RIFF.cpp

/***************************************************************************
 *                                                                         *
 *   libgig - C++ cross-platform Gigasampler format file access library    *
 *                                                                         *
 *   Copyright (C) 2003-2024 by Christian Schoenebeck                      *
 *                              <cuse@users.sourceforge.net>               *
 *                                                                         *
 *   This library 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 library 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 library; if not, write to the Free Software           *
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston,                 *
 *   MA  02111-1307  USA                                                   *
 ***************************************************************************/

#include <algorithm>
#include <set>
#include <string.h>

#include "RIFF.h"

#include "helper.h"

#if POSIX
# include <errno.h>
#endif

namespace RIFF {

// *************** Internal functions **************
// *

    static String __resolveChunkPath(Chunk* pCk) {
        String sPath;
        for (Chunk* pChunk = pCk; pChunk; pChunk = pChunk->GetParent()) {
            if (pChunk->GetChunkID() == CHUNK_ID_LIST) {
                List* pList = (List*) pChunk;
                sPath = "->'" + pList->GetListTypeString() + "'" + sPath;
            } else {
                sPath = "->'" + pChunk->GetChunkIDString() + "'" + sPath;
            }
        }
        return sPath;
    }

    inline static bool _isValidHandle(File::Handle handle) {
        #if defined(WIN32)
        return handle != INVALID_HANDLE_VALUE;
        #else
        return handle;
        #endif
    }

    inline static void _close(File::Handle handle) {
        if (!_isValidHandle(handle)) return;
        #if POSIX
        close(handle);
        #elif defined(WIN32)
        CloseHandle(handle);
        #else
        fclose(handle);
        #endif
    }



// *************** progress_t ***************
// *

    progress_t::progress_t() {
        callback    = NULL;
        custom      = NULL;
        __range_min = 0.0f;
        __range_max = 1.0f;
    }

    std::vector<progress_t> progress_t::subdivide(int iSubtasks) {
        std::vector<progress_t> v;
        for (int i = 0; i < iSubtasks; ++i) {
            progress_t p;
            __divide_progress(this, &p, iSubtasks, i);
            v.push_back(p);
        }
        return v;
    }

    std::vector<progress_t> progress_t::subdivide(std::vector<float> vSubTaskPortions) {
        float fTotal = 0.f; // usually 1.0, but we sum the portions up below to be sure
        for (int i = 0; i < vSubTaskPortions.size(); ++i)
            fTotal += vSubTaskPortions[i];

        float fLow = 0.f, fHigh = 0.f;
        std::vector<progress_t> v;
        for (int i = 0; i < vSubTaskPortions.size(); ++i) {
            fLow  = fHigh;
            fHigh = vSubTaskPortions[i];
            progress_t p;
            __divide_progress(this, &p, fTotal, fLow, fHigh);
            v.push_back(p);
        }
        return v;
    }



// *************** Chunk **************
// *

    Chunk::Chunk(File* pFile) {
        #if DEBUG_RIFF
        std::cout << "Chunk::Chunk(File* pFile)" << std::endl;
        #endif // DEBUG_RIFF
        chunkPos.ullPos = 0;
        pParent    = NULL;
        pChunkData = NULL;
        ullCurrentChunkSize = 0;
        ullNewChunkSize = 0;
        ullChunkDataSize = 0;
        ChunkID    = CHUNK_ID_RIFF;
        this->pFile = pFile;
    }

    Chunk::Chunk(File* pFile, file_offset_t StartPos, List* Parent) {
        #if DEBUG_RIFF
        std::cout << "Chunk::Chunk(File*,file_offset_t,List*),StartPos=" << StartPos << std::endl;
        #endif // DEBUG_RIFF
        this->pFile   = pFile;
        ullStartPos   = StartPos + CHUNK_HEADER_SIZE(pFile->FileOffsetSize);
        pParent       = Parent;
        chunkPos.ullPos = 0;
        pChunkData    = NULL;
        ullCurrentChunkSize = 0;
        ullNewChunkSize = 0;
        ullChunkDataSize = 0;
        ReadHeader(StartPos);
    }

    Chunk::Chunk(File* pFile, List* pParent, uint32_t uiChunkID, file_offset_t ullBodySize) {
        this->pFile      = pFile;
        ullStartPos      = 0; // arbitrary usually, since it will be updated when we write the chunk
        this->pParent    = pParent;
        chunkPos.ullPos  = 0;
        pChunkData       = NULL;
        ChunkID          = uiChunkID;
        ullChunkDataSize = 0;
        ullCurrentChunkSize = 0;
        ullNewChunkSize  = ullBodySize;
    }

    Chunk::~Chunk() {
        if (pChunkData) delete[] pChunkData;
    }

    void Chunk::ReadHeader(file_offset_t filePos) {
        #if DEBUG_RIFF
        std::cout << "Chunk::Readheader(" << filePos << ") ";
        #endif // DEBUG_RIFF
        ChunkID = 0;
        ullNewChunkSize = ullCurrentChunkSize = 0;

        const File::Handle hRead = pFile->FileHandle();

        #if POSIX
        if (lseek(hRead, filePos, SEEK_SET) != -1) {
            read(hRead, &ChunkID, 4);
            read(hRead, &ullCurrentChunkSize, pFile->FileOffsetSize);
        #elif defined(WIN32)
        LARGE_INTEGER liFilePos;
        liFilePos.QuadPart = filePos;
        if (SetFilePointerEx(hRead, liFilePos, NULL/*new pos pointer*/, FILE_BEGIN)) {
            DWORD dwBytesRead;
            ReadFile(hRead, &ChunkID, 4, &dwBytesRead, NULL);
            ReadFile(hRead, &ullCurrentChunkSize, pFile->FileOffsetSize, &dwBytesRead, NULL);
        #else
        if (!fseeko(hRead, filePos, SEEK_SET)) {
            fread(&ChunkID, 4, 1, hRead);
            fread(&ullCurrentChunkSize, pFile->FileOffsetSize, 1, hRead);
        #endif // POSIX
            #if WORDS_BIGENDIAN
            if (ChunkID == CHUNK_ID_RIFF) {
                pFile->bEndianNative = false;
            }
            #else // little endian
            if (ChunkID == CHUNK_ID_RIFX) {
                pFile->bEndianNative = false;
                ChunkID = CHUNK_ID_RIFF;
            }
            #endif // WORDS_BIGENDIAN
            if (!pFile->bEndianNative) {
                //swapBytes_32(&ChunkID);
                if (pFile->FileOffsetSize == 4)
                    swapBytes_32(&ullCurrentChunkSize);
                else
                    swapBytes_64(&ullCurrentChunkSize);
            }
            #if DEBUG_RIFF
            std::cout << "ckID=" << convertToString(ChunkID) << " ";
            std::cout << "ckSize=" << ullCurrentChunkSize << " ";
            std::cout << "bEndianNative=" << pFile->bEndianNative << std::endl;
            #endif // DEBUG_RIFF
            ullNewChunkSize = ullCurrentChunkSize;
        }
    }

    void Chunk::WriteHeader(file_offset_t filePos) {
        uint32_t uiNewChunkID = ChunkID;
        if (ChunkID == CHUNK_ID_RIFF) {
            #if WORDS_BIGENDIAN
            if (pFile->bEndianNative) uiNewChunkID = CHUNK_ID_RIFX;
            #else // little endian
            if (!pFile->bEndianNative) uiNewChunkID = CHUNK_ID_RIFX;
            #endif // WORDS_BIGENDIAN
        }

        uint64_t ullNewChunkSize = this->ullNewChunkSize;
        if (!pFile->bEndianNative) {
            if (pFile->FileOffsetSize == 4)
                swapBytes_32(&ullNewChunkSize);
            else
                swapBytes_64(&ullNewChunkSize);
        }

        const File::Handle hWrite = pFile->FileWriteHandle();

        #if POSIX
        if (lseek(hWrite, filePos, SEEK_SET) != -1) {
            write(hWrite, &uiNewChunkID, 4);
            write(hWrite, &ullNewChunkSize, pFile->FileOffsetSize);
        }
        #elif defined(WIN32)
        LARGE_INTEGER liFilePos;
        liFilePos.QuadPart = filePos;
        if (SetFilePointerEx(hWrite, liFilePos, NULL/*new pos pointer*/, FILE_BEGIN)) {
            DWORD dwBytesWritten;
            WriteFile(hWrite, &uiNewChunkID, 4, &dwBytesWritten, NULL);
            WriteFile(hWrite, &ullNewChunkSize, pFile->FileOffsetSize, &dwBytesWritten, NULL);
        }
        #else
        if (!fseeko(hWrite, filePos, SEEK_SET)) {
            fwrite(&uiNewChunkID, 4, 1, hWrite);
            fwrite(&ullNewChunkSize, pFile->FileOffsetSize, 1, hWrite);
        }
        #endif // POSIX
    }

    String Chunk::GetChunkIDString() const {
        return convertToString(ChunkID);
    }

    file_offset_t& Chunk::GetPosUnsafeRef() {
        if (!pFile->IsIOPerThread()) return chunkPos.ullPos;
        const std::thread::id tid = std::this_thread::get_id();
        return chunkPos.byThread[tid];
    }

    file_offset_t Chunk::GetPos() const {
        if (!pFile->IsIOPerThread()) return chunkPos.ullPos;
        const std::thread::id tid = std::this_thread::get_id();
        std::lock_guard<std::mutex> lock(chunkPos.mutex);
        return chunkPos.byThread[tid];
    }

    file_offset_t Chunk::GetFilePos() const {
        return ullStartPos + GetPos();
    }

    file_offset_t Chunk::SetPos(file_offset_t Where, stream_whence_t Whence) {
        #if DEBUG_RIFF
        std::cout << "Chunk::SetPos(file_offset_t,stream_whence_t)" << std::endl;
        #endif // DEBUG_RIFF
        std::lock_guard<std::mutex> lock(chunkPos.mutex);
        file_offset_t& pos = GetPosUnsafeRef();
        switch (Whence) {
            case stream_curpos:
                pos += Where;
                break;
            case stream_end:
                pos = ullCurrentChunkSize - 1 - Where;
                break;
            case stream_backward:
                pos -= Where;
                break;
            case stream_start: default:
                pos = Where;
                break;
        }
        if (pos > ullCurrentChunkSize) pos = ullCurrentChunkSize;
        return pos;
    }

    file_offset_t Chunk::RemainingBytes() const {
        #if DEBUG_RIFF
        std::cout << "Chunk::Remainingbytes()=" << ullCurrentChunkSize - ullPos << std::endl;
        #endif // DEBUG_RIFF
        const file_offset_t pos = GetPos();
        return (ullCurrentChunkSize > pos) ? ullCurrentChunkSize - pos : 0;
    }

    file_offset_t Chunk::RequiredPhysicalSize(int fileOffsetSize) {
        return CHUNK_HEADER_SIZE(fileOffsetSize) + // RIFF chunk header
               ullNewChunkSize + // chunks's actual data body
               ullNewChunkSize % 2; // optional pad byte
    }

    stream_state_t Chunk::GetState() const {
        #if DEBUG_RIFF
        std::cout << "Chunk::GetState()" << std::endl;
        #endif // DEBUG_RIFF

        const File::Handle hRead = pFile->FileHandle();

        if (!_isValidHandle(hRead))
            return stream_closed;

        const file_offset_t pos = GetPos();
        if (pos < ullCurrentChunkSize)    return stream_ready;
        else                              return stream_end_reached;
    }

    file_offset_t Chunk::Read(void* pData, file_offset_t WordCount, file_offset_t WordSize) {
        #if DEBUG_RIFF
        std::cout << "Chunk::Read(void*,file_offset_t,file_offset_t)" << std::endl;
        #endif // DEBUG_RIFF
        //if (ulStartPos == 0) return 0; // is only 0 if this is a new chunk, so nothing to read (yet)
        const file_offset_t pos = GetPos();
        if (pos >= ullCurrentChunkSize) return 0;
        if (pos + WordCount * WordSize >= ullCurrentChunkSize)
            WordCount = (ullCurrentChunkSize - pos) / WordSize;

        const File::Handle hRead = pFile->FileHandle();

        #if POSIX
        if (lseek(hRead, ullStartPos + pos, SEEK_SET) < 0) return 0;
        ssize_t readWords = read(hRead, pData, WordCount * WordSize);
        if (readWords < 1) {
            #if DEBUG_RIFF
            std::cerr << "POSIX read() failed: " << strerror(errno) << std::endl << std::flush;
            #endif // DEBUG_RIFF
            return 0;
        }
        readWords /= WordSize;
        #elif defined(WIN32)
        LARGE_INTEGER liFilePos;
        liFilePos.QuadPart = ullStartPos + pos;
        if (!SetFilePointerEx(hRead, liFilePos, NULL/*new pos pointer*/, FILE_BEGIN))
            return 0;
        DWORD readWords;
        ReadFile(hRead, pData, WordCount * WordSize, &readWords, NULL); //FIXME: does not work for reading buffers larger than 2GB (even though this should rarely be the case in practice)
        if (readWords < 1) return 0;
        readWords /= WordSize;
        #else // standard C functions
        if (fseeko(hRead, ullStartPos + pos, SEEK_SET)) return 0;
        file_offset_t readWords = fread(pData, WordSize, WordCount, hRead);
        #endif // POSIX
        if (!pFile->bEndianNative && WordSize != 1) {
            switch (WordSize) {
                case 2:
                    for (file_offset_t iWord = 0; iWord < readWords; iWord++)
                        swapBytes_16((uint16_t*) pData + iWord);
                    break;
                case 4:
                    for (file_offset_t iWord = 0; iWord < readWords; iWord++)
                        swapBytes_32((uint32_t*) pData + iWord);
                    break;
                case 8:
                    for (file_offset_t iWord = 0; iWord < readWords; iWord++)
                        swapBytes_64((uint64_t*) pData + iWord);
                    break;
                default:
                    for (file_offset_t iWord = 0; iWord < readWords; iWord++)
                        swapBytes((uint8_t*) pData + iWord * WordSize, WordSize);
                    break;
            }
        }
        SetPos(readWords * WordSize, stream_curpos);
        return readWords;
    }

    file_offset_t Chunk::Write(void* pData, file_offset_t WordCount, file_offset_t WordSize) {
        const File::HandlePair io = pFile->FileHandlePair();
        if (io.Mode != stream_mode_read_write)
            throw Exception("Cannot write data to chunk, file has to be opened in read+write mode first");
        const file_offset_t pos = GetPos();
        if (pos >= ullCurrentChunkSize || pos + WordCount * WordSize > ullCurrentChunkSize)
            throw Exception("End of chunk reached while trying to write data");
        if (!pFile->bEndianNative && WordSize != 1) {
            switch (WordSize) {
                case 2:
                    for (file_offset_t iWord = 0; iWord < WordCount; iWord++)
                        swapBytes_16((uint16_t*) pData + iWord);
                    break;
                case 4:
                    for (file_offset_t iWord = 0; iWord < WordCount; iWord++)
                        swapBytes_32((uint32_t*) pData + iWord);
                    break;
                case 8:
                    for (file_offset_t iWord = 0; iWord < WordCount; iWord++)
                        swapBytes_64((uint64_t*) pData + iWord);
                    break;
                default:
                    for (file_offset_t iWord = 0; iWord < WordCount; iWord++)
                        swapBytes((uint8_t*) pData + iWord * WordSize, WordSize);
                    break;
            }
        }
        #if POSIX
        if (lseek(io.hWrite, ullStartPos + pos, SEEK_SET) < 0) {
            throw Exception("Could not seek to position " + ToString(pos) +
                            " in chunk (" + ToString(ullStartPos + pos) + " in file)");
        }
        ssize_t writtenWords = write(io.hWrite, pData, WordCount * WordSize);
        if (writtenWords < 1) throw Exception("POSIX IO Error while trying to write chunk data");
        writtenWords /= WordSize;
        #elif defined(WIN32)
        LARGE_INTEGER liFilePos;
        liFilePos.QuadPart = ullStartPos + pos;
        if (!SetFilePointerEx(io.hWrite, liFilePos, NULL/*new pos pointer*/, FILE_BEGIN)) {
            throw Exception("Could not seek to position " + ToString(pos) +
                            " in chunk (" + ToString(ullStartPos + pos) + " in file)");
        }
        DWORD writtenWords;
        WriteFile(io.hWrite, pData, WordCount * WordSize, &writtenWords, NULL); //FIXME: does not work for writing buffers larger than 2GB (even though this should rarely be the case in practice)
        if (writtenWords < 1) throw Exception("Windows IO Error while trying to write chunk data");
        writtenWords /= WordSize;
        #else // standard C functions
        if (fseeko(io.hWrite, ullStartPos + pos, SEEK_SET)) {
            throw Exception("Could not seek to position " + ToString(pos) +
                            " in chunk (" + ToString(ullStartPos + pos) + " in file)");
        }
        file_offset_t writtenWords = fwrite(pData, WordSize, WordCount, io.hWrite);
        #endif // POSIX
        SetPos(writtenWords * WordSize, stream_curpos);
        return writtenWords;
    }

    file_offset_t Chunk::ReadSceptical(void* pData, file_offset_t WordCount, file_offset_t WordSize) {
        file_offset_t readWords = Read(pData, WordCount, WordSize);
        if (readWords != WordCount) throw RIFF::Exception("End of chunk data reached.");
        return readWords;
    }

    file_offset_t Chunk::ReadInt8(int8_t* pData, file_offset_t WordCount) {
        #if DEBUG_RIFF
        std::cout << "Chunk::ReadInt8(int8_t*,file_offset_t)" << std::endl;
        #endif // DEBUG_RIFF
        return ReadSceptical(pData, WordCount, 1);
    }

    file_offset_t Chunk::WriteInt8(int8_t* pData, file_offset_t WordCount) {
        return Write(pData, WordCount, 1);
    }

    file_offset_t Chunk::ReadUint8(uint8_t* pData, file_offset_t WordCount) {
        #if DEBUG_RIFF
        std::cout << "Chunk::ReadUint8(uint8_t*,file_offset_t)" << std::endl;
        #endif // DEBUG_RIFF
        return ReadSceptical(pData, WordCount, 1);
    }

    file_offset_t Chunk::WriteUint8(uint8_t* pData, file_offset_t WordCount) {
        return Write(pData, WordCount, 1);
    }

    file_offset_t Chunk::ReadInt16(int16_t* pData, file_offset_t WordCount) {
        #if DEBUG_RIFF
        std::cout << "Chunk::ReadInt16(int16_t*,file_offset_t)" << std::endl;
        #endif // DEBUG_RIFF
        return ReadSceptical(pData, WordCount, 2);
    }

    file_offset_t Chunk::WriteInt16(int16_t* pData, file_offset_t WordCount) {
        return Write(pData, WordCount, 2);
    }

    file_offset_t Chunk::ReadUint16(uint16_t* pData, file_offset_t WordCount) {
        #if DEBUG_RIFF
        std::cout << "Chunk::ReadUint16(uint16_t*,file_offset_t)" << std::endl;
        #endif // DEBUG_RIFF
        return ReadSceptical(pData, WordCount, 2);
    }

    file_offset_t Chunk::WriteUint16(uint16_t* pData, file_offset_t WordCount) {
        return Write(pData, WordCount, 2);
    }

    file_offset_t Chunk::ReadInt32(int32_t* pData, file_offset_t WordCount) {
        #if DEBUG_RIFF
        std::cout << "Chunk::ReadInt32(int32_t*,file_offset_t)" << std::endl;
        #endif // DEBUG_RIFF
        return ReadSceptical(pData, WordCount, 4);
    }

    file_offset_t Chunk::WriteInt32(int32_t* pData, file_offset_t WordCount) {
        return Write(pData, WordCount, 4);
    }

    file_offset_t Chunk::ReadUint32(uint32_t* pData, file_offset_t WordCount) {
        #if DEBUG_RIFF
        std::cout << "Chunk::ReadUint32(uint32_t*,file_offset_t)" << std::endl;
        #endif // DEBUG_RIFF
        return ReadSceptical(pData, WordCount, 4);
    }

    void Chunk::ReadString(String& s, int size) {
        char* buf = new char[size];
        ReadSceptical(buf, 1, size);
        s.assign(buf, std::find(buf, buf + size, '\0'));
        delete[] buf;
    }

    file_offset_t Chunk::WriteUint32(uint32_t* pData, file_offset_t WordCount) {
        return Write(pData, WordCount, 4);
    }

    int8_t Chunk::ReadInt8() {
        #if DEBUG_RIFF
        std::cout << "Chunk::ReadInt8()" << std::endl;
        #endif // DEBUG_RIFF
        int8_t word;
        ReadSceptical(&word,1,1);
        return word;
    }

    uint8_t Chunk::ReadUint8() {
        #if DEBUG_RIFF
        std::cout << "Chunk::ReadUint8()" << std::endl;
        #endif // DEBUG_RIFF
        uint8_t word;
        ReadSceptical(&word,1,1);
        return word;
    }

    int16_t Chunk::ReadInt16() {
        #if DEBUG_RIFF
        std::cout << "Chunk::ReadInt16()" << std::endl;
        #endif // DEBUG_RIFF
        int16_t word;
        ReadSceptical(&word,1,2);
        return word;
    }

    uint16_t Chunk::ReadUint16() {
        #if DEBUG_RIFF
        std::cout << "Chunk::ReadUint16()" << std::endl;
        #endif // DEBUG_RIFF
        uint16_t word;
        ReadSceptical(&word,1,2);
        return word;
    }

    int32_t Chunk::ReadInt32() {
        #if DEBUG_RIFF
        std::cout << "Chunk::ReadInt32()" << std::endl;
        #endif // DEBUG_RIFF
        int32_t word;
        ReadSceptical(&word,1,4);
        return word;
    }

    uint32_t Chunk::ReadUint32() {
        #if DEBUG_RIFF
        std::cout << "Chunk::ReadUint32()" << std::endl;
        #endif // DEBUG_RIFF
        uint32_t word;
        ReadSceptical(&word,1,4);
        return word;
    }

    void* Chunk::LoadChunkData() {
        if (!pChunkData && pFile->Filename != "" /*&& ulStartPos != 0*/) {
            File::Handle hRead = pFile->FileHandle();
            #if POSIX
            if (lseek(hRead, ullStartPos, SEEK_SET) == -1) return NULL;
            #elif defined(WIN32)
            LARGE_INTEGER liFilePos;
            liFilePos.QuadPart = ullStartPos;
            if (!SetFilePointerEx(hRead, liFilePos, NULL/*new pos pointer*/, FILE_BEGIN)) return NULL;
            #else
            if (fseeko(hRead, ullStartPos, SEEK_SET)) return NULL;
            #endif // POSIX
            file_offset_t ullBufferSize = (ullCurrentChunkSize > ullNewChunkSize) ? ullCurrentChunkSize : ullNewChunkSize;
            pChunkData = new uint8_t[ullBufferSize];
            if (!pChunkData) return NULL;
            memset(pChunkData, 0, ullBufferSize);
            #if POSIX
            file_offset_t readWords = read(hRead, pChunkData, GetSize());
            #elif defined(WIN32)
            DWORD readWords;
            ReadFile(hRead, pChunkData, GetSize(), &readWords, NULL); //FIXME: won't load chunks larger than 2GB !
            #else
            file_offset_t readWords = fread(pChunkData, 1, GetSize(), hRead);
            #endif // POSIX
            if (readWords != GetSize()) {
                delete[] pChunkData;
                return (pChunkData = NULL);
            }
            ullChunkDataSize = ullBufferSize;
        } else if (ullNewChunkSize > ullChunkDataSize) {
            uint8_t* pNewBuffer = new uint8_t[ullNewChunkSize];
            if (!pNewBuffer) throw Exception("Could not enlarge chunk data buffer to " + ToString(ullNewChunkSize) + " bytes");
            memset(pNewBuffer, 0 , ullNewChunkSize);
            if (pChunkData) {
                memcpy(pNewBuffer, pChunkData, ullChunkDataSize);
                delete[] pChunkData;
            }
            pChunkData       = pNewBuffer;
            ullChunkDataSize = ullNewChunkSize;
        }
        return pChunkData;
    }

    void Chunk::ReleaseChunkData() {
        if (pChunkData) {
            delete[] pChunkData;
            pChunkData = NULL;
        }
    }

    void Chunk::Resize(file_offset_t NewSize) {
        if (NewSize == 0)
            throw Exception("There is at least one empty chunk (zero size): " + __resolveChunkPath(this));
        if ((NewSize >> 48) != 0)
            throw Exception("Unrealistic high chunk size detected: " + __resolveChunkPath(this));
        if (ullNewChunkSize == NewSize) return;
        ullNewChunkSize = NewSize;
    }

    file_offset_t Chunk::WriteChunk(file_offset_t ullWritePos, file_offset_t ullCurrentDataOffset, progress_t* pProgress) {
        const file_offset_t ullOriginalPos = ullWritePos;
        ullWritePos += CHUNK_HEADER_SIZE(pFile->FileOffsetSize);

        const File::HandlePair io = pFile->FileHandlePair();

        if (io.Mode != stream_mode_read_write)
            throw Exception("Cannot write list chunk, file has to be opened in read+write mode");

        // if the whole chunk body was loaded into RAM
        if (pChunkData) {
            // make sure chunk data buffer in RAM is at least as large as the new chunk size
            LoadChunkData();
            // write chunk data from RAM persistently to the file
            #if POSIX
            lseek(io.hWrite, ullWritePos, SEEK_SET);
            if (write(io.hWrite, pChunkData, ullNewChunkSize) != ullNewChunkSize) {
                throw Exception("Writing Chunk data (from RAM) failed");
            }
            #elif defined(WIN32)
            LARGE_INTEGER liFilePos;
            liFilePos.QuadPart = ullWritePos;
            SetFilePointerEx(io.hWrite, liFilePos, NULL/*new pos pointer*/, FILE_BEGIN);
            DWORD dwBytesWritten;
            WriteFile(io.hWrite, pChunkData, ullNewChunkSize, &dwBytesWritten, NULL); //FIXME: won't save chunks larger than 2GB !
            if (dwBytesWritten != ullNewChunkSize) {
                throw Exception("Writing Chunk data (from RAM) failed");
            }
            #else
            fseeko(io.hWrite, ullWritePos, SEEK_SET);
            if (fwrite(pChunkData, 1, ullNewChunkSize, io.hWrite) != ullNewChunkSize) {
                throw Exception("Writing Chunk data (from RAM) failed");
            }
            #endif // POSIX
        } else {
            // move chunk data from the end of the file to the appropriate position
            int8_t* pCopyBuffer = new int8_t[4096];
            file_offset_t ullToMove = (ullNewChunkSize < ullCurrentChunkSize) ? ullNewChunkSize : ullCurrentChunkSize;
            #if defined(WIN32)
            DWORD iBytesMoved = 1; // we have to pass it via pointer to the Windows API, thus the correct size must be ensured
            #else
            int iBytesMoved = 1;
            #endif
            for (file_offset_t ullOffset = 0; ullToMove > 0 && iBytesMoved > 0; ullOffset += iBytesMoved, ullToMove -= iBytesMoved) {
                iBytesMoved = (ullToMove < 4096) ? int(ullToMove) : 4096;
                #if POSIX
                lseek(io.hRead, ullStartPos + ullCurrentDataOffset + ullOffset, SEEK_SET);
                iBytesMoved = (int) read(io.hRead, pCopyBuffer, (size_t) iBytesMoved);
                lseek(io.hWrite, ullWritePos + ullOffset, SEEK_SET);
                iBytesMoved = (int) write(io.hWrite, pCopyBuffer, (size_t) iBytesMoved);
                #elif defined(WIN32)
                LARGE_INTEGER liFilePos;
                liFilePos.QuadPart = ullStartPos + ullCurrentDataOffset + ullOffset;
                SetFilePointerEx(io.hRead, liFilePos, NULL/*new pos pointer*/, FILE_BEGIN);
                ReadFile(io.hRead, pCopyBuffer, iBytesMoved, &iBytesMoved, NULL);
                liFilePos.QuadPart = ullWritePos + ullOffset;
                SetFilePointerEx(io.hWrite, liFilePos, NULL/*new pos pointer*/, FILE_BEGIN);
                WriteFile(io.hWrite, pCopyBuffer, iBytesMoved, &iBytesMoved, NULL);
                #else
                fseeko(io.hRead, ullStartPos + ullCurrentDataOffset + ullOffset, SEEK_SET);
                iBytesMoved = fread(pCopyBuffer, 1, iBytesMoved, io.hRead);
                fseeko(io.hWrite, ullWritePos + ullOffset, SEEK_SET);
                iBytesMoved = fwrite(pCopyBuffer, 1, iBytesMoved, io.hWrite);
                #endif
            }
            delete[] pCopyBuffer;
            if (iBytesMoved < 0) throw Exception("Writing Chunk data (from file) failed");
        }

        // update this chunk's header
        ullCurrentChunkSize = ullNewChunkSize;
        WriteHeader(ullOriginalPos);

        if (pProgress)
            __notify_progress(pProgress, 1.0); // notify done

        // update chunk's position pointers
        ullStartPos = ullOriginalPos + CHUNK_HEADER_SIZE(pFile->FileOffsetSize);
        Chunk::__resetPos();

        // add pad byte if needed
        if ((ullStartPos + ullNewChunkSize) % 2 != 0) {
            const char cPadByte = 0;
            #if POSIX
            lseek(io.hWrite, ullStartPos + ullNewChunkSize, SEEK_SET);
            write(io.hWrite, &cPadByte, 1);
            #elif defined(WIN32)
            LARGE_INTEGER liFilePos;
            liFilePos.QuadPart = ullStartPos + ullNewChunkSize;
            SetFilePointerEx(io.hWrite, liFilePos, NULL/*new pos pointer*/, FILE_BEGIN);
            DWORD dwBytesWritten;
            WriteFile(io.hWrite, &cPadByte, 1, &dwBytesWritten, NULL);
            #else
            fseeko(io.hWrite, ullStartPos + ullNewChunkSize, SEEK_SET);
            fwrite(&cPadByte, 1, 1, io.hWrite);
            #endif
            return ullStartPos + ullNewChunkSize + 1;
        }

        return ullStartPos + ullNewChunkSize;
    }

    void Chunk::__resetPos() {
        std::lock_guard<std::mutex> lock(chunkPos.mutex);
        chunkPos.ullPos = 0;
        chunkPos.byThread.clear();
    }



// *************** List ***************
// *

    List::List(File* pFile) : Chunk(pFile) {
        #if DEBUG_RIFF
        std::cout << "List::List(File* pFile)" << std::endl;
        #endif // DEBUG_RIFF
        pSubChunks    = NULL;
        pSubChunksMap = NULL;
    }

    List::List(File* pFile, file_offset_t StartPos, List* Parent)
      : Chunk(pFile, StartPos, Parent) {
        #if DEBUG_RIFF
        std::cout << "List::List(File*,file_offset_t,List*)" << std::endl;
        #endif // DEBUG_RIFF
        pSubChunks    = NULL;
        pSubChunksMap = NULL;
        ReadHeader(StartPos);
        ullStartPos = StartPos + LIST_HEADER_SIZE(pFile->FileOffsetSize);
    }

    List::List(File* pFile, List* pParent, uint32_t uiListID)
      : Chunk(pFile, pParent, CHUNK_ID_LIST, 0) {
        pSubChunks    = NULL;
        pSubChunksMap = NULL;
        ListType      = uiListID;
    }

    List::~List() {
        #if DEBUG_RIFF
        std::cout << "List::~List()" << std::endl;
        #endif // DEBUG_RIFF
        DeleteChunkList();
    }

    void List::DeleteChunkList() {
        if (pSubChunks) {
            ChunkList::iterator iter = pSubChunks->begin();
            ChunkList::iterator end  = pSubChunks->end();
            while (iter != end) {
                delete *iter;
                iter++;
            }
            delete pSubChunks;
            pSubChunks = NULL;
        }
        if (pSubChunksMap) {
            delete pSubChunksMap;
            pSubChunksMap = NULL;
        }
    }

    Chunk* List::GetSubChunkAt(size_t pos) {
        if (!pSubChunks) LoadSubChunks();
        if (pos >= pSubChunks->size()) return NULL;
        return (*pSubChunks)[pos];
    }

    Chunk* List::GetSubChunk(uint32_t ChunkID) {
        #if DEBUG_RIFF
        std::cout << "List::GetSubChunk(uint32_t)" << std::endl;
        #endif // DEBUG_RIFF
        if (!pSubChunksMap) LoadSubChunks();
        return (*pSubChunksMap)[ChunkID];
    }

    List* List::GetSubListAt(size_t pos) {
        if (!pSubChunks) LoadSubChunks();
        if (pos >= pSubChunks->size()) return NULL;
        for (size_t iCk = 0, iLst = 0; iCk < pSubChunks->size(); ++iCk) {
            Chunk* pChunk = (*pSubChunks)[iCk];
            if (pChunk->GetChunkID() != CHUNK_ID_LIST) continue;
            if (iLst == pos) return (List*) pChunk;
            ++iLst;
        }
        return NULL;
    }

    List* List::GetSubList(uint32_t ListType) {
        #if DEBUG_RIFF
        std::cout << "List::GetSubList(uint32_t)" << std::endl;
        #endif // DEBUG_RIFF
        if (!pSubChunks) LoadSubChunks();
        ChunkList::iterator iter = pSubChunks->begin();
        ChunkList::iterator end  = pSubChunks->end();
        while (iter != end) {
            if ((*iter)->GetChunkID() == CHUNK_ID_LIST) {
                List* l = (List*) *iter;
                if (l->GetListType() == ListType) return l;
            }
            iter++;
        }
        return NULL;
    }

    Chunk* List::GetFirstSubChunk() {
        #if DEBUG_RIFF
        std::cout << "List::GetFirstSubChunk()" << std::endl;
        #endif // DEBUG_RIFF
        if (!pSubChunks) LoadSubChunks();
        ChunksIterator = pSubChunks->begin();
        return (ChunksIterator != pSubChunks->end()) ? *ChunksIterator : NULL;
    }

    Chunk* List::GetNextSubChunk() {
        #if DEBUG_RIFF
        std::cout << "List::GetNextSubChunk()" << std::endl;
        #endif // DEBUG_RIFF
        if (!pSubChunks) return NULL;
        ChunksIterator++;
        return (ChunksIterator != pSubChunks->end()) ? *ChunksIterator : NULL;
    }

    List* List::GetFirstSubList() {
        #if DEBUG_RIFF
        std::cout << "List::GetFirstSubList()" << std::endl;
        #endif // DEBUG_RIFF
        if (!pSubChunks) LoadSubChunks();
        ListIterator            = pSubChunks->begin();
        ChunkList::iterator end = pSubChunks->end();
        while (ListIterator != end) {
            if ((*ListIterator)->GetChunkID() == CHUNK_ID_LIST) return (List*) *ListIterator;
            ListIterator++;
        }
        return NULL;
    }

    List* List::GetNextSubList() {
        #if DEBUG_RIFF
        std::cout << "List::GetNextSubList()" << std::endl;
        #endif // DEBUG_RIFF
        if (!pSubChunks) return NULL;
        if (ListIterator == pSubChunks->end()) return NULL;
        ListIterator++;
        ChunkList::iterator end = pSubChunks->end();
        while (ListIterator != end) {
            if ((*ListIterator)->GetChunkID() == CHUNK_ID_LIST) return (List*) *ListIterator;
            ListIterator++;
        }
        return NULL;
    }

    size_t List::CountSubChunks() {
        if (!pSubChunks) LoadSubChunks();
        return pSubChunks->size();
    }

    size_t List::CountSubChunks(uint32_t ChunkID) {
        size_t result = 0;
        if (!pSubChunks) LoadSubChunks();
        ChunkList::iterator iter = pSubChunks->begin();
        ChunkList::iterator end  = pSubChunks->end();
        while (iter != end) {
            if ((*iter)->GetChunkID() == ChunkID) {
                result++;
            }
            iter++;
        }
        return result;
    }

    size_t List::CountSubLists() {
        return CountSubChunks(CHUNK_ID_LIST);
    }

    size_t List::CountSubLists(uint32_t ListType) {
        size_t result = 0;
        if (!pSubChunks) LoadSubChunks();
        ChunkList::iterator iter = pSubChunks->begin();
        ChunkList::iterator end  = pSubChunks->end();
        while (iter != end) {
            if ((*iter)->GetChunkID() == CHUNK_ID_LIST) {
                List* l = (List*) *iter;
                if (l->GetListType() == ListType) result++;
            }
            iter++;
        }
        return result;
    }

    Chunk* List::AddSubChunk(uint32_t uiChunkID, file_offset_t ullBodySize) {
        if (ullBodySize == 0) throw Exception("Chunk body size must be at least 1 byte");
        if (!pSubChunks) LoadSubChunks();
        Chunk* pNewChunk = new Chunk(pFile, this, uiChunkID, 0);
        pSubChunks->push_back(pNewChunk);
        (*pSubChunksMap)[uiChunkID] = pNewChunk;
        pNewChunk->Resize(ullBodySize);
        ullNewChunkSize += CHUNK_HEADER_SIZE(pFile->FileOffsetSize);
        return pNewChunk;
    }

    void List::MoveSubChunk(Chunk* pSrc, Chunk* pDst) {
        if (!pSubChunks) LoadSubChunks();
        for (size_t i = 0; i < pSubChunks->size(); ++i) {
            if ((*pSubChunks)[i] == pSrc) {
                pSubChunks->erase(pSubChunks->begin() + i);
                ChunkList::iterator iter =
                    find(pSubChunks->begin(), pSubChunks->end(), pDst);
                pSubChunks->insert(iter, pSrc);
                return;
            }
        }
    }

    void List::MoveSubChunk(Chunk* pSrc, List* pNewParent) {
        if (pNewParent == this || !pNewParent) return;
        if (!pSubChunks) LoadSubChunks();
        if (!pNewParent->pSubChunks) pNewParent->LoadSubChunks();
        ChunkList::iterator iter =
            find(pSubChunks->begin(), pSubChunks->end(), pSrc);
        if (iter == pSubChunks->end()) return;
        pSubChunks->erase(iter);
        pNewParent->pSubChunks->push_back(pSrc);
        // update chunk id map of this List
        if ((*pSubChunksMap)[pSrc->GetChunkID()] == pSrc) {
            pSubChunksMap->erase(pSrc->GetChunkID());
            // try to find another chunk of the same chunk ID
            ChunkList::iterator iter = pSubChunks->begin();
            ChunkList::iterator end  = pSubChunks->end();
            for (; iter != end; ++iter) {
                if ((*iter)->GetChunkID() == pSrc->GetChunkID()) {
                    (*pSubChunksMap)[pSrc->GetChunkID()] = *iter;
                    break; // we're done, stop search
                }
            }
        }
        // update chunk id map of other list
        if (!(*pNewParent->pSubChunksMap)[pSrc->GetChunkID()])
            (*pNewParent->pSubChunksMap)[pSrc->GetChunkID()] = pSrc;
    }

    List* List::AddSubList(uint32_t uiListType) {
        if (!pSubChunks) LoadSubChunks();
        List* pNewListChunk = new List(pFile, this, uiListType);
        pSubChunks->push_back(pNewListChunk);
        (*pSubChunksMap)[CHUNK_ID_LIST] = pNewListChunk;
        ullNewChunkSize += LIST_HEADER_SIZE(pFile->FileOffsetSize);
        return pNewListChunk;
    }

    void List::DeleteSubChunk(Chunk* pSubChunk) {
        if (!pSubChunks) LoadSubChunks();
        ChunkList::iterator iter =
            find(pSubChunks->begin(), pSubChunks->end(), pSubChunk);
        if (iter == pSubChunks->end()) return;
        pSubChunks->erase(iter);
        if ((*pSubChunksMap)[pSubChunk->GetChunkID()] == pSubChunk) {
            pSubChunksMap->erase(pSubChunk->GetChunkID());
            // try to find another chunk of the same chunk ID
            ChunkList::iterator iter = pSubChunks->begin();
            ChunkList::iterator end  = pSubChunks->end();
            for (; iter != end; ++iter) {
                if ((*iter)->GetChunkID() == pSubChunk->GetChunkID()) {
                    (*pSubChunksMap)[pSubChunk->GetChunkID()] = *iter;
                    break; // we're done, stop search
                }
            }
        }
        delete pSubChunk;
    }

    file_offset_t List::RequiredPhysicalSize(int fileOffsetSize) {
        if (!pSubChunks) LoadSubChunks();
        file_offset_t size = LIST_HEADER_SIZE(fileOffsetSize);
        ChunkList::iterator iter = pSubChunks->begin();
        ChunkList::iterator end  = pSubChunks->end();
        for (; iter != end; ++iter)
            size += (*iter)->RequiredPhysicalSize(fileOffsetSize);
        return size;
    }

    void List::ReadHeader(file_offset_t filePos) {
        #if DEBUG_RIFF
        std::cout << "List::Readheader(file_offset_t) ";
        #endif // DEBUG_RIFF
        Chunk::ReadHeader(filePos);
        if (ullCurrentChunkSize < 4) return;
        ullNewChunkSize = ullCurrentChunkSize -= 4;

        const File::Handle hRead = pFile->FileHandle();

        #if POSIX
        lseek(hRead, filePos + CHUNK_HEADER_SIZE(pFile->FileOffsetSize), SEEK_SET);
        read(hRead, &ListType, 4);
        #elif defined(WIN32)
        LARGE_INTEGER liFilePos;
        liFilePos.QuadPart = filePos + CHUNK_HEADER_SIZE(pFile->FileOffsetSize);
        SetFilePointerEx(hRead, liFilePos, NULL/*new pos pointer*/, FILE_BEGIN);
        DWORD dwBytesRead;
        ReadFile(hRead, &ListType, 4, &dwBytesRead, NULL);
        #else
        fseeko(hRead, filePos + CHUNK_HEADER_SIZE(pFile->FileOffsetSize), SEEK_SET);
        fread(&ListType, 4, 1, hRead);
        #endif // POSIX
        #if DEBUG_RIFF
        std::cout << "listType=" << convertToString(ListType) << std::endl;
        #endif // DEBUG_RIFF
        if (!pFile->bEndianNative) {
            //swapBytes_32(&ListType);
        }
    }

    void List::WriteHeader(file_offset_t filePos) {
        // the four list type bytes officially belong the chunk's body in the RIFF format
        ullNewChunkSize += 4;
        Chunk::WriteHeader(filePos);
        ullNewChunkSize -= 4; // just revert the +4 incrementation

        const File::Handle hWrite = pFile->FileWriteHandle();

        #if POSIX
        lseek(hWrite, filePos + CHUNK_HEADER_SIZE(pFile->FileOffsetSize), SEEK_SET);
        write(hWrite, &ListType, 4);
        #elif defined(WIN32)
        LARGE_INTEGER liFilePos;
        liFilePos.QuadPart = filePos + CHUNK_HEADER_SIZE(pFile->FileOffsetSize);
        SetFilePointerEx(hWrite, liFilePos, NULL/*new pos pointer*/, FILE_BEGIN);
        DWORD dwBytesWritten;
        WriteFile(hWrite, &ListType, 4, &dwBytesWritten, NULL);
        #else
        fseeko(hWrite, filePos + CHUNK_HEADER_SIZE(pFile->FileOffsetSize), SEEK_SET);
        fwrite(&ListType, 4, 1, hWrite);
        #endif // POSIX
    }

    void List::LoadSubChunks(progress_t* pProgress) {
        #if DEBUG_RIFF
        std::cout << "List::LoadSubChunks()";
        #endif // DEBUG_RIFF
        if (!pSubChunks) {
            pSubChunks    = new ChunkList();
            pSubChunksMap = new ChunkMap();

            const File::Handle hRead = pFile->FileHandle();
            if (!_isValidHandle(hRead)) return;

            const file_offset_t ullOriginalPos = GetPos();
            SetPos(0); // jump to beginning of list chunk body
            while (RemainingBytes() >= CHUNK_HEADER_SIZE(pFile->FileOffsetSize)) {
                Chunk* ck;
                uint32_t ckid;
                // return value check is required here to prevent a potential
                // garbage data use of 'ckid' below in case Read() failed
                if (Read(&ckid, 4, 1) != 4)
                    throw Exception("LoadSubChunks(): Failed reading RIFF chunk ID");
                #if DEBUG_RIFF
                std::cout << " ckid=" << convertToString(ckid) << std::endl;
                #endif // DEBUG_RIFF
                const file_offset_t pos = GetPos();
                if (ckid == CHUNK_ID_LIST) {
                    ck = new RIFF::List(pFile, ullStartPos + pos - 4, this);
                    SetPos(ck->GetSize() + LIST_HEADER_SIZE(pFile->FileOffsetSize) - 4, RIFF::stream_curpos);
                }
                else { // simple chunk
                    ck = new RIFF::Chunk(pFile, ullStartPos + pos - 4, this);
                    SetPos(ck->GetSize() + CHUNK_HEADER_SIZE(pFile->FileOffsetSize) - 4, RIFF::stream_curpos);
                }
                pSubChunks->push_back(ck);
                (*pSubChunksMap)[ckid] = ck;
                if (GetPos() % 2 != 0) SetPos(1, RIFF::stream_curpos); // jump over pad byte
            }
            SetPos(ullOriginalPos); // restore position before this call
        }
        if (pProgress)
            __notify_progress(pProgress, 1.0); // notify done
    }

    void List::LoadSubChunksRecursively(progress_t* pProgress) {
        const int n = (int) CountSubLists();
        int i = 0;
        for (List* pList = GetSubListAt(i); pList; pList = GetSubListAt(++i)) {
            if (pProgress) {
                // divide local progress into subprogress
                progress_t subprogress;
                __divide_progress(pProgress, &subprogress, n, i);
                // do the actual work
                pList->LoadSubChunksRecursively(&subprogress);
            } else
                pList->LoadSubChunksRecursively(NULL);
        }
        if (pProgress)
            __notify_progress(pProgress, 1.0); // notify done
    }

    file_offset_t List::WriteChunk(file_offset_t ullWritePos, file_offset_t ullCurrentDataOffset, progress_t* pProgress) {
        const file_offset_t ullOriginalPos = ullWritePos;
        ullWritePos += LIST_HEADER_SIZE(pFile->FileOffsetSize);

        if (pFile->GetMode() != stream_mode_read_write)
            throw Exception("Cannot write list chunk, file has to be opened in read+write mode");

        // write all subchunks (including sub list chunks) recursively
        if (pSubChunks) {
            size_t i = 0;
            const size_t n = pSubChunks->size();
            for (ChunkList::iterator iter = pSubChunks->begin(), end = pSubChunks->end(); iter != end; ++iter, ++i) {
                if (pProgress) {
                    // divide local progress into subprogress for loading current Instrument
                    progress_t subprogress;
                    __divide_progress(pProgress, &subprogress, n, i);
                    // do the actual work
                    ullWritePos = (*iter)->WriteChunk(ullWritePos, ullCurrentDataOffset, &subprogress);
                } else
                    ullWritePos = (*iter)->WriteChunk(ullWritePos, ullCurrentDataOffset, NULL);
            }
        }

        // update this list chunk's header
        ullCurrentChunkSize = ullNewChunkSize = ullWritePos - ullOriginalPos - LIST_HEADER_SIZE(pFile->FileOffsetSize);
        WriteHeader(ullOriginalPos);

        // offset of this list chunk in new written file may have changed
        ullStartPos = ullOriginalPos + LIST_HEADER_SIZE(pFile->FileOffsetSize);

        if (pProgress)
            __notify_progress(pProgress, 1.0); // notify done

        return ullWritePos;
    }

    void List::__resetPos() {
        Chunk::__resetPos();
        if (pSubChunks) {
            for (ChunkList::iterator iter = pSubChunks->begin(), end = pSubChunks->end(); iter != end; ++iter) {
                (*iter)->__resetPos();
            }
        }
    }

    String List::GetListTypeString() const {
        return convertToString(ListType);
    }



// *************** File ***************
// *

    File::File(uint32_t FileType)
        : List(this), bIsNewFile(true), Layout(layout_standard),
          FileOffsetPreference(offset_size_auto)
    {
        io.isPerThread = false;
        #if defined(WIN32)
        io.hRead = io.hWrite = INVALID_HANDLE_VALUE;
        #else
        io.hRead = io.hWrite = 0;
        #endif
        io.Mode = stream_mode_closed;
        bEndianNative = true;
        ListType = FileType;
        FileOffsetSize = 4;
        ullStartPos = RIFF_HEADER_SIZE(FileOffsetSize);
    }

    File::File(const String& path)
        : List(this), Filename(path), bIsNewFile(false), Layout(layout_standard),
          FileOffsetPreference(offset_size_auto)
    {
        #if DEBUG_RIFF
        std::cout << "File::File("<<path<<")" << std::endl;
        #endif // DEBUG_RIFF
        bEndianNative = true;
        FileOffsetSize = 4;
        try {
            __openExistingFile(path);
            if (ChunkID != CHUNK_ID_RIFF && ChunkID != CHUNK_ID_RIFX) {
                throw RIFF::Exception("Not a RIFF file");
            }
        }
        catch (...) {
            Cleanup();
            throw;
        }
    }

    File::File(const String& path, uint32_t FileType, endian_t Endian, layout_t layout, offset_size_t fileOffsetSize)
        : List(this), Filename(path), bIsNewFile(false), Layout(layout),
          FileOffsetPreference(fileOffsetSize)
    {
        SetByteOrder(Endian);
        if (fileOffsetSize < offset_size_auto || fileOffsetSize > offset_size_64bit)
            throw Exception("Invalid RIFF::offset_size_t");
        FileOffsetSize = 4;
        try {
            __openExistingFile(path, &FileType);
        }
        catch (...) {
            Cleanup();
            throw;
        }
    }

    void File::__openExistingFile(const String& path, uint32_t* FileType) {
        io.isPerThread = false;
        #if POSIX
        io.hRead = io.hWrite = open(path.c_str(), O_RDONLY | O_NONBLOCK);
        if (io.hRead == -1) {
            io.hRead = io.hWrite = 0;
            String sError = strerror(errno);
            throw RIFF::Exception("Can't open \"" + path + "\": " + sError);
        }
        #elif defined(WIN32)
        io.hRead = io.hWrite = CreateFile(
                                     path.c_str(), GENERIC_READ,
                                     FILE_SHARE_READ | FILE_SHARE_WRITE,
                                     NULL, OPEN_EXISTING,
                                     FILE_ATTRIBUTE_NORMAL |
                                     FILE_FLAG_RANDOM_ACCESS, NULL
                                 );
        if (io.hRead == INVALID_HANDLE_VALUE) {
            io.hRead = io.hWrite = INVALID_HANDLE_VALUE;
            throw RIFF::Exception("Can't open \"" + path + "\"");
        }
        #else
        io.hRead = io.hWrite = fopen(path.c_str(), "rb");
        if (!io.hRead) throw RIFF::Exception("Can't open \"" + path + "\"");
        #endif // POSIX
        io.Mode = stream_mode_read;

        // determine RIFF file offset size to be used (in RIFF chunk headers)
        // according to the current file offset preference
        FileOffsetSize = FileOffsetSizeFor(GetCurrentFileSize());

        switch (Layout) {
            case layout_standard: // this is a normal RIFF file
                ullStartPos = RIFF_HEADER_SIZE(FileOffsetSize);
                ReadHeader(0);
                if (FileType && ChunkID != *FileType)
                    throw RIFF::Exception("Invalid file container ID");
                break;
            case layout_flat: // non-standard RIFF-alike file
                ullStartPos = 0;
                ullNewChunkSize = ullCurrentChunkSize = GetCurrentFileSize();
                if (FileType) {
                    uint32_t ckid;
                    if (Read(&ckid, 4, 1) != 4) {
                        throw RIFF::Exception("Invalid file header ID (premature end of header)");
                    } else if (ckid != *FileType) {
                        String s = " (expected '" + convertToString(*FileType) + "' but got '" + convertToString(ckid) + "')";
                        throw RIFF::Exception("Invalid file header ID" + s);
                    }
                    SetPos(0); // reset to first byte of file
                }
                LoadSubChunks();
                break;
        }
    }

    String File::GetFileName() const {
        return Filename;
    }
    
    void File::SetFileName(const String& path) {
        Filename = path;
    }

    File::HandlePair& File::FileHandlePairUnsafeRef() {
        if (io.byThread.empty()) return io;
        const std::thread::id tid = std::this_thread::get_id();
        const auto it = io.byThread.find(tid);
        return (it != io.byThread.end()) ?
            it->second :
            io.byThread[tid] = {
                // designated initializers require C++20, so commented for now
                #if defined(WIN32)
                /* .hRead  = */ INVALID_HANDLE_VALUE,
                /* .hWrite = */ INVALID_HANDLE_VALUE,
                #else
                /* .hRead  = */ 0,
                /* .hWrite = */ 0,
                #endif
                /* .Mode = */ stream_mode_closed
            };
    }

    File::HandlePair File::FileHandlePair() const {
        std::lock_guard<std::mutex> lock(io.mutex);
        if (io.byThread.empty()) return io;
        const std::thread::id tid = std::this_thread::get_id();
        const auto it = io.byThread.find(tid);
        return (it != io.byThread.end()) ?
            it->second :
            io.byThread[tid] = {
                // designated initializers require C++20, so commented for now
                #if defined(WIN32)
                /* .hRead  = */ INVALID_HANDLE_VALUE,
                /* .hWrite = */ INVALID_HANDLE_VALUE,
                #else
                /* .hRead  = */ 0,
                /* .hWrite = */ 0,
                #endif
                /* .Mode = */ stream_mode_closed
            };
     }

    File::Handle File::FileHandle() const {
        return FileHandlePair().hRead;
    }

    File::Handle File::FileWriteHandle() const {
        return FileHandlePair().hWrite;
    }

    stream_mode_t File::GetMode() const {
        return FileHandlePair().Mode;
    }

    layout_t File::GetLayout() const {
        return Layout;
    }

    bool File::SetMode(stream_mode_t NewMode) {
        bool bResetPos = false;
        bool res = SetModeInternal(NewMode, &bResetPos);
        // resetting position must be handled outside above's call to avoid any
        // potential dead lock, as SetModeInternal() acquires a lock and
        // __resetPos() acquires a lock by itself (not a theoretical issue!)
        if (bResetPos)
            __resetPos(); // reset read/write position of ALL 'Chunk' objects
        return res;
    }

    bool File::SetModeInternal(stream_mode_t NewMode, bool* pResetPos) {
        std::lock_guard<std::mutex> lock(io.mutex);
        HandlePair& io = FileHandlePairUnsafeRef();
        if (NewMode != io.Mode) {
            switch (NewMode) {
                case stream_mode_read:
                    if (_isValidHandle(io.hRead)) _close(io.hRead);
                    #if POSIX
                    io.hRead = io.hWrite = open(Filename.c_str(), O_RDONLY | O_NONBLOCK);
                    if (io.hRead == -1) {
                        io.hRead = io.hWrite = 0;
                        String sError = strerror(errno);
                        throw Exception("Could not (re)open file \"" + Filename + "\" in read mode: " + sError);
                    }
                    #elif defined(WIN32)
                    io.hRead = io.hWrite = CreateFile(
                                                 Filename.c_str(), GENERIC_READ,
                                                 FILE_SHARE_READ | FILE_SHARE_WRITE,
                                                 NULL, OPEN_EXISTING,
                                                 FILE_ATTRIBUTE_NORMAL |
                                                 FILE_FLAG_RANDOM_ACCESS,
                                                 NULL
                                             );
                    if (io.hRead == INVALID_HANDLE_VALUE) {
                        io.hRead = io.hWrite = INVALID_HANDLE_VALUE;
                        throw Exception("Could not (re)open file \"" + Filename + "\" in read mode");
                    }
                    #else
                    io.hRead = io.hWrite = fopen(Filename.c_str(), "rb");
                    if (!io.hRead) throw Exception("Could not (re)open file \"" + Filename + "\" in read mode");
                    #endif
                    *pResetPos = true;
                    break;
                case stream_mode_read_write:
                    if (_isValidHandle(io.hRead)) _close(io.hRead);
                    #if POSIX
                    io.hRead = io.hWrite = open(Filename.c_str(), O_RDWR | O_NONBLOCK);
                    if (io.hRead == -1) {
                        io.hRead = io.hWrite = open(Filename.c_str(), O_RDONLY | O_NONBLOCK);
                        String sError = strerror(errno);
                        throw Exception("Could not open file \"" + Filename + "\" in read+write mode: " + sError);
                    }
                    #elif defined(WIN32)
                    io.hRead = io.hWrite = CreateFile(
                                                 Filename.c_str(),
                                                 GENERIC_READ | GENERIC_WRITE,
                                                 FILE_SHARE_READ,
                                                 NULL, OPEN_ALWAYS,
                                                 FILE_ATTRIBUTE_NORMAL |
                                                 FILE_FLAG_RANDOM_ACCESS,
                                                 NULL
                                             );
                    if (io.hRead == INVALID_HANDLE_VALUE) {
                        io.hRead = io.hWrite = CreateFile(
                                                     Filename.c_str(), GENERIC_READ,
                                                     FILE_SHARE_READ | FILE_SHARE_WRITE,
                                                     NULL, OPEN_EXISTING,
                                                     FILE_ATTRIBUTE_NORMAL |
                                                     FILE_FLAG_RANDOM_ACCESS,
                                                     NULL
                                                 );
                        throw Exception("Could not (re)open file \"" + Filename + "\" in read+write mode");
                    }
                    #else
                    io.hRead = io.hWrite = fopen(Filename.c_str(), "r+b");
                    if (!io.hRead) {
                        io.hRead = io.hWrite = fopen(Filename.c_str(), "rb");
                        throw Exception("Could not open file \"" + Filename + "\" in read+write mode");
                    }
                    #endif
                    *pResetPos = true;
                    break;
                case stream_mode_closed:
                    if (_isValidHandle(io.hRead)) _close(io.hRead);
                    if (_isValidHandle(io.hWrite)) _close(io.hWrite);
                    #if POSIX
                    io.hRead = io.hWrite = 0;
                    #elif defined(WIN32)
                    io.hRead = io.hWrite = INVALID_HANDLE_VALUE;
                    #else
                    io.hRead = io.hWrite = NULL;
                    #endif
                    break;
                default:
                    throw Exception("Unknown file access mode");
            }
            io.Mode = NewMode;
            return true;
        }
        return false;
    }

    void File::SetByteOrder(endian_t Endian) {
        #if WORDS_BIGENDIAN
        bEndianNative = Endian != endian_little;
        #else
        bEndianNative = Endian != endian_big;
        #endif
    }

    void File::Save(progress_t* pProgress) {
        //TODO: implementation for the case where first chunk is not a global container (List chunk) is not implemented yet (i.e. Korg files)
        if (Layout == layout_flat)
            throw Exception("Saving a RIFF file with layout_flat is not implemented yet");

        // make sure the RIFF tree is built (from the original file)
        if (pProgress) {
            // divide progress into subprogress
            progress_t subprogress;
            __divide_progress(pProgress, &subprogress, 3.f, 0.f); // arbitrarily subdivided into 1/3 of total progress
            // do the actual work
            LoadSubChunksRecursively(&subprogress);
            // notify subprogress done
            __notify_progress(&subprogress, 1.f);
        } else
            LoadSubChunksRecursively(NULL);

        // reopen file in write mode
        SetMode(stream_mode_read_write);

        // get the current file size as it is now still physically stored on disk
        const file_offset_t workingFileSize = GetCurrentFileSize();

        // get the overall file size required to save this file
        const file_offset_t newFileSize = GetRequiredFileSize(FileOffsetPreference);

        // determine whether this file will yield in a large file (>=4GB) and
        // the RIFF file offset size to be used accordingly for all chunks
        FileOffsetSize = FileOffsetSizeFor(newFileSize);

        const HandlePair io = FileHandlePair();
        const Handle hRead  = io.hRead;
        const Handle hWrite = io.hWrite;

        // to be able to save the whole file without loading everything into
        // RAM and without having to store the data in a temporary file, we
        // enlarge the file with the overall positive file size change,
        // then move current data towards the end of the file by the calculated
        // positive file size difference and finally update / rewrite the file
        // by copying the old data back to the right position at the beginning
        // of the file

        // if there are positive size changes...
        file_offset_t positiveSizeDiff = 0;
        if (newFileSize > workingFileSize) {
            positiveSizeDiff = newFileSize - workingFileSize;

            // divide progress into subprogress
            progress_t subprogress;
            if (pProgress)
                __divide_progress(pProgress, &subprogress, 3.f, 1.f); // arbitrarily subdivided into 1/3 of total progress

            // ... we enlarge this file first ...
            ResizeFile(newFileSize);

            // ... and move current data by the same amount towards end of file.
            int8_t* pCopyBuffer = new int8_t[4096];
            #if defined(WIN32)
            DWORD iBytesMoved = 1; // we have to pass it via pointer to the Windows API, thus the correct size must be ensured
            #else
            ssize_t iBytesMoved = 1;
            #endif
            for (file_offset_t ullPos = workingFileSize, iNotif = 0; iBytesMoved > 0; ++iNotif) {
                iBytesMoved = (ullPos < 4096) ? ullPos : 4096;
                ullPos -= iBytesMoved;
                #if POSIX
                lseek(hRead, ullPos, SEEK_SET);
                iBytesMoved = read(hRead, pCopyBuffer, iBytesMoved);
                lseek(hWrite, ullPos + positiveSizeDiff, SEEK_SET);
                iBytesMoved = write(hWrite, pCopyBuffer, iBytesMoved);
                #elif defined(WIN32)
                LARGE_INTEGER liFilePos;
                liFilePos.QuadPart = ullPos;
                SetFilePointerEx(hRead, liFilePos, NULL/*new pos pointer*/, FILE_BEGIN);
                ReadFile(hRead, pCopyBuffer, iBytesMoved, &iBytesMoved, NULL);
                liFilePos.QuadPart = ullPos + positiveSizeDiff;
                SetFilePointerEx(hWrite, liFilePos, NULL/*new pos pointer*/, FILE_BEGIN);
                WriteFile(hWrite, pCopyBuffer, iBytesMoved, &iBytesMoved, NULL);
                #else
                fseeko(hRead, ullPos, SEEK_SET);
                iBytesMoved = fread(pCopyBuffer, 1, iBytesMoved, hRead);
                fseeko(hWrite, ullPos + positiveSizeDiff, SEEK_SET);
                iBytesMoved = fwrite(pCopyBuffer, 1, iBytesMoved, hWrite);
                #endif
                if (pProgress && !(iNotif % 8) && iBytesMoved > 0)
                    __notify_progress(&subprogress, float(workingFileSize - ullPos) / float(workingFileSize));
            }
            delete[] pCopyBuffer;
            if (iBytesMoved < 0) throw Exception("Could not modify file while trying to enlarge it");

            if (pProgress)
                __notify_progress(&subprogress, 1.f); // notify subprogress done
        }

        // rebuild / rewrite complete RIFF tree ...

        // divide progress into subprogress
        progress_t subprogress;
        if (pProgress)
            __divide_progress(pProgress, &subprogress, 3.f, 2.f); // arbitrarily subdivided into 1/3 of total progress
        // do the actual work
        const file_offset_t finalSize = WriteChunk(0, positiveSizeDiff, pProgress ? &subprogress : NULL);
        const file_offset_t finalActualSize = __GetFileSize(hWrite);
        // notify subprogress done
        if (pProgress)
            __notify_progress(&subprogress, 1.f);

        // resize file to the final size
        if (finalSize < finalActualSize) ResizeFile(finalSize);

        if (pProgress)
            __notify_progress(pProgress, 1.0); // notify done
    }

    void File::Save(const String& path, progress_t* pProgress) {
        //TODO: we should make a check here if somebody tries to write to the same file and automatically call the other Save() method in that case

        //TODO: implementation for the case where first chunk is not a global container (List chunk) is not implemented yet (i.e. Korg files)
        if (Layout == layout_flat)
            throw Exception("Saving a RIFF file with layout_flat is not implemented yet");

        // make sure the RIFF tree is built (from the original file)
        if (pProgress) {
            // divide progress into subprogress
            progress_t subprogress;
            __divide_progress(pProgress, &subprogress, 2.f, 0.f); // arbitrarily subdivided into 1/2 of total progress
            // do the actual work
            LoadSubChunksRecursively(&subprogress);
            // notify subprogress done
            __notify_progress(&subprogress, 1.f);
        } else
            LoadSubChunksRecursively(NULL);

        if (!bIsNewFile) SetMode(stream_mode_read);

        {
            std::lock_guard<std::mutex> lock(io.mutex);
            HandlePair& io = FileHandlePairUnsafeRef();

            // open the other (new) file for writing and truncate it to zero size
            #if POSIX
            io.hWrite = open(path.c_str(), O_RDWR | O_CREAT, S_IRUSR | S_IWUSR | S_IRGRP);
            if (io.hWrite == -1) {
                io.hWrite = io.hRead;
                String sError = strerror(errno);
                throw Exception("Could not open file \"" + path + "\" for writing: " + sError);
            }
            #elif defined(WIN32)
            io.hWrite = CreateFile(
                path.c_str(), GENERIC_WRITE, FILE_SHARE_READ,
                NULL, OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL |
                FILE_FLAG_RANDOM_ACCESS, NULL
            );
            if (io.hWrite == INVALID_HANDLE_VALUE) {
                io.hWrite = io.hRead;
                throw Exception("Could not open file \"" + path + "\" for writing");
            }
            #else
            io.hWrite = fopen(path.c_str(), "w+b");
            if (!io.hWrite) {
                io.hWrite = io.hRead;
                throw Exception("Could not open file \"" + path + "\" for writing");
            }
            #endif // POSIX
            io.Mode = stream_mode_read_write;
        }

        // get the overall file size required to save this file
        const file_offset_t newFileSize = GetRequiredFileSize(FileOffsetPreference);

        // determine whether this file will yield in a large file (>=4GB) and
        // the RIFF file offset size to be used accordingly for all chunks
        FileOffsetSize = FileOffsetSizeFor(newFileSize);

        // write complete RIFF tree to the other (new) file
        file_offset_t ullTotalSize;
        if (pProgress) {
            // divide progress into subprogress
            progress_t subprogress;
            __divide_progress(pProgress, &subprogress, 2.f, 1.f); // arbitrarily subdivided into 1/2 of total progress
            // do the actual work
            ullTotalSize = WriteChunk(0, 0, &subprogress);
            // notify subprogress done
            __notify_progress(&subprogress, 1.f);
        } else
            ullTotalSize = WriteChunk(0, 0, NULL);

        const file_offset_t ullActualSize = __GetFileSize(FileWriteHandle());

        // resize file to the final size (if the file was originally larger)
        if (ullActualSize > ullTotalSize) ResizeFile(ullTotalSize);

        {
            std::lock_guard<std::mutex> lock(io.mutex);
            HandlePair& io = FileHandlePairUnsafeRef();

            if (_isValidHandle(io.hWrite)) _close(io.hWrite);
            io.hWrite = io.hRead;

            // associate new file with this File object from now on
            Filename = path;
            bIsNewFile = false;
            io.Mode = (stream_mode_t) -1; // Just set it to an undefined mode ...
        }
        SetMode(stream_mode_read_write); // ... so SetMode() has to reopen the file handles.

        if (pProgress)
            __notify_progress(pProgress, 1.0); // notify done
    }

    void File::ResizeFile(file_offset_t ullNewSize) {
        const Handle hWrite = FileWriteHandle();
        #if POSIX
        if (ftruncate(hWrite, ullNewSize) < 0)
            throw Exception("Could not resize file \"" + Filename + "\"");
        #elif defined(WIN32)
        LARGE_INTEGER liFilePos;
        liFilePos.QuadPart = ullNewSize;
        if (
            !SetFilePointerEx(hWrite, liFilePos, NULL/*new pos pointer*/, FILE_BEGIN) ||
            !SetEndOfFile(hWrite)
        ) throw Exception("Could not resize file \"" + Filename + "\"");
        #else
        # error Sorry, this version of libgig only supports POSIX and Windows systems yet.
        # error Reason: portable implementation of RIFF::File::ResizeFile() is missing (yet)!
        #endif
    }

    File::~File() {
        #if DEBUG_RIFF
        std::cout << "File::~File()" << std::endl;
        #endif // DEBUG_RIFF
        Cleanup();
    }

    bool File::IsNew() const {
        return bIsNewFile;
    }

    void File::Cleanup() {
        if (IsIOPerThread()) {
            for (auto it = io.byThread.begin(); it != io.byThread.end(); ++it) {
                _close(it->second.hRead);
            }
        } else {
            _close(io.hRead);
        }
        DeleteChunkList();
        pFile = NULL;
    }

    file_offset_t File::GetCurrentFileSize() const {
        file_offset_t size = 0;
        const Handle hRead = FileHandle();
        try {
            size = __GetFileSize(hRead);
        } catch (...) {
            size = 0;
        }
        return size;
    }

    file_offset_t File::GetRequiredFileSize() {
        return GetRequiredFileSize(FileOffsetPreference);
    }

    file_offset_t File::GetRequiredFileSize(offset_size_t fileOffsetSize) {
        switch (fileOffsetSize) {
            case offset_size_auto: {
                file_offset_t fileSize = GetRequiredFileSize(offset_size_32bit);
                if (fileSize >> 32)
                    return GetRequiredFileSize(offset_size_64bit);
                else
                    return fileSize;
            }
            case offset_size_32bit: break;
            case offset_size_64bit: break;
            default: throw Exception("Internal error: Invalid RIFF::offset_size_t");
        }
        return RequiredPhysicalSize(FileOffsetSize);
    }

    int File::FileOffsetSizeFor(file_offset_t fileSize) const {
        switch (FileOffsetPreference) {
            case offset_size_auto:
                return (fileSize >> 32) ? 8 : 4; 
            case offset_size_32bit:
                return 4;
            case offset_size_64bit:
                return 8;
            default:
                throw Exception("Internal error: Invalid RIFF::offset_size_t");
        }
    }

    int File::GetFileOffsetSize() const {
        return FileOffsetSize;
    }

    int File::GetRequiredFileOffsetSize() {
        return FileOffsetSizeFor(GetCurrentFileSize());
    }

    bool File::IsIOPerThread() const {
        //NOTE: Not caring about atomicity here at all, for three reasons:
        // 1. SetIOPerThread() is assumed to be called only once for the entire
        //    life time of a RIFF::File, usually very early at its lifetime, and
        //    hence a change to isPerThread should already safely be propagated
        //    before any other thread would actually read this boolean flag.
        // 2. This method is called very frequently, and therefore any
        //    synchronization techique would hurt runtime efficiency.
        // 3. Using even a mutex lock here might easily cause a deadlock due to
        //    other locks been taken in this .cpp file, i.e. at a higher call
        //    stack level (and this is the main reason why I removed it here).
        return io.isPerThread;
    }

    void File::SetIOPerThread(bool enable) {
        std::lock_guard<std::mutex> lock(io.mutex);
        if (!io.byThread.empty() == enable) return;
        io.isPerThread = enable;
        if (enable) {
            const std::thread::id tid = std::this_thread::get_id();
            io.byThread[tid] = io;
        } else {
            // retain an arbitrary handle pair, close all other handle pairs
            for (auto it = io.byThread.begin(); it != io.byThread.end(); ++it) {
                if (it == io.byThread.begin()) {
                    io.hRead  = it->second.hRead;
                    io.hWrite = it->second.hWrite;
                } else {
                    _close(it->second.hRead);
                    _close(it->second.hWrite);
                }
            }
            io.byThread.clear();
        }
    }

    #if POSIX
    file_offset_t File::__GetFileSize(int hFile) const {
        struct stat filestat;
        if (fstat(hFile, &filestat) == -1)
            throw Exception("POSIX FS error: could not determine file size");
        return filestat.st_size;
    }
    #elif defined(WIN32)
    file_offset_t File::__GetFileSize(HANDLE hFile) const {
        LARGE_INTEGER size;
        if (!GetFileSizeEx(hFile, &size))
            throw Exception("Windows FS error: could not determine file size");
        return size.QuadPart;
    }
    #else // standard C functions
    file_offset_t File::__GetFileSize(FILE* hFile) const {
        off_t curpos = ftello(hFile);
        if (fseeko(hFile, 0, SEEK_END) == -1)
            throw Exception("FS error: could not determine file size");
        off_t size = ftello(hFile);
        fseeko(hFile, curpos, SEEK_SET);
        return size;
    }
    #endif


// *************** Exception ***************
// *

    Exception::Exception() {
    }

    Exception::Exception(String format, ...) {
        va_list arg;
        va_start(arg, format);
        Message = assemble(format, arg);
        va_end(arg);
    }

    Exception::Exception(String format, va_list arg) {
        Message = assemble(format, arg);
    }

    void Exception::PrintMessage() {
        std::cout << "RIFF::Exception: " << Message << std::endl;
    }

    String Exception::assemble(String format, va_list arg) {
        char* buf = NULL;
        vasprintf(&buf, format.c_str(), arg);
        String s = buf;
        free(buf);
        return s;
    }


// *************** functions ***************
// *

    String libraryName() {
        return PACKAGE;
    }

    String libraryVersion() {
        return VERSION;
    }

} // namespace RIFF