Struct atm::utils::BatchedMIDIArchive

pub struct BatchedMIDIArchive {
    pub partition_depth: u32,
    pub max_files: f32,
    pub partition_size: u32,
    pub batch_size: u32,
    pub state: BatchedMIDIArchiveState,
    // some fields omitted
}

Container for tar archive of MIDI files

BatchedMIDIArchive is a convenience wrapper around functionality to create tar archives of batches of MIDI files. Most hard drives and OS's align files to 512 bytes, and the official tar spec aligns headers and entries the same way. However, MIDI files generated by libatm::MIDIFile, depending on sequence length, tend to be much smaller (95 bytes for a 12-note sequence). Thus, in order to maximize disk space usage, this class bundles batches of MIDI files (compressed tar archives) into each entry in the output tar archive. During testing, All the Music was able to compress up to 25 MIDI files per batch using the flate2 crate with the default compression level.

Examples

// Assumes sequence length of 10, 8 possible notes, and partition depth of 2
let mut archive = atm::utils::BatchedMIDIArchive::new(
    "archive.tar",
    2,
    4096.0,
    atm::utils::gen_partition_size(8.0, 10, 4096.0, 2),
    20
);
let sequence = "C:4,D:4,E:4,C:4,D:4,E:4,C:4,D:4,E:4,C:4"
    .parse::<libatm::MIDINoteSequence>()
    .unwrap();
let mfile = libatm::MIDIFile::new(sequence, libatm::MIDIFormat::Format0, 1, 1);
archive.push(mfile).unwrap();
archive.finish().unwrap();

Fields

partition_depth: u32

Number of partitions

max_files: f32

Maximum number of files per partition

partition_size: u32

Number of MIDI notes per partition

batch_size: u32

Number of MIDI files per batch

state: BatchedMIDIArchiveState

Whether archive is Open or Closed

Methods

impl BatchedMIDIArchive

pub fn new(
    target_path: &str,
    partition_depth: u32,
    max_files: f32,
    partition_size: u32,
    batch_size: u32
) -> BatchedMIDIArchive

Create new BatchedMIDIArchive

pub fn push(&mut self, mfile: MIDIFile) -> Result<()>

Add a MIDI file to the archive

If adding the MIDI file breaks a partition or batch boundary, this function will flush the current batch to the underlying tar archive.

pub fn finish(&mut self) -> Result<()>

Flush current batch to the tar archive and set the state to Closed

After this function is called, no more files can be written to the archive and the push function will panic.