@node chainqueue-states
@section State transitions

Queued transactions are controlled using a combination of state bits, enumerated to human-readable labels.

Some of these bits may only be set if certain bits have previously been set.

Certain combinations of bits constitute @emph{semantic} states, intended for human consumption.


@subsection State bits

@table @code
@item QUEUED
Transaction is ready to send to network. 
@item RESERVED
Transaction is assigned to a process which will send it to the network.
@item IN_NETWORK
The transaction has been sent to the network.
@item DEFERRED
A transaction send could not be completed, and should be retried later.
@item GAS_ISSUES
The transaction sender does not have sufficient network token balance to send the transaction.
@item LOCAL_ERROR
The transaction request could not be sent, e.g. because the node was unavailable.
@item NODE_ERROR
The network gateway node rejected the transaction. (will always be a FINAL state).
@item NETWORK_ERROR
The network rejected the state change requested by the transaction (will always be a FINAL state).
@item UNKNOWN_ERROR
Any other error (will always be a FINAL state).
@item FINAL
The transaction request will not be processed further.
@item OBSOLETE
The transaction request has been superseded by a different transaction, e.g. an identical replacement transaction with a higher fee.
@item MANUAL
The state of the transaction request has been manipulated manually.
@end table

@subsection State bit transitions

When the @strong{FINAL} bit is set, no further state changes may be made.

@multitable .25. 75
@headitem bit
@tab precondition
@item QUEUED
@tab @emph{none} | DEFERRED | GAS_ISSUES
@item RESERVED
@tab QUEUED
@item IN_NETWORK
@tab RESERVED
@item GAS_ISSUES
@tab @emph{none}
@item DEFERRED
@tab RESERVED
@end multitable


@subsection State semantics

@subsubsection Clean states

@multitable .25 .50 .25
@headitem state
@tab description
@tab bits set
@item PENDING
@tab The state of the transaction when it first enters the queue.
@tab (none)
@item READYSEND
@tab Transaction is ready to send to network
@tab QUEUED
@item RESERVED
@tab Transaction is assigned to a process which will send it to the network.
@tab QUEUED, RESERVED
@item SENT
@tab Transaction has been sent to the network
@tab IN_NETWORK
@item SUCCESS
@tab The transaction has successfully changed the network state.
@tab IN_NETWORK, FINAL
@item REVERTED
@tab The transaction was included by the network, but failed to change the network state.
@tab IN_NETWORK, NETWORK_ERROR, FINAL
@end multitable


@subsubsection Exception states

@multitable .25 .50 .25
@headitem state
@tab description
@tab bits set
@item GAS_ISSUES
@tab The transaction sender does not have sufficient network token balance to send the transaction.
@tab GAS_ISSUES
@item RETRY
@tab Transaction should be retried after a grace period
@tab QUEUED, DEFERRED
@item SENDFAIL
@tab The transaction request could not be sent, e.g. because the node was unavailable.
@tab DEFERRED, LOCAL_ERROR
@item REJECTED
@tab The transaction was rejected by the node. 
@tab NODE_ERROR, FINAL
@end multitable


@subsubsection Replacement states

@multitable .25 .50 .25
@headitem state
@tab description
@tab bits set
@item OBSOLETED
@tab A attempt has been made to replace the transaction. 
@tab OBSOLETE[, IN_NETWORK]
@item CANCELLED
@tab A different replacement transaction has been confirmed by the network.
@tab OBSOLETE, FINAL[, IN_NETWORK]
@item OVERRIDDEN
@tab The transaction has been cancelled by an explicit command.
@tab OBSOLETE, FINAL, MANUAL[, IN_NETWORK]
@end multitable


@subsection State log

State transisitons can optionally be logged. This provides a list of date to state bitfield values for every change for every transaction.