#[macro_use] extern crate cdrs; #[macro_use] extern crate cdrs_helpers_derive; use cdrs::authenticators::NoneAuthenticator; use cdrs::cluster::session::{new as new_session, Session}; use cdrs::cluster::{ClusterTcpConfig, NodeTcpConfigBuilder, PagerState, TcpConnectionPool}; use cdrs::load_balancing::RoundRobin; use cdrs::query::*; use cdrs::frame::IntoBytes; use cdrs::types::from_cdrs::FromCDRSByName; use cdrs::types::prelude::*; type CurrentSession = Session>>; #[derive(Clone, Debug, IntoCDRSValue, TryFromRow, PartialEq)] struct RowStruct { key: i32, } impl RowStruct { fn into_query_values(self) -> QueryValues { query_values!("key" => self.key) } } fn main() { let node = NodeTcpConfigBuilder::new("127.0.0.1:9042", NoneAuthenticator {}).build(); let cluster_config = ClusterTcpConfig(vec![node]); let lb = RoundRobin::new(); let no_compression = new_session(&cluster_config, lb).expect("session should be created"); create_keyspace(&no_compression); create_table(&no_compression); fill_table(&no_compression); println!("Internal pager state\n"); paged_selection_query(&no_compression); println!("\n\nExternal pager state for stateless executions\n"); paged_selection_query_with_state(&no_compression, PagerState::new()); } fn create_keyspace(session: &CurrentSession) { let create_ks: &'static str = "CREATE KEYSPACE IF NOT EXISTS test_ks WITH REPLICATION = { \ 'class' : 'SimpleStrategy', 'replication_factor' : 1 };"; session.query(create_ks).expect("Keyspace creation error"); } fn create_table(session: &CurrentSession) { let create_table_cql = "CREATE TABLE IF NOT EXISTS test_ks.my_test_table (key int PRIMARY KEY, \ user test_ks.user, map map>, list list>);"; session .query(create_table_cql) .expect("Table creation error"); } fn fill_table(session: &CurrentSession) { let insert_struct_cql = "INSERT INTO test_ks.my_test_table (key) VALUES (?)"; for k in 100..110 { let row = RowStruct { key: k as i32 }; session .query_with_values(insert_struct_cql, row.into_query_values()) .expect("insert"); } } fn paged_selection_query(session: &CurrentSession) { let q = "SELECT * FROM test_ks.my_test_table;"; let mut pager = session.paged(2); let mut query_pager = pager.query(q); loop { let rows = query_pager.next().expect("pager next"); for row in rows { let my_row = RowStruct::try_from_row(row).expect("decode row"); println!("row - {:?}", my_row); } if !query_pager.has_more() { break; } } } fn paged_selection_query_with_state(session: &CurrentSession, state: PagerState) { let mut st = state; loop { let q = "SELECT * FROM test_ks.my_test_table;"; let mut pager = session.paged(2); let mut query_pager = pager.query_with_pager_state(q, st); let rows = query_pager.next().expect("pager next"); for row in rows { let my_row = RowStruct::try_from_row(row).expect("decode row"); println!("row - {:?}", my_row); } if !query_pager.has_more() { break; } st = query_pager.pager_state(); } }