Package org.apache.kafka.streams.state

Interface WindowStore<K,​V>

    • Method Detail

      • put

        @Deprecated
void put​(K key,
         V value)
        Deprecated.
        as timestamp is not provided for the key-value pair, this causes inconsistency to identify the window frame to which the key belongs. Use put(Object, Object, long) instead.
        Use the current record timestamp as the windowStartTimestamp and delegate to put(Object, Object, long).

        It's highly recommended to use put(Object, Object, long) instead, as the record timestamp is unlikely to be the correct windowStartTimestamp in general.

        Parameters:
        key - The key to associate the value to
        value - The value to update, it can be null; if the serialized bytes are also null it is interpreted as delete
        Throws:
        NullPointerException - if the given key is null

      • put

        void put​(K key,
         V value,
         long windowStartTimestamp)
        Put a key-value pair into the window with given window start timestamp

        If serialized value bytes are null it is interpreted as delete. Note that deletes will be ignored in the case of an underlying store that retains duplicates.

        Parameters:
        key - The key to associate the value to
        value - The value; can be null
        windowStartTimestamp - The timestamp of the beginning of the window to put the key/value into
        Throws:
        NullPointerException - if the given key is null

      • fetch

        WindowStoreIterator<V> fetch​(K key,
                             long timeFrom,
                             long timeTo)
        Get all the key-value pairs with the given key and the time range from all the existing windows.

        This iterator must be closed after use.

        The time range is inclusive and applies to the starting timestamp of the window. For example, if we have the following windows: 

         +-------------------------------+
 |  key  | start time | end time |
 +-------+------------+----------+
 |   A   |     10     |    20    |
 +-------+------------+----------+
 |   A   |     15     |    25    |
 +-------+------------+----------+
 |   A   |     20     |    30    |
 +-------+------------+----------+
 |   A   |     25     |    35    |
 +--------------------------------
        And we call store.fetch("A", 10, 20) then the results will contain the first three windows from the table above, i.e., all those where 10 <= start time <= 20.

        For each key, the iterator guarantees ordering of windows, starting from the oldest/earliest available window to the newest/latest window.

        Specified by:
        fetch in interface ReadOnlyWindowStore<K,​V>
        Parameters:
        key - the key to fetch
        timeFrom - time range start (inclusive)
        timeTo - time range end (inclusive)
        Returns:
        an iterator over key-value pairs <timestamp, value>
        Throws:
        InvalidStateStoreException - if the store is not initialized
        NullPointerException - if the given key is null

      • fetch

        default WindowStoreIterator<V> fetch​(K key,
                                     Instant from,
                                     Instant to)
        Description copied from interface: ReadOnlyWindowStore
        Get all the key-value pairs with the given key and the time range from all the existing windows.

        This iterator must be closed after use.

        The time range is inclusive and applies to the starting timestamp of the window. For example, if we have the following windows: 

         +-------------------------------+
 |  key  | start time | end time |
 +-------+------------+----------+
 |   A   |     10     |    20    |
 +-------+------------+----------+
 |   A   |     15     |    25    |
 +-------+------------+----------+
 |   A   |     20     |    30    |
 +-------+------------+----------+
 |   A   |     25     |    35    |
 +--------------------------------
        And we call store.fetch("A", Instant.ofEpochMilli(10), Instant.ofEpochMilli(20)) then the results will contain the first three windows from the table above, i.e., all those where 10 <= start time <= 20.

        For each key, the iterator guarantees ordering of windows, starting from the oldest/earliest available window to the newest/latest window.

        Specified by:
        fetch in interface ReadOnlyWindowStore<K,​V>
        Parameters:
        key - the key to fetch
        from - time range start (inclusive)
        to - time range end (inclusive)
        Returns:
        an iterator over key-value pairs <timestamp, value>

      • fetch

        KeyValueIterator<Windowed<K>,​V> fetch​(K from,
                                            K to,
                                            long timeFrom,
                                            long timeTo)
        Get all the key-value pairs in the given key range and time range from all the existing windows.

        This iterator must be closed after use.

        Specified by:
        fetch in interface ReadOnlyWindowStore<K,​V>
        Parameters:
        from - the first key in the range
        to - the last key in the range
        timeFrom - time range start (inclusive)
        timeTo - time range end (inclusive)
        Returns:
        an iterator over windowed key-value pairs <Windowed<K>, value>
        Throws:
        InvalidStateStoreException - if the store is not initialized
        NullPointerException - if one of the given keys is null

      • fetch

        default KeyValueIterator<Windowed<K>,​V> fetch​(K from,
                                                    K to,
                                                    Instant fromTime,
                                                    Instant toTime)
        Description copied from interface: ReadOnlyWindowStore
        Get all the key-value pairs in the given key range and time range from all the existing windows.

        This iterator must be closed after use.

        Specified by:
        fetch in interface ReadOnlyWindowStore<K,​V>
        Parameters:
        from - the first key in the range
        to - the last key in the range
        fromTime - time range start (inclusive)
        toTime - time range end (inclusive)
        Returns:
        an iterator over windowed key-value pairs <Windowed<K>, value>

      • fetchAll

        KeyValueIterator<Windowed<K>,​V> fetchAll​(long timeFrom,
                                               long timeTo)
        Gets all the key-value pairs that belong to the windows within in the given time range.
        Specified by:
        fetchAll in interface ReadOnlyWindowStore<K,​V>
        Parameters:
        timeFrom - the beginning of the time slot from which to search (inclusive)
        timeTo - the end of the time slot from which to search (inclusive)
        Returns:
        an iterator over windowed key-value pairs <Windowed<K>, value>
        Throws:
        InvalidStateStoreException - if the store is not initialized

      • fetchAll

        default KeyValueIterator<Windowed<K>,​V> fetchAll​(Instant from,
                                                       Instant to)
        Description copied from interface: ReadOnlyWindowStore
        Gets all the key-value pairs that belong to the windows within in the given time range.
        Specified by:
        fetchAll in interface ReadOnlyWindowStore<K,​V>
        Parameters:
        from - the beginning of the time slot from which to search (inclusive)
        to - the end of the time slot from which to search (inclusive)
        Returns:
        an iterator over windowed key-value pairs <Windowed<K>, value>