Fix structured data metadata only trim

mdio/utils/trim.h

@@ -67,34 +67,18 @@ Future<void> TrimDataset(std::string dataset_path,
     MDIO_ASSIGN_OR_RETURN(auto var, ds.variables.at(varIdentifier))
     var.set_metadata_publish_flag(true);
 
-    if (var.dimensions().labels().back() == "") {
-      auto spec = var.spec();
-      if (!spec.status().ok()) {
-        // Something went wrong with Tensorstore retrieving the spec
-        return spec.status();
-      }
-      auto specJsonResult = spec.value().ToJson(IncludeDefaults{});
-      if (!specJsonResult.status().ok()) {
-        return specJsonResult.status();
-      }
-      // This will fall over if the first dtype is itself structured data
-      nlohmann::json specJson =
-          specJsonResult.value()["metadata"]["dtype"][0][0];
-      std::string field = specJson.get<std::string>();
-      // If the variable is structured data we will pick the first dimension
-      // arbitrarially
-      auto selection = ds.SelectField(varIdentifier, field);
-      if (!selection.status().ok()) {
-        return selection.status();
-      }
-      MDIO_ASSIGN_OR_RETURN(var, ds.variables.at(varIdentifier))
-    }
+    bool wasStruct = var.dimensions().labels().back() == "";
 
     auto varStore = var.get_store();
     std::vector<tensorstore::Index> implicitDims;
     std::vector<tensorstore::Index> newShape;
 
-    for (size_t i = 0; i < var.dimensions().shape().size(); i++) {
+    auto dims = var.dimensions().shape().size();
+    if (wasStruct) {
+      --dims;
+    }
+
+    for (size_t i = 0; i < dims; i++) {
       implicitDims.push_back(tensorstore::kImplicit);
       if (shapeDescriptors.count(var.dimensions().labels()[i]) > 0) {
         newShape.push_back(shapeDescriptors[var.dimensions().labels()[i]]);
@@ -103,9 +87,16 @@ Future<void> TrimDataset(std::string dataset_path,
       }
     }
 
+    if (wasStruct) {
+      implicitDims.push_back(tensorstore::kImplicit);
+      newShape.push_back(tensorstore::kImplicit);
+    }
+
     tensorstore::ResizeOptions resizeOptions;
     if (delete_sliced_out_chunks) {
       resizeOptions.mode = tensorstore::ResizeMode::resize_tied_bounds;
+    } else if (wasStruct) {
+      resizeOptions.mode = tensorstore::ResizeMode::resize_metadata_only;
     } else {
       resizeOptions.mode = tensorstore::ResizeMode::resize_metadata_only;
     }

mdio/utils/trim_test.cc

@@ -234,6 +234,55 @@ TEST(TrimDataset, oneSliceData) {
   }
 }
 
+TEST(TrimDataset, oneSliceDataNoDelete) {
+  // Set up the dataset
+  ASSERT_TRUE(SETUP(kTestPath).status().ok());
+  auto dsRes = mdio::Dataset::Open(kTestPath, mdio::constants::kOpen);
+  ASSERT_TRUE(dsRes.status().ok()) << dsRes.status();
+  auto ds = dsRes.value();
+
+  // Write some data to the inline variable
+  auto inlineVarRes = ds.variables.get<mdio::dtypes::uint32_t>("inline");
+  ASSERT_TRUE(inlineVarRes.status().ok()) << inlineVarRes.status();
+  auto inlineVar = inlineVarRes.value();
+
+  auto inlineVarFuture = inlineVar.Read();
+  ASSERT_TRUE(inlineVarFuture.status().ok()) << inlineVarFuture.status();
+  auto inlineVarData = inlineVarFuture.value();
+
+  auto inlineDataAccessor = inlineVarData.get_data_accessor();
+
+  for (int i = 0; i < 256; ++i) {
+    inlineDataAccessor({i}) = i + 256;
+  }
+
+  auto writeFuture = inlineVar.Write(inlineVarData);
+  ASSERT_TRUE(writeFuture.status().ok()) << writeFuture.status();
+
+  // Trim outside of a chunk boundry
+  mdio::RangeDescriptor<mdio::Index> slice = {"inline", 0, 128, 1};
+  auto res = mdio::utils::TrimDataset(kTestPath, false, slice);
+  ASSERT_TRUE(res.status().ok()) << res.status();
+
+  auto newDsRes = mdio::Dataset::Open(kTestPath, mdio::constants::kOpen);
+  ASSERT_TRUE(newDsRes.status().ok()) << newDsRes.status();
+  auto newDs = newDsRes.value();
+
+  std::string name = "inline";
+  auto varRes = newDs.get_variable(name);
+  ASSERT_TRUE(varRes.status().ok()) << varRes.status();
+  auto var = varRes.value();
+  auto varFuture = var.Read();
+  ASSERT_TRUE(varFuture.status().ok()) << varFuture.status();
+  auto varData = varFuture.value();
+
+  auto varDataAccessor = reinterpret_cast<mdio::dtypes::uint32_t*>(
+      varData.get_data_accessor().data());
+  for (int i = 0; i < 128; ++i) {
+    EXPECT_EQ(varDataAccessor[i], i + 256) << "i: " << i;
+  }
+}
+
 TEST(TrimDataset, metadataConsistency) {
   ASSERT_TRUE(SETUP(kTestPath).status().ok());
   nlohmann::json imageData;