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// --------------------------------------------------------------------------
//
// File
// Name: RaidFileUtil.cpp
// Purpose: Utilities for raid files
// Created: 2003/07/11
//
// --------------------------------------------------------------------------
#include "Box.h"
#include <sys/types.h>
#include <sys/stat.h>
#include "RaidFileUtil.h"
#include "FileModificationTime.h"
#include "RaidFileRead.h" // for type definition
#include "MemLeakFindOn.h"
// --------------------------------------------------------------------------
//
// Function
// Name: RaidFileUtil::RaidFileExists(RaidFileDiscSet &, const std::string &)
// Purpose: Check to see the state of a RaidFile on disc (doesn't look at contents,
// just at existense of files)
// Created: 2003/07/11
//
// --------------------------------------------------------------------------
RaidFileUtil::ExistType RaidFileUtil::RaidFileExists(RaidFileDiscSet &rDiscSet, const std::string &rFilename, int *pStartDisc, int *pExisitingFiles, int64_t *pRevisionID)
{
if(pExisitingFiles)
{
*pExisitingFiles = 0;
}
// For stat call, although the results are not examined
struct stat st;
// check various files
int startDisc = 0;
{
std::string writeFile(RaidFileUtil::MakeWriteFileName(rDiscSet, rFilename, &startDisc));
if(pStartDisc)
{
*pStartDisc = startDisc;
}
if(::stat(writeFile.c_str(), &st) == 0)
{
// write file exists, use that
// Get unique ID
if(pRevisionID != 0)
{
(*pRevisionID) = FileModificationTime(st);
#ifndef HAVE_STRUCT_STAT_ST_MTIMESPEC
// On linux, the time resolution is very low for modification times.
// So add the size to it to give a bit more chance of it changing.
// TODO: Make this better.
(*pRevisionID) += st.st_size;
#endif
}
// return non-raid file
return NonRaid;
}
}
// Now see how many of the raid components exist
int64_t revisionID = 0;
int setSize = rDiscSet.size();
int rfCount = 0;
#ifndef HAVE_STRUCT_STAT_ST_MTIMESPEC
// TODO: replace this with better linux revision ID detection
int64_t revisionIDplus = 0;
#endif
for(int f = 0; f < setSize; ++f)
{
std::string componentFile(RaidFileUtil::MakeRaidComponentName(rDiscSet, rFilename, (f + startDisc) % setSize));
if(::stat(componentFile.c_str(), &st) == 0)
{
// Component file exists, add to count
rfCount++;
// Set flags for existance?
if(pExisitingFiles)
{
(*pExisitingFiles) |= (1 << f);
}
// Revision ID
if(pRevisionID != 0)
{
int64_t rid = FileModificationTime(st);
if(rid > revisionID) revisionID = rid;
#ifndef HAVE_STRUCT_STAT_ST_MTIMESPEC
revisionIDplus += st.st_size;
#endif
}
}
}
if(pRevisionID != 0)
{
(*pRevisionID) = revisionID;
#ifndef HAVE_STRUCT_STAT_ST_MTIMESPEC
(*pRevisionID) += revisionIDplus;
#endif
}
// Return a status based on how many parts are available
if(rfCount == setSize)
{
return AsRaid;
}
else if((setSize > 1) && rfCount == (setSize - 1))
{
return AsRaidWithMissingReadable;
}
else if(rfCount > 0)
{
return AsRaidWithMissingNotRecoverable;
}
return NoFile; // Obviously doesn't exist
}
// --------------------------------------------------------------------------
//
// Function
// Name: RaidFileUtil::DiscUsageInBlocks(int64_t, const RaidFileDiscSet &)
// Purpose: Returns the size of the file in blocks, given the file size and disc set
// Created: 2003/09/03
//
// --------------------------------------------------------------------------
int64_t RaidFileUtil::DiscUsageInBlocks(int64_t FileSize, const RaidFileDiscSet &rDiscSet)
{
// Get block size
int blockSize = rDiscSet.GetBlockSize();
// OK... so as the size of the file is always sizes of stripe1 + stripe2, we can
// do a very simple calculation for the main data.
int64_t blocks = (FileSize + (((int64_t)blockSize) - 1)) / ((int64_t)blockSize);
// It's just that simple calculation for non-RAID disc sets
if(rDiscSet.IsNonRaidSet())
{
return blocks;
}
// It's the parity which is mildly complex.
// First of all, add in size for all but the last two blocks.
int64_t parityblocks = (FileSize / ((int64_t)blockSize)) / 2;
blocks += parityblocks;
// Work out how many bytes are left
int bytesOver = (int)(FileSize - (parityblocks * ((int64_t)(blockSize*2))));
// Then... (let compiler optimise this out)
if(bytesOver == 0)
{
// Extra block for the size info
blocks++;
}
else if(bytesOver == sizeof(RaidFileRead::FileSizeType))
{
// For last block of parity, plus the size info
blocks += 2;
}
else if(bytesOver < blockSize)
{
// Just want the parity block
blocks += 1;
}
else if(bytesOver == blockSize || bytesOver >= ((blockSize*2)-((int)sizeof(RaidFileRead::FileSizeType))))
{
// Last block, plus size info
blocks += 2;
}
else
{
// Just want parity block
blocks += 1;
}
return blocks;
}
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