s3fs-fuse/src/fdcache_page.h
2022-09-24 15:45:13 +09:00

136 lines
4.6 KiB
C++

/*
* s3fs - FUSE-based file system backed by Amazon S3
*
* Copyright(C) 2007 Randy Rizun <rrizun@gmail.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#ifndef S3FS_FDCACHE_PAGE_H_
#define S3FS_FDCACHE_PAGE_H_
#include <list>
#include <sys/types.h>
//------------------------------------------------
// Symbols
//------------------------------------------------
// [NOTE]
// If the following symbols in lseek whence are undefined, define them.
// If it is not supported by lseek, s3fs judges by the processing result of lseek.
//
#ifndef SEEK_DATA
#define SEEK_DATA 3
#endif
#ifndef SEEK_HOLE
#define SEEK_HOLE 4
#endif
//------------------------------------------------
// Structure fdpage
//------------------------------------------------
// page block information
struct fdpage
{
off_t offset;
off_t bytes;
bool loaded;
bool modified;
explicit fdpage(off_t start = 0, off_t size = 0, bool is_loaded = false, bool is_modified = false) :
offset(start), bytes(size), loaded(is_loaded), modified(is_modified) {}
off_t next() const
{
return (offset + bytes);
}
off_t end() const
{
return (0 < bytes ? offset + bytes - 1 : 0);
}
};
typedef std::list<struct fdpage> fdpage_list_t;
//------------------------------------------------
// Class PageList
//------------------------------------------------
class CacheFileStat;
class FdEntity;
// cppcheck-suppress copyCtorAndEqOperator
class PageList
{
friend class FdEntity; // only one method access directly pages.
private:
fdpage_list_t pages;
bool is_shrink; // [NOTE] true if it has been shrinked even once
public:
enum page_status{
PAGE_NOT_LOAD_MODIFIED = 0,
PAGE_LOADED,
PAGE_MODIFIED,
PAGE_LOAD_MODIFIED
};
private:
static bool GetSparseFilePages(int fd, size_t file_size, fdpage_list_t& sparse_list);
static bool CheckZeroAreaInFile(int fd, off_t start, size_t bytes);
static bool CheckAreaInSparseFile(const struct fdpage& checkpage, const fdpage_list_t& sparse_list, int fd, fdpage_list_t& err_area_list, fdpage_list_t& warn_area_list);
void Clear();
bool Parse(off_t new_pos);
public:
static void FreeList(fdpage_list_t& list);
explicit PageList(off_t size = 0, bool is_loaded = false, bool is_modified = false, bool shrinked = false);
explicit PageList(const PageList& other);
~PageList();
bool Init(off_t size, bool is_loaded, bool is_modified);
off_t Size() const;
bool Resize(off_t size, bool is_loaded, bool is_modified);
bool IsPageLoaded(off_t start = 0, off_t size = 0) const; // size=0 is checking to end of list
bool SetPageLoadedStatus(off_t start, off_t size, PageList::page_status pstatus = PAGE_LOADED, bool is_compress = true);
bool FindUnloadedPage(off_t start, off_t& resstart, off_t& ressize) const;
off_t GetTotalUnloadedPageSize(off_t start = 0, off_t size = 0, off_t limit_size = 0) const; // size=0 is checking to end of list
size_t GetUnloadedPages(fdpage_list_t& unloaded_list, off_t start = 0, off_t size = 0) const; // size=0 is checking to end of list
bool GetPageListsForMultipartUpload(fdpage_list_t& dlpages, fdpage_list_t& mixuppages, off_t max_partsize);
bool GetNoDataPageLists(fdpage_list_t& nodata_pages, off_t start = 0, size_t size = 0);
off_t BytesModified() const;
bool IsModified() const;
bool ClearAllModified();
bool Compress();
bool Serialize(CacheFileStat& file, bool is_output, ino_t inode);
void Dump() const;
bool CompareSparseFile(int fd, size_t file_size, fdpage_list_t& err_area_list, fdpage_list_t& warn_area_list);
};
#endif // S3FS_FDCACHE_PAGE_H_
/*
* Local variables:
* tab-width: 4
* c-basic-offset: 4
* End:
* vim600: expandtab sw=4 ts=4 fdm=marker
* vim<600: expandtab sw=4 ts=4
*/