src/chrome/browser/sync_file_system/local/local_file_sync_status.cc

   1 // Copyright 2013 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 "chrome/browser/sync_file_system/local/local_file_sync_status.h"
   6
   7 #include "base/logging.h"
   8 #include "base/stl_util.h"
   9 #include "webkit/common/fileapi/file_system_util.h"
  10
  11 using fileapi::FileSystemURL;
  12 using fileapi::FileSystemURLSet;
  13
  14 namespace sync_file_system {
  15
  16 namespace {
  17
  18 typedef LocalFileSyncStatus::OriginAndType OriginAndType;
  19
  20 OriginAndType GetOriginAndType(const fileapi::FileSystemURL& url) {
  21   return std::make_pair(url.origin(), url.type());
  22 }
  23
  24 base::FilePath NormalizePath(const base::FilePath& path) {
  25   // Ensure |path| has single trailing path-separator, so that we can use
  26   // prefix-match to find descendants of |path| in an ordered container.
  27   return base::FilePath(path.StripTrailingSeparators().value() +
  28                         fileapi::VirtualPath::kSeparator);
  29 }
  30
  31 struct SetKeyHelper {
  32   template <typename Iterator>
  33   static const base::FilePath& GetKey(Iterator itr) {
  34     return *itr;
  35   }
  36 };
  37
  38 struct MapKeyHelper {
  39   template <typename Iterator>
  40   static const base::FilePath& GetKey(Iterator itr) {
  41     return itr->first;
  42   }
  43 };
  44
  45 template <typename Container, typename GetKeyHelper>
  46 bool ContainsChildOrParent(const Container& paths,
  47                            const base::FilePath& path,
  48                            const GetKeyHelper& get_key_helper) {
  49   base::FilePath normalized_path = NormalizePath(path);
  50
  51   // Check if |paths| has a child of |normalized_path|.
  52   // Note that descendants of |normalized_path| are stored right after
  53   // |normalized_path| since |normalized_path| has trailing path separator.
  54   typename Container::const_iterator upper =
  55       paths.upper_bound(normalized_path);
  56
  57   if (upper != paths.end() &&
  58       normalized_path.IsParent(get_key_helper.GetKey(upper)))
  59     return true;
  60
  61   // Check if any ancestor of |normalized_path| is in |writing_|.
  62   while (true) {
  63     if (ContainsKey(paths, normalized_path))
  64       return true;
  65
  66     if (fileapi::VirtualPath::IsRootPath(normalized_path))
  67       return false;
  68
  69     normalized_path =
  70         NormalizePath(fileapi::VirtualPath::DirName(normalized_path));
  71   }
  72 }
  73
  74 }  // namespace
  75
  76 LocalFileSyncStatus::LocalFileSyncStatus() {}
  77
  78 LocalFileSyncStatus::~LocalFileSyncStatus() {}
  79
  80 void LocalFileSyncStatus::StartWriting(const FileSystemURL& url) {
  81   DCHECK(CalledOnValidThread());
  82   DCHECK(!IsChildOrParentSyncing(url));
  83   writing_[GetOriginAndType(url)][NormalizePath(url.path())]++;
  84 }
  85
  86 void LocalFileSyncStatus::EndWriting(const FileSystemURL& url) {
  87   DCHECK(CalledOnValidThread());
  88   base::FilePath normalized_path = NormalizePath(url.path());
  89   OriginAndType origin_and_type = GetOriginAndType(url);
  90
  91   int count = --writing_[origin_and_type][normalized_path];
  92   if (count == 0) {
  93     writing_[origin_and_type].erase(normalized_path);
  94     if (writing_[origin_and_type].empty())
  95       writing_.erase(origin_and_type);
  96     FOR_EACH_OBSERVER(Observer, observer_list_, OnSyncEnabled(url));
  97   }
  98 }
  99
 100 void LocalFileSyncStatus::StartSyncing(const FileSystemURL& url) {
 101   DCHECK(CalledOnValidThread());
 102   DCHECK(!IsChildOrParentWriting(url));
 103   DCHECK(!IsChildOrParentSyncing(url));
 104   syncing_[GetOriginAndType(url)].insert(NormalizePath(url.path()));
 105 }
 106
 107 void LocalFileSyncStatus::EndSyncing(const FileSystemURL& url) {
 108   DCHECK(CalledOnValidThread());
 109   base::FilePath normalized_path = NormalizePath(url.path());
 110   OriginAndType origin_and_type = GetOriginAndType(url);
 111
 112   syncing_[origin_and_type].erase(normalized_path);
 113   if (syncing_[origin_and_type].empty())
 114     syncing_.erase(origin_and_type);
 115   FOR_EACH_OBSERVER(Observer, observer_list_, OnSyncEnabled(url));
 116   FOR_EACH_OBSERVER(Observer, observer_list_, OnWriteEnabled(url));
 117 }
 118
 119 bool LocalFileSyncStatus::IsWriting(const FileSystemURL& url) const {
 120   DCHECK(CalledOnValidThread());
 121   return IsChildOrParentWriting(url);
 122 }
 123
 124 bool LocalFileSyncStatus::IsWritable(const FileSystemURL& url) const {
 125   DCHECK(CalledOnValidThread());
 126   return !IsChildOrParentSyncing(url);
 127 }
 128
 129 bool LocalFileSyncStatus::IsSyncable(const FileSystemURL& url) const {
 130   DCHECK(CalledOnValidThread());
 131   return !IsChildOrParentSyncing(url) && !IsChildOrParentWriting(url);
 132 }
 133
 134 void LocalFileSyncStatus::AddObserver(Observer* observer) {
 135   DCHECK(CalledOnValidThread());
 136   observer_list_.AddObserver(observer);
 137 }
 138
 139 void LocalFileSyncStatus::RemoveObserver(Observer* observer) {
 140   DCHECK(CalledOnValidThread());
 141   observer_list_.RemoveObserver(observer);
 142 }
 143
 144 bool LocalFileSyncStatus::IsChildOrParentWriting(
 145     const FileSystemURL& url) const {
 146   DCHECK(CalledOnValidThread());
 147
 148   URLBucket::const_iterator found = writing_.find(GetOriginAndType(url));
 149   if (found == writing_.end())
 150     return false;
 151   return ContainsChildOrParent(found->second, url.path(),
 152                                MapKeyHelper());
 153 }
 154
 155 bool LocalFileSyncStatus::IsChildOrParentSyncing(
 156     const FileSystemURL& url) const {
 157   DCHECK(CalledOnValidThread());
 158   URLSet::const_iterator found = syncing_.find(GetOriginAndType(url));
 159   if (found == syncing_.end())
 160     return false;
 161   return ContainsChildOrParent(found->second, url.path(),
 162                                SetKeyHelper());
 163 }
 164
 165 }  // namespace sync_file_system