postgleam/message

Types

AuthType

Authentication request types

pub type AuthType {
  AuthOk
  AuthKerberos
  AuthCleartext
  AuthMd5(salt: BitArray)
  AuthScm
  AuthGss
  AuthGssContinue(data: BitArray)
  AuthSspi
  AuthSasl(mechanisms: List(String))
  AuthSaslContinue(data: BitArray)
  AuthSaslFinal(data: BitArray)
}

Constructors

```
AuthOk
```
```
AuthKerberos
```
```
AuthCleartext
```
```
AuthMd5(salt: BitArray)
```
```
AuthScm
```
```
AuthGss
```
```
AuthGssContinue(data: BitArray)
```
```
AuthSspi
```
```
AuthSasl(mechanisms: List(String))
```
```
AuthSaslContinue(data: BitArray)
```
```
AuthSaslFinal(data: BitArray)
```

BackendMessage

</>

Messages sent from PostgreSQL backend to client

pub type BackendMessage {
  AuthenticationMsg(auth: AuthType)
  BackendKeyData(pid: Int, key: Int)
  ReadyForQuery(status: TransactionStatus)
  ParameterStatus(name: String, value: String)
  RowDescription(fields: List(RowField))
  DataRow(values: BitArray)
  CommandComplete(tag: String)
  ParseComplete
  BindComplete
  CloseComplete
  NoData
  PortalSuspended
  EmptyQueryResponse
  ErrorResponse(fields: dict.Dict(String, String))
  NoticeResponse(fields: dict.Dict(String, String))
  NotificationResponse(
    pg_pid: Int,
    channel: String,
    payload: String,
  )
  ParameterDescription(type_oids: List(Int))
  CopyInResponse(format: Format, columns: List(Format))
  CopyOutResponse(format: Format, columns: List(Format))
  CopyBothResponse(format: Format, columns: List(Format))
  CopyData(data: BitArray)
  CopyDone
}

Constructors

```
AuthenticationMsg(auth: AuthType)
```
```
BackendKeyData(pid: Int, key: Int)
```

ReadyForQuery(status: TransactionStatus)

ParameterStatus(name: String, value: String)

```
RowDescription(fields: List(RowField))
```
```
DataRow(values: BitArray)
```
```
CommandComplete(tag: String)
```
```
ParseComplete
```
```
BindComplete
```
```
CloseComplete
```
```
NoData
```
```
PortalSuspended
```
```
EmptyQueryResponse
```

ErrorResponse(fields: dict.Dict(String, String))

NoticeResponse(fields: dict.Dict(String, String))

NotificationResponse(
  pg_pid: Int,
  channel: String,
  payload: String,
)

ParameterDescription(type_oids: List(Int))

CopyInResponse(format: Format, columns: List(Format))

CopyOutResponse(format: Format, columns: List(Format))

CopyBothResponse(format: Format, columns: List(Format))

```
CopyData(data: BitArray)
```
```
CopyDone
```

DecodeResult

</>

Result of trying to decode a message from a byte buffer

pub type DecodeResult {
  Decoded(message: BackendMessage, rest: BitArray)
  Incomplete
  DecodeFailed(reason: String)
}

Constructors

```
Decoded(message: BackendMessage, rest: BitArray)
```
Successfully decoded a message, with remaining bytes
```
Incomplete
```
Not enough data yet — need more bytes
```
DecodeFailed(reason: String)
```
Unrecoverable decode error

DescribeType

</>

Describe target type

pub type DescribeType {
  DescribeStatement
  DescribePortal
}

Constructors

```
DescribeStatement
```
```
DescribePortal
```

Format

</>

Format code for column data

pub type Format {
  TextFormat
  BinaryFormat
}

Constructors

```
TextFormat
```
```
BinaryFormat
```

FrontendMessage

</>

Messages sent from client to PostgreSQL backend

pub type FrontendMessage {
  StartupMessage(params: List(#(String, String)))
  PasswordMessage(password: String)
  SASLInitialResponse(mechanism: String, data: BitArray)
  SASLResponse(data: BitArray)
  SimpleQuery(statement: String)
  Parse(name: String, statement: String, type_oids: List(Int))
  Describe(type_: DescribeType, name: String)
  Bind(
    portal: String,
    statement: String,
    param_formats: List(Format),
    params: List(option.Option(BitArray)),
    result_formats: List(Format),
  )
  Execute(portal: String, max_rows: Int)
  Close(type_: DescribeType, name: String)
  Sync
  Flush
  Terminate
  SSLRequest
  CancelRequest(pid: Int, key: Int)
  CopyDataMsg(data: BitArray)
  CopyDoneMsg
  CopyFail(message: String)
}

Constructors

StartupMessage(params: List(#(String, String)))

```
PasswordMessage(password: String)
```

SASLInitialResponse(mechanism: String, data: BitArray)

```
SASLResponse(data: BitArray)
```
```
SimpleQuery(statement: String)
```

Parse(name: String, statement: String, type_oids: List(Int))

Describe(type_: DescribeType, name: String)

Bind(
  portal: String,
  statement: String,
  param_formats: List(Format),
  params: List(option.Option(BitArray)),
  result_formats: List(Format),
)

```
Execute(portal: String, max_rows: Int)
```

Close(type_: DescribeType, name: String)

```
Sync
```
```
Flush
```
```
Terminate
```
```
SSLRequest
```
```
CancelRequest(pid: Int, key: Int)
```
```
CopyDataMsg(data: BitArray)
```
```
CopyDoneMsg
```
```
CopyFail(message: String)
```

RowField

</>

A field descriptor in a RowDescription

pub type RowField {
  RowField(
    name: String,
    table_oid: Int,
    column: Int,
    type_oid: Int,
    type_size: Int,
    type_mod: Int,
    format: Format,
  )
}

Constructors

RowField(
  name: String,
  table_oid: Int,
  column: Int,
  type_oid: Int,
  type_size: Int,
  type_mod: Int,
  format: Format,
)

TransactionStatus

</>

Transaction status reported by ReadyForQuery

pub type TransactionStatus {
  Idle
  InTransaction
  FailedTransaction
}

Constructors

```
Idle
```
```
InTransaction
```
```
FailedTransaction
```

Values

decode_backend

</>

pub fn decode_backend(buffer: BitArray) -> DecodeResult

Try to decode one backend message from a byte buffer. Returns Decoded(msg, remaining_bytes), Incomplete, or DecodeFailed.

decode_cstring

</>

pub fn decode_cstring(
  data: BitArray,
) -> Result(#(String, BitArray), Nil)

Decode a null-terminated C string from a BitArray. Returns the string and the remaining bytes after the null terminator.

encode_frontend

</>

pub fn encode_frontend(msg: FrontendMessage) -> BitArray

Encode a frontend message to bytes ready to send on the wire

extract_row_values

</>

pub fn extract_row_values(
  values: BitArray,
) -> List(option.Option(BitArray))

Extract column values from a DataRow’s raw value bytes. Returns a list of Option(BitArray) — None for NULL columns.