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package chord
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import (
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	"context"
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	"errors"
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	"github.com/twitchtv/twirp"
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)
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type Error struct {
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	msg string
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}
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func (e *Error) Error() string {
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	return e.msg
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}
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var (
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	ErrJoinInvalidState     = errorDef("chord/membership: node cannot handle join request at the moment", true)
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	ErrJoinTransferFailure  = errorDef("chord/membership: failed to transfer keys to joiner node", true)
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	ErrJoinInvalidSuccessor = errorDef("chord/membership: join request was routed to the wrong successor node", true)
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	ErrLeaveInvalidState    = errorDef("chord/membership: node cannot handle leave request at the moment", true)
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	ErrLeaveTransferFailure = errorDef("chord/membership: failed to transfer keys to successor node", true)
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	ErrKVStaleOwnership     = errorDef("chord/kv: processing node no longer has ownership over requested key", true)
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	ErrKVPendingTransfer    = errorDef("chord/kv: kv transfer inprogress, state may be outdated", true)
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	ErrNodeGone          = errorDef("chord: node is not part of the chord ring", false)
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	ErrNodeNotStarted    = errorDef("chord: node is not running", false)
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	ErrNodeNoSuccessor   = errorDef("chord: node has no successor, possibly invalid chord ring", false)
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	ErrNodeNil           = errorDef("chord: node cannot be nil", false)
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	ErrDuplicateJoinerID = errorDef("chord/membership: joining node has duplicate ID as its successor", false)
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	ErrKVSimpleConflict  = errorDef("chord/kv: simple key was concurrently modified", false)
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	ErrKVPrefixConflict  = errorDef("chord/kv: child already exists under prefix", false)
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	ErrKVLeaseConflict   = errorDef("chord/kv: lease has not expired or was acquired by a different requester", false)
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	ErrKVLeaseExpired    = errorDef("chord/kv: lease has expired with the given token", false)
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	ErrKVLeaseInvalidTTL = errorDef("chord/kv: lease ttl must be greater than a second", false)
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	ErrKVHashFnChanged   = errorDef("chord/kv: calculated hash is different from storage", false)
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)
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func ErrorIsRetryable(err error) bool {
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	for _, e := range retryableErrs {
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		if errors.Is(err, e) {
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			return true
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		}
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	}
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	return false
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}
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// this is needed because RPC call squash type information, so in call site with signature
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// if err == ErrABC will fail (but err.Error() == ErrABC.Error() will work).
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func ErrorMapper(err error) error {
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	if err == nil {
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		return err
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	}
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	var (
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		srcErr    = err.Error()
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		parsedErr = err
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	)
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	if twirpErr, ok := err.(twirp.Error); ok {
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		srcErr = twirpErr.Msg()
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	}
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	if mapped, ok := errorStrMap[srcErr]; ok {
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		parsedErr = mapped
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	}
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	return parsedErr
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}
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var retryableErrs []error = []error{
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	context.DeadlineExceeded,
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}
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var errorStrMap map[string]error = map[string]error{}
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func errorDef(str string, retryable bool) error {
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	err := &Error{
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		msg: str,
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	}
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	if retryable {
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		retryableErrs = append(retryableErrs, err)
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	}
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	errorStrMap[str] = err
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	return err
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}