Struct Session

pub struct Session {

    pub in_transaction: bool,
    pub shard_sessions: Vec<ShardSession>,
    pub autocommit: bool,
    pub target_string: String,
    pub options: Option<ExecuteOptions>,
    pub transaction_mode: i32,
    pub warnings: Vec<QueryWarning>,
    pub pre_sessions: Vec<ShardSession>,
    pub post_sessions: Vec<ShardSession>,
    pub last_insert_id: u64,
    pub found_rows: u64,
    pub user_defined_variables: HashMap<String, BindVariable>,
    pub system_variables: HashMap<String, String>,
    pub row_count: i64,
    pub savepoints: Vec<String>,
    pub in_reserved_conn: bool,
    pub lock_session: Option<ShardSession>,
    pub last_lock_heartbeat: i64,
    pub read_after_write: Option<ReadAfterWrite>,
    pub ddl_strategy: String,
    pub session_uuid: String,
    pub enable_system_settings: bool,
    pub advisory_lock: HashMap<String, i64>,
    pub query_timeout: i64,
    pub prepare_statement: HashMap<String, PrepareData>,
    pub migration_context: String,
}

Session objects are exchanged like cookies through various calls to VTGate. The behavior differs between V2 & V3 APIs. V3 APIs are Execute, ExecuteBatch and StreamExecute. All other APIs are V2. For the V3 APIs, the session must be sent with every call to Execute or ExecuteBatch. For the V2 APIs, Begin does not accept a session. It instead returns a brand new one with in_transaction set to true. After a call to Commit or Rollback, the session can be discarded. If you’re not in a transaction, Session is an optional parameter for the V2 APIs.

Fields

in_transaction: bool

in_transaction is set to true if the session is in a transaction.

shard_sessions: Vec<ShardSession>

shard_sessions keep track of per-shard transaction info.

autocommit: bool

autocommit specifies if the session is in autocommit mode. This is used only for V3.

target_string: String

target_string is the target expressed as a string. Valid names are: keyspace:shard@target, keyspace@target or @target. This is used only for V3.

options: Option<ExecuteOptions>

options is used only for V3.

transaction_mode: i32

transaction_mode specifies the current transaction mode.

warnings: Vec<QueryWarning>

warnings contains non-fatal warnings from the previous query

pre_sessions: Vec<ShardSession>

pre_sessions contains sessions that have to be committed first.

post_sessions: Vec<ShardSession>

post_sessions contains sessions that have to be committed last.

last_insert_id: u64

last_insert_id keeps track of the last seen insert_id for this session

found_rows: u64

found_rows keeps track of how many rows the last query returned

user_defined_variables: HashMap<String, BindVariable>

user_defined_variables contains all the @variables defined for this session

system_variables: HashMap<String, String>

system_variables keeps track of all session variables set for this connection TODO: systay should we keep this so we can apply it ordered?

row_count: i64

row_count keeps track of the last seen rows affected for this session

savepoints: Vec<String>

Stores savepoint and release savepoint calls inside a transaction and is reset once transaction is committed or rolled back.

in_reserved_conn: bool

in_reserved_conn is set to true if the session should be using reserved connections.

lock_session: Option<ShardSession>

lock_session keep tracks of shard on which the lock query is sent.

last_lock_heartbeat: i64

last_lock_heartbeat keep tracks of when last lock heartbeat was sent.

read_after_write: Option<ReadAfterWrite>

read_after_write tracks the ReadAfterWrite settings for this session.

ddl_strategy: String

DDL strategy

session_uuid: String

Session UUID

enable_system_settings: bool

enable_system_settings defines if we can use reserved connections.

advisory_lock: HashMap<String, i64>

query_timeout: i64

query_timeout is the maximum amount of time a query is permitted to run

prepare_statement: HashMap<String, PrepareData>

migration_context: String

MigrationContext

Implementations

impl Session

pub fn transaction_mode(&self) -> TransactionMode

Returns the enum value of transaction_mode, or the default if the field is set to an invalid enum value.

pub fn set_transaction_mode(&mut self, value: TransactionMode)

Sets transaction_mode to the provided enum value.

Trait Implementations

impl Clone for Session

fn clone(&self) -> Session

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Session

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

Formats the value using the given formatter.

impl Default for Session

fn default() -> Self

Returns the “default value” for a type.

impl Message for Session

fn encoded_len(&self) -> usize

Returns the encoded length of the message without a length delimiter.

fn clear(&mut self)

Clears the message, resetting all fields to their default.

fn encode<B>(&self, buf: &mut B) -> Result<(), EncodeError>

where B: BufMut, Self: Sized,

Encodes the message to a buffer.

fn encode_to_vec(&self) -> Vec<u8>

where Self: Sized,

Encodes the message to a newly allocated buffer.

fn encode_length_delimited<B>(&self, buf: &mut B) -> Result<(), EncodeError>

where B: BufMut, Self: Sized,

Encodes the message with a length-delimiter to a buffer.

fn encode_length_delimited_to_vec(&self) -> Vec<u8>

where Self: Sized,

Encodes the message with a length-delimiter to a newly allocated buffer.

fn decode<B>(buf: B) -> Result<Self, DecodeError>

where B: Buf, Self: Default,

Decodes an instance of the message from a buffer.

fn decode_length_delimited<B>(buf: B) -> Result<Self, DecodeError>

where B: Buf, Self: Default,

Decodes a length-delimited instance of the message from the buffer.

fn merge<B>(&mut self, buf: B) -> Result<(), DecodeError>

where B: Buf, Self: Sized,

Decodes an instance of the message from a buffer, and merges it into self.

fn merge_length_delimited<B>(&mut self, buf: B) -> Result<(), DecodeError>

where B: Buf, Self: Sized,

Decodes a length-delimited instance of the message from buffer, and merges it into self.

impl PartialEq for Session

fn eq(&self, other: &Session) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for Session