Struct Client

pub struct Client { /* private fields */ }

Client for Amazon QLDB Session

Client for invoking operations on Amazon QLDB Session. Each operation on Amazon QLDB Session is a method on this this struct. .send() MUST be invoked on the generated operations to dispatch the request to the service.

Constructing a Client

A Config is required to construct a client. For most use cases, the aws-config crate should be used to automatically resolve this config using aws_config::load_from_env(), since this will resolve an SdkConfig which can be shared across multiple different AWS SDK clients. This config resolution process can be customized by calling aws_config::from_env() instead, which returns a ConfigLoader that uses the builder pattern to customize the default config.

In the simplest case, creating a client looks as follows:

let config = aws_config::load_from_env().await;
let client = aws_sdk_qldbsession::Client::new(&config);

Occasionally, SDKs may have additional service-specific values that can be set on the Config that is absent from SdkConfig, or slightly different settings for a specific client may be desired. The Builder struct implements From<&SdkConfig>, so setting these specific settings can be done as follows:

let sdk_config = ::aws_config::load_from_env().await;
let config = aws_sdk_qldbsession::config::Builder::from(&sdk_config)
    .some_service_specific_setting("value")
    .build();

See the aws-config docs and Config for more information on customizing configuration.

Note: Client construction is expensive due to connection thread pool initialization, and should be done once at application start-up.

Using the Client

A client has a function for every operation that can be performed by the service. For example, the SendCommand operation has a Client::send_command, function which returns a builder for that operation. The fluent builder ultimately has a send() function that returns an async future that returns a result, as illustrated below:

let result = client.send_command()
    .session_token("example")
    .send()
    .await;

The underlying HTTP requests that get made by this can be modified with the customize_operation function on the fluent builder. See the customize module for more information.

Implementations

impl Client

pub fn send_command(&self) -> SendCommandFluentBuilder

Constructs a fluent builder for the SendCommand operation.

• The fluent builder is configurable:
  • session_token(impl Into<String>) / set_session_token(Option<String>):
    required: false
    

    Specifies the session token for the current command. A session token is constant throughout the life of the session.

    To obtain a session token, run the StartSession command. This SessionToken is required for every subsequent command that is issued during the current session.

    
    
  • start_session(StartSessionRequest) / set_start_session(Option<StartSessionRequest>):
    required: false
    

    Command to start a new session. A session token is obtained as part of the response.

    
    
  • start_transaction(StartTransactionRequest) / set_start_transaction(Option<StartTransactionRequest>):
    required: false
    

    Command to start a new transaction.

    
    
  • end_session(EndSessionRequest) / set_end_session(Option<EndSessionRequest>):
    required: false
    

    Command to end the current session.

    
    
  • commit_transaction(CommitTransactionRequest) / set_commit_transaction(Option<CommitTransactionRequest>):
    required: false
    

    Command to commit the specified transaction.

    
    
  • abort_transaction(AbortTransactionRequest) / set_abort_transaction(Option<AbortTransactionRequest>):
    required: false
    

    Command to abort the current transaction.

    
    
  • execute_statement(ExecuteStatementRequest) / set_execute_statement(Option<ExecuteStatementRequest>):
    required: false
    

    Command to execute a statement in the specified transaction.

    
    
  • fetch_page(FetchPageRequest) / set_fetch_page(Option<FetchPageRequest>):
    required: false
    

    Command to fetch a page.

    
    
• On success, responds with SendCommandOutput with field(s):
  • start_session(Option<StartSessionResult>):

    Contains the details of the started session that includes a session token. This SessionToken is required for every subsequent command that is issued during the current session.

  • start_transaction(Option<StartTransactionResult>):

    Contains the details of the started transaction.

  • end_session(Option<EndSessionResult>):

    Contains the details of the ended session.

  • commit_transaction(Option<CommitTransactionResult>):

    Contains the details of the committed transaction.

  • abort_transaction(Option<AbortTransactionResult>):

    Contains the details of the aborted transaction.

  • execute_statement(Option<ExecuteStatementResult>):

    Contains the details of the executed statement.

  • fetch_page(Option<FetchPageResult>):

    Contains the details of the fetched page.

• On failure, responds with SdkError<SendCommandError>

impl Client

pub fn from_conf(conf: Config) -> Self

Creates a new client from the service Config.

Panics

This method will panic in the following cases:

• Retries or timeouts are enabled without a sleep_impl configured.
• Identity caching is enabled without a sleep_impl and time_source configured.
• No behavior_version is provided.

The panic message for each of these will have instructions on how to resolve them.

pub fn config(&self) -> &Config

Returns the client’s configuration.

impl Client

pub fn new(sdk_config: &SdkConfig) -> Self

Creates a new client from an SDK Config.

Panics

• This method will panic if the sdk_config is missing an async sleep implementation. If you experience this panic, set the sleep_impl on the Config passed into this function to fix it.
• This method will panic if the sdk_config is missing an HTTP connector. If you experience this panic, set the http_connector on the Config passed into this function to fix it.
• This method will panic if no BehaviorVersion is provided. If you experience this panic, set behavior_version on the Config or enable the behavior-version-latest Cargo feature.

Trait Implementations

impl Clone for Client

fn clone(&self) -> Client

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Client

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

Formats the value using the given formatter.