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#ifndef LOCK_HOLDER_H_INCLUDED
#define LOCK_HOLDER_H_INCLUDED
#include <map>
#include <zen/zstring.h>
#include <zen/stl_tools.h>
#include "dir_lock.h"
#include "status_handler.h"
#include "dir_exist_async.h"
namespace zen
{
const Zstring LOCK_FILE_ENDING = Zstr(".ffs_lock"); //intermediate locks created by DirLock use this extension, too!
//hold locks for a number of directories without blocking during lock creation
class LockHolder
{
public:
LockHolder(const std::vector<Zstring>& dirnamesFmt, //resolved dirname ending with path separator
ProcessCallback& procCallback,
bool allowUserInteraction) : allowUserInteraction_(allowUserInteraction)
{
std::vector<Zstring> dirs = dirnamesFmt;
vector_remove_if(dirs, [](const Zstring& dir) { return dir.empty(); });
for (auto it = dirs.begin(); it != dirs.end(); ++it)
{
const Zstring& dirnameFmt = *it;
if (!dirExistsUpdating(dirnameFmt, allowUserInteraction_, procCallback))
continue;
if (lockHolder.find(dirnameFmt) != lockHolder.end())
continue;
assert(endsWith(dirnameFmt, FILE_NAME_SEPARATOR)); //this is really the contract, formatting does other things as well, e.g. macro substitution
class WaitOnLockHandler : public DirLockCallback
{
public:
WaitOnLockHandler(ProcessCallback& pc) : pc_(pc) {}
virtual void requestUiRefresh() { pc_.requestUiRefresh(); } //allowed to throw exceptions
virtual void reportInfo(const std::wstring& text) { pc_.reportStatus(text); }
private:
ProcessCallback& pc_;
} callback(procCallback);
try
{
//lock file creation is synchronous and may block noticeably for very slow devices (usb sticks, mapped cloud storages)
procCallback.forceUiRefresh(); //=> make sure the right folder name is shown on GUI during this time!
lockHolder.insert(std::make_pair(dirnameFmt, DirLock(dirnameFmt + Zstr("sync") + LOCK_FILE_ENDING, &callback)));
}
catch (const FileError& e)
{
bool dummy = false; //this warning shall not be shown but logged only
procCallback.reportWarning(e.toString(), dummy); //may throw!
}
}
}
private:
typedef std::map<Zstring, DirLock, LessFilename> DirnameLockMap;
DirnameLockMap lockHolder;
const bool allowUserInteraction_;
};
}
#endif // LOCK_HOLDER_H_INCLUDED
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