posixstorage.cxx

SP是一个基于GNU C++编译器

Boolean PosixStorageManager::transformNeutral(StringC &, Boolean,
					      Messenger &) const
{
  return 1;
}

#endif /* not FILENAME_TYPE_DEFINED */

Boolean PosixStorageManager::resolveRelative(const StringC &baseId,
					     StringC &specId,
					     Boolean search) const
{
  if (isAbsolute(specId))
    return 1;
  if (!search || searchDirs_.size() == 0) {
    specId = combineDir(extractDir(baseId), specId);
    return 1;
  }
  return 0;
}

StorageObject *
PosixStorageManager::makeStorageObject(const StringC &spec,
				       const StringC &base,
				       Boolean search,
				       Boolean mayRewind,
				       Messenger &mgr,
				       StringC &found)
{
  if (spec.size() == 0) {
    mgr.message(PosixStorageMessages::invalidFilename,
		StringMessageArg(spec));
    return 0;
  }
  descriptorManager_.acquireD();
  Boolean absolute = isAbsolute(spec);
  SearchResultMessageArg sr;
  for (size_t i = 0; i < searchDirs_.size() + 1; i++) {
    StringC filename;
    if (absolute)
      filename = spec;
    else if (i == 0)
    	filename = combineDir(extractDir(base), spec);
    else
      filename = combineDir(searchDirs_[i - 1], spec);
#ifdef SP_WIDE_SYSTEM
    String<FChar> cfilename(filename);
    cfilename += FChar(0);
#else
    String<FChar> cfilename = filenameCodingSystem_->convertOut(filename);
#endif
    int fd;
    do {
      fd = openFile(cfilename.data());
    } while (fd < 0 && errno == EINTR);
    if (fd >= 0) {
      found = filename;
      return new PosixStorageObject(fd,
				    filename,
				    cfilename,
				    mayRewind,
				    &descriptorManager_);
    }
    int savedErrno = errno;
    if (absolute || !search || searchDirs_.size() == 0) {
      ParentLocationMessenger(mgr).message(PosixStorageMessages::openSystemCall,
					   StringMessageArg(filename),
					   ErrnoMessageArg(savedErrno));
      descriptorManager_.releaseD();
      return 0;
    }
    sr.add(filename, savedErrno);
  }
  descriptorManager_.releaseD();
  ParentLocationMessenger(mgr).message(PosixStorageMessages::cannotFind,
				       StringMessageArg(spec), sr);
  return 0;
}

PosixStorageObject::PosixStorageObject(int fd,
				       const StringC &filename,
				       const String<FChar> &cfilename,
				       Boolean mayRewind,
				       DescriptorManager *manager)
: DescriptorUser(manager),
  PosixBaseStorageObject(fd, mayRewind),
  suspended_(0),
  filename_(filename),
  cfilename_(cfilename)
{
}

PosixStorageObject::~PosixStorageObject()
{
  if (fd_ >= 0) {
    (void)xclose(fd_);
    releaseD();
  }
}

Boolean PosixStorageObject::seek(off_t off, Messenger &mgr)
{
  if (lseek(fd_, off, SEEK_SET) < 0) {
    fd_ = -1;
    systemError(mgr, PosixStorageMessages::lseekSystemCall, errno);
    return 0;
  }
  else
    return 1;
}

Boolean PosixStorageObject::read(char *buf, size_t bufSize, Messenger &mgr,
				 size_t &nread)
{
  if (readSaved(buf, bufSize, nread))
    return 1;
  if (suspended_)
    resume(mgr);
  if (fd_ < 0 || eof_)
    return 0;
  long n;
  do {
    n = ::read(fd_, buf, bufSize);
  } while (n < 0 && errno == EINTR);
  if (n > 0) {
    nread = size_t(n);
    saveBytes(buf, nread);
    return 1;
  }
  if (n < 0) {
    int saveErrno = errno;
    releaseD();
    (void)xclose(fd_);
    systemError(mgr, PosixStorageMessages::readSystemCall, saveErrno);
    fd_ = -1;
  }
  else {
    eof_ = 1;
    // n == 0, so end of file
    if (!mayRewind_) {
      releaseD();
      if (xclose(fd_) < 0)
	systemError(mgr, PosixStorageMessages::closeSystemCall, errno);
      fd_ = -1;
    }
    
  }
  return 0;
}

void PosixStorageObject::willNotRewind()
{
  RewindStorageObject::willNotRewind();
  if (eof_ && fd_ >= 0) {
    releaseD();
    (void)xclose(fd_);
    fd_ = -1;
  }
}

Boolean PosixStorageObject::suspend()
{
  if (fd_ < 0 || suspended_)
    return 0;
  struct stat sb;
  if (fstat(fd_, &sb) < 0 || !S_ISREG(sb.st_mode))
    return 0;
  suspendFailedMessage_ = 0;
  suspendPos_ = lseek(fd_, 0, SEEK_CUR);
  if (suspendPos_ == (off_t)-1) {
    suspendFailedMessage_ = &PosixStorageMessages::lseekSystemCall;
    suspendErrno_ = errno;
  }
  if (xclose(fd_) < 0 && !suspendFailedMessage_) {
    suspendFailedMessage_ = &PosixStorageMessages::closeSystemCall;
    suspendErrno_ = errno;
  }
  fd_ = -1;
  suspended_ = 1;
  releaseD();
  return 1;
}

void PosixStorageObject::resume(Messenger &mgr)
{
  ASSERT(suspended_);
  if (suspendFailedMessage_) {
    systemError(mgr, *suspendFailedMessage_, suspendErrno_);
    suspended_ = 0;
    return;
  }
  acquireD();
  // suspended_ must be 1 until after acquireD() is called,
  // so that we don't try to suspend this one before it is resumed.
  suspended_ = 0;
  do {
    fd_ = openFile(cfilename_.data());
  } while (fd_ < 0 && errno == EINTR);
  if (fd_ < 0) {
    releaseD();
    systemError(mgr, PosixStorageMessages::openSystemCall, errno);
    return;
  }
  if (lseek(fd_, suspendPos_, SEEK_SET) < 0) {
    systemError(mgr, PosixStorageMessages::lseekSystemCall, errno);
    (void)xclose(fd_);
    fd_ = -1;
    releaseD();
  }
}

#ifdef SP_STAT_BLKSIZE

size_t PosixBaseStorageObject::getBlockSize() const
{
  struct stat sb;
  long sz;
  if (fstat(fd_, &sb) < 0)
    return defaultBlockSize;
  if (!S_ISREG(sb.st_mode))
    return defaultBlockSize;
  if ((unsigned long)sb.st_blksize > size_t(-1))
    sz = size_t(-1);
  else
    sz = sb.st_blksize;
  return sz;
}

#else /* not SP_STAT_BLKSIZE */

size_t PosixBaseStorageObject::getBlockSize() const
{
  return defaultBlockSize;
}

#endif /* not SP_STAT_BLKSIZE */

void PosixStorageObject::systemError(Messenger &mgr,
				     const MessageType2 &msg,
				     int err)
{
  ParentLocationMessenger(mgr).message(msg,
				       StringMessageArg(filename_),
				       ErrnoMessageArg(err));
}

class PosixFdStorageObject : public PosixBaseStorageObject {
public:
  PosixFdStorageObject(int, Boolean mayRewind);
  Boolean read(char *buf, size_t bufSize, Messenger &mgr, size_t &nread);
  Boolean seek(off_t, Messenger &);
  enum {
    noError,
    readError,
    invalidNumberError,
    lseekError
  };
private:
  int origFd_;
};

PosixFdStorageManager::PosixFdStorageManager(const char *type,
					     const CharsetInfo *idCharset)
: IdStorageManager(idCharset), type_(type)
{
}

Boolean PosixFdStorageManager::inheritable() const
{
  return 0;
}

StorageObject *PosixFdStorageManager::makeStorageObject(const StringC &id,
							const StringC &,
							Boolean,
							Boolean mayRewind,
							Messenger &mgr,
							StringC &foundId)
{
  int n = 0;
  size_t i;
  for (i = 0; i < id.size(); i++) {
    UnivChar ch;
    if (!idCharset()->descToUniv(id[i], ch))
      break;
    if (ch < UnivCharsetDesc::zero || ch > UnivCharsetDesc::zero + 9)
      break;
    int digit = ch - UnivCharsetDesc::zero;
    // Allow the division to be done at compile-time.
    if (n > INT_MAX/10)
      break;
    n *= 10;
    if (n > INT_MAX - digit)
      break;
    n += digit;
  }
  if (i < id.size() || i == 0) {
    mgr.message(PosixStorageMessages::invalidNumber,
		StringMessageArg(id));
    return 0;
  }
  foundId = id;
  // Could check access mode with fcntl(n, F_GETFL).
  return new PosixFdStorageObject(n, mayRewind);
}

PosixFdStorageObject::PosixFdStorageObject(int fd, Boolean mayRewind)
: PosixBaseStorageObject(fd, mayRewind), origFd_(fd)
{
}

const char *PosixFdStorageManager::type() const
{
  return type_;
}

Boolean PosixFdStorageObject::read(char *buf, size_t bufSize, Messenger &mgr,
				   size_t &nread)
{
  if (readSaved(buf, bufSize, nread))
    return 1;
  if (fd_ < 0 || eof_)
    return 0;
  long n;
  do {
    n = ::read(fd_, buf, bufSize);
  } while (n < 0 && errno == EINTR);
  if (n > 0) {
    nread = size_t(n);
    saveBytes(buf, nread);
    return 1;
  }
  if (n < 0) {
    ParentLocationMessenger(mgr).message(PosixStorageMessages::fdRead,
					 NumberMessageArg(fd_),
					 ErrnoMessageArg(errno));
    fd_ = -1;
  }
  else
    eof_ = 1;
  return 0;
}

Boolean PosixFdStorageObject::seek(off_t off, Messenger &mgr)
{
  if (lseek(fd_, off, SEEK_SET) < 0) {
    ParentLocationMessenger(mgr).message(PosixStorageMessages::fdLseek,
					 NumberMessageArg(fd_),
					 ErrnoMessageArg(errno));
    return 0;
  }
  else
    return 1;
}

#ifdef SP_NAMESPACE
}
#endif