get_bounds(hctx, bound);
+  if (rc < 0 && rc != -ENOENT) {
+    return rc;
+  }
+
+  rc = bound.delete_marker(op.entity_id);
+  if (rc < 0) {
+    return rc;
+  }
+
+  return write_bounds(hctx, bound);
+}
+
+static int cls_replica_log_get(cls_method_context_t hctx,
+                               bufferlist *in, bufferlist *out)
+{
+  bufferlist::iterator in_iter = in->begin();
+
+  cls_replica_log_get_bounds_op op;
+  try {
+    ::decode(op, in_iter);
+  } catch (buffer::error& err) {
+    CLS_LOG(0, "ERROR: cls_replica_log_get(): failed to decode op");
+    return -EINVAL;
+  }
+
+  cls_replica_log_bound bound;
+  int rc = get_bounds(hctx, bound);
+  if (rc < 0) {
+    return rc;
+  }
+
+  cls_replica_log_get_bounds_ret ret;
+  ret.oldest_time = bound.get_oldest_time();
+  ret.position_marker = bound.get_lowest_marker_bound();
+  bound.get_markers(ret.markers);
+
+  ::encode(ret, *out);
+  return 0;
+}
+
+void __cls_init()
+{
+  CLS_LOG(1, "Loaded replica log class!");
+
+  cls_register("replica_log", &h_class);
+
+  cls_register_cxx_method(h_class, "set", CLS_METHOD_RD | CLS_METHOD_WR,
+                          cls_replica_log_set, &h_replica_log_set);
+  cls_register_cxx_method(h_class, "get", CLS_METHOD_RD,
+                          cls_replica_log_get, &h_replica_log_get);
+  cls_register_cxx_method(h_class, "delete", CLS_METHOD_RD | CLS_METHOD_WR,
+                          cls_replica_log_delete, &h_replica_log_delete);
+}