Package com.apple.foundationdb.record

Class ExecuteState

java.lang.Object
com.apple.foundationdb.record.ExecuteState
@API(UNSTABLE) 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 Details

    • NO_LIMITS

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

  • Constructor Details

    • 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

      public ExecuteState()

  • Method Details

    • 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

    • toString

      public String toString()
      Overrides:
      toString in class Object