Package com.apple.foundationdb.record

Class ExecuteState

  • @API(MAINTAINED)
public class ExecuteState
extends Object
    An encapsulation of the mutable state of query or scan execution. In general, parameters that affect a query/scan execution (as opposed to a query plan) belong here if they involve mutable state and in ExecuteProperties otherwise. In general, the state object should be constructed by as part of a "root" ExecuteProperties rather than directly by the client.

    • Field Detail

      • NO_LIMITS

        public static final ExecuteState NO_LIMITS
        An execute state with no scan limits.

      • NO_SCANNED_RECORDS_LIMIT

        @API(DEPRECATED)
@Deprecated
public static final ExecuteState NO_SCANNED_RECORDS_LIMIT
        Deprecated.
        in favor of NO_LIMITS when the byte scan limit was added
        An empty execute state with no scan limits.

    • Constructor Detail

      • ExecuteState

        public ExecuteState​(@Nullable
                    RecordScanLimiter recordScanLimiter,
                    @Nullable
                    ByteScanLimiter byteScanLimiter)
        Creates an execute state with a supplied set of resource limiters.
        Parameters:
        recordScanLimiter - a record scan limiter or null to indicate an unlimited number of records may be scanned
        byteScanLimiter - a byte scan limiter or null to indicate an unlimited number of bytes may be scanned

      • ExecuteState

        @API(DEPRECATED)
@Deprecated
public ExecuteState​(@Nullable
                    RecordScanLimiter recordScanLimiter)
        Deprecated.
        in favor of the constructor that takes multiple limiters
        A deprecated constructor that takes only a RecordScanLimiter and not a ByteScanLimiter.
        Parameters:
        recordScanLimiter - a RecordScanLimiter to use in this state

      • ExecuteState

        public ExecuteState()

    • Method Detail

      • reset

        @Nonnull
public ExecuteState reset()
        Create a new ExecuteState that represents the same properties of the execution that this state represented when it was first created, but with an independent set of mutable objects. For example, the RecordScanLimiter of the returned ExecuteState has a limit equal to the original limit that was used to create this state's RecordScanLimiter. It is up to the implementor to ensure that all components of the state are reset in a meaningful way, since this might vary depending on that piece of state.
        Returns:
        a new state that represents the same properties but does not share mutable state with this ExecuteState

      • getRecordScanLimiter

        @Nonnull
public RecordScanLimiter getRecordScanLimiter()
        Get a limiter for the maximum number of records that can be retrieved from the database. Note that this limit is not strictly enforced, depending on the underlying BaseCursor implementation. All base cursors are always permitted to load at least one key-value entry before it is stopped by the record scan limit to ensure that cursors with multiple child cursors (such as UnionCursor) can always make progress. Thus, a query execution might overrun its scanned records limit by up to the number of base cursors in the cursor tree. Particular base cursors may exceed the record scan limit in other ways, which are documented in their Javadocs.
        Returns:
        the record scan limiter

      • getByteScanLimiter

        @Nonnull
public ByteScanLimiter getByteScanLimiter()
        Get a limiter for the maximum number of bytes that can be retrieved from the database. Note that this limit is not strictly enforced, depending on the underlying BaseCursor implementation. All base cursors are always permitted to load at least one entry before it is stopped by the byte scan limit to ensure that cursors with multiple child cursors (such as UnionCursor) can always make progress. Thus, a query execution might overrun the byte scan limit by an effectively arbitrary amount. Particular base cursors may exceed the record scan limit in other ways which are documented in their Javadocs.
        Returns:
        the byte scan limiter

      • getRecordsScanned

        public int getRecordsScanned()
        Return the number of records that have been scanned.
        Returns:
        the number of records that have been scanned

      • getBytesScanned

        public long getBytesScanned()
        Return the number of bytes that have been scanned.
        Returns:
        the number of bytes that have been scanned