FiffDataRef

Namespace: FIFFLIB  ·  Library: FIFF Library

#include <fiff/fiff_data_ref.h>

class FIFFLIB::FiffDataRef

External data reference: type, endian, byte size and offset into an external FIFF payload file.

Mirrors the original fiffDataRefRec exactly: a 24-byte record made of two qint32 (type, endianness flag) followed by two qint64 (payload size in bytes, byte offset into the external file). The 64-bit fields let referenced payloads exceed 2 GiB, which is required by long continuous Neuromag recordings split into multi-file FIFF trees.

src/examples/ex_fiff_structure/main.cpp

// A reference to data in an external file: 2 x 32-bit type and byte order, 2 x 64-bit size and offset.
FiffDataRef reference;
reference.size = 3LL << 31; // beyond 2 GiB
reference.offset = 1024;

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Public Methods

FiffDataRef()

Default constructor.

Initializes all fields to zero.

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~FiffDataRef()

Destroys the FiffDataRef.

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Static Methods

storageSize()

Size of the old struct (fiffDataRefRec) 2int + 2long = 24 + 28 = 24.

Returns:

• qint32 — the size of the old struct fiffDataRefRec.

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Example

• Full source: src/examples/ex_fiff_structure/main.cpp
• Build target: ex_fiff_structure (runs under CTest)
• Data: mne-cpp-test-data

Used in examples

ex_fiff_structure

FIFF library: fixed-length epochs, CTF compensation, the file directory and raw buffers, and handing.

src/examples/ex_fiff_structure/main.cpp, line 132

// A reference to data in an external file: 2 x 32-bit type and byte order, 2 x 64-bit size and offset.
FiffDataRef reference;
reference.size = 3LL << 31; // beyond 2 GiB
reference.offset = 1024;
ok &= expect(FiffDataRef::storageSize() == 24 && reference.size > std::numeric_limits<qint32>::max(), "FiffDataRef: 24-byte record with 64-bit size and offset");

Authors of this file

• Christoph Dinh <christoph.dinh@mne-cpp.org>