Reader

The entry point is Reader. Opening a .d directory parses MSScan.bin (the per-scan index) up front; individual scan payloads are read on demand from MSPeak.bin / MSProfile.bin as you iterate.

use openaraw::reader::Reader;

let reader = Reader::open("sample.d")?;

Reader::open fails if the directory does not contain an AcqData subdirectory (the modern MassHunter layout this reader targets - see Format specification).

Reader implements openmassspec_core::SpectrumSource, the shared trait every vendor reader in the OpenMassSpec stack implements:

use openmassspec_core::SpectrumSource;

let metadata = reader.run_metadata();
let scan_count = reader.spectrum_count_hint().unwrap_or(0);
println!("{} ({} scans)", metadata.source_file_name, scan_count);

let mut reader = reader;
for spectrum in reader.iter_spectra() {
    let spectrum = spectrum?;
    println!("{}\t{}\t{} peaks", spectrum.native_id, spectrum.ms_level, spectrum.mz.len());
}

iter_spectra yields one openmassspec_core::Result<SpectrumRecord> per MSScan.bin record, in file order. A scan whose payload block cannot be read or decoded is yielded as an Err, and iteration continues with the next scan.

Each SpectrumRecord carries index, scan_number, native_id, ms_level, scan_mode (Centroid or Profile), analyzer (TOFMS for Q-TOF, TQMS for QQQ), retention_time_sec, mz/intensity arrays, and

for MS2+ scans - a precursor (PrecursorInfo) populated either from the Q-TOF isolation target m/z or the QQQ MRM channel ID. See Scan data for how each field is derived from the on-disk records.

Error handling

Public functions return openaraw::Result<T>. The error type is openaraw::Error: Io, Parse (a message), or Scan (a scan's payload block failed: its scan_id, which block, and the underlying error). The enum is #[non_exhaustive], so match it with a wildcard arm.

SpectrumSource methods return openmassspec_core::Error. An openaraw::Error converts into it with From (I/O errors become Error::Io, the rest Error::Vendor, which can be downcast back to openaraw::Error).

The reader also exposes dir(), bundle_name(), msscan() (the decoded MSScan.bin records), device() (the Devices.xml mass spectrometer entry) and calibration(i). profile_decode_failures() and centroid_decode_failures() count the scans yielded as errors so far.

Error handling​

Error handling