Class ov::util::NativeIfstream#

class NativeIfstream : public std::istream#

A read-only std::istream backed by NativeStreamBuf.

Uses native OS file handles and the platform io_read_into backend instead of C-runtime stdio, making it a drop-in replacement for std::ifstream for binary sequential and random-access reads.

Three construction modes:

  • default constructor: stream not associated with any file; behaves like a default-constructed std::ifstream — reads immediately return EOF.

  • path constructor (owning): opens a read-only native handle from a path; closes it on destruction.

  • handle constructor (non-owning): borrows a caller-provided handle for a sub-region [offset, offset + size); the handle is never closed by this class.

Supports move construction and move assignment (via swap). Copy is deleted.

ov::util::NativeIfstream empty;                      // default — not associated with any file
ov::util::NativeIfstream file(path);                 // owning — whole file from offset 0
ov::util::NativeIfstream view(handle, off, size);    // non-owning — sub-region [off, off+size)
file.seekg(blob_offset);
file.read(dst, n);

Public Functions

NativeIfstream() noexcept#

Constructs a stream not associated with any file. Any read immediately returns EOF.

explicit NativeIfstream(const std::filesystem::path &path)#

Opens a read-only native handle from path and takes ownership of it.

The stream is positioned at the beginning of the file. Use seekg() to reposition.

Parameters:

path – Path to the file to open.

explicit NativeIfstream(FileHandle handle, std::streamoff offset, std::streamoff size)#

Builds a stream over a caller-owned native handle. The handle is never closed by this class.

The caller must keep handle valid for the entire lifetime of the stream.

Parameters:

  • handle – Read-only native handle. Ownership remains with the caller.

  • offset – Absolute file offset that maps to logical stream position 0.

  • size – Number of readable bytes from offset.