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mod schema;
mod serialize;
use crate::{array::Array, chunk::Chunk, datatypes::Field, error::Result};
use super::api;
pub use schema::infer_descriptions;
pub use serialize::serialize;
pub fn buffer_from_description(
descriptions: Vec<api::ColumnDescription>,
capacity: usize,
) -> api::buffers::ColumnarBuffer<api::buffers::AnyColumnBuffer> {
let descs = descriptions
.into_iter()
.map(|description| api::buffers::BufferDescription {
nullable: description.could_be_nullable(),
kind: api::buffers::BufferKind::from_data_type(description.data_type).unwrap(),
});
api::buffers::buffer_from_description(capacity, descs)
}
pub struct Writer<'a> {
fields: Vec<Field>,
buffer: api::buffers::ColumnarBuffer<api::buffers::AnyColumnBuffer>,
prepared: api::Prepared<'a>,
}
impl<'a> Writer<'a> {
pub fn try_new(prepared: api::Prepared<'a>, fields: Vec<Field>) -> Result<Self> {
let buffer = buffer_from_description(infer_descriptions(&fields)?, 0);
Ok(Self {
fields,
buffer,
prepared,
})
}
pub fn write<A: AsRef<dyn Array>>(&mut self, chunk: &Chunk<A>) -> Result<()> {
if chunk.len() > self.buffer.num_rows() {
self.buffer = buffer_from_description(infer_descriptions(&self.fields)?, chunk.len());
}
self.buffer.set_num_rows(chunk.len());
for (i, column) in chunk.arrays().iter().enumerate() {
serialize(column.as_ref(), &mut self.buffer.column_mut(i))?;
}
self.prepared.execute(&self.buffer)?;
Ok(())
}
}