ceph/src/osdc/Striper.h

   1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
   2 // vim: ts=8 sw=2 smarttab
   3 /*
   4  * Ceph - scalable distributed file system
   5  *
   6  * Copyright (C) 2004-2006 Sage Weil <sage@newdream.net>
   7  *
   8  * This is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License version 2.1, as published by the Free Software
  11  * Foundation.  See file COPYING.
  12  *
  13  */
  14
  15 #ifndef CEPH_STRIPER_H
  16 #define CEPH_STRIPER_H
  17
  18 #include "include/types.h"
  19 #include "osd/osd_types.h"
  20
  21 class CephContext;
  22
  23 //namespace ceph {
  24
  25   class Striper {
  26   public:
  27     /*
  28      * map (ino, layout, offset, len) to a (list of) ObjectExtents (byte
  29      * ranges in objects on (primary) osds)
  30      */
  31     static void file_to_extents(CephContext *cct, const char *object_format,
  32                                 const file_layout_t *layout,
  33                                 uint64_t offset, uint64_t len,
  34                                 uint64_t trunc_size,
  35                                 map<object_t, vector<ObjectExtent> >& extents,
  36                                 uint64_t buffer_offset=0);
  37
  38     static void file_to_extents(CephContext *cct, const char *object_format,
  39                                 const file_layout_t *layout,
  40                                 uint64_t offset, uint64_t len,
  41                                 uint64_t trunc_size,
  42                                 vector<ObjectExtent>& extents,
  43                                 uint64_t buffer_offset=0);
  44
  45     static void file_to_extents(CephContext *cct, inodeno_t ino,
  46                                 const file_layout_t *layout,
  47                                 uint64_t offset, uint64_t len,
  48                                 uint64_t trunc_size,
  49                                 vector<ObjectExtent>& extents) {
  50       // generate prefix/format
  51       char buf[32];
  52       snprintf(buf, sizeof(buf), "%llx.%%08llx", (long long unsigned)ino);
  53
  54       file_to_extents(cct, buf, layout, offset, len, trunc_size, extents);
  55     }
  56
  57     static void assimilate_extents(
  58       map<object_t, vector<ObjectExtent> >& object_extents,
  59       vector<ObjectExtent>& extents);
  60
  61     /**
  62      * reverse map an object extent to file extents
  63      */
  64     static void extent_to_file(CephContext *cct, file_layout_t *layout,
  65                                uint64_t objectno, uint64_t off, uint64_t len,
  66                                vector<pair<uint64_t, uint64_t> >& extents);
  67
  68     static uint64_t object_truncate_size(
  69       CephContext *cct, const file_layout_t *layout,
  70       uint64_t objectno, uint64_t trunc_size);
  71
  72     static uint64_t get_num_objects(const file_layout_t& layout,
  73                                     uint64_t size);
  74     /*
  75      * helper to assemble a striped result
  76      */
  77     class StripedReadResult {
  78       // offset -> (data, intended length)
  79       map<uint64_t, pair<bufferlist, uint64_t> > partial;
  80       uint64_t total_intended_len = 0; //sum of partial.second.second
  81
  82     public:
  83       void add_partial_result(
  84         CephContext *cct, bufferlist& bl,
  85         const vector<pair<uint64_t,uint64_t> >& buffer_extents);
  86       /**
  87        * add sparse read into results
  88        *
  89        * @param bl buffer
  90        * @param bl_map map of which logical source extents this covers
  91        * @param bl_off logical buffer offset (e.g., first bl_map key
  92        *               if the buffer is not sparse)
  93        * @param buffer_extents output buffer extents the data maps to
  94        */
  95       void add_partial_sparse_result(
  96         CephContext *cct, bufferlist& bl,
  97         const map<uint64_t, uint64_t>& bl_map, uint64_t bl_off,
  98         const vector<pair<uint64_t,uint64_t> >& buffer_extents);
  99
 100       void assemble_result(CephContext *cct, bufferlist& bl, bool zero_tail);
 101
 102       /**
 103        * @buffer copy read data into buffer
 104        * @len the length of buffer
 105        */
 106       void assemble_result(CephContext *cct, char *buffer, size_t len);
 107     };
 108
 109   };
 110
 111 //};
 112
 113 #endif