Enum Message 

#[non_exhaustive]
pub enum Message {
    AuthenticationOk,
    AuthenticationCleartextPassword,
    AuthenticationMd5Password(AuthenticationMd5PasswordBody),
    AuthenticationSasl(AuthenticationSaslBody),
    AuthenticationSaslContinue(AuthenticationSaslContinueBody),
    AuthenticationSaslFinal(AuthenticationSaslFinalBody),
    BackendKeyData(BackendKeyDataBody),
    BindComplete,
    CloseComplete,
    CommandComplete(CommandCompleteBody),
    CopyData(CopyDataBody),
    CopyDone,
    CopyInResponse(CopyInResponseBody),
    CopyOutResponse(CopyOutResponseBody),
    DataRow(DataRowBody),
    EmptyQueryResponse,
    ErrorResponse(ErrorResponseBody),
    NoData,
    NoticeResponse(NoticeResponseBody),
    NotificationResponse(NotificationResponseBody),
    ParameterDescription(ParameterDescriptionBody),
    ParameterStatus(ParameterStatusBody),
    ParseComplete,
    PortalSuspended,
    ReadyForQuery(ReadyForQueryBody),
    RowDescription(RowDescriptionBody),
}

An enum representing backend messages from Hyper server.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

AuthenticationOk

Authentication request completed successfully.

AuthenticationCleartextPassword

Authentication via cleartext password.

AuthenticationMd5Password(AuthenticationMd5PasswordBody)

Authentication via MD5 password.

AuthenticationSasl(AuthenticationSaslBody)

Authentication via SASL.

AuthenticationSaslContinue(AuthenticationSaslContinueBody)

SASL authentication continue.

AuthenticationSaslFinal(AuthenticationSaslFinalBody)

SASL authentication final.

BackendKeyData(BackendKeyDataBody)

Backend key data for cancel requests.

BindComplete

Bind operation complete.

CloseComplete

Close operation complete.

CommandComplete(CommandCompleteBody)

Command completed.

CopyData(CopyDataBody)

COPY data.

CopyDone

COPY operation done.

CopyInResponse(CopyInResponseBody)

COPY IN response (client should send data).

CopyOutResponse(CopyOutResponseBody)

COPY OUT response (server will send data).

DataRow(DataRowBody)

A row of data.

EmptyQueryResponse

Empty query response.

ErrorResponse(ErrorResponseBody)

Error response.

NoData

No data (for empty result sets).

NoticeResponse(NoticeResponseBody)

Notice response (warning).

NotificationResponse(NotificationResponseBody)

Notification from LISTEN/NOTIFY.

ParameterDescription(ParameterDescriptionBody)

Parameter description for prepared statement.

ParameterStatus(ParameterStatusBody)

Parameter status update.

ParseComplete

Parse operation complete.

PortalSuspended

Portal suspended (for partial results).

ReadyForQuery(ReadyForQueryBody)

Ready for query.

RowDescription(RowDescriptionBody)

Row description (column metadata).

Implementations

impl Message

pub fn parse(buf: &mut BytesMut) -> Result<Option<Message>>

Parses a backend message from a buffer.

Reads the message header (5 bytes: tag + length) and parses the complete message body. Returns Ok(None) if the buffer doesn’t contain a complete message yet. The buffer is advanced when a complete message is parsed.

Arguments

• buf - Buffer containing message data (may be partial)

Errors

• Returns io::ErrorKind::InvalidInput if the declared length field is less than 4 (below the minimum valid message size).
• Returns an I/O error from the inner Buffer reads when a body field is truncated, a C-string is not NUL-terminated, or a string field contains invalid UTF-8.
• Returns io::ErrorKind::InvalidInput for unexpected authentication sub-tags or unknown top-level message tags.

Panics

Does not panic in practice. The read_u32 call on &buf[1..5] is proven infallible by the preceding buf.len() < 5 short-circuit.

Trait Implementations

impl Debug for Message

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

Formats the value using the given formatter.