# LAS Stream Viewer

A drilling-data viewer for **very large (10 GB+) LAS well-log files**. A Java 21 / Quarkus backend
indexes the file in a single streaming pass (constant, tiny memory footprint); a React + Vite UI
presents the data three ways:

- **📈 Log Plot** — a multi-track drilling strip-chart / log plot (the way an engineer reads a well).
- **⊕ Crossplot** — WOB-vs-ROP (and any X/Y) drilling-optimization scatter, colored by depth/time.
- **𝍌 Raw / QC** — line-by-line virtualized view with live SSE streaming and whole-file search.

Built for the Pason-style LAS 2.0 logs in `Desktop\LAS files` (up to ~12.5 GB, ~426 curves,
~2.5 M rows). Nothing in the design assumes the file fits in memory.

## Why it scales

| Concern | Approach |
|---|---|
| Open a 12.5 GB file | **Open-in-place** (no copy) — or resumable 16 MiB chunked upload |
| Random line access | One-pass **sparse byte-offset index** (a checkpoint every 256 lines ≈ 80 KB for 2.5 M lines) |
| Curve plots over millions of samples | **Pyramid** of min/max **and mean** built per 32-row bucket during the same pass |
| Honest decimation | **min/max per pixel, never averaging** — a 2 s gas kick or torque spike survives when zoomed out |
| Indexing memory | Single streaming pass, 1 MiB buffer + tiny index + tens-of-MB pyramid — independent of file size |
| Raw streaming | One `BufferedReader` advanced sequentially; lines pushed over **SSE** with backpressure |
| Browser memory | Virtualized line list + capped (20 K-line) cache; plots fetch only the visible window, decimated |

## Drilling features

- **Channel-role resolver** maps the ~426 raw Pason mnemonics to drilling roles (ROP, WOB, RPM,
  torque, MSE, SPP, flow, total gas + C1–C5, gamma, inclination/azimuth, stick-slip/vibration, pit
  gain-loss, on-bottom, …) with sensible **physical default scales** so sensor-glitch spikes clip
  instead of flattening the trace.
- **Log Plot**: index vertical (depth **or** time, with a toggle), value horizontal in side-by-side
  tracks; min/max envelope + mid trace; **scrollbar** + wheel-zoom + Fit to navigate; **auto-fit**
  (scale each track to the visible window); hover **crosshair + readout**; **curve picker** to
  customize tracks; **EDR-style replay** (curves scroll like a rig strip-chart); **Σ Stats** panel
  (min/avg/max per channel over the window).
- **Crossplot**: bucket-mean X vs Y (default WOB vs ROP) colored by depth/time/channel, **on-bottom
  only** filter, robust (1st–99th pct) auto-ranges so outliers don't blow up the axes, colorbar, hover.
- **Robust axes/depth**: hole-depth is jump-capped so one garbage `DEPT` sample can't poison the
  depth axis; an axis is only offered when its real extent is non-degenerate.

## Layout

```
las-stream-viewer/
├─ pom.xml                      Quarkus 3.34.3, Java 21
├─ run.ps1                      dev: Vite (:5173) + Quarkus (:8090)
├─ build.ps1                    prod: bundle UI into the jar, serve on :8090
├─ src/main/java/com/oiusa/las/
│  ├─ model/                    LasFile, Curve, HeaderSection, ResolvedRole
│  ├─ index/                    LineIndex (sparse offsets), LineReader, Pyramid (min/max/mean overview), RowParser
│  ├─ service/                  FileStore, IndexService (one-pass index+pyramid), LasHeaderParser,
│  │                            ChannelRoles (role mapping), CurveDataService (decimation/crossplot), UploadService
│  └─ web/                      File / Lines / Stream(SSE) / Search(SSE) / Upload / Curve (roles, curve-data, crossplot)
└─ frontend/src/
   ├─ components/               App, IngestPanel, FileList, Section, WellInfo, ChannelList,
   │                            HeaderPanel, Viewer (raw), LogPlot, Crossplot
   └─ api.ts, types.ts, las.ts, styles.css
```

## Run (dev)

```powershell
cd C:\Users\Dell\Desktop\las-stream-viewer
.\run.ps1
```

Installs UI deps on first run, starts Vite in a new window, runs the Quarkus dev server.
Open **http://localhost:5173**.

By hand:

```powershell
$env:JAVA_HOME="C:\Program Files\Java\jdk-21.0.11"
$mvn = "C:\Users\Dell\.m2\wrapper\dists\apache-maven-3.9.9-bin\4nf9hui3q3djbarqar9g711ggc\apache-maven-3.9.9\bin\mvn.cmd"
& $mvn quarkus:dev                 # backend :8090
cd frontend; npm install; npm run dev   # frontend :5173 (separate window)
```

## Run (production, single port)

```powershell
.\build.ps1
$env:JAVA_HOME="C:\Program Files\Java\jdk-21.0.11"
java -jar target\quarkus-app\quarkus-run.jar
# open http://localhost:8090
```

## Using it

1. **Open a file** (left panel): **Open on disk** browses the server filesystem (constrained to
   `las.allowed-roots`) and opens a `.las` **in place, no copy** — ideal for the multi-GB logs.
   Or **Upload** to stream a file in 16 MiB chunks. Indexing + the curve overview build in the
   background; the well info and channels appear in the sidebar as soon as the header is parsed.
2. **📈 Log Plot** — scroll the scrollbar (or wheel-zoom / Fit) through depth or time, hover for a
   readout, **▶ Replay** to animate, toggle **auto-fit** and **Σ Stats**, add channels via **＋ Curves**.
3. **⊕ Crossplot** — pick X/Y/Color, toggle **on-bottom only** for a clean founder-point view.
4. **𝍌 Raw / QC** — stream the raw lines (speed slider), jump to Top/Data/End/any line, search the
   whole file. Good for verifying export integrity (column alignment, NULLs, etc.).

Collapse the left panel with the **⮜** button in the top bar for a bigger workspace.

## Notes & caveats

- The channel→role mapping is auto-resolved from mnemonics; verify with the **＋ Curves** picker and
  swap channels if a mapping looks off for your file.
- Data quality is the data's own: some exports have broken channels (e.g. a stuck `DEPT`), in which
  case that axis is suppressed and the **Raw / QC** tab is the place to confirm. Sensor-glitch spikes
  are handled by fixed physical scales (Log Plot) and robust percentile ranges (Crossplot).
- First index of a 12.5 GB file takes a few minutes (it parses ~40 channels/row for the pyramid);
  shown with a progress bar. Smaller logs index in seconds.

## Configuration (`src/main/resources/application.properties`)

| Key | Default | Notes |
|---|---|---|
| `quarkus.http.port` | `8090` | API (and prod UI) port |
| `las.data-dir` | `${user.home}/.las-stream-viewer` | where uploaded files live |
| `las.allowed-roots` | `${user.home}` | local files may only be opened from under these roots |
| `las.index-stride` | `256` | lines per index checkpoint (smaller = faster seeks, larger index) |
| `las.upload-chunk-size` | `16777216` | upload chunk size hint (16 MiB) |