Cube Histogram

See the source code: FITS | CASA | HDF5

Measures the time to compute a full cube histogram across all channels. The HDF5 format pre-computes histograms at write time, so the HDF5 variant uses a much tighter timeout (500 ms vs 300,000 ms) to verify the cached result is returned quickly. The elapsed time is measured between the SET_HISTOGRAM_REQUIREMENTS request and the REGION_HISTOGRAM_DATA response with progress = 1.

skinparam style strictuml hide footbox title PERF_CUBE_HISTOGRAM box "Client (Test Runner)" #EDEDED participant Client end box box "Server (Backend)" #lightblue participant Backend end box == Step 1: Open file and load initial tiles == Client -> Backend : OPEN_FILE activate Backend Client <-- Backend : OPEN_FILE_ACK Client <-- Backend : REGION_HISTOGRAM_DATA deactivate Backend Client -> Backend : ADD_REQUIRED_TILES (9 tiles) activate Backend Client -> Backend : SET_CURSOR (x=1, y=1) Client -> Backend : SET_SPATIAL_REQUIREMENTS Client <-- Backend : RASTER_TILE_DATA (9 tiles + sync start/end) Client <-- Backend : SPATIAL_PROFILE_DATA deactivate Backend == Step 2: Request cube histogram == note over Client, Backend **Timeout starts** FITS/CASA: 300,000 ms | HDF5: 500 ms end note Client -[#red]> Backend : <font color="red">SET_HISTOGRAM_REQUIREMENTS</font>\n(region=-2, channel=-2, num_bins=-1) activate Backend note right of Backend #FFEEEE <font color="red">Elapsed time measurement starts end note loop streaming progress Client <-- Backend : REGION_HISTOGRAM_DATA (progress < 1) end Client <--[#red] Backend : <font color="red">REGION_HISTOGRAM_DATA (progress = 1)</font> deactivate Backend note right of Backend #FFEEEE <font color="red">Elapsed time measurement ends end note note over Client **Assert:** progress reaches 1 end note

  1. Frontend opens cube_B_06400_z00100.<fits|image|hdf5> and loads initial tiles

  2. Frontend sends: SET_HISTOGRAM_REQUIREMENTS (SetHistogramRequirements)

    file_id = 0
region_id = -2
histograms = [{channel: -2, num_bins: -1}]

  3. Backend streams: REGION_HISTOGRAM_DATA with increasing progress

Check 1: within the cube histogram timeout:

  • FITS/CASA: 300,000 ms

  • HDF5: 500 ms (pre-computed)

  • REGION_HISTOGRAM_DATA reaches progress = 1