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// fgfshelp.cc
#include "fgfshelp.h"
#ifndef _FGDLIST_H
#include "fgdlist.h"
#endif
#ifndef _FGSTRING_H
#include "fgstring.h"
#endif
#ifndef _FGEXC_H
#include "fgexc.h"
#endif
#include <sys/types.h>
#include <dirent.h>
#include <errno.h>
#include <sys/time.h>
#include <unistd.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/file.h>
#include <assert.h>
#include <string.h>
FGDirListing
FGFileSystemHelper::GetDirListing(const FGString& dir)
{
FGDirListing ret(dir);
DIR* pDir = opendir(dir);
if (pDir == NULL) {
// Oh dear
throw FGException(FGException::kLocalNoSuchDir, dir);
}
struct dirent* pDirEnt;
while ((pDirEnt = readdir(pDir)) != NULL) {
// Only report the file if it's not partially downloaded
// (this is indicated by permissions ---------T)
struct stat statBuf;
FGString fname(dir);
fname += '/';
fname += pDirEnt->d_name;
if (stat(fname, &statBuf) != -1) {
if (statBuf.st_mode != (S_ISVTX | S_IWUSR)) {
FGFileInfo fileInfo(pDirEnt->d_name, statBuf.st_size,
S_ISDIR(statBuf.st_mode),
S_ISREG(statBuf.st_mode));
ret.push_back(fileInfo);
}
}
}
closedir(pDir);
return ret;
}
void
FGFileSystemHelper::TransferRemoteToLocal(int fromFD, int toFD,
int bytes)
{
// Preconditions
assert(fromFD >= 0);
assert(toFD >= 0);
// Transfer buffer
char buf[msTransferBufSize];
// Accounting
int bytesWritten = 0;
bool hitEOF = false;
// Monitoring
fd_set remoteFDset;
FD_ZERO(&remoteFDset);
FD_SET(fromFD, &remoteFDset);
try {
while ((bytes == -1 || bytesWritten < bytes) && !hitEOF) {
// Timeout on remote read
// For now we will use 5 minutes
struct timeval tv;
tv.tv_usec = 0;
tv.tv_sec = 60 * 5;
int selectRet = select(fromFD+1, &remoteFDset, NULL, NULL, &tv);
// Did we timeout
if (selectRet == 0) {
// How irritating
throw FGException(FGException::kDownloadTimeout);
}
int numRead = read(fromFD, buf, sizeof(buf));
if (!numRead) {
hitEOF = true;
// Throw exception if expecting specific number of bytes
if (bytes != -1 && bytesWritten < bytes) {
throw FGException(FGException::kFileTooShort);
}
} else if (numRead == -1) {
throw FGException(FGException::kNetworkReadError, strerror(errno));
} else {
int writeRet = write(toFD, buf, numRead);
if (writeRet == -1) {
throw FGException(FGException::kWriteFailed, strerror(errno));
}
bytesWritten += numRead;
}
} // end: while (want more bytes)
}
catch (FGException& e) {
close(toFD);
throw e;
}
// If we completed the transfer fully, update file permissions to
// reflect this
if (bytes == -1 || bytes == bytesWritten) {
fchmod(toFD, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
}
// We are no longer writing to the file - so lose the lock
flock(toFD, LOCK_UN);
// And close it
close(toFD);
}
int
FGFileSystemHelper::CreateLocalFile(const FGString& file)
{
// Create with permissions "1400" == "---w-----T"
// This flags file as "in transit"
int theFD = open(file, O_CREAT | O_WRONLY,
S_ISVTX | S_IWUSR);
if (theFD == -1) {
FGString details(file);
details += ": ";
details += strerror(errno);
throw FGException(FGException::kFileCreateFailed, details);
}
// Before truncating, lock the file - in case another thread / process
// is currently downloading the file
int lockRet = flock(theFD, LOCK_EX | LOCK_NB);
if (lockRet == -1) {
close(theFD);
throw FGException(FGException::kConcurrentGrabs);
}
int ret = ftruncate(theFD, 0);
(void) ret;
return theFD;
}
void
FGFileSystemHelper::DeleteFile(const FGString& file)
{
int delRet = unlink(file);
if (delRet == -1) {
switch (errno) {
case EACCES:
case EPERM:
case EROFS:
throw FGException(FGException::kLocalPermissionDenied);
case ENOENT:
throw FGException(FGException::kLocalNoSuchFile);
default:
throw FGException(FGException::kUnlinkFailed);
}
}
}
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