Enum FrontendMessage 

pub enum FrontendMessage {
    Startup {
        user: String,
        database: String,
        startup_params: Vec<(String, String)>,
    },
    PasswordMessage(String),
    Query(String),
    Parse {
        name: String,
        query: String,
        param_types: Vec<u32>,
    },
    Bind {
        portal: String,
        statement: String,
        params: Vec<Option<Vec<u8>>>,
    },
    Execute {
        portal: String,
        max_rows: i32,
    },
    Sync,
    Terminate,
    SASLInitialResponse {
        mechanism: String,
        data: Vec<u8>,
    },
    SASLResponse(Vec<u8>),
    GSSResponse(Vec<u8>),
    CopyFail(String),
    Close {
        is_portal: bool,
        name: String,
    },
}

Frontend (client → server) message types

Variants

Startup

Startup message (sent first, no type byte)

Fields

user: String

Database role / user name.

database: String

Target database name.

startup_params: Vec<(String, String)>

Additional startup parameters (e.g. replication=database).

PasswordMessage(String)

Password response (MD5 or cleartext).

Query(String)

Simple query (SQL text).

Parse

Parse (prepared statement)

Fields

name: String

Prepared statement name (empty string = unnamed).

query: String

SQL query text with $1-style parameter placeholders.

param_types: Vec<u32>

OIDs of the parameter types (empty = server infers).

Bind

Bind parameters to prepared statement

Fields

portal: String

Destination portal name (empty = unnamed).

statement: String

Source prepared statement name.

params: Vec<Option<Vec<u8>>>

Parameter values (None = SQL NULL).

Execute

Execute portal

Fields

portal: String

Portal name to execute.

max_rows: i32

Maximum rows to return (0 = no limit).

Sync

Sync — marks the end of an extended-query pipeline.

Terminate

Terminate — closes the connection.

SASLInitialResponse

SASL initial response (first message in SCRAM)

Fields

mechanism: String

SASL mechanism name (e.g. SCRAM-SHA-256).

data: Vec<u8>

Client-first message bytes.

SASLResponse(Vec<u8>)

SASL response (subsequent messages in SCRAM)

GSSResponse(Vec<u8>)

GSS/SSPI response token.

CopyFail(String)

CopyFail — abort a COPY IN with an error message

Close

Close — explicitly release a prepared statement or portal

Fields

is_portal: bool

true for portal, false for prepared statement.

name: String

Name of the portal or statement to close.

Implementations

impl FrontendMessage

pub fn encode_checked(&self) -> Result<Vec<u8>, FrontendEncodeError>

Fallible encoder that returns explicit reason on invalid input.

Trait Implementations

impl Clone for FrontendMessage

fn clone(&self) -> FrontendMessage

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for FrontendMessage

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

Formats the value using the given formatter.