feat(file_index): add basic bitmap index

crates/paimon/Cargo.toml

@@ -40,6 +40,8 @@ bytes = "1.7.1"
 bitflags = "2.6.0"
 tokio = { version = "1.39.2", features = ["macros"] }
 chrono = { version = "0.4.38", features = ["serde"] }
+roaring = "0.10.6"
+indexmap = { version = "2.5.0", features = ["serde"] }
 serde = { version = "1", features = ["derive"] }
 serde_bytes = "0.11.15"
 serde_json = "1.0.120"

crates/paimon/src/error.rs

@@ -65,6 +65,20 @@ pub enum Error {
         display("Paimon hitting invalid file index format: {}", message)
     )]
     FileIndexFormatInvalid { message: String },
+    #[snafu(visibility(pub(crate)), display("Serialization error: {}", source))]
+    SerializationError { source: serde_json::Error },
+    #[snafu(visibility(pub(crate)), display("Deserialization error: {}", source))]
+    DeserializationError { source: serde_json::Error },
+    #[snafu(
+        visibility(pub(crate)),
+        display("Roaring bitmap serialization error: {}", source)
+    )]
+    BitmapSerializationError { source: std::io::Error },
+    #[snafu(
+        visibility(pub(crate)),
+        display("Bitmap deserialization error: {}", source)
+    )]
+    BitmapDeserializationError { source: std::io::Error },
 }
 
 impl From<opendal::Error> for Error {

crates/paimon/src/file_index/bitmap_index.rs

@@ -0,0 +1,347 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+use std::hash::Hash;
+use std::sync::Arc;
+
+use crate::error::{BitmapSerializationSnafu, DeserializationSnafu, SerializationSnafu};
+use crate::io::{FileRead, InputFile};
+
+use bytes::{Buf, BufMut, Bytes, BytesMut};
+use indexmap::IndexMap;
+use roaring::RoaringTreemap;
+use serde::de::DeserializeOwned;
+use serde::{Deserialize, Serialize};
+use snafu::ResultExt;
+
+const BITMAP_VERSION_1: u8 = 1;
+
+#[derive(Serialize, Deserialize)]
+struct BitmapFileIndexMeta<K>
+where
+    K: Serialize + DeserializeOwned + Clone + Eq + Hash,
+{
+    row_count: u64,
+    non_null_bitmap_number: u64,
+    has_null_value: bool,
+    null_value_offset: Option<i64>,
+    #[serde(with = "indexmap::map::serde_seq")]
+    bitmap_offsets: IndexMap<K, i64>,
+}
+
+pub struct BitmapFileIndexWriter<K>
+where
+    K: Serialize + DeserializeOwned + Clone + Eq + Hash,
+{
+    id2bitmap: IndexMap<K, RoaringTreemap>,
+    null_bitmap: RoaringTreemap,
+    row_number: u64,
+}
+
+impl<K> Default for BitmapFileIndexWriter<K>
+where
+    K: Serialize + DeserializeOwned + Clone + Eq + Hash,
+{
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl<K> BitmapFileIndexWriter<K>
+where
+    K: Serialize + DeserializeOwned + Clone + Eq + Hash,
+{
+    pub fn new() -> Self {
+        Self {
+            id2bitmap: IndexMap::new(),
+            null_bitmap: RoaringTreemap::new(),
+            row_number: 0,
+        }
+    }
+
+    pub fn write(&mut self, key: Option<K>) {
+        if let Some(key) = key {
+            self.id2bitmap
+                .entry(key)
+                .or_default()
+                .insert(self.row_number);
+        } else {
+            self.null_bitmap.insert(self.row_number);
+        }
+        self.row_number += 1;
+    }
+
+    pub fn serialized_bytes(&self) -> crate::Result<Bytes> {
+        // 1. Serialize the null_bitmap
+        let mut null_bitmap_bytes = Vec::new();
+        self.null_bitmap
+            .serialize_into(&mut null_bitmap_bytes)
+            .context(BitmapSerializationSnafu)?;
+        let null_bitmap_size = null_bitmap_bytes.len();
+
+        // 2. Serialize each bitmap and calculate total size
+        let mut bitmap_offsets = IndexMap::new();
+        let mut serialized_bitmaps = Vec::new();
+        let mut total_bitmap_size = 0;
+
+        for (key, bitmap) in &self.id2bitmap {
+            if bitmap.len() == 1 {
+                // Single value bitmap, offset is negative
+                let value = -1_i64 - (bitmap.iter().next().unwrap() as i64);
+                bitmap_offsets.insert(key.clone(), value);
+            } else {
+                let mut bitmap_bytes = Vec::new();
+                bitmap
+                    .serialize_into(&mut bitmap_bytes)
+                    .context(BitmapSerializationSnafu)?;
+                let bitmap_size = bitmap_bytes.len();
+                serialized_bitmaps.push((bitmap_bytes, bitmap_size));
+                bitmap_offsets.insert(key.clone(), total_bitmap_size as i64);
+                total_bitmap_size += bitmap_size;
+            }
+        }
+
+        // 3. Handle null bitmap offset
+        let null_value_offset = if !self.null_bitmap.is_empty() {
+            Some(if self.null_bitmap.len() == 1 {
+                -1_i64 - (self.null_bitmap.iter().next().unwrap() as i64)
+            } else {
+                0_i64
+            })
+        } else {
+            None
+        };
+
+        // 4. Create metadata and serialize it
+        let meta = BitmapFileIndexMeta {
+            row_count: self.row_number,
+            non_null_bitmap_number: self.id2bitmap.len() as u64,
+            has_null_value: !self.null_bitmap.is_empty(),
+            null_value_offset,
+            bitmap_offsets,
+        };
+
+        let meta_bytes = serde_json::to_vec(&meta).context(SerializationSnafu)?;
+        let meta_size = meta_bytes.len();
+
+        // 5. Calculate total size
+        let version_size = 1; // BITMAP_VERSION_1 is a single byte
+        let meta_size_size = 8; // u64
+        let total_size = version_size
+            + meta_size_size
+            + meta_size
+            + if self.null_bitmap.len() > 1 {
+                null_bitmap_size
+            } else {
+                0
+            }
+            + total_bitmap_size;
+
+        // 6. Allocate buffer with total_size
+        let mut output = BytesMut::with_capacity(total_size);
+
+        // 7. Write data into buffer
+        // Write version
+        output.put_u8(BITMAP_VERSION_1);
+
+        // Write meta_size as u64 (little-endian)
+        output.put_u64_le(meta_size as u64);
+
+        // Write metadata
+        output.put_slice(&meta_bytes);
+
+        // Write null_bitmap if necessary
+        if self.null_bitmap.len() > 1 {
+            output.put_slice(&null_bitmap_bytes);
+        }
+
+        // Write all bitmaps
+        for (bitmap_bytes, _size) in serialized_bitmaps {
+            output.put_slice(&bitmap_bytes);
+        }
+
+        Ok(output.freeze())
+    }
+}
+
+pub struct BitmapFileIndexReader<K>
+where
+    K: Serialize + DeserializeOwned + Clone + Eq + Hash,
+{
+    input_file: Arc<InputFile>,
+    meta: BitmapFileIndexMeta<K>,
+    bitmaps: IndexMap<K, RoaringTreemap>,
+    null_bitmap: Option<RoaringTreemap>,
+    body_offset: u64,
+}
+
+impl<K> BitmapFileIndexReader<K>
+where
+    K: Serialize + DeserializeOwned + Clone + Eq + Hash,
+{
+    pub async fn new(input_file: Arc<InputFile>) -> crate::Result<Self> {
+        let input = input_file.read().await?;
+        let mut buf = input.clone();
+
+        if buf.remaining() < 1 {
+            return Err(crate::Error::FileIndexFormatInvalid {
+                message: "File too small to contain version byte".to_string(),
+            });
+        }
+        let version = buf.get_u8();
+        if version != BITMAP_VERSION_1 {
+            return Err(crate::Error::FileIndexFormatInvalid {
+                message: format!("Unsupported version: {}", version),
+            });
+        }
+
+        if buf.remaining() < 8 {
+            return Err(crate::Error::FileIndexFormatInvalid {
+                message: "File too small to contain meta_size".to_string(),
+            });
+        }
+        let meta_size = buf.get_u64_le() as usize;
+
+        if buf.remaining() < meta_size {
+            return Err(crate::Error::FileIndexFormatInvalid {
+                message: "File too small to contain metadata".to_string(),
+            });
+        }
+        let meta_bytes = buf.copy_to_bytes(meta_size);
+
+        let meta: BitmapFileIndexMeta<K> =
+            serde_json::from_slice(&meta_bytes).context(DeserializationSnafu)?;
+
+        let body_offset = input.len() - buf.remaining();
+
+        Ok(Self {
+            input_file,
+            meta,
+            bitmaps: IndexMap::new(),
+            null_bitmap: None,
+            body_offset: body_offset as u64,
+        })
+    }
+
+    pub async fn get_bitmap(&mut self, key: Option<&K>) -> crate::Result<RoaringTreemap> {
+        if let Some(key) = key {
+            if let Some(bitmap) = self.bitmaps.get(key) {
+                return Ok(bitmap.clone());
+            }
+            if let Some(&offset) = self.meta.bitmap_offsets.get(key) {
+                let bitmap = self.load_bitmap(offset).await?;
+                self.bitmaps.insert(key.clone(), bitmap.clone());
+                Ok(bitmap)
+            } else {
+                Ok(RoaringTreemap::new())
+            }
+        } else {
+            if let Some(bitmap) = &self.null_bitmap {
+                return Ok(bitmap.clone());
+            }
+            if let Some(offset) = self.meta.null_value_offset {
+                let bitmap = self.load_bitmap(offset).await?;
+                self.null_bitmap = Some(bitmap.clone());
+                Ok(bitmap)
+            } else {
+                Ok(RoaringTreemap::new())
+            }
+        }
+    }
+
+    async fn load_bitmap(&self, offset: i64) -> crate::Result<RoaringTreemap> {
+        if offset < 0 {
+            let index = (-1 - offset) as u64;
+            let mut bitmap = RoaringTreemap::new();
+            bitmap.insert(index);
+            Ok(bitmap)
+        } else {
+            let bitmap_pos = self.body_offset as i64 + offset;
+            let file_meta = self.input_file.metadata().await?;
+            if bitmap_pos < 0 {
+                return Err(crate::Error::FileIndexFormatInvalid {
+                    message: format!("Invalid bitmap offset: {}", bitmap_pos),
+                });
+            }
+
+            if bitmap_pos as u64 > file_meta.size {
+                return Err(crate::Error::FileIndexFormatInvalid {
+                    message: format!(
+                        "Bitmap offset {} exceeds file size {}",
+                        bitmap_pos, file_meta.size
+                    ),
+                });
+            }
+
+            let reader = self.input_file.reader().await?;
+            let range = bitmap_pos as u64..file_meta.size;
+            let buf = reader.read(range).await?;
+            let bitmap = RoaringTreemap::deserialize_from(&mut &buf[..])
+                .map_err(|e| crate::Error::BitmapDeserializationError { source: e })?;
+
+            Ok(bitmap)
+        }
+    }
+}
+
+#[cfg(test)]
+mod basic_bitmap_index_test {
+    use super::*;
+    use crate::io::FileIO;
+    use std::sync::Arc;
+
+    #[tokio::test]
+    async fn test_basic_bitmap_index_read_write() -> crate::Result<()> {
+        let path = "memory:/tmp/test_basic_bitmap_index";
+        let file_io = FileIO::from_url(path)?.build()?;
+
+        let mut writer = BitmapFileIndexWriter::<String>::new();
+
+        writer.write(Some("key1".to_string()));
+        writer.write(None);
+        writer.write(Some("key2".to_string()));
+        writer.write(Some("key1".to_string()));
+
+        let bytes = writer.serialized_bytes()?;
+
+        let output = file_io.new_output(path)?;
+        let mut file_writer = output.writer().await?;
+        file_writer.write(bytes).await?;
+        file_writer.close().await?;
+
+        let input_file = output.to_input_file();
+
+        let mut reader = BitmapFileIndexReader::<String>::new(Arc::new(input_file)).await?;
+
+        let bitmap_key1 = reader.get_bitmap(Some(&"key1".to_string())).await?;
+        assert_eq!(bitmap_key1.len(), 2);
+        assert!(bitmap_key1.contains(0));
+        assert!(bitmap_key1.contains(3));
+
+        let bitmap_key2 = reader.get_bitmap(Some(&"key2".to_string())).await?;
+        assert_eq!(bitmap_key2.len(), 1);
+        assert!(bitmap_key2.contains(2));
+
+        let bitmap_none = reader.get_bitmap(None).await?;
+        assert_eq!(bitmap_none.len(), 1);
+        assert!(bitmap_none.contains(1));
+
+        file_io.delete_file(path).await?;
+
+        Ok(())
+    }
+}

crates/paimon/src/file_index/mod.rs

@@ -17,3 +17,6 @@
 
 mod file_index_format;
 pub use file_index_format::*;
+
+mod bitmap_index;
+pub use bitmap_index::*;