Adding Debug/Display impl. Refining the ColumnIndex::get_cardinality

columnar/src/column/dictionary_encoded.rs

@@ -1,6 +1,6 @@
-use std::io;
 use std::ops::Deref;
 use std::sync::Arc;
+use std::{fmt, io};
 
 use sstable::{Dictionary, VoidSSTable};
 
@@ -21,6 +21,14 @@ pub struct BytesColumn {
     pub(crate) term_ord_column: Column<u64>,
 }
 
+impl fmt::Debug for BytesColumn {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("BytesColumn")
+            .field("term_ord_column", &self.term_ord_column)
+            .finish()
+    }
+}
+
 impl BytesColumn {
     /// Fills the given `output` buffer with the term associated to the ordinal `ord`.
     ///
@@ -56,6 +64,12 @@ impl BytesColumn {
 #[derive(Clone)]
 pub struct StrColumn(BytesColumn);
 
+impl fmt::Debug for StrColumn {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{:?}", self.term_ord_column)
+    }
+}
+
 impl From<StrColumn> for BytesColumn {
     fn from(str_column: StrColumn) -> BytesColumn {
         str_column.0

columnar/src/column/mod.rs

@@ -1,7 +1,7 @@
 mod dictionary_encoded;
 mod serialize;
 
-use std::fmt::Debug;
+use std::fmt::{self, Debug};
 use std::io::Write;
 use std::ops::{Deref, Range, RangeInclusive};
 use std::sync::Arc;
@@ -24,6 +24,16 @@ pub struct Column<T = u64> {
     pub values: Arc<dyn ColumnValues<T>>,
 }
 
+impl<T: Debug + PartialOrd + Send + Sync + Copy + 'static> Debug for Column<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let num_docs = self.num_docs();
+        let entries = (0..num_docs)
+            .map(|i| (i, self.values_for_doc(i).collect::<Vec<_>>()))
+            .filter(|(_, vals)| !vals.is_empty());
+        f.debug_map().entries(entries).finish()
+    }
+}
+
 impl<T: PartialOrd + Default> Column<T> {
     pub fn build_empty_column(num_docs: u32) -> Column<T> {
         Column {

columnar/src/column_index/mod.rs

@@ -12,7 +12,7 @@ pub use serialize::{open_column_index, serialize_column_index, SerializableColum
 use crate::column_index::multivalued_index::MultiValueIndex;
 use crate::{Cardinality, DocId, RowId};
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub enum ColumnIndex {
     Empty {
         num_docs: u32,
@@ -37,11 +37,15 @@ impl From<MultiValueIndex> for ColumnIndex {
 }
 
 impl ColumnIndex {
+    // Returns the cardinality of the column index.
+    //
+    // By convention, if the column contains no docs, we consider that it is
+    // full.
     #[inline]
     pub fn get_cardinality(&self) -> Cardinality {
         match self {
+            ColumnIndex::Empty { num_docs: 0 } | ColumnIndex::Full => Cardinality::Full,
             ColumnIndex::Empty { .. } => Cardinality::Optional,
-            ColumnIndex::Full => Cardinality::Full,
             ColumnIndex::Optional(_) => Cardinality::Optional,
             ColumnIndex::Multivalued(_) => Cardinality::Multivalued,
         }
@@ -152,3 +156,21 @@ impl ColumnIndex {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use crate::{Cardinality, ColumnIndex};
+
+    #[test]
+    fn test_column_index_get_cardinality() {
+        assert_eq!(
+            ColumnIndex::Empty { num_docs: 0 }.get_cardinality(),
+            Cardinality::Full
+        );
+        assert_eq!(ColumnIndex::Full.get_cardinality(), Cardinality::Full);
+        assert_eq!(
+            ColumnIndex::Empty { num_docs: 1 }.get_cardinality(),
+            Cardinality::Optional
+        );
+    }
+}

columnar/src/column_index/multivalued_index.rs

@@ -35,6 +35,14 @@ pub struct MultiValueIndex {
     pub start_index_column: Arc<dyn crate::ColumnValues<RowId>>,
 }
 
+impl std::fmt::Debug for MultiValueIndex {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        f.debug_struct("MultiValuedIndex")
+            .field("num_rows", &self.start_index_column.num_vals())
+            .finish_non_exhaustive()
+    }
+}
+
 impl From<Arc<dyn ColumnValues<RowId>>> for MultiValueIndex {
     fn from(start_index_column: Arc<dyn ColumnValues<RowId>>) -> Self {
         MultiValueIndex { start_index_column }

columnar/src/column_index/optional_index/mod.rs

@@ -88,6 +88,15 @@ pub struct OptionalIndex {
     block_metas: Arc<[BlockMeta]>,
 }
 
+impl std::fmt::Debug for OptionalIndex {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("OptionalIndex")
+            .field("num_rows", &self.num_rows)
+            .field("num_non_null_rows", &self.num_non_null_rows)
+            .finish_non_exhaustive()
+    }
+}
+
 /// Splits a value address into lower and upper 16bits.
 /// The lower 16 bits are the value in the block
 /// The upper 16 bits are the block index

columnar/src/columnar/column_type.rs

@@ -1,3 +1,4 @@
+use std::fmt;
 use std::fmt::Debug;
 use std::net::Ipv6Addr;
 
@@ -21,6 +22,22 @@ pub enum ColumnType {
     DateTime = 7u8,
 }
 
+impl fmt::Display for ColumnType {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let short_str = match self {
+            ColumnType::I64 => "i64",
+            ColumnType::U64 => "u64",
+            ColumnType::F64 => "f64",
+            ColumnType::Bytes => "bytes",
+            ColumnType::Str => "str",
+            ColumnType::Bool => "bool",
+            ColumnType::IpAddr => "ip",
+            ColumnType::DateTime => "datetime",
+        };
+        write!(f, "{}", short_str)
+    }
+}
+
 // The order needs to match _exactly_ the order in the enum
 const COLUMN_TYPES: [ColumnType; 8] = [
     ColumnType::I64,

columnar/src/columnar/reader/mod.rs

@@ -1,4 +1,4 @@
-use std::{io, mem};
+use std::{fmt, io, mem};
 
 use common::file_slice::FileSlice;
 use common::BinarySerializable;
@@ -21,6 +21,32 @@ pub struct ColumnarReader {
     num_rows: RowId,
 }
 
+impl fmt::Debug for ColumnarReader {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let num_rows = self.num_rows();
+        let columns = self.list_columns().unwrap();
+        let num_cols = columns.len();
+        let mut debug_struct = f.debug_struct("Columnar");
+        debug_struct
+            .field("num_rows", &num_rows)
+            .field("num_cols", &num_cols);
+        for (col_name, dynamic_column_handle) in columns.into_iter().take(5) {
+            let col = dynamic_column_handle.open().unwrap();
+            if col.num_values() > 10 {
+                debug_struct.field(&col_name, &"..");
+            } else {
+                debug_struct.field(&col_name, &col);
+            }
+        }
+        if num_cols > 5 {
+            debug_struct.finish_non_exhaustive()?;
+        } else {
+            debug_struct.finish()?;
+        }
+        Ok(())
+    }
+}
+
 /// Functions by both the async/sync code listing columns.
 /// It takes a stream from the column sstable and return the list of
 /// `DynamicColumn` available in it.

columnar/src/dynamic_column.rs

@@ -1,6 +1,6 @@
-use std::io;
 use std::net::Ipv6Addr;
 use std::sync::Arc;
+use std::{fmt, io};
 
 use common::file_slice::FileSlice;
 use common::{ByteCount, DateTime, HasLen, OwnedBytes};
@@ -8,7 +8,7 @@ use common::{ByteCount, DateTime, HasLen, OwnedBytes};
 use crate::column::{BytesColumn, Column, StrColumn};
 use crate::column_values::{monotonic_map_column, StrictlyMonotonicFn};
 use crate::columnar::ColumnType;
-use crate::{Cardinality, NumericalType};
+use crate::{Cardinality, ColumnIndex, NumericalType};
 
 #[derive(Clone)]
 pub enum DynamicColumn {
@@ -22,19 +22,54 @@ pub enum DynamicColumn {
     Str(StrColumn),
 }
 
-impl DynamicColumn {
-    pub fn get_cardinality(&self) -> Cardinality {
+impl fmt::Debug for DynamicColumn {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "[{} {} |", self.get_cardinality(), self.column_type())?;
         match self {
-            DynamicColumn::Bool(c) => c.get_cardinality(),
-            DynamicColumn::I64(c) => c.get_cardinality(),
-            DynamicColumn::U64(c) => c.get_cardinality(),
-            DynamicColumn::F64(c) => c.get_cardinality(),
-            DynamicColumn::IpAddr(c) => c.get_cardinality(),
-            DynamicColumn::DateTime(c) => c.get_cardinality(),
-            DynamicColumn::Bytes(c) => c.ords().get_cardinality(),
-            DynamicColumn::Str(c) => c.ords().get_cardinality(),
+            DynamicColumn::Bool(col) => write!(f, " {:?}", col)?,
+            DynamicColumn::I64(col) => write!(f, " {:?}", col)?,
+            DynamicColumn::U64(col) => write!(f, " {:?}", col)?,
+            DynamicColumn::F64(col) => write!(f, "{:?}", col)?,
+            DynamicColumn::IpAddr(col) => write!(f, "{:?}", col)?,
+            DynamicColumn::DateTime(col) => write!(f, "{:?}", col)?,
+            DynamicColumn::Bytes(col) => write!(f, "{:?}", col)?,
+            DynamicColumn::Str(col) => write!(f, "{:?}", col)?,
+        }
+        write!(f, "]")
+    }
+}
+
+impl DynamicColumn {
+    pub fn column_index(&self) -> &ColumnIndex {
+        match self {
+            DynamicColumn::Bool(c) => &c.index,
+            DynamicColumn::I64(c) => &c.index,
+            DynamicColumn::U64(c) => &c.index,
+            DynamicColumn::F64(c) => &c.index,
+            DynamicColumn::IpAddr(c) => &c.index,
+            DynamicColumn::DateTime(c) => &c.index,
+            DynamicColumn::Bytes(c) => &c.ords().index,
+            DynamicColumn::Str(c) => &c.ords().index,
         }
     }
+
+    pub fn get_cardinality(&self) -> Cardinality {
+        self.column_index().get_cardinality()
+    }
+
+    pub fn num_values(&self) -> u32 {
+        match self {
+            DynamicColumn::Bool(c) => c.values.num_vals(),
+            DynamicColumn::I64(c) => c.values.num_vals(),
+            DynamicColumn::U64(c) => c.values.num_vals(),
+            DynamicColumn::F64(c) => c.values.num_vals(),
+            DynamicColumn::IpAddr(c) => c.values.num_vals(),
+            DynamicColumn::DateTime(c) => c.values.num_vals(),
+            DynamicColumn::Bytes(c) => c.ords().values.num_vals(),
+            DynamicColumn::Str(c) => c.ords().values.num_vals(),
+        }
+    }
+
     pub fn column_type(&self) -> ColumnType {
         match self {
             DynamicColumn::Bool(_) => ColumnType::Bool,

columnar/src/lib.rs

@@ -7,6 +7,7 @@ extern crate more_asserts;
 #[cfg(all(test, feature = "unstable"))]
 extern crate test;
 
+use std::fmt::Display;
 use std::io;
 
 mod block_accessor;
@@ -75,6 +76,17 @@ pub enum Cardinality {
     Multivalued = 2,
 }
 
+impl Display for Cardinality {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        let short_str = match self {
+            Cardinality::Full => "full",
+            Cardinality::Optional => "opt",
+            Cardinality::Multivalued => "mult",
+        };
+        write!(f, "{short_str}")
+    }
+}
+
 impl Cardinality {
     pub fn is_optional(&self) -> bool {
         matches!(self, Cardinality::Optional)
@@ -85,7 +97,6 @@ impl Cardinality {
     pub(crate) fn to_code(self) -> u8 {
         self as u8
     }
-
     pub(crate) fn try_from_code(code: u8) -> Result<Cardinality, InvalidData> {
         match code {
             0 => Ok(Cardinality::Full),