sync/syncable/syncable_id.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "sync/syncable/syncable_id.h"
   6
   7 #include <iosfwd>
   8
   9 #include "base/logging.h"
  10 #include "base/values.h"
  11
  12 using std::ostream;
  13 using std::string;
  14
  15 namespace syncer {
  16 namespace syncable {
  17
  18 ostream& operator<<(ostream& out, const Id& id) {
  19   out << id.s_;
  20   return out;
  21 }
  22
  23 base::StringValue* Id::ToValue() const {
  24   return new base::StringValue(s_);
  25 }
  26
  27 string Id::GetServerId() const {
  28   // Currently root is the string "0". We need to decide on a true value.
  29   // "" would be convenient here, as the IsRoot call would not be needed.
  30   DCHECK(!IsNull());
  31   if (IsRoot())
  32     return "0";
  33   return s_.substr(1);
  34 }
  35
  36 Id Id::CreateFromServerId(const string& server_id) {
  37   Id id;
  38   if (!server_id.empty()) {
  39     if (server_id == "0")
  40       id.s_ = "r";
  41     else
  42       id.s_ = string("s") + server_id;
  43   }
  44   return id;
  45 }
  46
  47 Id Id::CreateFromClientString(const string& local_id) {
  48   Id id;
  49   if (!local_id.empty()) {
  50     if (local_id == "0")
  51       id.s_ = "r";
  52     else
  53       id.s_ = string("c") + local_id;
  54   }
  55   return id;
  56 }
  57
  58 Id Id::GetRoot() {
  59   Id id;
  60   id.s_ = "r";
  61   return id;
  62 }
  63
  64 Id Id::GetLexicographicSuccessor() const {
  65   // The successor of a string is given by appending the least
  66   // character in the alphabet.
  67   Id id = *this;
  68   id.s_.push_back(0);
  69   return id;
  70 }
  71
  72 // static
  73 Id Id::GetLeastIdForLexicographicComparison() {
  74   Id id;
  75   id.s_.clear();
  76   return id;
  77 }
  78
  79 }  // namespace syncable
  80 }  // namespace syncer