[arrow-rs] branch master updated: Creates PrimitiveDictionaryBuilder from provided keys and values builders (#3777)

[viirya]

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viirya pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/arrow-rs.git


The following commit(s) were added to refs/heads/master by this push:
     new 5edc954a9 Creates PrimitiveDictionaryBuilder from provided keys and 
values builders (#3777)
5edc954a9 is described below

commit 5edc954a939c129e1386c2ac19add45e6fcdc9cb
Author: Liang-Chi Hsieh <vii...@gmail.com>
AuthorDate: Wed Mar 1 00:07:25 2023 -0800

    Creates PrimitiveDictionaryBuilder from provided keys and values builders 
(#3777)
    
    * Creates PrimitiveDictionaryBuilder from provided keys and values builders
    
    * Panics the function if provided builder is not empty
---
 .../src/builder/primitive_dictionary_builder.rs    | 37 +++++++++++++++++++++-
 1 file changed, 36 insertions(+), 1 deletion(-)

diff --git a/arrow-array/src/builder/primitive_dictionary_builder.rs 
b/arrow-array/src/builder/primitive_dictionary_builder.rs
index 00187cdde..742c09d8c 100644
--- a/arrow-array/src/builder/primitive_dictionary_builder.rs
+++ b/arrow-array/src/builder/primitive_dictionary_builder.rs
@@ -113,6 +113,26 @@ where
         }
     }
 
+    /// Creates a new `PrimitiveDictionaryBuilder` from the provided keys and 
values builders.
+    ///
+    /// # Panics
+    ///
+    /// This method panics if `keys_builder` or `values_builder` is not empty.
+    pub fn new_from_builders(
+        keys_builder: PrimitiveBuilder<K>,
+        values_builder: PrimitiveBuilder<V>,
+    ) -> Self {
+        assert!(
+            keys_builder.is_empty() && values_builder.is_empty(),
+            "keys and values builders must be empty"
+        );
+        Self {
+            keys_builder,
+            values_builder,
+            map: HashMap::new(),
+        }
+    }
+
     /// Creates a new `PrimitiveDictionaryBuilder` with the provided capacities
     ///
     /// `keys_capacity`: the number of keys, i.e. length of array to build
@@ -276,7 +296,8 @@ mod tests {
     use crate::array::Array;
     use crate::array::UInt32Array;
     use crate::array::UInt8Array;
-    use crate::types::{Int32Type, UInt32Type, UInt8Type};
+    use crate::builder::Decimal128Builder;
+    use crate::types::{Decimal128Type, Int32Type, UInt32Type, UInt8Type};
 
     #[test]
     fn test_primitive_dictionary_builder() {
@@ -329,4 +350,18 @@ mod tests {
         // Special error if the key overflows (256th entry)
         builder.append(1257).unwrap();
     }
+
+    #[test]
+    fn test_primitive_dictionary_with_builders() {
+        let keys_builder = PrimitiveBuilder::<Int32Type>::new();
+        let values_builder =
+            Decimal128Builder::new().with_data_type(DataType::Decimal128(1, 
2));
+        let mut builder =
+            PrimitiveDictionaryBuilder::<Int32Type, 
Decimal128Type>::new_from_builders(
+                keys_builder,
+                values_builder,
+            );
+        let dict_array = builder.finish();
+        assert_eq!(dict_array.value_type(), DataType::Decimal128(1, 2));
+    }
 }