Struct Channel

pub struct Channel(/* private fields */);

The “Channel” class contains all functions to manipulate channels.

Please refer to HAProxy documentation to get more information.

Implementations

impl Channel

pub fn append(&self, data: impl AsRef<[u8]>) -> Result<isize>

Copies the string string at the end of incoming data of the channel buffer.

Returns the copied length on success or -1 if data cannot be copied.

pub fn data( &self, offset: Option<isize>, length: Option<isize>, ) -> Result<Option<LuaString>>

Returns length bytes of incoming data from the channel buffer, starting at the offset.

The data are not removed from the buffer.

pub fn forward(&self, length: usize) -> Result<usize>

Forwards length bytes of data from the channel buffer.

Returns the amount of data forwarded and must not be called from an action to avoid yielding.

pub fn input(&self) -> Result<usize>

Returns the length of incoming data in the channel buffer.

pub fn insert( &self, data: impl AsRef<[u8]>, offset: Option<isize>, ) -> Result<isize>

Copies the data at the offset in incoming data of the channel buffer.

Returns the copied length on success or -1 if data cannot be copied.

By default, if no offset is provided, the string is copied in front of incoming data. A positive offset is relative to the beginning of incoming data of the channel buffer while negative offset is relative to their end.

pub fn is_full(&self) -> Result<bool>

Returns true if the channel buffer is full.

pub fn is_resp(&self) -> Result<bool>

Returns true if the channel is the response one.

pub fn line( &self, offset: Option<isize>, length: Option<isize>, ) -> Result<Option<LuaString>>

Parses length bytes of incoming data of the channel buffer, starting at offset, and returns the first line found, including the \n.

The data are not removed from the buffer. If no line is found, all data are returned.

pub fn may_recv(&self) -> Result<bool>

Returns true if the channel may still receive data.

pub fn output(&self) -> Result<usize>

Returns the length of outgoing data of the channel buffer.

pub fn prepend(&self, data: impl AsRef<[u8]>) -> Result<isize>

Copies the data in front of incoming data of the channel buffer.

Returns the copied length on success or -1 if data cannot be copied.

pub fn remove( &self, offset: Option<isize>, length: Option<usize>, ) -> Result<isize>

Removes length bytes of incoming data of the channel buffer, starting at offset.

Returns number of bytes removed on success.

pub fn send(&self, data: impl AsRef<[u8]>) -> Result<isize>

Requires immediate send of the data.

It means the data is copied at the beginning of incoming data of the channel buffer and immediately forwarded.

pub fn set( &self, data: impl AsRef<[u8]>, offset: Option<isize>, length: Option<usize>, ) -> Result<isize>

Replaces length bytes of incoming data of the channel buffer, starting at offset, by the new data.

Returns the copied length on success or -1 if data cannot be copied.

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 Channel

fn clone(&self) -> Channel

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Deref for Channel

type Target = Table

The resulting type after dereferencing.

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

Dereferences the value.

impl FromLua for Channel

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

Performs the conversion.

impl IntoLua for Channel

fn into_lua(self, _: &Lua) -> Result<Value>

Performs the conversion.