Struct Txn

pub struct Txn {
    pub c: Converters,
    pub f: Fetches,
    /* private fields */
}

The txn class contain all the functions relative to the http or tcp transaction.

Fields

c: Converters

f: Fetches

Implementations

impl Txn

pub fn http(&self) -> Result<Http>

Returns an HTTP class object.

pub fn http_req(&self) -> Result<HttpMessage>

Returns the request HTTPMessage object.

pub fn http_res(&self) -> Result<HttpMessage>

Returns the response HTTPMessage object.

pub fn log(&self, level: LogLevel, msg: impl AsRef<str>) -> Result<()>

Sends a log on the default syslog server if it is configured and on the stderr if it is allowed.

pub fn deflog(&self, msg: impl AsRef<str>) -> Result<()>

Sends a log line with the default loglevel for the proxy associated with the transaction.

pub fn get_priv<R: FromLua>(&self) -> Result<R>

Returns data stored in the current transaction (with the set_priv()) function.

pub fn set_priv(&self, val: impl IntoLua) -> Result<()>

Stores any data in the current HAProxy transaction. This action replaces the old stored data.

pub fn get_var<R: FromLua>(&self, name: &str) -> Result<R>

Returns data stored in the variable name.

pub fn set_var(&self, name: &str, val: impl IntoLua) -> Result<()>

Store variable name in an HAProxy converting the type.

pub fn set_var_if_exists(&self, name: &str, val: impl IntoLua) -> Result<()>

Store variable name in an HAProxy if the variable already exists.

pub fn unset_var(&self, name: &str) -> Result<()>

Unsets the variable name.

pub fn set_loglevel(&self, level: LogLevel) -> Result<()>

Changes the log level of the current request. The level must be an integer between 0 and 7.

Methods from Deref<Target = Table>

pub fn set(&self, key: impl IntoLua, value: impl IntoLua) -> Result<(), Error>

Sets a key-value pair in the table.

If the value is nil, this will effectively remove the pair.

This might invoke the __newindex metamethod. Use the raw_set method if that is not desired.

Examples

Export a value as a global to make it usable from Lua:

let globals = lua.globals();

globals.set("assertions", cfg!(debug_assertions))?;

lua.load(r#"
    if assertions == true then
        -- ...
    elseif assertions == false then
        -- ...
    else
        error("assertions neither on nor off?")
    end
"#).exec()?;

pub fn get<V>(&self, key: impl IntoLua) -> Result<V, Error>

where V: FromLua,

Gets the value associated to key from the table.

If no value is associated to key, returns the nil value.

This might invoke the __index metamethod. Use the raw_get method if that is not desired.

Examples

Query the version of the Lua interpreter:

let globals = lua.globals();

let version: String = globals.get("_VERSION")?;
println!("Lua version: {}", version);

pub fn contains_key(&self, key: impl IntoLua) -> Result<bool, Error>

Checks whether the table contains a non-nil value for key.

This might invoke the __index metamethod.

pub fn push(&self, value: impl IntoLua) -> Result<(), Error>

Appends a value to the back of the table.

This might invoke the __len and __newindex metamethods.

pub fn pop<V>(&self) -> Result<V, Error>

where V: FromLua,

Removes the last element from the table and returns it.

This might invoke the __len and __newindex metamethods.

pub fn equals(&self, other: &Table) -> Result<bool, Error>

Compares two tables for equality.

Tables are compared by reference first. If they are not primitively equals, then mlua will try to invoke the __eq metamethod. mlua will check self first for the metamethod, then other if not found.

Examples

Compare two tables using __eq metamethod:

let table1 = lua.create_table()?;
table1.set(1, "value")?;

let table2 = lua.create_table()?;
table2.set(2, "value")?;

let always_equals_mt = lua.create_table()?;
always_equals_mt.set("__eq", lua.create_function(|_, (_t1, _t2): (Table, Table)| Ok(true))?)?;
table2.set_metatable(Some(always_equals_mt))?;

assert!(table1.equals(&table1.clone())?);
assert!(table1.equals(&table2)?);

pub fn raw_set( &self, key: impl IntoLua, value: impl IntoLua, ) -> Result<(), Error>

Sets a key-value pair without invoking metamethods.

pub fn raw_get<V>(&self, key: impl IntoLua) -> Result<V, Error>

where V: FromLua,

Gets the value associated to key without invoking metamethods.

pub fn raw_insert(&self, idx: i64, value: impl IntoLua) -> Result<(), Error>

Inserts element value at position idx to the table, shifting up the elements from table[idx].

The worst case complexity is O(n), where n is the table length.

pub fn raw_push(&self, value: impl IntoLua) -> Result<(), Error>

Appends a value to the back of the table without invoking metamethods.

pub fn raw_pop<V>(&self) -> Result<V, Error>

where V: FromLua,

Removes the last element from the table and returns it, without invoking metamethods.

pub fn raw_remove(&self, key: impl IntoLua) -> Result<(), Error>

Removes a key from the table.

If key is an integer, mlua shifts down the elements from table[key+1], and erases element table[key]. The complexity is O(n) in the worst case, where n is the table length.

For other key types this is equivalent to setting table[key] = nil.

pub fn clear(&self) -> Result<(), Error>

Clears the table, removing all keys and values from array and hash parts, without invoking metamethods.

This method is useful to clear the table while keeping its capacity.

pub fn len(&self) -> Result<i64, Error>

Returns the result of the Lua # operator.

This might invoke the __len metamethod. Use the Table::raw_len method if that is not desired.

pub fn raw_len(&self) -> usize

Returns the result of the Lua # operator, without invoking the __len metamethod.

pub fn is_empty(&self) -> bool

Returns true if the table is empty, without invoking metamethods.

It checks both the array part and the hash part.

pub fn metatable(&self) -> Option<Table>

Returns a reference to the metatable of this table, or None if no metatable is set.

Unlike the getmetatable Lua function, this method ignores the __metatable field.

pub fn set_metatable(&self, metatable: Option<Table>) -> Result<(), Error>

Sets or removes the metatable of this table.

If metatable is None, the metatable is removed (if no metatable is set, this does nothing).

pub fn to_pointer(&self) -> *const c_void

Converts this table to a generic C pointer.

Different tables will give different pointers. There is no way to convert the pointer back to its original value.

Typically this function is used only for hashing and debug information.

pub fn pairs<K, V>(&self) -> TablePairs<'_, K, V>

where K: FromLua, V: FromLua,

Returns an iterator over the pairs of the table.

This works like the Lua pairs function, but does not invoke the __pairs metamethod.

The pairs are wrapped in a Result, since they are lazily converted to K and V types.

Examples

Iterate over all globals:

let globals = lua.globals();

for pair in globals.pairs::<Value, Value>() {
    let (key, value) = pair?;
    // ...
}

pub fn for_each<K, V>( &self, f: impl FnMut(K, V) -> Result<(), Error>, ) -> Result<(), Error>

where K: FromLua, V: FromLua,

Iterates over the pairs of the table, invoking the given closure on each pair.

This method is similar to Table::pairs, but optimized for performance. It does not invoke the __pairs metamethod.

pub fn sequence_values<V>(&self) -> TableSequence<'_, V>

where V: FromLua,

Returns an iterator over all values in the sequence part of the table.

The iterator will yield all values t[1], t[2] and so on, until a nil value is encountered. This mirrors the behavior of Lua’s ipairs function but does not invoke any metamethods.

Examples

let my_table: Table = lua.load(r#"
    {
        [1] = 4,
        [2] = 5,
        [4] = 7,
        key = 2
    }
"#).eval()?;

let expected = [4, 5];
for (&expected, got) in expected.iter().zip(my_table.sequence_values::<u32>()) {
    assert_eq!(expected, got?);
}

Trait Implementations

impl Clone for Txn

fn clone(&self) -> Txn

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Deref for Txn

type Target = Table

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl FromLua for Txn

fn from_lua(value: Value, lua: &Lua) -> Result<Self>

Performs the conversion.