Enum CaError 

pub enum CaError {
    Io(Error),
    Timeout,
    ChannelNotFound(String),
    Protocol(String),
    UnsupportedType(u16),
    WriteFailed(u32),
    FieldNotFound(String),
    ReadOnlyField(String),
    TypeMismatch(String),
    InvalidValue(String),
    BadField(String),
    BadChoice(String),
    BadDbrType(String),
    PutDisabled(String),
    LinkError(String),
    DbParseError {
        line: usize,
        token: String,
        message: String,
    },
    DbLoadFailed(String),
    CalcError(String),
    Disconnected,
    Shutdown,
    ServerError(u32),
    TooLarge,
    BadCount,
    GetConvertFailed(String),
}

Variants

Io(Error)

Timeout

ChannelNotFound(String)

Protocol(String)

UnsupportedType(u16)

WriteFailed(u32)

FieldNotFound(String)

ReadOnlyField(String)

TypeMismatch(String)

InvalidValue(String)

BadField(String)

C S_db_badField (“Illegal RECORD FIELD”) — a record’s special() refused the value that dbPut had already stored, e.g. calcRecord.c:146-152 returning it for an uncompilable CALC. The value stays written, the field’s monitor is not posted, the record is not processed, and the status propagates to the client (rsrv write_action → ECA_PUTFAIL).

BadChoice(String)

C S_db_badChoice (“Illegal choice”) — a DBR_STRING write to a DBF_MENU field named neither an exact choice label nor an in-range index (dbConvert.c::putStringMenu:1216-1229). C’s converter returns this from inside dbPut, before the value is stored (dbAccess.c:1362), so the field keeps its old value, no monitor is posted and the record is not processed.

BadDbrType(String)

C S_db_badDbrtype (“Illegal Database Request Type”) — dbPut refusing a put to a DBF link field (field_type > DBF_DEVICE, dbAccess.c:1340-1347). Only dbPutField changes link fields, by routing them through dbPutFieldLink (dbAccess.c:1261-1262); a dbPut reached from a record’s OUT link (dbPutLink → dbDbPutValue) or from internal code refuses, so a DB link cannot silently rewire another record’s link field. rsrv answers it with ECA_PUTFAIL like every non-zero put status — and with ECA_GETFAIL when the same refusal comes back from a get, which is why CaError::to_eca_status takes the direction.

PutDisabled(String)

LinkError(String)

DbParseError

A .db/.dbd parse abort, carried as C yyerror prints it (dbYacc.y:370-383): the line, the sentence, and yytext — the token the lexer had matched when the parser rejected it, which is what C quotes in its at or before '%s' clause. An empty token is a failure raised where no token was matched, and prints no such clause.

Fields

line: usize

token: String

message: String

DbLoadFailed(String)

C dbLoadRecords returning non-zero after yyerror(NULL) recovered from a bad item (dbAccess.c:795-813). The records that parsed are still there; the load’s status is the failure, and softMain exits 2 on it (softMain.cpp:198,274-278).

CalcError(String)

Disconnected

Shutdown

ServerError(u32)

Server-emitted ECA status carried out-of-band on an otherwise data-shaped frame — used by libca cac::eventAddRespAction (cac.cpp:973-977) when a monitor frame’s m_cid is non- NORMAL (e.g. ECA_NORDACCESS from no_read_access_event after an ACF reload). Routed to the per-subscription callback as Err(CaError::ServerError(eca_status)) so the subscriber surfaces the status instead of seeing the bogus zeroed payload that travels with the frame.

TooLarge

Request cannot be framed for the peer: it needs the extended (24-byte) CA header, and the peer’s protocol version predates CA_V49, or the element count exceeds what the peer can carry. libca raises this locally — comQueSend::insertRequestHeader throws cacChannel::outOfBounds() (comQueSend.cpp:299,313) and ca_array_get/ca_array_put return ECA_TOLARGE — so no byte reaches the wire.

BadCount

Element count out of bounds for the request C would build. libca’s put path throws cacChannel::outOfBounds() for an array that cannot fit the peer’s message-body limit (comQueSend.cpp:361) or that needs an extended header the peer cannot parse (comQueSend.cpp:313); oldChannelNotify.cpp:309,378,453 map that to ECA_BADCOUNT. Raised locally — no byte reaches the wire.

GetConvertFailed(String)

A get conversion returned a non-zero status: C dbGetConvertRoutine/dbFastGetConvertRoutine refusing to render a field in the requested DBR type, which for the DBF_STRING row means epicsParse* rejecting the stored text (cvt_st_d, dbFastLinkConv.c:233-244). dbChannel_get turns it into -1 (db_access.c:816) and rsrv answers the read with a ZEROED payload and m_cid = ECA_GETFAIL (camessage.c:545-561) rather than a value. Distinct from Self::InvalidValue, which the put direction raises and rsrv answers ECA_PUTFAIL.

Implementations

impl CaError

pub fn to_eca_status(&self, op: CaOp) -> u32

The ECA status a CA CLIENT reports for this error on op.

Layered as C’s read_action/write_action are. A status the error already carries, or that a gate ABOVE the database produced, is the same word whichever way the request was going; everything the database itself refused is decided by op alone, because that is the point at which C stops looking at the status.

This is the client-side table, which sees libca’s local statuses too. The server’s reply table is PutStatus::of_failure (epics-ca-rs/src/server/tcp.rs) and is deliberately narrower: by the time rsrv reaches dbChannel_put, the gates above it have already answered, so every error left there is a database refusal.

Trait Implementations

impl Debug for CaError

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for CaError

fn fmt(&self, __formatter: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Error for CaError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl From<CaError> for AutosaveError

fn from(e: CaError) -> Self

Converts to this type from the input type.

impl From<CaError> for IocRunFailure

The lifecycle’s default phase: every ? inside it is a boot step, which is why only the two exceptions are written out by hand.

fn from(e: CaError) -> Self

Converts to this type from the input type.

impl From<Error> for CaError

fn from(source: Error) -> Self

Converts to this type from the input type.

impl From<IocRunFailure> for CaError

fn from(failure: IocRunFailure) -> Self

Converts to this type from the input type.