[Sync] Move //sync to //components/sync.

sync/syncable/syncable_id.h

-// Copyright 2012 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef SYNC_SYNCABLE_SYNCABLE_ID_H_
-#define SYNC_SYNCABLE_SYNCABLE_ID_H_
-
-#include <iosfwd>
-#include <limits>
-#include <memory>
-#include <sstream>
-#include <string>
-
-#include "base/containers/hash_tables.h"
-#include "sync/base/sync_export.h"
-
-namespace base {
-class StringValue;
-}
-
-namespace sql {
-class Statement;
-}
-
-namespace syncer {
-namespace syncable {
-struct EntryKernel;
-class Id;
-
-SYNC_EXPORT std::ostream& operator<<(std::ostream& out, const Id& id);
-
-// For historical reasons, 3 concepts got everloaded into the Id:
-// 1. A unique, opaque identifier for the object.
-// 2. Flag specifing whether server know about this object.
-// 3. Flag for root.
-//
-// We originally wrapped an integer for this information, but now we use a
-// string. It will have one of three forms:
-// 1. c<client only opaque id> for client items that have not been committed.
-// 2. r for the root item.
-// 3. s<server provided opaque id> for items that the server knows about.
-class SYNC_EXPORT Id {
- public:
-  inline Id() {}
-  inline Id(const Id& that) {
-    Copy(that);
-  }
-  inline Id& operator = (const Id& that) {
-    Copy(that);
-    return *this;
-  }
-  inline void Copy(const Id& that) {
-    this->s_ = that.s_;
-  }
-  inline bool IsRoot() const {
-    return "r" == s_;
-  }
-  inline bool ServerKnows() const {
-    return !IsNull() && (s_[0] == 's' || s_ == "r");
-  }
-
-  inline bool IsNull() const { return s_.empty(); }
-  inline void Clear() { s_.clear(); }
-  inline int compare(const Id& that) const {
-    return s_.compare(that.s_);
-  }
-  inline bool operator == (const Id& that) const {
-    return s_ == that.s_;
-  }
-  inline bool operator != (const Id& that) const {
-    return s_ != that.s_;
-  }
-  inline bool operator < (const Id& that) const {
-    return s_ < that.s_;
-  }
-  inline bool operator > (const Id& that) const {
-    return s_ > that.s_;
-  }
-
-  const std::string& value() const {
-    return s_;
-  }
-
-  // Return the next highest ID in the lexicographic ordering.  This is
-  // useful for computing upper bounds on std::sets that are ordered
-  // by operator<.
-  Id GetLexicographicSuccessor() const;
-
-  // Dumps the ID as a value and returns it.  Transfers ownership of
-  // the StringValue to the caller.
-  base::StringValue* ToValue() const;
-
-  // Three functions are used to work with our proto buffers.
-  std::string GetServerId() const;
-  static Id CreateFromServerId(const std::string& server_id);
-  // This should only be used if you get back a reference to a local
-  // id from the server. Returns a client only opaque id.
-  static Id CreateFromClientString(const std::string& local_id);
-
-  // This method returns an ID that will compare less than any valid ID.
-  // The returned ID is not a valid ID itself.  This is useful for
-  // computing lower bounds on std::sets that are ordered by operator<.
-  static Id GetLeastIdForLexicographicComparison();
-
-  // Gets root ID.
-  static Id GetRoot();
-
- private:
-  friend std::unique_ptr<EntryKernel> UnpackEntry(sql::Statement* statement,
-                                                  int* total_created_entries);
-  friend void BindFields(const EntryKernel& entry,
-                         sql::Statement* statement);
-  SYNC_EXPORT friend std::ostream& operator<<(std::ostream& out, const Id& id);
-  friend class SyncableIdTest;
-
-  std::string s_;
-};
-
-}  // namespace syncable
-}  // namespace syncer
-
-#endif  // SYNC_SYNCABLE_SYNCABLE_ID_H_