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//! Session pool blocking mode implementation
use super::{SessionPool, SPool};
use crate::{Result, oci::{self, *}, Environment, Session};
use std::{ptr, marker::PhantomData, sync::Arc};
impl SPool {
pub(crate) fn new(env: &Environment, dbname: &str, username: &str, password: &str, min: usize, inc: usize, max: usize, session_state_fixup_callback: &str) -> Result<Self> {
let err = Handle::<OCIError>::new(env)?;
let pool = Handle::<OCISPool>::new(env)?;
let info = Handle::<OCIAuthInfo>::new(env)?;
info.set_attr(OCI_ATTR_DRIVER_NAME, "sibyl", &err)?;
if session_state_fixup_callback.len() > 0 {
info.set_attr(OCI_ATTR_FIXUP_CALLBACK, session_state_fixup_callback, &err)?;
}
pool.set_attr(OCI_ATTR_SPOOL_AUTH, info.get_ptr(), &err)?;
let mut pool_name_ptr = ptr::null::<u8>();
let mut pool_name_len = 0u32;
oci::session_pool_create(
env.as_ref(), &err, &pool,
&mut pool_name_ptr, &mut pool_name_len,
dbname.as_ptr(), dbname.len() as u32,
min as u32, max as u32, inc as u32,
username.as_ptr(), username.len() as u32,
password.as_ptr(), password.len() as u32,
OCI_SPC_HOMOGENEOUS | OCI_SPC_STMTCACHE
)?;
let name = unsafe { std::slice::from_raw_parts(pool_name_ptr, pool_name_len as usize) };
let name = name.to_vec();
Ok(Self {env: env.get_env(), err, info, pool, name})
}
}
impl<'a> SessionPool<'a> {
pub(crate) fn new(env: &'a Environment, dbname: &str, username: &str, password: &str, min: usize, inc: usize, max: usize, session_state_fixup_callback: &str) -> Result<Self> {
let inner = SPool::new(env, dbname, username, password, min, inc, max, session_state_fixup_callback)?;
let inner = Arc::new(inner);
Ok(Self { inner, phantom_env: PhantomData })
}
/**
Returns a default (untagged) session from this session pool.
# Example
```
use sibyl::{Environment, Session, Date, Result};
use once_cell::sync::OnceCell;
use std::{env, thread, sync::Arc};
fn main() -> Result<()> {
static ORACLE : OnceCell<Environment> = OnceCell::new();
let oracle = ORACLE.get_or_try_init(|| {
Environment::new()
})?;
let dbname = env::var("DBNAME").expect("database name");
let dbuser = env::var("DBUSER").expect("user name");
let dbpass = env::var("DBPASS").expect("password");
let pool = oracle.create_session_pool(&dbname, &dbuser, &dbpass, 0, 1, 3)?;
let pool = Arc::new(pool);
let mut workers = Vec::with_capacity(10);
while workers.len() < 10 {
let pool = pool.clone();
let handle = thread::spawn(move || -> String {
let session = pool.get_session().expect("database session");
select_latest_hire(&session).expect("selected employee name")
});
workers.push(handle);
}
for handle in workers {
let name = handle.join().expect("select result");
assert_eq!(name, "Amit Banda was hired on April 21, 2008");
}
Ok(())
}
fn select_latest_hire(session: &Session) -> Result<String> {
let stmt = session.prepare("
SELECT first_name, last_name, hire_date
FROM (
SELECT first_name, last_name, hire_date
, Row_Number() OVER (ORDER BY hire_date DESC, last_name) AS hire_date_rank
FROM hr.employees
)
WHERE hire_date_rank = 1
")?;
if let Some( row ) = stmt.query_single(())? {
let first_name : Option<&str> = row.get(0)?;
let last_name : &str = row.get(1)?;
let name = first_name.map_or(last_name.to_string(), |first_name| format!("{} {}", first_name, last_name));
let hire_date : Date = row.get(2)?;
let hire_date = hire_date.to_string("FMMonth DD, YYYY")?;
Ok(format!("{} was hired on {}", name, hire_date))
} else {
Ok("Not found".to_string())
}
}
```
*/
pub fn get_session(&self) -> Result<Session<'_>> {
let (session, _found) = Session::from_session_pool(self, "")?;
Ok(session)
}
/**
Returns a tagged session, i.e. a session with the specified type/tag.
The tags provide a way to customize sessions in the pool. A client can get a default or untagged
session from a pool, set certain attributes on the session (such as globalization settings) and
label it with an appropriate tag.
This session or a session with the same attributes can then be requested by providing the same
tag that was used during session customization.
If a user asks for a session with tag 'A', and a matching session is not available, an appropriately
authenticated untagged session is returned, if such a session is free.
# Parameters
- `taginfo` - Either a single or a [Multi-Property Tag](https://docs.oracle.com/en/database/oracle/oracle-database/19/lnoci/session-and-connection-pooling.html#GUID-DFA21225-E83C-4177-A79A-B8BA29DC662C).
# Returns
A tuple with the returned session and the boolean flag. The flag indicates whether the type of the returned
session is the same as requested.
# Example
```
# let oracle = sibyl::env()?;
# let dbname = std::env::var("DBNAME").expect("database name");
# let dbuser = std::env::var("DBUSER").expect("user name");
# let dbpass = std::env::var("DBPASS").expect("password");
let pool = oracle.create_session_pool(&dbname, &dbuser, &dbpass, 0, 1, 5)?;
{
let (session,found) = pool.get_tagged_session("CUSTOM")?;
assert!(!found, "a default (not yet tagged) session was returned");
if !found {
# let stmt = session.prepare("SELECT value FROM nls_session_parameters WHERE parameter=:PARAM_NAME")?;
# let row = stmt.query_single("NLS_DATE_FORMAT")?.expect("one row");
# let fmt: &str = row.get(0)?;
# assert_ne!(fmt, "YYYY-MM-DD", "Default NLS_DATE_FORMAT differs from what we want to set");
let stmt = session.prepare("ALTER SESSION SET NLS_DATE_FORMAT='YYYY-MM-DD'")?;
stmt.execute(())?;
session.set_tag("CUSTOM")?;
}
} // session is released back to the pool here
{
let (session,found) = pool.get_tagged_session("CUSTOM")?;
assert!(found, "the customized session was returned");
let stmt = session.prepare("SELECT value FROM nls_session_parameters WHERE parameter=:PARAM_NAME")?;
let row = stmt.query_single("NLS_DATE_FORMAT")?.expect("one row");
let fmt: &str = row.get(0)?;
assert_eq!(fmt, "YYYY-MM-DD", "Session uses custom NLS_DATE_FORMAT");
}
# Ok::<(),Box<dyn std::error::Error>>(())
```
*/
pub fn get_tagged_session(&self, taginfo: &str) -> Result<(Session<'_>,bool)> {
Session::from_session_pool(self, taginfo)
}
}