Added support for page-level filter pushdown (column and offset index…

…es) (#107)

examples/read_metadata.rs

@@ -1,6 +1,5 @@
 use parquet2::bloom_filter;
 use parquet2::error::Result;
-use parquet2::indexes;
 
 // ANCHOR: deserialize
 use parquet2::encoding::Encoding;
@@ -52,24 +51,21 @@ fn main() -> Result<()> {
     // ANCHOR: column_metadata
     let row_group = 0;
     let column = 0;
-    let column_metadata = metadata.row_groups[row_group].column(column);
+    let columns = metadata.row_groups[row_group].columns();
+    let column_metadata = &columns[column];
     // ANCHOR_END: column_metadata
 
     // ANCHOR: column_index
-    // read the column index
-    let index = indexes::read_column(&mut reader, column_metadata.column_chunk())?;
-    if let Some(index) = index {
-        // these are the minimum and maximum within each page, which can be used
-        // to skip pages.
-        println!("{index:?}");
-    }
-
-    // read the offset index containing page locations
-    let maybe_pages = indexes::read_page_locations(&mut reader, column_metadata.column_chunk())?;
-    if let Some(pages) = maybe_pages {
-        // there are page locations in the file
-        println!("{pages:?}");
-    }
+    // read the column indexes of every column
+    use parquet2::read;
+    let index = read::read_columns_indexes(&mut reader, columns)?;
+    // these are the minimum and maximum within each page, which can be used
+    // to skip pages.
+    println!("{index:?}");
+
+    // read the offset indexes containing page locations of every column
+    let pages = read::read_pages_locations(&mut reader, columns)?;
+    println!("{pages:?}");
     // ANCHOR_END: column_index
 
     // ANCHOR: statistics

src/bloom_filter/read.rs

@@ -16,10 +16,7 @@ pub fn read<R: Read + Seek>(
     mut reader: &mut R,
     bitset: &mut Vec<u8>,
 ) -> Result<(), ParquetError> {
-    let offset = column_metadata
-        .metadata()
-        .ok_or_else(|| ParquetError::OutOfSpec("Column metadata is required".to_string()))?
-        .bloom_filter_offset;
+    let offset = column_metadata.metadata().bloom_filter_offset;
 
     let offset = if let Some(offset) = offset {
         offset as u64

src/error.rs

@@ -76,6 +76,12 @@ impl From<std::num::TryFromIntError> for ParquetError {
     }
 }
 
+impl From<std::array::TryFromSliceError> for ParquetError {
+    fn from(e: std::array::TryFromSliceError) -> ParquetError {
+        ParquetError::OutOfSpec(format!("Can't deserialize to parquet native type: {}", e))
+    }
+}
+
 /// A specialized `Result` for Parquet errors.
 pub type Result<T> = std::result::Result<T, ParquetError>;
 

src/indexes/index.rs

@@ -0,0 +1,321 @@
+use std::any::Any;
+
+use parquet_format_async_temp::ColumnIndex;
+
+use crate::parquet_bridge::BoundaryOrder;
+use crate::schema::types::PrimitiveType;
+use crate::{error::ParquetError, schema::types::PhysicalType, types::NativeType};
+
+/// Trait object representing a [`ColumnIndex`] in Rust's native format.
+///
+/// See [`NativeIndex`], [`ByteIndex`] and [`FixedLenByteIndex`] for concrete implementations.
+pub trait Index: Send + Sync + std::fmt::Debug {
+    fn as_any(&self) -> &dyn Any;
+
+    fn physical_type(&self) -> &PhysicalType;
+}
+
+impl PartialEq for dyn Index + '_ {
+    fn eq(&self, that: &dyn Index) -> bool {
+        equal(self, that)
+    }
+}
+
+impl Eq for dyn Index + '_ {}
+
+fn equal(lhs: &dyn Index, rhs: &dyn Index) -> bool {
+    if lhs.physical_type() != rhs.physical_type() {
+        return false;
+    }
+
+    match lhs.physical_type() {
+        PhysicalType::Boolean => {
+            lhs.as_any().downcast_ref::<BooleanIndex>().unwrap()
+                == rhs.as_any().downcast_ref::<BooleanIndex>().unwrap()
+        }
+        PhysicalType::Int32 => {
+            lhs.as_any().downcast_ref::<NativeIndex<i32>>().unwrap()
+                == rhs.as_any().downcast_ref::<NativeIndex<i32>>().unwrap()
+        }
+        PhysicalType::Int64 => {
+            lhs.as_any().downcast_ref::<NativeIndex<i64>>().unwrap()
+                == rhs.as_any().downcast_ref::<NativeIndex<i64>>().unwrap()
+        }
+        PhysicalType::Int96 => {
+            lhs.as_any()
+                .downcast_ref::<NativeIndex<[u32; 3]>>()
+                .unwrap()
+                == rhs
+                    .as_any()
+                    .downcast_ref::<NativeIndex<[u32; 3]>>()
+                    .unwrap()
+        }
+        PhysicalType::Float => {
+            lhs.as_any().downcast_ref::<NativeIndex<f32>>().unwrap()
+                == rhs.as_any().downcast_ref::<NativeIndex<f32>>().unwrap()
+        }
+        PhysicalType::Double => {
+            lhs.as_any().downcast_ref::<NativeIndex<f64>>().unwrap()
+                == rhs.as_any().downcast_ref::<NativeIndex<f64>>().unwrap()
+        }
+        PhysicalType::ByteArray => {
+            lhs.as_any().downcast_ref::<ByteIndex>().unwrap()
+                == rhs.as_any().downcast_ref::<ByteIndex>().unwrap()
+        }
+        PhysicalType::FixedLenByteArray(_) => {
+            lhs.as_any().downcast_ref::<FixedLenByteIndex>().unwrap()
+                == rhs.as_any().downcast_ref::<FixedLenByteIndex>().unwrap()
+        }
+    }
+}
+
+/// An index of a column of [`NativeType`] physical representation
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct NativeIndex<T: NativeType> {
+    /// The primitive type
+    pub primitive_type: PrimitiveType,
+    /// The indexes, one item per page
+    pub indexes: Vec<PageIndex<T>>,
+    /// the order
+    pub boundary_order: BoundaryOrder,
+}
+
+impl<T: NativeType> NativeIndex<T> {
+    /// Creates a new [`NativeIndex`]
+    pub(crate) fn try_new(
+        index: ColumnIndex,
+        primitive_type: PrimitiveType,
+    ) -> Result<Self, ParquetError> {
+        let len = index.min_values.len();
+
+        let null_counts = index
+            .null_counts
+            .map(|x| x.into_iter().map(Some).collect::<Vec<_>>())
+            .unwrap_or_else(|| vec![None; len]);
+
+        let indexes = index
+            .min_values
+            .iter()
+            .zip(index.max_values.into_iter())
+            .zip(index.null_pages.into_iter())
+            .zip(null_counts.into_iter())
+            .map(|(((min, max), is_null), null_count)| {
+                let (min, max) = if is_null {
+                    (None, None)
+                } else {
+                    let min = min.as_slice().try_into()?;
+                    let max = max.as_slice().try_into()?;
+                    (Some(T::from_le_bytes(min)), Some(T::from_le_bytes(max)))
+                };
+                Ok(PageIndex {
+                    min,
+                    max,
+                    null_count,
+                })
+            })
+            .collect::<Result<Vec<_>, ParquetError>>()?;
+
+        Ok(Self {
+            primitive_type,
+            indexes,
+            boundary_order: index.boundary_order.try_into()?,
+        })
+    }
+}
+
+/// The index of a page, containing the min and max values of the page.
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct PageIndex<T> {
+    /// The minimum value in the page. It is None when all values are null
+    pub min: Option<T>,
+    /// The maximum value in the page. It is None when all values are null
+    pub max: Option<T>,
+    /// The number of null values in the page
+    pub null_count: Option<i64>,
+}
+
+impl<T: NativeType> Index for NativeIndex<T> {
+    fn as_any(&self) -> &dyn Any {
+        self
+    }
+
+    fn physical_type(&self) -> &PhysicalType {
+        &T::TYPE
+    }
+}
+
+/// An index of a column of bytes physical type
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct ByteIndex {
+    /// The [`PrimitiveType`].
+    pub primitive_type: PrimitiveType,
+    /// The indexes, one item per page
+    pub indexes: Vec<PageIndex<Vec<u8>>>,
+    pub boundary_order: BoundaryOrder,
+}
+
+impl ByteIndex {
+    pub(crate) fn try_new(
+        index: ColumnIndex,
+        primitive_type: PrimitiveType,
+    ) -> Result<Self, ParquetError> {
+        let len = index.min_values.len();
+
+        let null_counts = index
+            .null_counts
+            .map(|x| x.into_iter().map(Some).collect::<Vec<_>>())
+            .unwrap_or_else(|| vec![None; len]);
+
+        let indexes = index
+            .min_values
+            .into_iter()
+            .zip(index.max_values.into_iter())
+            .zip(index.null_pages.into_iter())
+            .zip(null_counts.into_iter())
+            .map(|(((min, max), is_null), null_count)| {
+                let (min, max) = if is_null {
+                    (None, None)
+                } else {
+                    (Some(min), Some(max))
+                };
+                Ok(PageIndex {
+                    min,
+                    max,
+                    null_count,
+                })
+            })
+            .collect::<Result<Vec<_>, ParquetError>>()?;
+
+        Ok(Self {
+            primitive_type,
+            indexes,
+            boundary_order: index.boundary_order.try_into()?,
+        })
+    }
+}
+
+impl Index for ByteIndex {
+    fn as_any(&self) -> &dyn Any {
+        self
+    }
+
+    fn physical_type(&self) -> &PhysicalType {
+        &PhysicalType::ByteArray
+    }
+}
+
+/// An index of a column of fixed len byte physical type
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct FixedLenByteIndex {
+    /// The [`PrimitiveType`].
+    pub primitive_type: PrimitiveType,
+    /// The indexes, one item per page
+    pub indexes: Vec<PageIndex<Vec<u8>>>,
+    pub boundary_order: BoundaryOrder,
+}
+
+impl FixedLenByteIndex {
+    pub(crate) fn try_new(
+        index: ColumnIndex,
+        primitive_type: PrimitiveType,
+    ) -> Result<Self, ParquetError> {
+        let len = index.min_values.len();
+
+        let null_counts = index
+            .null_counts
+            .map(|x| x.into_iter().map(Some).collect::<Vec<_>>())
+            .unwrap_or_else(|| vec![None; len]);
+
+        let indexes = index
+            .min_values
+            .into_iter()
+            .zip(index.max_values.into_iter())
+            .zip(index.null_pages.into_iter())
+            .zip(null_counts.into_iter())
+            .map(|(((min, max), is_null), null_count)| {
+                let (min, max) = if is_null {
+                    (None, None)
+                } else {
+                    (Some(min), Some(max))
+                };
+                Ok(PageIndex {
+                    min,
+                    max,
+                    null_count,
+                })
+            })
+            .collect::<Result<Vec<_>, ParquetError>>()?;
+
+        Ok(Self {
+            primitive_type,
+            indexes,
+            boundary_order: index.boundary_order.try_into()?,
+        })
+    }
+}
+
+impl Index for FixedLenByteIndex {
+    fn as_any(&self) -> &dyn Any {
+        self
+    }
+
+    fn physical_type(&self) -> &PhysicalType {
+        &self.primitive_type.physical_type
+    }
+}
+
+/// An index of a column of boolean physical type
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct BooleanIndex {
+    /// The indexes, one item per page
+    pub indexes: Vec<PageIndex<bool>>,
+    pub boundary_order: BoundaryOrder,
+}
+
+impl BooleanIndex {
+    pub(crate) fn try_new(index: ColumnIndex) -> Result<Self, ParquetError> {
+        let len = index.min_values.len();
+
+        let null_counts = index
+            .null_counts
+            .map(|x| x.into_iter().map(Some).collect::<Vec<_>>())
+            .unwrap_or_else(|| vec![None; len]);
+
+        let indexes = index
+            .min_values
+            .into_iter()
+            .zip(index.max_values.into_iter())
+            .zip(index.null_pages.into_iter())
+            .zip(null_counts.into_iter())
+            .map(|(((min, max), is_null), null_count)| {
+                let (min, max) = if is_null {
+                    (None, None)
+                } else {
+                    let min = min[0] == 1;
+                    let max = max[0] == 1;
+                    (Some(min), Some(max))
+                };
+                Ok(PageIndex {
+                    min,
+                    max,
+                    null_count,
+                })
+            })
+            .collect::<Result<Vec<_>, ParquetError>>()?;
+
+        Ok(Self {
+            indexes,
+            boundary_order: index.boundary_order.try_into()?,
+        })
+    }
+}
+
+impl Index for BooleanIndex {
+    fn as_any(&self) -> &dyn Any {
+        self
+    }
+
+    fn physical_type(&self) -> &PhysicalType {
+        &PhysicalType::Boolean
+    }
+}