A batch of zero or more rows returned by a scan operation. More...

#include <scan_batch.h>

Inheritance diagram for kudu::client::KuduScanBatch:

Collaboration diagram for kudu::client::KuduScanBatch:

Public Types
typedef RowPtr	value_type
	A handy typedef for the RowPtr.

Public Member Functions

int NumRows () const

KuduScanBatch::RowPtr Row (int idx) const

const_iterator begin () const

const_iterator end () const

const KuduSchema * projection_schema () const

RowPtr ()

bool IsNull (const Slice &col_name) const

bool IsNull (int col_idx) const

const void * cell (int col_idx) const

std::string ToString () const

KuduScanBatch::RowPtr operator* () const

const_iterator & operator++ ()

const_iterator operator++ (int)

bool operator== (const const_iterator &other) const

bool operator!= (const const_iterator &other) const

Advanced/Unstable API

There are no guarantees on the stability of the format returned by these methods, which might change at any given time.

Note: The Slices returned by both direct_data() and indirect_data() are only valid for the lifetime of the KuduScanBatch.

Slice direct_data () const

Slice indirect_data () const

Getters for integral type columns by column name.

Parameters

[in]	col_name	The name of the target column.
[out]	val	Placeholder for the result value.

Returns

Operation result status. Return a bad Status if at least one of the following is true:

The type does not match.
The value is unset.
The value is NULL.

Status GetBool (const Slice &col_name, bool *val) const WARN_UNUSED_RESULT

Status GetInt8 (const Slice &col_name, int8_t *val) const WARN_UNUSED_RESULT

Status GetInt16 (const Slice &col_name, int16_t *val) const WARN_UNUSED_RESULT

Status GetInt32 (const Slice &col_name, int32_t *val) const WARN_UNUSED_RESULT

Status GetInt64 (const Slice &col_name, int64_t *val) const WARN_UNUSED_RESULT

Status GetUnixTimeMicros (const Slice &col_name, int64_t *micros_since_utc_epoch) const WARN_UNUSED_RESULT

Status GetFloat (const Slice &col_name, float *val) const WARN_UNUSED_RESULT

Status GetDouble (const Slice &col_name, double *val) const WARN_UNUSED_RESULT

Getters for integral type columns by column index.

These methods are faster than their name-based counterparts since using indices avoids a hashmap lookup, so index-based getters should be preferred in performance-sensitive code.

Parameters

[in]	col_index	The index of the column.
[out]	val	Pointer to the placeholder to put the resulting value.

Returns

Operation result status. Return a bad Status if at least one of the following is true:

The type does not match.
The value is unset.
The value is NULL.

Status GetBool (int col_idx, bool *val) const WARN_UNUSED_RESULT

Status GetInt8 (int col_idx, int8_t *val) const WARN_UNUSED_RESULT

Status GetInt16 (int col_idx, int16_t *val) const WARN_UNUSED_RESULT

Status GetInt32 (int col_idx, int32_t *val) const WARN_UNUSED_RESULT

Status GetInt64 (int col_idx, int64_t *val) const WARN_UNUSED_RESULT

Status GetUnixTimeMicros (int col_idx, int64_t *micros_since_utc_epoch) const WARN_UNUSED_RESULT

Status GetFloat (int col_idx, float *val) const WARN_UNUSED_RESULT

Status GetDouble (int col_idx, double *val) const WARN_UNUSED_RESULT

Getters for string/binary column by column name.

Get the string/binary value for a column by its name.

Parameters

[in]	col_name	Name of the column.
[out]	val	Pointer to the placeholder to put the resulting value. Note that the method does not copy the value. Callers should copy the resulting Slice if necessary.

Returns

Operation result status. Return a bad Status if at least one of the following is true:

The type does not match.
The value is unset.
The value is NULL.

Status GetString (const Slice &col_name, Slice *val) const WARN_UNUSED_RESULT

Status GetBinary (const Slice &col_name, Slice *val) const WARN_UNUSED_RESULT

Getters for string/binary column by column index.

Get the string/binary value for a column by its index.

These methods are faster than their name-based counterparts since using indices avoids a hashmap lookup, so index-based getters should be preferred in performance-sensitive code.

Parameters

[in]	col_index	The index of the column.
[out]	val	Pointer to the placeholder to put the resulting value. Note that the method does not copy the value. Callers should copy the resulting Slice if necessary.

Returns

Operation result status. Return a bad Status if at least one of the following is true:

The type does not match.
The value is unset.
The value is NULL.

Status GetString (int col_idx, Slice *val) const WARN_UNUSED_RESULT

Status GetBinary (int col_idx, Slice *val) const WARN_UNUSED_RESULT

Detailed Description

A batch of zero or more rows returned by a scan operation.

Every call to KuduScanner::NextBatch() returns a batch of zero or more rows. You can iterate over the rows in the batch using:

range-foreach loop (C++11):

for (KuduScanBatch::RowPtr row : batch) {
  ... row.GetInt(1, ...)
  ...
}

regular for loop (C++03):

for (KuduScanBatch::const_iterator it = batch.begin(), it != batch.end();
     ++it) {
  KuduScanBatch::RowPtr row(*it);
  ...
}

or

for (int i = 0, num_rows = batch.NumRows();
     i < num_rows;
     i++) {
  KuduScanBatch::RowPtr row = batch.Row(i);
  ...
}

Note: In the above example, NumRows() is only called once at the beginning of the loop to avoid extra calls to the non-inlined method.

Member Function Documentation

KuduScanBatch::const_iterator kudu::client::KuduScanBatch::begin ( ) const

inline

Returns: Forward iterator to the start of the rows in the batch.

const void* kudu::client::KuduScanBatch::cell ( int col_idx ) const

Get the column's row data.

Note: Should be avoided unless absolutely necessary.

Parameters

[in] col_idx The index of the column.

Returns: Raw cell data for the specified index.

Slice kudu::client::KuduScanBatch::direct_data ( ) const

Return a slice that points to the direct row data received from the server. Users of this API must have knowledge of the data format in order to decode the data.

Returns: a Slice that points to the raw direct row data.

KuduScanBatch::const_iterator kudu::client::KuduScanBatch::end ( ) const

inline

Returns: Forward iterator to the end of the rows in the batch.

Slice kudu::client::KuduScanBatch::indirect_data ( ) const

Like the method above, but for indirect data.

Returns: a Slice that points to the raw indirect row data.

bool kudu::client::KuduScanBatch::IsNull ( const Slice & col_name ) const

Parameters

[in] col_name Name of the column.

Returns: true iff the specified column of the row has NULL value.

bool kudu::client::KuduScanBatch::IsNull ( int col_idx ) const

Parameters

[in] col_idx Index of the column.

Returns: true iff the specified column of the row has NULL value.

int kudu::client::KuduScanBatch::NumRows ( ) const

Returns: The number of rows in this batch.

bool kudu::client::KuduScanBatch::operator!= ( const const_iterator & other ) const

inline

An operator to check whether two iterators are 'not equal'.

Parameters

[in] other The iterator to compare with.

Returns: true iff the other iterator points to a different row in the same batch, or to a row belonging to a different batch altogether.

KuduScanBatch::RowPtr kudu::client::KuduScanBatch::operator* ( ) const

inline

Returns: The row in the batch the iterator is pointing at.

const_iterator& kudu::client::KuduScanBatch::operator++ ( )

inline

Prefix increment operator: advances the iterator to the next position.

Returns: The reference to the iterator, pointing to the next position.

const_iterator kudu::client::KuduScanBatch::operator++ ( int )

inline

Postfix increment operator: advances the iterator to the next position.

Returns: A copy of the iterator pointing to the pre-increment position.

bool kudu::client::KuduScanBatch::operator== ( const const_iterator & other ) const

inline

An operator to check whether two iterators are 'equal'.

Parameters

[in] other The iterator to compare with.

Returns: true iff the other iterator points to the same row of the same batch.

const KuduSchema* kudu::client::KuduScanBatch::projection_schema ( ) const

Returns: The projection schema for this batch. All KuduScanBatch::RowPtr returned by this batch are guaranteed to have this schema.

KuduScanBatch::RowPtr kudu::client::KuduScanBatch::Row ( int idx ) const

Get a row at the specified index.

Parameters

[in] idx The index of the row to return.

Returns: A reference to one of the rows in this batch. The returned object is only valid for as long as this KuduScanBatch object is valid.

kudu::client::KuduScanBatch::RowPtr ( )

inline

Construct an invalid RowPtr. Before use, you must assign a properly-initialized value.

std::string kudu::client::KuduScanBatch::ToString ( ) const

Returns: String representation for this row.

The documentation for this class was generated from the following file:

include/kudu/client/scan_batch.h

Public Types

Public Member Functions

Detailed Description

Member Function Documentation