FSSTCompressor

Cargo.toml

@@ -81,7 +81,7 @@ fastlanes = "0.1.5"
 flatbuffers = "24.3.25"
 flexbuffers = "2.0.0"
 fs_extra = "1.3.0"
-fsst-rs = "0.2.0"
+fsst-rs = "0.3.0"
 futures = { version = "0.3.30", default-features = false }
 futures-executor = "0.3.30"
 futures-util = "0.3.30"
@@ -139,8 +139,9 @@ vortex-dict = { version = "0.7.0", path = "./encodings/dict" }
 vortex-dtype = { version = "0.7.0", path = "./vortex-dtype", default-features = false }
 vortex-error = { version = "0.7.0", path = "./vortex-error" }
 vortex-expr = { version = "0.7.0", path = "./vortex-expr" }
-vortex-flatbuffers = { version = "0.7.0", path = "./vortex-flatbuffers" }
 vortex-fastlanes = { version = "0.7.0", path = "./encodings/fastlanes" }
+vortex-flatbuffers = { version = "0.7.0", path = "./vortex-flatbuffers" }
+vortex-fsst = { version = "0.7.0", path = "./encodings/fsst" }
 vortex-proto = { version = "0.7.0", path = "./vortex-proto" }
 vortex-roaring = { version = "0.7.0", path = "./encodings/roaring" }
 vortex-runend = { version = "0.7.0", path = "./encodings/runend" }
@@ -169,5 +170,4 @@ panic_in_result_fn = { level = "deny" }
 same_name_method = { level = "deny" }
 tests_outside_test_module = { level = "deny" }
 unwrap_in_result = { level = "deny" }
-#unwrap_used = { level = "deny" }
 use_debug = { level = "deny" }

bench-vortex/Cargo.toml

@@ -77,15 +77,19 @@ bench = false
 [[bench]]
 name = "compress_benchmark"
 harness = false
+test = false
 
 [[bench]]
 name = "random_access"
+test = false
 harness = false
 
 [[bench]]
 name = "datafusion_benchmark"
+test = false
 harness = false
 
 [[bench]]
 name = "tpch_benchmark"
+test = false
 harness = false

bench-vortex/benches/compress_benchmark.rs

@@ -1,9 +1,13 @@
-use bench_vortex::compress_taxi_data;
 use bench_vortex::data_downloads::BenchmarkDataset;
 use bench_vortex::public_bi_data::BenchmarkDatasets;
 use bench_vortex::public_bi_data::PBIDataset::Medicare1;
 use bench_vortex::taxi_data::taxi_data_parquet;
+use bench_vortex::tpch::dbgen::{DBGen, DBGenOptions};
+use bench_vortex::{compress_taxi_data, tpch};
 use criterion::{black_box, criterion_group, criterion_main, Criterion};
+use vortex::{IntoArray, IntoCanonical};
+use vortex_sampling_compressor::compressors::fsst::FSSTCompressor;
+use vortex_sampling_compressor::SamplingCompressor;
 
 fn vortex_compress_taxi(c: &mut Criterion) {
     taxi_data_parquet();
@@ -24,5 +28,63 @@ fn vortex_compress_medicare1(c: &mut Criterion) {
     group.finish()
 }
 
-criterion_group!(benches, vortex_compress_taxi, vortex_compress_medicare1);
+fn vortex_compress_tpch(c: &mut Criterion) {
+    let data_dir = DBGen::new(DBGenOptions::default()).generate().unwrap();
+    let rt = tokio::runtime::Builder::new_current_thread()
+        .enable_all()
+        .build()
+        .unwrap();
+    let lineitem_vortex = rt.block_on(tpch::load_table(
+        data_dir,
+        "lineitem",
+        &tpch::schema::LINEITEM,
+    ));
+
+    let compressor = SamplingCompressor::default().excluding(&FSSTCompressor);
+
+    let compressor_fsst = SamplingCompressor::default();
+
+    // l_comment column only
+    let mut group = c.benchmark_group("l_comment");
+    let comments = lineitem_vortex.with_dyn(|a| {
+        a.as_struct_array_unchecked()
+            .field_by_name("l_comment")
+            .unwrap()
+    });
+
+    group.sample_size(10);
+    group.bench_function("compress-default", |b| {
+        b.iter_with_large_drop(|| {
+            std::hint::black_box(compressor.compress(&comments, None)).unwrap()
+        });
+    });
+
+    group.bench_function("compress-fsst-chunked", |b| {
+        b.iter_with_large_drop(|| {
+            std::hint::black_box(compressor_fsst.compress(&comments, None)).unwrap()
+        });
+    });
+
+    // Compare canonicalizing
+    let comments_canonical = comments
+        .into_canonical()
+        .unwrap()
+        .into_varbin()
+        .unwrap()
+        .into_array();
+    group.bench_function("compress-fsst-canonicalized", |b| {
+        b.iter_with_large_drop(|| {
+            std::hint::black_box(compressor_fsst.compress(&comments_canonical, None)).unwrap()
+        });
+    });
+
+    group.finish();
+}
+
+criterion_group!(
+    benches,
+    vortex_compress_taxi,
+    vortex_compress_medicare1,
+    vortex_compress_tpch
+);
 criterion_main!(benches);

bench-vortex/benches/random_access.rs

@@ -44,11 +44,13 @@ fn random_access_vortex(c: &mut Criterion) {
         })
     });
 
-    let r2_fs = Arc::new(AmazonS3Builder::from_env().build().unwrap()) as Arc<dyn ObjectStore>;
-    let r2_path =
-        object_store::path::Path::from_url_path(taxi_vortex.file_name().unwrap().to_str().unwrap())
-            .unwrap();
     group.sample_size(10).bench_function("R2", |b| {
+        let r2_fs = Arc::new(AmazonS3Builder::from_env().build().unwrap()) as Arc<dyn ObjectStore>;
+        let r2_path = object_store::path::Path::from_url_path(
+            taxi_vortex.file_name().unwrap().to_str().unwrap(),
+        )
+        .unwrap();
+
         b.to_async(Runtime::new().unwrap()).iter(|| async {
             black_box(
                 take_vortex_object_store(&r2_fs, &r2_path, &INDICES)
@@ -63,18 +65,19 @@ fn random_access_parquet(c: &mut Criterion) {
     let mut group = c.benchmark_group("parquet");
     group.sample_size(10);
 
-    let r2_fs = Arc::new(AmazonS3Builder::from_env().build().unwrap());
     let taxi_parquet = taxi_data_parquet();
     group.bench_function("tokio local disk", |b| {
         b.to_async(Runtime::new().unwrap())
             .iter(|| async { black_box(take_parquet(&taxi_parquet, &INDICES).await.unwrap()) })
     });
 
-    let r2_parquet_path = object_store::path::Path::from_url_path(
-        taxi_parquet.file_name().unwrap().to_str().unwrap(),
-    )
-    .unwrap();
     group.bench_function("R2", |b| {
+        let r2_fs = Arc::new(AmazonS3Builder::from_env().build().unwrap());
+        let r2_parquet_path = object_store::path::Path::from_url_path(
+            taxi_parquet.file_name().unwrap().to_str().unwrap(),
+        )
+        .unwrap();
+
         b.to_async(Runtime::new().unwrap()).iter(|| async {
             black_box(
                 take_parquet_object_store(r2_fs.clone(), &r2_parquet_path, &INDICES)

bench-vortex/src/lib.rs

@@ -31,6 +31,7 @@ use vortex_sampling_compressor::compressors::alp::ALPCompressor;
 use vortex_sampling_compressor::compressors::bitpacked::BitPackedCompressor;
 use vortex_sampling_compressor::compressors::date_time_parts::DateTimePartsCompressor;
 use vortex_sampling_compressor::compressors::dict::DictCompressor;
+use vortex_sampling_compressor::compressors::fsst::FSSTCompressor;
 use vortex_sampling_compressor::compressors::r#for::FoRCompressor;
 use vortex_sampling_compressor::compressors::roaring_bool::RoaringBoolCompressor;
 use vortex_sampling_compressor::compressors::runend::DEFAULT_RUN_END_COMPRESSOR;
@@ -72,6 +73,7 @@ lazy_static! {
         &DictCompressor,
         &BitPackedCompressor,
         &FoRCompressor,
+        &FSSTCompressor,
         &DateTimePartsCompressor,
         &DEFAULT_RUN_END_COMPRESSOR,
         &RoaringBoolCompressor,

bench-vortex/src/tpch/mod.rs

@@ -377,6 +377,43 @@ async fn register_vortex(
     Ok(())
 }
 
+/// Load a table as an uncompressed Vortex array.
+pub async fn load_table(data_dir: impl AsRef<Path>, name: &str, schema: &Schema) -> Array {
+    // Create a local session to load the CSV file from the path.
+    let path = data_dir
+        .as_ref()
+        .to_owned()
+        .join(format!("{name}.tbl"))
+        .to_str()
+        .unwrap()
+        .to_string();
+    let record_batches = SessionContext::new()
+        .read_csv(
+            &path,
+            CsvReadOptions::default()
+                .delimiter(b'|')
+                .has_header(false)
+                .file_extension("tbl")
+                .schema(schema),
+        )
+        .await
+        .unwrap()
+        .collect()
+        .await
+        .unwrap();
+
+    let chunks: Vec<Array> = record_batches
+        .iter()
+        .cloned()
+        .map(ArrowStructArray::from)
+        .map(|struct_array| Array::from_arrow(&struct_array, false))
+        .collect();
+
+    let dtype = chunks[0].dtype().clone();
+
+    ChunkedArray::try_new(chunks, dtype).unwrap().into_array()
+}
+
 pub fn tpch_queries() -> impl Iterator<Item = (usize, Vec<String>)> {
     (1..=22).map(|q| (q, tpch_query(q)))
 }

encodings/fsst/src/array.rs

@@ -1,6 +1,6 @@
 use std::sync::Arc;
 
-use fsst::{Decompressor, Symbol, MAX_CODE};
+use fsst::{Decompressor, Symbol};
 use serde::{Deserialize, Serialize};
 use vortex::stats::{ArrayStatisticsCompute, StatsSet};
 use vortex::validity::{ArrayValidity, LogicalValidity};
@@ -13,6 +13,7 @@ use vortex_error::{vortex_bail, VortexResult};
 impl_encoding!("vortex.fsst", 24u16, FSST);
 
 static SYMBOLS_DTYPE: DType = DType::Primitive(PType::U64, Nullability::NonNullable);
+static SYMBOL_LENS_DTYPE: DType = DType::Primitive(PType::U8, Nullability::NonNullable);
 
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct FSSTMetadata {
@@ -29,26 +30,39 @@ impl FSSTArray {
     /// The `codes` array is a Binary array where each binary datum is a sequence of 8-bit codes.
     /// Each code corresponds either to a symbol, or to the "escape code",
     /// which tells the decoder to emit the following byte without doing a table lookup.
-    pub fn try_new(dtype: DType, symbols: Array, codes: Array) -> VortexResult<Self> {
+    pub fn try_new(
+        dtype: DType,
+        symbols: Array,
+        symbol_lengths: Array,
+        codes: Array,
+    ) -> VortexResult<Self> {
         // Check: symbols must be a u64 array
-        if symbols.dtype() != &DType::Primitive(PType::U64, Nullability::NonNullable) {
+        if symbols.dtype() != &SYMBOLS_DTYPE {
             vortex_bail!(InvalidArgument: "symbols array must be of type u64")
         }
 
+        if symbol_lengths.dtype() != &SYMBOL_LENS_DTYPE {
+            vortex_bail!(InvalidArgument: "symbol_lengths array must be of type u8")
+        }
+
         // Check: symbols must not have length > MAX_CODE
-        if symbols.len() > MAX_CODE as usize {
-            vortex_bail!(InvalidArgument: "symbols array must have length <= 255")
+        if symbols.len() > 255 {
+            vortex_bail!(InvalidArgument: "symbols array must have length <= 255");
+        }
+
+        if symbols.len() != symbol_lengths.len() {
+            vortex_bail!(InvalidArgument: "symbols and symbol_lengths arrays must have same length");
         }
 
         // Check: strings must be a Binary array.
         if !matches!(codes.dtype(), DType::Binary(_)) {
-            vortex_bail!(InvalidArgument: "strings array must be DType::Binary type");
+            vortex_bail!(InvalidArgument: "codes array must be DType::Binary type");
         }
 
         let symbols_len = symbols.len();
         let len = codes.len();
         let strings_dtype = codes.dtype().clone();
-        let children = Arc::new([symbols, codes]);
+        let children = Arc::new([symbols, symbol_lengths, codes]);
 
         Self::try_from_parts(
             dtype,
@@ -69,18 +83,28 @@ impl FSSTArray {
             .expect("FSSTArray must have a symbols child array")
     }
 
+    /// Access the symbol table array
+    pub fn symbol_lengths(&self) -> Array {
+        self.array()
+            .child(1, &SYMBOL_LENS_DTYPE, self.metadata().symbols_len)
+            .expect("FSSTArray must have a symbols child array")
+    }
+
     /// Access the codes array
     pub fn codes(&self) -> Array {
         self.array()
-            .child(1, &self.metadata().codes_dtype, self.len())
+            .child(2, &self.metadata().codes_dtype, self.len())
             .expect("FSSTArray must have a codes child array")
     }
 
     /// Build a [`Decompressor`][fsst::Decompressor] that can be used to decompress values from
-    /// this array.
+    /// this array, and pass it to the given function.
     ///
-    /// This is private to the crate to avoid leaking `fsst` as part of the public API.
-    pub(crate) fn decompressor(&self) -> Decompressor {
+    /// This is private to the crate to avoid leaking `fsst-rs` types as part of the public API.
+    pub(crate) fn with_decompressor<F, R>(&self, apply: F) -> R
+    where
+        F: FnOnce(Decompressor) -> R,
+    {
         // canonicalize the symbols child array, so we can view it contiguously
         let symbols_array = self
             .symbols()
@@ -90,18 +114,28 @@ impl FSSTArray {
             .expect("Symbols must be a Primitive Array");
         let symbols = symbols_array.maybe_null_slice::<u64>();
 
+        let symbol_lengths_array = self
+            .symbol_lengths()
+            .into_canonical()
+            .unwrap()
+            .into_primitive()
+            .unwrap();
+        let symbol_lengths = symbol_lengths_array.maybe_null_slice::<u8>();
+
         // Transmute the 64-bit symbol values into fsst `Symbol`s.
         // SAFETY: Symbol is guaranteed to be 8 bytes, guaranteed by the compiler.
         let symbols = unsafe { std::mem::transmute::<&[u64], &[Symbol]>(symbols) };
 
         // Build a new decompressor that uses these symbols.
-        Decompressor::new(symbols)
+        let decompressor = Decompressor::new(symbols, symbol_lengths);
+        apply(decompressor)
     }
 }
 
 impl AcceptArrayVisitor for FSSTArray {
-    fn accept(&self, _visitor: &mut dyn vortex::visitor::ArrayVisitor) -> VortexResult<()> {
-        todo!("implement this")
+    fn accept(&self, visitor: &mut dyn vortex::visitor::ArrayVisitor) -> VortexResult<()> {
+        visitor.visit_child("symbols", &self.symbols())?;
+        visitor.visit_child("codes", &self.codes())
     }
 }