initial code repo
[stor4nfv.git] / src / ceph / src / osdc / Striper.h
diff --git a/src/ceph/src/osdc/Striper.h b/src/ceph/src/osdc/Striper.h
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+// -*- 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) 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 CEPH_STRIPER_H
+#define CEPH_STRIPER_H
+
+#include "include/types.h"
+#include "osd/osd_types.h"
+
+class CephContext;
+
+//namespace ceph {
+
+  class Striper {
+  public:
+    /*
+     * map (ino, layout, offset, len) to a (list of) ObjectExtents (byte
+     * ranges in objects on (primary) osds)
+     */
+    static void file_to_extents(CephContext *cct, const char *object_format,
+                               const file_layout_t *layout,
+                               uint64_t offset, uint64_t len,
+                               uint64_t trunc_size,
+                               map<object_t, vector<ObjectExtent> >& extents,
+                               uint64_t buffer_offset=0);
+
+    static void file_to_extents(CephContext *cct, const char *object_format,
+                               const file_layout_t *layout,
+                               uint64_t offset, uint64_t len,
+                               uint64_t trunc_size,
+                               vector<ObjectExtent>& extents,
+                               uint64_t buffer_offset=0);
+
+    static void file_to_extents(CephContext *cct, inodeno_t ino,
+                               const file_layout_t *layout,
+                               uint64_t offset, uint64_t len,
+                               uint64_t trunc_size,
+                               vector<ObjectExtent>& extents) {
+      // generate prefix/format
+      char buf[32];
+      snprintf(buf, sizeof(buf), "%llx.%%08llx", (long long unsigned)ino);
+
+      file_to_extents(cct, buf, layout, offset, len, trunc_size, extents);
+    }
+
+    static void assimilate_extents(
+      map<object_t, vector<ObjectExtent> >& object_extents,
+      vector<ObjectExtent>& extents);
+
+    /**
+     * reverse map an object extent to file extents
+     */
+    static void extent_to_file(CephContext *cct, file_layout_t *layout,
+                              uint64_t objectno, uint64_t off, uint64_t len,
+                              vector<pair<uint64_t, uint64_t> >& extents);
+
+    static uint64_t object_truncate_size(
+      CephContext *cct, const file_layout_t *layout,
+      uint64_t objectno, uint64_t trunc_size);
+
+    static uint64_t get_num_objects(const file_layout_t& layout,
+                                   uint64_t size);
+    /*
+     * helper to assemble a striped result
+     */
+    class StripedReadResult {
+      // offset -> (data, intended length)
+      map<uint64_t, pair<bufferlist, uint64_t> > partial;
+      uint64_t total_intended_len = 0; //sum of partial.second.second
+
+    public:
+      void add_partial_result(
+       CephContext *cct, bufferlist& bl,
+       const vector<pair<uint64_t,uint64_t> >& buffer_extents);
+      /**
+       * add sparse read into results
+       *
+       * @param bl buffer
+       * @param bl_map map of which logical source extents this covers
+       * @param bl_off logical buffer offset (e.g., first bl_map key
+       *               if the buffer is not sparse)
+       * @param buffer_extents output buffer extents the data maps to
+       */
+      void add_partial_sparse_result(
+       CephContext *cct, bufferlist& bl,
+       const map<uint64_t, uint64_t>& bl_map, uint64_t bl_off,
+       const vector<pair<uint64_t,uint64_t> >& buffer_extents);
+
+      void assemble_result(CephContext *cct, bufferlist& bl, bool zero_tail);
+
+      /**
+       * @buffer copy read data into buffer
+       * @len the length of buffer
+       */
+      void assemble_result(CephContext *cct, char *buffer, size_t len);
+    };
+
+  };
+
+//};
+
+#endif