@loaders.gl/zarr/dist/index.cjs

Framework-independent loaders for Zarr

"use strict";
var __defProp = Object.defineProperty;
var __getOwnPropDesc = Object.getOwnPropertyDescriptor;
var __getOwnPropNames = Object.getOwnPropertyNames;
var __hasOwnProp = Object.prototype.hasOwnProperty;
var __export = (target, all) => {
  for (var name in all)
    __defProp(target, name, { get: all[name], enumerable: true });
};
var __copyProps = (to, from, except, desc) => {
  if (from && typeof from === "object" || typeof from === "function") {
    for (let key of __getOwnPropNames(from))
      if (!__hasOwnProp.call(to, key) && key !== except)
        __defProp(to, key, { get: () => from[key], enumerable: !(desc = __getOwnPropDesc(from, key)) || desc.enumerable });
  }
  return to;
};
var __toCommonJS = (mod) => __copyProps(__defProp({}, "__esModule", { value: true }), mod);

// dist/index.js
var dist_exports = {};
__export(dist_exports, {
  ZarrPixelSource: () => zarr_pixel_source_default,
  loadZarr: () => loadZarr
});
module.exports = __toCommonJS(dist_exports);

// dist/lib/utils.js
var import_zarr = require("zarr");
function normalizeStore(source) {
  if (typeof source === "string") {
    return new import_zarr.HTTPStore(source);
  }
  return source;
}
async function loadMultiscales(store, path = "") {
  const grp = await (0, import_zarr.openGroup)(store, path);
  const rootAttrs = await grp.attrs.asObject();
  if (!Array.isArray(rootAttrs.multiscales)) {
    throw new Error("Cannot find Zarr multiscales metadata.");
  }
  const { datasets } = rootAttrs.multiscales[0];
  const promises = datasets.map((d) => grp.getItem(d.path));
  return {
    data: await Promise.all(promises),
    rootAttrs
  };
}
function getDims(labels) {
  const lookup = new Map(labels.map((name, i) => [name, i]));
  if (lookup.size !== labels.length) {
    throw Error("Labels must be unique, found duplicated label.");
  }
  return (name) => {
    const index = lookup.get(name);
    if (index === void 0) {
      throw Error("Invalid dimension.");
    }
    return index;
  };
}
function prevPowerOf2(x) {
  return 2 ** Math.floor(Math.log2(x));
}
function isInterleaved(shape) {
  const lastDimSize = shape[shape.length - 1];
  return lastDimSize === 3 || lastDimSize === 4;
}
function guessTileSize(arr) {
  const interleaved = isInterleaved(arr.shape);
  const [yChunk, xChunk] = arr.chunks.slice(interleaved ? -3 : -2);
  const size = Math.min(yChunk, xChunk);
  return prevPowerOf2(size);
}
function guessLabels(rootAttrs) {
  if ("omero" in rootAttrs) {
    return ["t", "c", "z", "y", "x"];
  }
  throw new Error("Could not infer dimension labels for Zarr source. Must provide dimension labels.");
}
function getIndexer(labels) {
  const size = labels.length;
  const dims = getDims(labels);
  return (sel) => {
    if (Array.isArray(sel)) {
      return [...sel];
    }
    const selection = Array(size).fill(0);
    for (const [key, value] of Object.entries(sel)) {
      selection[dims(key)] = value;
    }
    return selection;
  };
}
function getImageSize(source) {
  const interleaved = isInterleaved(source.shape);
  const [height, width] = source.shape.slice(interleaved ? -3 : -2);
  return { height, width };
}
function validLabels(labels, shape) {
  if (labels.length !== shape.length) {
    throw new Error("Labels do not match Zarr array shape.");
  }
  const n = shape.length;
  if (isInterleaved(shape)) {
    return labels[n - 3] === "y" && labels[n - 2] === "x" && labels[n - 1] === "_c";
  }
  return labels[n - 2] === "y" && labels[n - 1] === "x";
}

// dist/lib/zarr-pixel-source.js
var import_zarr2 = require("zarr");
var DTYPE_LOOKUP = {
  u1: "Uint8",
  u2: "Uint16",
  u4: "Uint32",
  f4: "Float32",
  f8: "Float64",
  i1: "Int8",
  i2: "Int16",
  i4: "Int32"
};
var ZarrPixelSource = class {
  labels;
  tileSize;
  _data;
  _indexer;
  _readChunks;
  constructor(data, labels, tileSize) {
    this._indexer = getIndexer(labels);
    this._data = data;
    const xChunkSize = data.chunks[this._xIndex];
    const yChunkSize = data.chunks[this._xIndex - 1];
    this._readChunks = tileSize === xChunkSize && tileSize === yChunkSize;
    this.labels = labels;
    this.tileSize = tileSize;
  }
  get shape() {
    return this._data.shape;
  }
  get dtype() {
    const suffix = this._data.dtype.slice(1);
    if (!(suffix in DTYPE_LOOKUP)) {
      throw Error(`Zarr dtype not supported, got ${suffix}.`);
    }
    return DTYPE_LOOKUP[suffix];
  }
  get _xIndex() {
    const interleave = isInterleaved(this._data.shape);
    return this._data.shape.length - (interleave ? 2 : 1);
  }
  _chunkIndex(selection, x, y) {
    const sel = this._indexer(selection);
    sel[this._xIndex] = x;
    sel[this._xIndex - 1] = y;
    return sel;
  }
  /**
   * Converts x, y tile indices to zarr dimension Slices within image bounds.
   */
  _getSlices(x, y) {
    const { height, width } = getImageSize(this);
    const [xStart, xStop] = [x * this.tileSize, Math.min((x + 1) * this.tileSize, width)];
    const [yStart, yStop] = [y * this.tileSize, Math.min((y + 1) * this.tileSize, height)];
    if (xStart === xStop || yStart === yStop) {
      throw new import_zarr2.BoundsCheckError("Tile slice is zero-sized.");
    }
    return [(0, import_zarr2.slice)(xStart, xStop), (0, import_zarr2.slice)(yStart, yStop)];
  }
  async getRaster({ selection }) {
    const sel = this._chunkIndex(selection, null, null);
    const { data, shape } = await this._data.getRaw(sel);
    const [height, width] = shape;
    return { data, width, height };
  }
  async getTile(props) {
    const { x, y, selection, signal } = props;
    let res;
    if (this._readChunks) {
      const sel = this._chunkIndex(selection, x, y);
      res = await this._data.getRawChunk(sel, { storeOptions: { signal } });
    } else {
      const [xSlice, ySlice] = this._getSlices(x, y);
      const sel = this._chunkIndex(selection, xSlice, ySlice);
      res = await this._data.getRaw(sel);
    }
    const { data, shape: [height, width] } = res;
    return { data, width, height };
  }
  onTileError(err) {
    if (!(err instanceof import_zarr2.BoundsCheckError)) {
      throw err;
    }
  }
};
var zarr_pixel_source_default = ZarrPixelSource;

// dist/lib/load-zarr.js
async function loadZarr(root, options = {}) {
  const store = normalizeStore(root);
  const { data, rootAttrs } = await loadMultiscales(store);
  const tileSize = guessTileSize(data[0]);
  const labels = options.labels ?? guessLabels(rootAttrs);
  if (!validLabels(labels, data[0].shape)) {
    throw new Error("Invalid labels for Zarr array dimensions.");
  }
  const pyramid = data.map((arr) => new zarr_pixel_source_default(arr, labels, tileSize));
  return {
    data: pyramid,
    metadata: rootAttrs
  };
}
//# sourceMappingURL=index.cjs.map