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use std::collections::VecDeque;
use std::sync::Arc;
use crate::array::Array;
use crate::chunk::Chunk;
use crate::datatypes::{DataType, Field};
use crate::error::Error;
use crate::ffi::mmap;
use crate::io::ipc::read::file::{get_dictionary_batch, get_record_batch};
use crate::io::ipc::read::{first_dict_field, Dictionaries, FileMetadata};
use crate::io::ipc::read::{IpcBuffer, Node, OutOfSpecKind};
use crate::io::ipc::{IpcField, CONTINUATION_MARKER};
use arrow_format::ipc::planus::ReadAsRoot;
use arrow_format::ipc::{Block, MessageRef, RecordBatchRef};
fn read_message(
mut bytes: &[u8],
block: arrow_format::ipc::Block,
) -> Result<(MessageRef, usize), Error> {
let offset: usize = block
.offset
.try_into()
.map_err(|_| Error::from(OutOfSpecKind::NegativeFooterLength))?;
let block_length: usize = block
.meta_data_length
.try_into()
.map_err(|_| Error::from(OutOfSpecKind::NegativeFooterLength))?;
bytes = &bytes[offset..];
let mut message_length = bytes[..4].try_into().unwrap();
bytes = &bytes[4..];
if message_length == CONTINUATION_MARKER {
message_length = bytes[..4].try_into().unwrap();
bytes = &bytes[4..];
};
let message_length: usize = i32::from_le_bytes(message_length)
.try_into()
.map_err(|_| Error::from(OutOfSpecKind::NegativeFooterLength))?;
let message = arrow_format::ipc::MessageRef::read_as_root(&bytes[..message_length])
.map_err(|err| Error::from(OutOfSpecKind::InvalidFlatbufferMessage(err)))?;
Ok((message, offset + block_length))
}
fn get_buffers_nodes(
batch: RecordBatchRef,
) -> Result<(VecDeque<IpcBuffer>, VecDeque<Node>), Error> {
let compression = batch.compression()?;
if compression.is_some() {
return Err(Error::nyi(
"mmap can only be done on uncompressed IPC files",
));
}
let buffers = batch
.buffers()
.map_err(|err| Error::from(OutOfSpecKind::InvalidFlatbufferBuffers(err)))?
.ok_or_else(|| Error::from(OutOfSpecKind::MissingMessageBuffers))?;
let buffers = buffers.iter().collect::<VecDeque<_>>();
let field_nodes = batch
.nodes()
.map_err(|err| Error::from(OutOfSpecKind::InvalidFlatbufferNodes(err)))?
.ok_or_else(|| Error::from(OutOfSpecKind::MissingMessageNodes))?;
let field_nodes = field_nodes.iter().collect::<VecDeque<_>>();
Ok((buffers, field_nodes))
}
unsafe fn _mmap_record<T: AsRef<[u8]>>(
fields: &[Field],
ipc_fields: &[IpcField],
data: Arc<T>,
batch: RecordBatchRef,
offset: usize,
dictionaries: &Dictionaries,
) -> Result<Chunk<Box<dyn Array>>, Error> {
let (mut buffers, mut field_nodes) = get_buffers_nodes(batch)?;
fields
.iter()
.map(|f| &f.data_type)
.cloned()
.zip(ipc_fields)
.map(|(data_type, ipc_field)| {
mmap::mmap(
data.clone(),
offset,
data_type,
ipc_field,
dictionaries,
&mut field_nodes,
&mut buffers,
)
})
.collect::<Result<_, Error>>()
.and_then(Chunk::try_new)
}
unsafe fn _mmap_unchecked<T: AsRef<[u8]>>(
fields: &[Field],
ipc_fields: &[IpcField],
data: Arc<T>,
block: Block,
dictionaries: &Dictionaries,
) -> Result<Chunk<Box<dyn Array>>, Error> {
let (message, offset) = read_message(data.as_ref().as_ref(), block)?;
let batch = get_record_batch(message)?;
_mmap_record(
fields,
ipc_fields,
data.clone(),
batch,
offset,
dictionaries,
)
}
pub unsafe fn mmap_unchecked<T: AsRef<[u8]>>(
metadata: &FileMetadata,
dictionaries: &Dictionaries,
data: Arc<T>,
chunk: usize,
) -> Result<Chunk<Box<dyn Array>>, Error> {
let block = metadata.blocks[chunk];
let (message, offset) = read_message(data.as_ref().as_ref(), block)?;
let batch = get_record_batch(message)?;
_mmap_record(
&metadata.schema.fields,
&metadata.ipc_schema.fields,
data.clone(),
batch,
offset,
dictionaries,
)
}
unsafe fn mmap_dictionary<T: AsRef<[u8]>>(
metadata: &FileMetadata,
data: Arc<T>,
block: Block,
dictionaries: &mut Dictionaries,
) -> Result<(), Error> {
let (message, offset) = read_message(data.as_ref().as_ref(), block)?;
let batch = get_dictionary_batch(&message)?;
let id = batch
.id()
.map_err(|err| Error::from(OutOfSpecKind::InvalidFlatbufferId(err)))?;
let (first_field, first_ipc_field) =
first_dict_field(id, &metadata.schema.fields, &metadata.ipc_schema.fields)?;
let batch = batch
.data()
.map_err(|err| Error::from(OutOfSpecKind::InvalidFlatbufferData(err)))?
.ok_or_else(|| Error::from(OutOfSpecKind::MissingData))?;
let value_type =
if let DataType::Dictionary(_, value_type, _) = first_field.data_type.to_logical_type() {
value_type.as_ref()
} else {
return Err(Error::from(OutOfSpecKind::InvalidIdDataType {
requested_id: id,
}));
};
let field = Field::new("", value_type.clone(), false);
let chunk = _mmap_record(
&[field],
&[first_ipc_field.clone()],
data.clone(),
batch,
offset,
dictionaries,
)?;
dictionaries.insert(id, chunk.into_arrays().pop().unwrap());
Ok(())
}
pub unsafe fn mmap_dictionaries_unchecked<T: AsRef<[u8]>>(
metadata: &FileMetadata,
data: Arc<T>,
) -> Result<Dictionaries, Error> {
let blocks = if let Some(blocks) = &metadata.dictionaries {
blocks
} else {
return Ok(Default::default());
};
let mut dictionaries = Default::default();
blocks
.iter()
.cloned()
.try_for_each(|block| mmap_dictionary(metadata, data.clone(), block, &mut dictionaries))?;
Ok(dictionaries)
}