Fix for Data Quality perf and issue other tweaks.

distribution/lib/Standard/Database/0.0.0-dev/src/DB_Table.enso

@@ -403,7 +403,7 @@ type DB_Table
             result = self.updated_columns (new_columns.map _.as_internal)
             Warning.attach (Deprecated.Warning "Standard.Database.DB_Table.DB_Table" "remove_columns_by_type" "Deprecated: use `remove_columns` with a `By_Type` instead.") result
 
-    ## ALIAS select_blank_fields, select_missing_columns, select_na
+    ## ALIAS select_blank_fields, select_missing_columns, select_na, filter_blank_columns
        GROUP Standard.Base.Selections
        ICON select_column
 
@@ -2559,7 +2559,7 @@ type DB_Table
         _ = [columns, shrink_types, error_on_missing_columns, on_problems]
         Error.throw (Unsupported_Database_Operation.Error "auto_cast")
 
-    ## ALIAS drop_missing_rows, dropna
+    ## ALIAS drop_missing_rows, dropna, remove_blank_rows, remove_empty_rows, remove_missing_rows, filter_empty_rows, drop_empty_rows
        GROUP Standard.Base.Selections
        ICON preparation
        Remove rows which are all blank or containing blank values.

distribution/lib/Standard/Snowflake/0.0.0-dev/src/Snowflake_Connection.enso

@@ -327,4 +327,4 @@ type Snowflake_Connection
        Converts this value to a JSON serializable object.
     to_js_object : JS_Object
     to_js_object self =
-        JS_Object.from_pairs [["type", "Snowflake_Connection"], ["links", self.tables.at "Name" . to_vector]]
+        JS_Object.from_pairs [["type", "Snowflake_Connection"], ["links", self.tables.at "Name" . to_vector], ["get_child_node_action", "query"]]

distribution/lib/Standard/Table/0.0.0-dev/src/Column.enso

@@ -40,6 +40,7 @@ from project.Internal.Storage import enso_to_java, java_to_enso
 polyglot java import org.enso.base.Time_Utils
 polyglot java import org.enso.table.data.column.operation.cast.CastProblemAggregator
 polyglot java import org.enso.table.data.column.operation.CountNothing
+polyglot java import org.enso.table.data.column.operation.CountUntrimmed
 polyglot java import org.enso.table.data.column.operation.unary.DatePartOperation
 polyglot java import org.enso.table.data.column.operation.unary.IsEmptyOperation
 polyglot java import org.enso.table.data.column.operation.unary.IsFiniteOperation
@@ -2213,6 +2214,19 @@ type Column
     count_nothing : Integer
     count_nothing self = CountNothing.apply self.java_column
 
+    ## PRIVATE
+       Counts the number of text values with leading or trailing whitespace.
+       Used for data quality indicator in Table Viz.
+    count_untrimmed : Integer -> Integer | Nothing
+    count_untrimmed self sample_size:Integer=Column.default_sample_size =
+        if (self.value_type == Value_Type.Mixed || self.value_type.is_text).not then Nothing else
+            CountUntrimmed.apply self.java_column sample_size
+
+    ## PRIVATE
+       Default size for sampling data quality indicators.
+    default_sample_size -> Integer =
+        CountUntrimmed.DEFAULT_SAMPLE_SIZE
+
     ## GROUP Standard.Base.Metadata
        ICON metadata
        Returns the number of non-null items in this column.

distribution/lib/Standard/Table/0.0.0-dev/src/Table.enso

@@ -690,7 +690,7 @@ type Table
         result = Table.new new_columns
         Warning.attach (Deprecated.Warning "Standard.Table.Table.Table" "remove_columns_by_type" "Deprecated: use `remove_columns` with a `By_Type` instead.") result
 
-    ## ALIAS select_blank_fields, select_missing_columns, select_na
+    ## ALIAS drop_missing_rows, dropna, remove_blank_rows, remove_empty_rows, remove_missing_rows, filter_empty_rows, drop_empty_rows
        GROUP Standard.Base.Selections
        ICON select_column
 
@@ -730,7 +730,7 @@ type Table
         new_columns = self.columns_helper.select_blank_columns_helper when treat_nans_as_blank
         Table.new new_columns
 
-    ## ALIAS drop_missing_columns, drop_na, select_blank_columns, select_blank_fields, select_missing_columns, select_na
+    ## ALIAS drop_missing_columns, drop_na, select_blank_columns, select_blank_fields, select_missing_columns, select_na, filter_blank_columns
        GROUP Standard.Base.Selections
        ICON select_column
 

distribution/lib/Standard/Visualization/0.0.0-dev/src/Table/Visualization.enso

@@ -32,14 +32,13 @@ prepare_visualization y max_rows=1000 = if y.is_error then (make_json_for_error
         _ : Row -> make_json_for_dictionary x.to_dictionary max_rows "column"
         _ : Column -> prepare_visualization x.to_table max_rows
         _ : Table ->
-            dataframe = x.take max_rows
             all_rows_count = x.row_count
-            make_json_for_table dataframe all_rows_count True False
+            make_json_for_table x max_rows all_rows_count True False
         _ : DB_Column -> prepare_visualization x.to_table max_rows
         _ : DB_Table ->
             dataframe = x.read (..First max_rows)
             all_rows_count = x.row_count
-            make_json_for_table dataframe all_rows_count True True
+            make_json_for_table dataframe max_rows all_rows_count True True
         _ : Function ->
             pairs = [['_display_text_', '[Function '+x.to_text+']']]
             value = JS_Object.from_pairs pairs
@@ -59,14 +58,6 @@ prepare_visualization y max_rows=1000 = if y.is_error then (make_json_for_error
    Column Limit
 max_columns = 250
 
-## PRIVATE
-whitespace_count : Column -> Integer | Nothing
-whitespace_count col =
-    find_whitespace col = 
-        filtered = col.to_vector.filter (c-> c.is_a Text && c.is_empty.not && (c.first.is_whitespace || c.last.is_whitespace))
-        filtered.length
-    if (col.value_type == Value_Type.Mixed || col.value_type.is_text) then find_whitespace col else Nothing 
-
 ## PRIVATE
    Render Error to JSON
 make_json_for_error : Any -> JS_Object
@@ -187,22 +178,24 @@ make_json_for_xml_element xml_element max_items type:Text="XML_Element" =
      to display.
    - all_rows_count: the number of all rows in the underlying data, useful if
      only a fragment is displayed.
-make_json_for_table : Table -> Integer -> Boolean -> Boolean -> JS_Object
-make_json_for_table dataframe all_rows_count include_index_col is_db_table =
-    get_vector c = Warning.set (c.to_vector.map v-> make_json_for_value v) []
-    columns     = dataframe.columns
-    header      = ["header", columns.map .name]
-    value_type  = ["value_type", columns.map .value_type]
-    data        = ["data",   columns.map get_vector]
-    all_rows    = ["all_rows_count", all_rows_count]
-    has_index_col = ["has_index_col", include_index_col]
-    links       = ["get_child_node_action", "get_row"]
-    number_of_nothing = if is_db_table then Nothing else columns.map c-> c.count_nothing
-    number_of_whitespace= if is_db_table then Nothing else columns.map c-> whitespace_count c
-    nothing_p = JS_Object.from_pairs [["name", "Number of nothings"], ["percentage_value", number_of_nothing]]
-    whitespace_p = JS_Object.from_pairs [["name", "Number of untrimmed whitespace"], ["percentage_value",number_of_whitespace]]
-    data_quality_metrics =  [nothing_p, whitespace_p]
-    pairs       = [header, value_type, data, all_rows, has_index_col, links, ["data_quality_metrics", data_quality_metrics] ,["type", "Table"]]
+make_json_for_table : Table -> Integer -> Integer -> Boolean -> Boolean -> JS_Object
+make_json_for_table dataframe max_rows all_rows_count include_index_col is_db_table =
+    act_max = if max_rows < all_rows_count then max_rows else all_rows_count
+    get_vector c         = Warning.set (Vector.new act_max i-> make_json_for_value (c.get i)) []
+    columns              = dataframe.columns
+    header               = ["header", columns.map .name]
+    value_type           = ["value_type", columns.map .value_type]
+    data                 = ["data",   columns.map get_vector]
+    all_rows             = ["all_rows_count", all_rows_count]
+    has_index_col        = ["has_index_col", include_index_col]
+    links                = ["get_child_node_action", "get_row"]
+    data_quality_metrics = if is_db_table then [] else
+        number_nothing = JS_Object.from_pairs [["name", "Count nothings"], ["percentage_value", columns.map .count_nothing]]
+        number_untrimmed = case all_rows_count > Column.default_sample_size of
+            False -> JS_Object.from_pairs [["name", "Count untrimmed whitespace"], ["percentage_value", columns.map .count_untrimmed]]
+            True -> JS_Object.from_pairs [["name", "Count untrimmed whitespace (sampled)"], ["percentage_value", columns.map .count_untrimmed]]
+        [number_nothing, number_untrimmed]
+    pairs                = [header, value_type, data, all_rows, has_index_col, links, ["data_quality_metrics", data_quality_metrics] ,["type", "Table"]]
     JS_Object.from_pairs pairs
 
 ## PRIVATE

std-bits/base/src/main/java/org/enso/base/Text_Utils.java

@@ -35,6 +35,30 @@ public static String substring(String string, int from, int to) {
     return string.substring(from, to);
   }
 
+  /**
+   * Checks if the string has leading or trailing whitespace.
+   *
+   * @param s the string to check
+   * @return whether the string has leading or trailing whitespace
+   */
+  public static boolean has_leading_trailing_whitespace(String s) {
+    if (s == null || s.isEmpty()) {
+      return false;
+    }
+
+    var leading = Text_Utils.take_prefix(s, 1);
+    if (leading != null && is_all_whitespace(leading)) {
+      return true;
+    }
+
+    var trailing = Text_Utils.take_suffix(s, 1);
+    if (trailing != null && is_all_whitespace(trailing)) {
+      return true;
+    }
+
+    return false;
+  }
+
   /**
    * Returns a new string containing characters starting at the given UTF-16 index.
    *

std-bits/table/src/main/java/org/enso/table/data/column/operation/CountUntrimmed.java

@@ -0,0 +1,66 @@
+package org.enso.table.data.column.operation;
+
+import java.util.Random;
+import org.enso.base.Text_Utils;
+import org.enso.table.data.column.storage.ColumnStorage;
+import org.enso.table.data.column.storage.StringStorage;
+import org.enso.table.data.table.Column;
+import org.graalvm.polyglot.Context;
+
+public class CountUntrimmed {
+  // Default seed for random number generation (no specific reason for this value, just stability on
+  // result).
+  private static final long RANDOM_SEED = 677280131;
+
+  // Default sample size for counting untrimmed cells.
+  public static final long DEFAULT_SAMPLE_SIZE = 10000;
+
+  /** Counts the number of cells in the columns with leading or trailing whitespace. */
+  public static Long apply(Column column, long sampleSize) throws InterruptedException {
+    ColumnStorage storage = column.getStorage();
+    return applyToStorage(storage, sampleSize);
+  }
+
+  /** Counts the number of cells in the given storage with leading or trailing whitespace. */
+  public static Long applyToStorage(ColumnStorage storage, long sampleSize)
+      throws InterruptedException {
+    return (sampleSize == DEFAULT_SAMPLE_SIZE && storage instanceof StringStorage stringStorage)
+        ? stringStorage.cachedUntrimmedCount()
+        : (Long) compute(storage, sampleSize, Context.getCurrent());
+  }
+
+  /** Internal method performing the calculation on a storage. */
+  public static long compute(ColumnStorage storage, long sampleSize, Context context) {
+    long size = storage.getSize();
+
+    long count = 0;
+    if (sampleSize < size) {
+      var rng = new Random(RANDOM_SEED);
+      for (int i = 0; i < sampleSize; i++) {
+        long idx = rng.nextInt(Math.toIntExact(size));
+        var val = storage.getItemAsObject(idx);
+        if (val instanceof String str && Text_Utils.has_leading_trailing_whitespace(str)) {
+          count++;
+        }
+
+        if (context != null) {
+          context.safepoint();
+        }
+      }
+      count = Math.min(size, (long) Math.ceil((double) count / sampleSize * size));
+    } else {
+      for (long i = 0; i < storage.getSize(); i++) {
+        var val = storage.getItemAsObject(i);
+        if (val instanceof String str && Text_Utils.has_leading_trailing_whitespace(str)) {
+          count++;
+        }
+
+        if (context != null) {
+          context.safepoint();
+        }
+      }
+    }
+
+    return count;
+  }
+}

std-bits/table/src/main/java/org/enso/table/data/column/storage/StringStorage.java

@@ -1,8 +1,12 @@
 package org.enso.table.data.column.storage;
 
 import java.util.BitSet;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Future;
 import org.enso.base.CompareException;
 import org.enso.base.Text_Utils;
+import org.enso.table.data.column.operation.CountUntrimmed;
 import org.enso.table.data.column.operation.map.BinaryMapOperation;
 import org.enso.table.data.column.operation.map.MapOperationProblemAggregator;
 import org.enso.table.data.column.operation.map.MapOperationStorage;
@@ -15,11 +19,14 @@
 import org.enso.table.data.column.storage.type.StorageType;
 import org.enso.table.data.column.storage.type.TextType;
 import org.graalvm.polyglot.Context;
+import org.slf4j.Logger;
 
 /** A column storing strings. */
 public final class StringStorage extends SpecializedStorage<String> {
+  private static final Logger LOGGER = org.slf4j.LoggerFactory.getLogger(StringStorage.class);
 
   private final TextType type;
+  private Future<Long> untrimmedCount;
 
   /**
    * @param data the underlying data
@@ -29,6 +36,10 @@ public final class StringStorage extends SpecializedStorage<String> {
   public StringStorage(String[] data, int size, TextType type) {
     super(data, size, buildOps());
     this.type = type;
+
+    untrimmedCount =
+        CompletableFuture.supplyAsync(
+            () -> CountUntrimmed.compute(this, CountUntrimmed.DEFAULT_SAMPLE_SIZE, null));
   }
 
   @Override
@@ -46,6 +57,29 @@ public TextType getType() {
     return type;
   }
 
+  /**
+   * Counts the number of cells in the columns with whitespace. If the calculation fails then it
+   * returns null.
+   *
+   * @return the number of cells with whitespace
+   */
+  public Long cachedUntrimmedCount() throws InterruptedException {
+    if (untrimmedCount.isCancelled()) {
+      // Need to recompute the value, as was cancelled.
+      untrimmedCount =
+          CompletableFuture.completedFuture(
+              CountUntrimmed.compute(
+                  this, CountUntrimmed.DEFAULT_SAMPLE_SIZE, Context.getCurrent()));
+    }
+
+    try {
+      return untrimmedCount.get();
+    } catch (ExecutionException e) {
+      LOGGER.error("Failed to compute untrimmed count", e);
+      return null;
+    }
+  }
+
   private static MapOperationStorage<String, SpecializedStorage<String>> buildOps() {
     MapOperationStorage<String, SpecializedStorage<String>> t = ObjectStorage.buildObjectOps();
     t.add(

std-bits/table/src/main/java/org/enso/table/data/column/storage/numeric/DoubleStorage.java

@@ -303,8 +303,18 @@ private static MapOperationStorage<Double, DoubleStorage> buildOps() {
   @Override
   public Storage<Double> slice(int offset, int limit) {
     int newSize = Math.min(size - offset, limit);
-    long[] newData = new long[newSize];
-    System.arraycopy(data, offset, newData, 0, newSize);
+    long[] newData;
+
+    // Special case if slice is after the actual data
+    if (offset >= data.length) {
+      newData = new long[0];
+    } else {
+      // Can only copy as much as there is data
+      int newDataSize = Math.min(data.length - offset, newSize);
+      newData = new long[newDataSize];
+      System.arraycopy(data, offset, newData, 0, newDataSize);
+    }
+
     BitSet newMask = isNothing.get(offset, offset + limit);
     return new DoubleStorage(newData, newSize, newMask);
   }

std-bits/table/src/main/java/org/enso/table/data/column/storage/numeric/LongStorage.java

@@ -210,8 +210,18 @@ public long[] getRawData() {
   @Override
   public LongStorage slice(int offset, int limit) {
     int newSize = Math.min(size - offset, limit);
-    long[] newData = new long[newSize];
-    System.arraycopy(data, offset, newData, 0, newSize);
+    long[] newData;
+
+    // Special case if slice is after the actual data
+    if (offset >= data.length) {
+      newData = new long[0];
+    } else {
+      // Can only copy as much as there is data
+      int newDataSize = Math.min(data.length - offset, newSize);
+      newData = new long[newDataSize];
+      System.arraycopy(data, offset, newData, 0, newDataSize);
+    }
+
     BitSet newMask = isNothing.get(offset, offset + limit);
     return new LongStorage(newData, newSize, newMask, type);
   }