/usr/local/lib64/python3.6/site-packages/pyarrow/include/arrow
Edit: /usr/local/lib64/python3.6/site-packages/pyarrow/include/arrow/record_batch.h (9398B)
// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements. See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership. The ASF licenses this file
// to you 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.
#pragma once
#include
#include
#include
#include
#include "arrow/result.h"
#include "arrow/status.h"
#include "arrow/type_fwd.h"
#include "arrow/util/macros.h"
#include "arrow/util/visibility.h"
namespace arrow {
/// \class RecordBatch
/// \brief Collection of equal-length arrays matching a particular Schema
///
/// A record batch is table-like data structure that is semantically a sequence
/// of fields, each a contiguous Arrow array
class ARROW_EXPORT RecordBatch {
public:
virtual ~RecordBatch() = default;
/// \param[in] schema The record batch schema
/// \param[in] num_rows length of fields in the record batch. Each array
/// should have the same length as num_rows
/// \param[in] columns the record batch fields as vector of arrays
static std::shared_ptr Make(std::shared_ptr schema,
int64_t num_rows,
std::vector> columns);
/// \brief Construct record batch from vector of internal data structures
/// \since 0.5.0
///
/// This class is intended for internal use, or advanced users.
///
/// \param schema the record batch schema
/// \param num_rows the number of semantic rows in the record batch. This
/// should be equal to the length of each field
/// \param columns the data for the batch's columns
static std::shared_ptr Make(
std::shared_ptr schema, int64_t num_rows,
std::vector> columns);
/// \brief Convert record batch to struct array
///
/// Create a struct array whose child arrays are the record batch's columns.
/// Note that the record batch's top-level field metadata cannot be reflected
/// in the resulting struct array.
Result> ToStructArray() const;
/// \brief Construct record batch from struct array
///
/// This constructs a record batch using the child arrays of the given
/// array, which must be a struct array. Note that the struct array's own
/// null bitmap is not reflected in the resulting record batch.
static Result> FromStructArray(
const std::shared_ptr& array);
/// \brief Determine if two record batches are exactly equal
///
/// \param[in] other the RecordBatch to compare with
/// \param[in] check_metadata if true, check that Schema metadata is the same
/// \return true if batches are equal
bool Equals(const RecordBatch& other, bool check_metadata = false) const;
/// \brief Determine if two record batches are approximately equal
bool ApproxEquals(const RecordBatch& other) const;
/// \return the record batch's schema
const std::shared_ptr& schema() const { return schema_; }
/// \brief Retrieve all columns at once
virtual const std::vector>& columns() const = 0;
/// \brief Retrieve an array from the record batch
/// \param[in] i field index, does not boundscheck
/// \return an Array object
virtual std::shared_ptr column(int i) const = 0;
/// \brief Retrieve an array from the record batch
/// \param[in] name field name
/// \return an Array or null if no field was found
std::shared_ptr GetColumnByName(const std::string& name) const;
/// \brief Retrieve an array's internal data from the record batch
/// \param[in] i field index, does not boundscheck
/// \return an internal ArrayData object
virtual std::shared_ptr column_data(int i) const = 0;
/// \brief Retrieve all arrays' internal data from the record batch.
virtual const ArrayDataVector& column_data() const = 0;
/// \brief Add column to the record batch, producing a new RecordBatch
///
/// \param[in] i field index, which will be boundschecked
/// \param[in] field field to be added
/// \param[in] column column to be added
virtual Result> AddColumn(
int i, const std::shared_ptr& field,
const std::shared_ptr& column) const = 0;
/// \brief Add new nullable column to the record batch, producing a new
/// RecordBatch.
///
/// For non-nullable columns, use the Field-based version of this method.
///
/// \param[in] i field index, which will be boundschecked
/// \param[in] field_name name of field to be added
/// \param[in] column column to be added
virtual Result> AddColumn(
int i, std::string field_name, const std::shared_ptr& column) const;
/// \brief Replace a column in the record batch, producing a new RecordBatch
///
/// \param[in] i field index, does boundscheck
/// \param[in] field field to be replaced
/// \param[in] column column to be replaced
virtual Result> SetColumn(
int i, const std::shared_ptr& field,
const std::shared_ptr& column) const = 0;
/// \brief Remove column from the record batch, producing a new RecordBatch
///
/// \param[in] i field index, does boundscheck
virtual Result> RemoveColumn(int i) const = 0;
virtual std::shared_ptr ReplaceSchemaMetadata(
const std::shared_ptr& metadata) const = 0;
/// \brief Name in i-th column
const std::string& column_name(int i) const;
/// \return the number of columns in the table
int num_columns() const;
/// \return the number of rows (the corresponding length of each column)
int64_t num_rows() const { return num_rows_; }
/// \brief Slice each of the arrays in the record batch
/// \param[in] offset the starting offset to slice, through end of batch
/// \return new record batch
virtual std::shared_ptr Slice(int64_t offset) const;
/// \brief Slice each of the arrays in the record batch
/// \param[in] offset the starting offset to slice
/// \param[in] length the number of elements to slice from offset
/// \return new record batch
virtual std::shared_ptr Slice(int64_t offset, int64_t length) const = 0;
/// \return PrettyPrint representation suitable for debugging
std::string ToString() const;
/// \brief Return new record batch with specified columns
Result> SelectColumns(
const std::vector& indices) const;
/// \brief Perform cheap validation checks to determine obvious inconsistencies
/// within the record batch's schema and internal data.
///
/// This is O(k) where k is the total number of fields and array descendents.
///
/// \return Status
virtual Status Validate() const;
/// \brief Perform extensive validation checks to determine inconsistencies
/// within the record batch's schema and internal data.
///
/// This is potentially O(k*n) where n is the number of rows.
///
/// \return Status
virtual Status ValidateFull() const;
protected:
RecordBatch(const std::shared_ptr& schema, int64_t num_rows);
std::shared_ptr schema_;
int64_t num_rows_;
private:
ARROW_DISALLOW_COPY_AND_ASSIGN(RecordBatch);
};
/// \brief Abstract interface for reading stream of record batches
class ARROW_EXPORT RecordBatchReader {
public:
using ValueType = std::shared_ptr;
virtual ~RecordBatchReader() = default;
/// \return the shared schema of the record batches in the stream
virtual std::shared_ptr schema() const = 0;
/// \brief Read the next record batch in the stream. Return null for batch
/// when reaching end of stream
///
/// \param[out] batch the next loaded batch, null at end of stream
/// \return Status
virtual Status ReadNext(std::shared_ptr* batch) = 0;
/// \brief Iterator interface
Result> Next() {
std::shared_ptr batch;
ARROW_RETURN_NOT_OK(ReadNext(&batch));
return batch;
}
/// \brief Consume entire stream as a vector of record batches
Status ReadAll(RecordBatchVector* batches);
/// \brief Read all batches and concatenate as arrow::Table
Status ReadAll(std::shared_ptr* table);
/// \brief Create a RecordBatchReader from a vector of RecordBatch.
///
/// \param[in] batches the vector of RecordBatch to read from
/// \param[in] schema schema to conform to. Will be inferred from the first
/// element if not provided.
static Result> Make(
RecordBatchVector batches, std::shared_ptr schema = NULLPTR);
};
} // namespace arrow