feat: support fastlanes bitpacking

protos/encodings.proto

@@ -190,6 +190,18 @@ message Bitpacked {
   bool signed = 4;
 }
 
+// Items are bitpacked in a buffer
+message BitpackedForNonNeg {
+  // the number of bits used for a value in the buffer
+  uint64 compressed_bits_per_value = 1;
+
+  // the number of bits of the uncompressed value. e.g. for a u32, this will be 32
+  uint64 uncompressed_bits_per_value = 2;
+
+  // The items in the list
+  Buffer buffer = 3;
+}
+
 // An array encoding for shredded structs that will never be null
 //
 // There is no actual data in this column.
@@ -240,6 +252,7 @@ message ArrayEncoding {
         PackedStruct packed_struct = 9;
         Bitpacked bitpacked = 10;
         FixedSizeBinary fixed_size_binary = 11;
+        BitpackedForNonNeg bitpacked_for_non_neg = 12;
     }
 }
 

rust/lance-encoding/Cargo.toml

@@ -37,6 +37,10 @@ snafu.workspace = true
 tokio.workspace = true
 tracing.workspace = true
 zstd.workspace = true
+bytemuck = "=1.18.0"
+arrayref = "0.3.7"
+paste = "1.0.15"
+seq-macro = "0.3.5"
 
 [dev-dependencies]
 lance-testing.workspace = true

rust/lance-encoding/benches/decoder.rs

@@ -65,8 +65,8 @@ fn bench_decode(c: &mut Criterion) {
     let mut group = c.benchmark_group("decode_primitive");
     for data_type in PRIMITIVE_TYPES {
         let data = lance_datagen::gen()
-            .anon_col(lance_datagen::array::rand_type(&DataType::Int32))
-            .into_batch_rows(lance_datagen::RowCount::from(1024 * 1024))
+            .anon_col(lance_datagen::array::rand_type(data_type))
+            .into_batch_rows(lance_datagen::RowCount::from(1024 * 1024 * 1024))
             .unwrap();
         let lance_schema =
             Arc::new(lance_core::datatypes::Schema::try_from(data.schema().as_ref()).unwrap());
@@ -96,6 +96,7 @@ fn bench_decode(c: &mut Criterion) {
         });
     }
 }
+
 fn bench_decode_fsl(c: &mut Criterion) {
     let rt = tokio::runtime::Runtime::new().unwrap();
     let mut group = c.benchmark_group("decode_primitive_fsl");

rust/lance-encoding/src/buffer.rs

@@ -283,6 +283,32 @@ impl LanceBuffer {
     pub fn copy_array<const N: usize>(array: [u8; N]) -> Self {
         Self::Owned(Vec::from(array))
     }
+
+    #[allow(clippy::len_without_is_empty)]
+    pub fn len(&self) -> usize {
+        match self {
+            Self::Borrowed(buffer) => buffer.len(),
+            Self::Owned(buffer) => buffer.len(),
+        }
+    }
+
+    /// Returns a new [LanceBuffer] that is a slice of this buffer starting at `offset`,
+    /// with `length` bytes.
+    /// Doing so allows the same memory region to be shared between lance buffers.
+    /// # Panics
+    /// Panics if `(offset + length)` is larger than the existing length.
+    /// If the buffer is owned this method will require a copy.
+    pub fn slice_with_length(&self, offset: usize, length: usize) -> Self {
+        let original_buffer_len = self.len();
+        assert!(
+            offset.saturating_add(length) <= original_buffer_len,
+            "the offset + length of the sliced Buffer cannot exceed the existing length"
+        );
+        match self {
+            Self::Borrowed(buffer) => Self::Borrowed(buffer.slice_with_length(offset, length)),
+            Self::Owned(buffer) => Self::Owned(buffer[offset..offset + length].to_vec()),
+        }
+    }
 }
 
 impl AsRef<[u8]> for LanceBuffer {