summaryrefslogtreecommitdiff
path: root/RealtimeSync/watcher.cpp
blob: 4e33bd98221d905128ff105fc6f3bbb8eeed1715 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
// **************************************************************************
// * This file is part of the FreeFileSync project. It is distributed under *
// * GNU General Public License: http://www.gnu.org/licenses/gpl.html       *
// * Copyright (C) Zenju (zenju AT gmx DOT de) - All Rights Reserved        *
// **************************************************************************

#include "watcher.h"
#include <set>
#include <zen/tick_count.h>
#include <zen/file_handling.h>
#include <zen/stl_tools.h>
#include <zen/dir_watcher.h>
#include <zen/thread.h>
#include <zen/assert_static.h>
#include <zen/tick_count.h>
#include <wx+/string_conv.h>
#include "../lib/resolve_path.h"
//#include "../library/db_file.h"     //SYNC_DB_FILE_ENDING -> complete file too much of a dependency; file ending too little to decouple into single header
//#include "../library/lock_holder.h" //LOCK_FILE_ENDING

using namespace zen;


namespace
{
const std::int64_t TICKS_UPDATE_INTERVAL = rts::UI_UPDATE_INTERVAL* ticksPerSec() / 1000;
TickVal lastExec = getTicks();
};

bool rts::updateUiIsAllowed()
{
    const TickVal now = getTicks(); //0 on error
    if (dist(lastExec, now) >= TICKS_UPDATE_INTERVAL)  //perform ui updates not more often than necessary
    {
        lastExec = now;
        return true;
    }
    return false;
}


namespace
{
const int CHECK_DIR_INTERVAL = 1; //unit: [s]


std::vector<Zstring> getFormattedDirs(const std::vector<Zstring>& dirs) //throw FileError
{
    std::set<Zstring, LessFilename> tmp; //make unique

    std::transform(dirs.begin(), dirs.end(), std::inserter(tmp, tmp.end()),
    [](const Zstring& dirnameNonFmt) { return getFormattedDirectoryName(dirnameNonFmt); });

    return std::vector<Zstring>(tmp.begin(), tmp.end());
}
}


rts::WaitResult rts::waitForChanges(const std::vector<Zstring>& dirNamesNonFmt, WaitCallback& statusHandler) //throw FileError
{
    const std::vector<Zstring> dirNamesFmt = getFormattedDirs(dirNamesNonFmt); //throw FileError
    if (dirNamesFmt.empty()) //pathological case, but we have to check else this function will wait endlessly
        throw zen::FileError(_("A folder input field is empty.")); //should have been checked by caller!

    //detect when volumes are removed/are not available anymore
    std::vector<std::pair<Zstring, std::shared_ptr<DirWatcher>>> watches;

    for (auto it = dirNamesFmt.begin(); it != dirNamesFmt.end(); ++it)
    {
        const Zstring& dirnameFmt = *it;
        try
        {
            //a non-existent network path may block, so check existence asynchronously!
            auto ftDirExists = async([=] { return zen::dirExists(dirnameFmt); });
            while (!ftDirExists.timed_wait(boost::posix_time::milliseconds(UI_UPDATE_INTERVAL / 2)))
                statusHandler.requestUiRefresh(); //may throw!
            if (!ftDirExists.get())
                return WaitResult(dirnameFmt);

            watches.push_back(std::make_pair(dirnameFmt, std::make_shared<DirWatcher>(dirnameFmt))); //throw FileError, ErrorNotExisting
        }
        catch (ErrorNotExisting&) //nice atomic behavior: *no* second directory existence check!!!
        {
            return WaitResult(dirnameFmt);
        }
        catch (FileError&) //play safe: remedy potential FileErrors that should have been ErrorNotExisting (e.g. Linux: errors during directory traversing)
        {
            if (!dirExists(dirnameFmt)) //file system race condition!!
                return WaitResult(dirnameFmt);
            throw;
        }
    }

    const std::int64_t TICKS_DIR_CHECK_INTERVAL = CHECK_DIR_INTERVAL * ticksPerSec(); //0 on error
    TickVal lastCheck = getTicks(); //0 on error
    while (true)
    {
        const bool checkDirExistNow = [&]() -> bool //checking once per sec should suffice
        {
            const TickVal now = getTicks(); //0 on error
            if (dist(lastCheck, now) >= TICKS_DIR_CHECK_INTERVAL)
            {
                lastCheck = now;
                return true;
            }
            return false;
        }();


        for (auto it = watches.begin(); it != watches.end(); ++it)
        {
            const Zstring& dirname = it->first;
            DirWatcher& watcher = *(it->second);

            //IMPORTANT CHECK: dirwatcher has problems detecting removal of top watched directories!
            if (checkDirExistNow)
                if (!dirExists(dirname)) //catch errors related to directory removal, e.g. ERROR_NETNAME_DELETED
                    return WaitResult(dirname);

            try
            {
                std::vector<DirWatcher::Entry> changedItems = watcher.getChanges([&] { statusHandler.requestUiRefresh(); }); //throw FileError, ErrorNotExisting

                //remove to be ignored changes
                vector_remove_if(changedItems, [](const DirWatcher::Entry& e)
                {
                    return endsWith(e.filename_, Zstr(".ffs_lock")) || //sync.ffs_lock, sync.Del.ffs_lock
                           endsWith(e.filename_, Zstr(".ffs_db"));     //sync.ffs_db, .sync.tmp.ffs_db
                    //no need to ignore temporal recycle bin directory: this must be caused by a file deletion anyway
                });

                if (!changedItems.empty())
                {
                    /*
                                    std::for_each(changedItems.begin(), changedItems.end(),
                                    [](const Zstring& fn) { wxMessageBox(toWx(fn));});
                    */
                    return WaitResult(changedItems[0]); //directory change detected
                }

            }
            catch (ErrorNotExisting&) //nice atomic behavior: *no* second directory existence check!!!
            {
                return WaitResult(dirname);
            }
            catch (FileError&) //play safe: remedy potential FileErrors that should have been ErrorNotExisting (e.g. Linux: errors during directory traversing)
            {
                if (!dirExists(dirname)) //file system race condition!!
                    return WaitResult(dirname);
                throw;
            }
        }

        boost::this_thread::sleep(boost::posix_time::milliseconds(rts::UI_UPDATE_INTERVAL / 2));
        statusHandler.requestUiRefresh(true); //throw ?: may start sync at this presumably idle time
    }
}


//support for monitoring newly connected directories volumes (e.g.: USB-sticks)
void rts::waitForMissingDirs(const std::vector<Zstring>& dirNamesNonFmt, WaitCallback& statusHandler) //throw FileError
{
    while (true)
    {
        //support specifying volume by name => call getFormattedDirectoryName() repeatedly
        const std::vector<Zstring>& dirNamesFmt = getFormattedDirs(dirNamesNonFmt); //throw FileError

        bool allExisting = true;
        for (auto it = dirNamesFmt.begin(); it != dirNamesFmt.end(); ++it)
        {
            const Zstring dirnameFmt = *it;
            auto ftDirExisting = async([=]() -> bool
            {
#ifdef FFS_WIN
                //1. login to network share, if necessary -> we probably do NOT want multiple concurrent runs: GUI!?
                loginNetworkShare(dirnameFmt, false); //login networks shares, no PW prompt -> is this really RTS's job?
#endif
                //2. check dir existence
                return zen::dirExists(dirnameFmt);
            });
            while (!ftDirExisting.timed_wait(boost::posix_time::milliseconds(rts::UI_UPDATE_INTERVAL / 2)))
                statusHandler.requestUiRefresh(); //may throw!

            if (!ftDirExisting.get())
            {
                allExisting = false;
                break;
            }
        }
        if (allExisting)
            return;

        //wait some time...
        const int refreshInterval = UI_UPDATE_INTERVAL / 2;
        assert_static(1000 * CHECK_DIR_INTERVAL % refreshInterval == 0);
        for (int i = 0; i < 1000 * CHECK_DIR_INTERVAL / refreshInterval; ++i)
        {
            boost::this_thread::sleep(boost::posix_time::milliseconds(refreshInterval));
            statusHandler.requestUiRefresh();
        }
    }
}
bgstack15