Struct unqlite::UnQLite

pub struct UnQLite { /* fields omitted */ }

UnQLite database entry point.

UnQLite support both in-memory and on-disk database. There's several constructors:

Constructor	Meaning
create_in_memory	Create a private, in-memory database.
create_temp	Create a private, temporary on-disk database.
create	Create if not exists, otherwise, open as read-write.
open_mmap	Obtain a read-only memory view of the whole database.
open_readonly	Open the database in a read-only mode.

Implementations

impl UnQLite

pub fn create<P: AsRef<str>>(filename: P) -> UnQLite

Create UnQLite database as filename.

By default, the database is created in read-write mode.

Panics

Will panic if failed in creating.

Example

let _ = UnQLite::create("test.db");

C

unqlite *pDb;

// on-disk database
rc = unqlite_open(&pDb,"test.db",UNQLITE_OPEN_CREATE);

// in-memory database
rc = unqlite_open(&pDb, ":mem:", UNQLITE_OPEN_MEM);

pub fn create_in_memory() -> UnQLite

Create database in memory.

Equivalent to:

let _ = UnQLite::create(":mem:");

Panics

Will panic if failed in creating.

pub fn create_temp() -> UnQLite

A private, temporary on-disk database will be created.

This private database will be automatically deleted as soon as the database connection is closed.

Panics

Will panic if failed in creating.

C

int rc = unqlite_open("test.db", UNQLITE_OPEN_TEMP_DB);

pub fn open_mmap<P: AsRef<str>>(filename: P) -> UnQLite

Obtain a read-only memory view of the whole database.

You will get significant performance improvements with this combination but your database is still read-only.

Panics

Panic if open failed.

C

unqlite_open(&pDb, "test.db", UNQLITE_OPEN_MMAP | UNQLITE_OPEN_READONLY);

pub fn open_readonly<P: AsRef<str>>(filename: P) -> UnQLite

Open the database in a read-only mode.

That is, you cannot perform a store, append, commit or rollback operations with this control flag.

Always prefer to use open_mmap for readonly in disk database.

Panics

Panic too.

C

unqlite_open(&pDb, "test.db", UNQLITE_OPEN_READONLY);

Trait Implementations

impl Config for UnQLite

fn max_page_cache(self, max: u32) -> Self

Maximum raw pages to cache in memory.

fn disable_auto_commit(self) -> Self

To diable automatically commit action.

fn kv_engine<S: Into<Vec<u8>>>(self, name: S) -> Self

Switch to another Key/Value storage engine.

fn err_log(&self) -> Option<String>

The database error log is stored in an internal buffer. When something goes wrong during a commit, rollback, store, append operation, a human-readable error message is generated to help clients diagnose the problem. This option can be used to point to that buffer.

fn jx9_err_log(&self) -> Option<String>

When something goes wrong during compilation of the target Jx9 script due to an erroneous Jx9 code, the compiler error log is redirected to an internal buffer. This option can be used to point to that buffer.

fn kv_name(&self) -> String

Extract the name of the underlying Key/Value storage engine.

impl Cursor for UnQLite

fn first(&self) -> Option<Entry>

Returns the first entry.

fn last(&self) -> Option<Entry>

Retruns the last entry.

fn seek<K: AsRef<[u8]>>(&self, key: K, pos: Direction) -> Option<Entry>

Seek an entry by key.

impl Drop for UnQLite

fn drop(&mut self)

Executes the destructor for this type.

impl Jx9 for UnQLite

Jx9 script compiler Interface.

fn compile<T: AsRef<[u8]>>(&self, jx9: T) -> Result<UnQLiteVm>

Compile a Jx9 script to a bytecode program.

fn compile_file<P: AsRef<str>>(&self, filename: P) -> Result<UnQLiteVm>

Compile a Jx9 script file to a bytecode program.

impl KV for UnQLite

Key-Value Store Interface

fn kv_store<K: AsRef<[u8]>, V: AsRef<[u8]>>(
    &self,
    key: K,
    value: V
) -> Result<()>

Store records in the database.

fn kv_append<K: AsRef<[u8]>, V: AsRef<[u8]>>(
    &self,
    key: K,
    value: V
) -> Result<()>

Append data to a database record.

fn kv_delete<K: AsRef<[u8]>>(&self, key: K) -> Result<()>

Remove a record from the database.

fn kv_contains<K: AsRef<[u8]>>(&self, key: K) -> bool

Check if key is contained in database.

fn kv_fetch_length<K: AsRef<[u8]>>(&self, key: K) -> Result<i64>

Fetch a record from the database and returns the length only

fn kv_fetch<K: AsRef<[u8]>>(&self, key: K) -> Result<Vec<u8>>

Fetch a record from the database.

fn kv_fetch_callback<K: AsRef<[u8]>>(
    &self,
    key: K,
    consumer: extern "C" fn(data: *const c_void, len: u32, user_data: *mut c_void) -> i32
) -> Result<()>

Fetch a record from the database and invoke the supplied callback to consume its data.

fn kv_config_hash(
    &self,
    hash: extern "C" fn(key: *const c_void, len: u32) -> u32
) -> Result<()>

Configure the hash function of the underlying Key/Value (KV) storage engine.

fn kv_config_cmp(
    &self,
    cmp: extern "C" fn(key: *const c_void, len: u32) -> u32
) -> Result<()>

Configure the compare function of the underlying Key/Value (KV) storage engine.

impl Send for UnQLite

impl Sync for UnQLite

impl Transaction for UnQLite

fn begin(&self) -> Result<()>

Manually begin a write-transaction on the specified database handle.

fn commit(&self) -> Result<()>

Commit all changes to the database.

fn rollback(&self) -> Result<()>

Rollback a write-transaction on the specified database handle.

impl Util for UnQLite

fn random_string(&self, buf_size: u32) -> Vec<u8>

Generate random string using the UnQLite PRNG.

fn random_num(&self) -> u32

Generate random number using the UnQLite PRNG.