add tests for string_view type

src/common/arrow/src/arrow/array/binview/ffi.rs

@@ -79,7 +79,7 @@ impl<T: ViewType + ?Sized, A: ffi::ArrowArrayRef> FromFfi<A> for BinaryViewArray
         let validity = unsafe { array.validity() }?;
         let views = unsafe { array.buffer::<View>(1) }?;
 
-        // 2 - validity + views
+        // n_buffers - 2, 2 means validity + views
         let n_buffers = array.n_buffers();
         let mut remaining_buffers = n_buffers - 2;
         if remaining_buffers <= 1 {

src/common/arrow/src/arrow/array/binview/from.rs

@@ -0,0 +1,24 @@
+// Copyright 2021 Datafuse Labs
+//
+// Licensed 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 crate::arrow::array::BinaryViewArrayGeneric;
+use crate::arrow::array::MutableBinaryViewArray;
+use crate::arrow::array::ViewType;
+
+impl<T: ViewType + ?Sized, P: AsRef<T>> FromIterator<Option<P>> for BinaryViewArrayGeneric<T> {
+    #[inline]
+    fn from_iter<I: IntoIterator<Item = Option<P>>>(iter: I) -> Self {
+        MutableBinaryViewArray::<T>::from_iter(iter).into()
+    }
+}

src/common/arrow/src/arrow/array/binview/mod.rs

@@ -15,6 +15,7 @@
 
 mod ffi;
 pub(crate) mod fmt;
+mod from;
 mod iterator;
 mod mutable;
 mod view;
@@ -23,6 +24,7 @@ mod private {
     pub trait Sealed: Send + Sync {}
 
     impl Sealed for str {}
+
     impl Sealed for [u8] {}
 }
 
@@ -33,6 +35,7 @@ use std::sync::atomic::AtomicU64;
 use std::sync::atomic::Ordering;
 use std::sync::Arc;
 
+use either::Either;
 pub use iterator::BinaryViewValueIter;
 pub use mutable::MutableBinaryViewArray;
 use private::Sealed;
@@ -70,7 +73,7 @@ pub trait ViewType: Sealed + 'static + PartialEq + AsRef<Self> {
     #[allow(clippy::wrong_self_convention)]
     fn into_owned(&self) -> Self::Owned;
 
-    fn dtype() -> &'static DataType;
+    fn data_type() -> &'static DataType;
 }
 
 impl ViewType for str {
@@ -92,7 +95,7 @@ impl ViewType for str {
         self.to_string()
     }
 
-    fn dtype() -> &'static DataType {
+    fn data_type() -> &'static DataType {
         &UTF8_VIEW_TYPE
     }
 }
@@ -116,7 +119,7 @@ impl ViewType for [u8] {
         self.to_vec()
     }
 
-    fn dtype() -> &'static DataType {
+    fn data_type() -> &'static DataType {
         &BIN_VIEW_TYPE
     }
 }
@@ -157,6 +160,7 @@ impl<T: ViewType + ?Sized> Clone for BinaryViewArrayGeneric<T> {
 }
 
 unsafe impl<T: ViewType + ?Sized> Send for BinaryViewArrayGeneric<T> {}
+
 unsafe impl<T: ViewType + ?Sized> Sync for BinaryViewArrayGeneric<T> {}
 
 fn buffers_into_raw<T>(buffers: &[Buffer<T>]) -> Arc<[(*const T, usize)]> {
@@ -233,6 +237,11 @@ impl<T: ViewType + ?Sized> BinaryViewArrayGeneric<T> {
         buffers: Arc<[Buffer<u8>]>,
         validity: Option<Bitmap>,
     ) -> Result<Self> {
+        if data_type.to_physical_type() != Self::default_data_type().to_physical_type() {
+            return Err(Error::oos(
+                "BinaryViewArray can only be initialized with DataType::BinaryView or DataType::Utf8View",
+            ));
+        }
         if T::IS_UTF8 {
             validate_utf8_view(views.as_ref(), buffers.as_ref())?;
         } else {
@@ -254,6 +263,12 @@ impl<T: ViewType + ?Sized> BinaryViewArrayGeneric<T> {
         }
     }
 
+    /// Returns a new [`BinaryViewArrayGeneric`] from a slice of `&T`.
+    // Note: this can't be `impl From` because Rust does not allow double `AsRef` on it.
+    pub fn from<V: AsRef<T>, P: AsRef<[Option<V>]>>(slice: P) -> Self {
+        MutableBinaryViewArray::<T>::from(slice).into()
+    }
+
     /// Creates an empty [`BinaryViewArrayGeneric`], i.e. whose `.len` is zero.
     #[inline]
     pub fn new_empty(data_type: DataType) -> Self {
@@ -438,6 +453,84 @@ impl<T: ViewType + ?Sized> BinaryViewArrayGeneric<T> {
             total_buffer_len: self.total_buffer_len,
         }
     }
+
+    #[must_use]
+    pub fn into_mut(self) -> Either<Self, MutableBinaryViewArray<T>> {
+        use Either::*;
+        let is_unique = (Arc::strong_count(&self.buffers) + Arc::weak_count(&self.buffers)) == 1;
+
+        if let Some(bitmap) = self.validity {
+            match bitmap.into_mut() {
+                Left(bitmap) => Left(Self::new_unchecked(
+                    self.data_type,
+                    self.views,
+                    self.buffers,
+                    Some(bitmap),
+                    self.total_bytes_len.load(Ordering::Relaxed) as usize,
+                    self.total_buffer_len,
+                )),
+                Right(mutable_bitmap) => match (self.views.into_mut(), is_unique) {
+                    (Right(views), true) => Right(MutableBinaryViewArray {
+                        views,
+                        completed_buffers: self.buffers.to_vec(),
+                        in_progress_buffer: vec![],
+                        validity: Some(mutable_bitmap),
+                        phantom: Default::default(),
+                        total_bytes_len: self.total_bytes_len.load(Ordering::Relaxed) as usize,
+                        total_buffer_len: self.total_buffer_len,
+                    }),
+                    (Right(views), false) => Left(Self::new_unchecked(
+                        self.data_type,
+                        views.into(),
+                        self.buffers,
+                        Some(mutable_bitmap.into()),
+                        self.total_bytes_len.load(Ordering::Relaxed) as usize,
+                        self.total_buffer_len,
+                    )),
+                    (Left(views), _) => Left(Self::new_unchecked(
+                        self.data_type,
+                        views,
+                        self.buffers,
+                        Some(mutable_bitmap.into()),
+                        self.total_bytes_len.load(Ordering::Relaxed) as usize,
+                        self.total_buffer_len,
+                    )),
+                },
+            }
+        } else {
+            match (self.views.into_mut(), is_unique) {
+                (Right(views), true) => Right(MutableBinaryViewArray {
+                    views,
+                    completed_buffers: self.buffers.to_vec(),
+                    in_progress_buffer: vec![],
+                    validity: None,
+                    phantom: Default::default(),
+                    total_bytes_len: self.total_bytes_len.load(Ordering::Relaxed) as usize,
+                    total_buffer_len: self.total_buffer_len,
+                }),
+                (Right(views), false) => Left(Self::new_unchecked(
+                    self.data_type,
+                    views.into(),
+                    self.buffers,
+                    None,
+                    self.total_bytes_len.load(Ordering::Relaxed) as usize,
+                    self.total_buffer_len,
+                )),
+                (Left(views), _) => Left(Self::new_unchecked(
+                    self.data_type,
+                    views,
+                    self.buffers,
+                    None,
+                    self.total_bytes_len.load(Ordering::Relaxed) as usize,
+                    self.total_buffer_len,
+                )),
+            }
+        }
+    }
+
+    pub fn default_data_type() -> &'static DataType {
+        T::data_type()
+    }
 }
 
 pub type BinaryViewArray = BinaryViewArrayGeneric<[u8]>;
@@ -500,7 +593,7 @@ impl<T: ViewType + ?Sized> Array for BinaryViewArrayGeneric<T> {
     }
 
     fn data_type(&self) -> &DataType {
-        T::dtype()
+        T::data_type()
     }
 
     fn validity(&self) -> Option<&Bitmap> {

src/common/arrow/src/arrow/array/binview/mutable.rs

@@ -113,7 +113,11 @@ impl<T: ViewType + ?Sized> MutableBinaryViewArray<T> {
         &self.views
     }
 
-    pub fn validity(&mut self) -> Option<&mut MutableBitmap> {
+    pub fn validity(&self) -> Option<&MutableBitmap> {
+        self.validity.as_ref()
+    }
+
+    pub fn validity_mut(&mut self) -> Option<&mut MutableBitmap> {
         self.validity.as_mut()
     }
 
@@ -175,8 +179,16 @@ impl<T: ViewType + ?Sized> MutableBinaryViewArray<T> {
         payload[0..4].copy_from_slice(&len.to_le_bytes());
 
         if len <= 12 {
+            // |   len   |  prefix  |  remaining(zero-padded)  |
+            //     ^          ^             ^
+            // | 4 bytes | 4 bytes |      8 bytes              |
             payload[4..4 + bytes.len()].copy_from_slice(bytes);
         } else {
+            // |   len   |  prefix  |  buffer |  offsets  |
+            //     ^          ^          ^         ^
+            // | 4 bytes | 4 bytes | 4 bytes |  4 bytes  |
+            //
+            // buffer index + offset -> real binary data
             self.total_buffer_len += bytes.len();
             let required_cap = self.in_progress_buffer.len() + bytes.len();
             if self.in_progress_buffer.capacity() < required_cap {
@@ -192,6 +204,7 @@ impl<T: ViewType + ?Sized> MutableBinaryViewArray<T> {
             let offset = self.in_progress_buffer.len() as u32;
             self.in_progress_buffer.extend_from_slice(bytes);
 
+            // set prefix
             unsafe { payload[4..8].copy_from_slice(bytes.get_unchecked(0..4)) };
             let buffer_idx: u32 = self.completed_buffers.len().try_into().unwrap();
             payload[8..12].copy_from_slice(&buffer_idx.to_le_bytes());
@@ -347,12 +360,13 @@ impl<T: ViewType + ?Sized> MutableBinaryViewArray<T> {
         let len = v.length;
 
         // view layout:
+        // for no-inlined layout:
         // length: 4 bytes
         // prefix: 4 bytes
         // buffer_index: 4 bytes
         // offset: 4 bytes
 
-        // inlined layout:
+        // for inlined layout:
         // length: 4 bytes
         // data: 12 bytes
         let bytes = if len <= 12 {
@@ -378,6 +392,10 @@ impl<T: ViewType + ?Sized> MutableBinaryViewArray<T> {
     pub fn values_iter(&self) -> MutableBinaryViewValueIter<T> {
         MutableBinaryViewValueIter::new(self)
     }
+
+    pub fn values(&self) -> Vec<&T> {
+        self.values_iter().collect()
+    }
 }
 
 impl MutableBinaryViewArray<[u8]> {
@@ -404,7 +422,7 @@ impl<T: ViewType + ?Sized, P: AsRef<T>> FromIterator<Option<P>> for MutableBinar
 
 impl<T: ViewType + ?Sized> MutableArray for MutableBinaryViewArray<T> {
     fn data_type(&self) -> &DataType {
-        T::dtype()
+        T::data_type()
     }
 
     fn len(&self) -> usize {

src/common/arrow/src/arrow/io/parquet/read/deserialize/utils.rs

@@ -116,7 +116,7 @@ impl<T: ViewType + ?Sized> Pushable<&T> for MutableBinaryViewArray<T> {
             views.push(view);
         }
 
-        if let Some(bitmap) = self.validity() {
+        if let Some(bitmap) = self.validity_mut() {
             bitmap.extend_constant(remaining, true)
         }
     }