size_t VSIMemHandle::Write( const void * pBuffer, size_t nSize, size_t nCount )
{
if( !bUpdate )
{
errno = EACCES;
return 0;
}
if( bExtendFileAtNextWrite )
{
bExtendFileAtNextWrite = FALSE;
if( !poFile->SetLength( nOffset ) )
return 0;
}
// FIXME: Integer overflow check should be placed here:
const size_t nBytesToWrite = nSize * nCount;
if( nBytesToWrite + nOffset > poFile->nLength )
{
if( !poFile->SetLength( nBytesToWrite + nOffset ) )
return 0;
}
if( nBytesToWrite )
memcpy( poFile->pabyData + nOffset, pBuffer, nBytesToWrite );
nOffset += nBytesToWrite;
time(&poFile->mTime);
return nCount;
}
size_t VSIMemHandle::Write( const void * pBuffer, size_t nSize, size_t nCount )
{
if( !bUpdate )
{
errno = EACCES;
return 0;
}
if( bExtendFileAtNextWrite )
{
bExtendFileAtNextWrite = FALSE;
if( !poFile->SetLength( nOffset ) )
return 0;
}
// FIXME: Integer overflow check should be placed here:
size_t nBytesToWrite = nSize * nCount;
//if( CSLTestBoolean(CPLGetConfigOption("VERBOSE_IO", "FALSE")) )
// CPLDebug("MEM", "Write(%d bytes in [%d,%d[)", (int)nBytesToWrite, (int)nOffset, (int)(nOffset+nBytesToWrite));
if( nBytesToWrite + nOffset > poFile->nLength )
{
if( !poFile->SetLength( nBytesToWrite + nOffset ) )
return 0;
}
memcpy( poFile->pabyData + nOffset, pBuffer, nBytesToWrite );
nOffset += nBytesToWrite;
time(&poFile->mTime);
return nCount;
}
int VSIMemHandle::Truncate( vsi_l_offset nNewSize )
{
if( !bUpdate )
{
errno = EACCES;
return -1;
}
if (poFile->SetLength( nNewSize ))
return 0;
else
return -1;
}
size_t VSIMemHandle::Write( const void * pBuffer, size_t nSize, size_t nCount )
{
if( !bUpdate )
{
errno = EACCES;
return 0;
}
if( bExtendFileAtNextWrite )
{
bExtendFileAtNextWrite = false;
if( !poFile->SetLength( m_nOffset ) )
return 0;
}
const size_t nBytesToWrite = nSize * nCount;
if( nCount > 0 && nBytesToWrite / nCount != nSize )
{
return 0;
}
if( nBytesToWrite + m_nOffset < nBytesToWrite )
{
return 0;
}
if( nBytesToWrite + m_nOffset > poFile->nLength )
{
if( !poFile->SetLength( nBytesToWrite + m_nOffset ) )
return 0;
}
if( nBytesToWrite )
memcpy( poFile->pabyData + m_nOffset, pBuffer, nBytesToWrite );
m_nOffset += nBytesToWrite;
time(&poFile->mTime);
return nCount;
}
int VSIMemHandle::Truncate( vsi_l_offset nNewSize )
{
if( !bUpdate )
{
errno = EACCES;
return -1;
}
bExtendFileAtNextWrite = FALSE;
if (poFile->SetLength( nNewSize ))
return 0;
else
return -1;
}
int VSIMemHandle::Seek( vsi_l_offset nOffset, int nWhence )
{
if( nWhence == SEEK_CUR )
this->nOffset += nOffset;
else if( nWhence == SEEK_SET )
this->nOffset = nOffset;
else if( nWhence == SEEK_END )
this->nOffset = poFile->nLength + nOffset;
else
{
errno = EINVAL;
return -1;
}
if( this->nOffset < 0 )
{
this->nOffset = 0;
return -1;
}
if( this->nOffset > poFile->nLength )
{
if( !bUpdate ) // Read-only files cannot be extended by seek.
{
CPLDebug( "VSIMemHandle",
"Attempt to extend read-only file '%s' to length %d from %d, .",
poFile->osFilename.c_str(),
(int) this->nOffset, (int) poFile->nLength );
this->nOffset = poFile->nLength;
errno = EACCES;
return -1;
}
else // Writeable files are zero-extended by seek past end.
{
if( !poFile->SetLength( this->nOffset ) )
return -1;
}
}
return 0;
}
VSIVirtualHandle *
VSIMemFilesystemHandler::Open( const char *pszFilename,
const char *pszAccess )
{
CPLMutexHolder oHolder( &hMutex );
VSIMemFile *poFile;
CPLString osFilename = pszFilename;
NormalizePath( osFilename );
/* -------------------------------------------------------------------- */
/* Get the filename we are opening, create if needed. */
/* -------------------------------------------------------------------- */
if( oFileList.find(osFilename) == oFileList.end() )
poFile = NULL;
else
poFile = oFileList[osFilename];
if( strstr(pszAccess,"w") == NULL && poFile == NULL )
{
errno = ENOENT;
return NULL;
}
if( strstr(pszAccess,"w") )
{
if( poFile )
poFile->SetLength( 0 );
else
{
poFile = new VSIMemFile;
poFile->osFilename = osFilename;
oFileList[poFile->osFilename] = poFile;
poFile->nRefCount++; // for file list
}
}
if( poFile->bIsDirectory )
{
errno = EISDIR;
return NULL;
}
/* -------------------------------------------------------------------- */
/* Setup the file handle on this file. */
/* -------------------------------------------------------------------- */
VSIMemHandle *poHandle = new VSIMemHandle;
poHandle->poFile = poFile;
poHandle->nOffset = 0;
if( strstr(pszAccess,"w") || strstr(pszAccess,"+")
|| strstr(pszAccess,"a") )
poHandle->bUpdate = TRUE;
else
poHandle->bUpdate = FALSE;
poFile->nRefCount++;
if( strstr(pszAccess,"a") )
poHandle->nOffset = poFile->nLength;
return poHandle;
}
VSIVirtualHandle *
VSIMemFilesystemHandler::Open( const char *pszFilename,
const char *pszAccess,
bool bSetError )
{
CPLMutexHolder oHolder( &hMutex );
CPLString osFilename = pszFilename;
NormalizePath( osFilename );
if( osFilename.empty() )
return nullptr;
vsi_l_offset nMaxLength = GUINTBIG_MAX;
const size_t iPos = osFilename.find("||maxlength=");
if( iPos != std::string::npos )
{
nMaxLength = static_cast<vsi_l_offset>(CPLAtoGIntBig(
osFilename.substr(iPos + strlen("||maxlength=")).c_str()));
}
/* -------------------------------------------------------------------- */
/* Get the filename we are opening, create if needed. */
/* -------------------------------------------------------------------- */
VSIMemFile *poFile = nullptr;
if( oFileList.find(osFilename) != oFileList.end() )
poFile = oFileList[osFilename];
// If no file and opening in read, error out.
if( strstr(pszAccess, "w") == nullptr
&& strstr(pszAccess, "a") == nullptr
&& poFile == nullptr )
{
if( bSetError )
{
VSIError(VSIE_FileError, "No such file or directory");
}
errno = ENOENT;
return nullptr;
}
// Create.
if( poFile == nullptr )
{
poFile = new VSIMemFile;
poFile->osFilename = osFilename;
oFileList[poFile->osFilename] = poFile;
CPLAtomicInc(&(poFile->nRefCount)); // For file list.
poFile->nMaxLength = nMaxLength;
}
// Overwrite
else if( strstr(pszAccess, "w") )
{
poFile->SetLength(0);
poFile->nMaxLength = nMaxLength;
}
if( poFile->bIsDirectory )
{
errno = EISDIR;
return nullptr;
}
/* -------------------------------------------------------------------- */
/* Setup the file handle on this file. */
/* -------------------------------------------------------------------- */
VSIMemHandle *poHandle = new VSIMemHandle;
poHandle->poFile = poFile;
poHandle->m_nOffset = 0;
poHandle->bEOF = false;
poHandle->bUpdate =
strstr(pszAccess, "w") ||
strstr(pszAccess, "+") ||
strstr(pszAccess, "a");
CPLAtomicInc(&(poFile->nRefCount));
if( strstr(pszAccess, "a") )
poHandle->m_nOffset = poFile->nLength;
return poHandle;
}