Merge pull request #1103 from silx-kit/h5wasm-slice

Implement slicing for h5wasm provider
silx-kit · May 9, 2022 · bd6ca61 · bd6ca61
2 parents 368c4e8 + 9243ee4
commit bd6ca61
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Showing 2 changed files with 23 additions and 1 deletion.
diff --git a/packages/h5wasm/src/h5wasm-api.ts b/packages/h5wasm/src/h5wasm-api.ts
@@ -22,6 +22,7 @@ import {
   isH5WasmDataset,
   isH5WasmGroup,
   isHDF5,
+  convertSelectionToRanges,
 } from './utils';
 
 export class H5WasmApi extends ProviderApi {
@@ -43,11 +44,16 @@ export class H5WasmApi extends ProviderApi {
   }
 
   public async getValue(params: ValuesStoreParams): Promise<unknown> {
-    const { dataset } = params;
+    const { dataset, selection } = params;
 
     const h5wDataset = await this.getH5WasmEntity(dataset.path);
     assertH5WasmDataset(h5wDataset);
 
+    if (selection) {
+      const ranges = convertSelectionToRanges(h5wDataset, selection);
+      return h5wDataset.slice(ranges);
+    }
+
     return h5wDataset.value;
   }
 

diff --git a/packages/h5wasm/src/utils.ts b/packages/h5wasm/src/utils.ts
@@ -70,3 +70,19 @@ export function convertMetadataToDType(metadata: Metadata): DType {
       };
   }
 }
+
+export function convertSelectionToRanges(
+  dataset: H5WasmDataset,
+  selection: string
+): number[][] {
+  const { shape } = dataset;
+  const selectionMembers = selection.split(',');
+
+  return selectionMembers.map((member, i) => {
+    if (member === ':') {
+      return [0, shape[i]];
+    }
+
+    return [Number(member), Number(member) + 1];
+  });
+}