MessageQueue¶

Calls¶

execute_overweight¶

See [Pallet::execute_overweight].

Attributes¶

Name	Type
message_origin	`MessageOriginOf<T>`
page	`PageIndex`
index	`T::Size`
weight_limit	`Weight`

Python¶

call = substrate.compose_call(
    'MessageQueue', 'execute_overweight', {
    'index': 'u32',
    'message_origin': {
        'Here': None,
        'Parent': None,
        'Sibling': 'u32',
    },
    'page': 'u32',
    'weight_limit': {
        'proof_size': 'u64',
        'ref_time': 'u64',
    },
}
)

reap_page¶

See [Pallet::reap_page].

Attributes¶

Name	Type
message_origin	`MessageOriginOf<T>`
page_index	`PageIndex`

Python¶

call = substrate.compose_call(
    'MessageQueue', 'reap_page', {
    'message_origin': {
        'Here': None,
        'Parent': None,
        'Sibling': 'u32',
    },
    'page_index': 'u32',
}
)

Events¶

OverweightEnqueued¶

Message placed in overweight queue.

Attributes¶

Name	Type	Composition
id	`[u8; 32]`	`[u8; 32]`
origin	`MessageOriginOf<T>`	`{'Here': None, 'Parent': None, 'Sibling': 'u32'}`
page_index	`PageIndex`	`u32`
message_index	`T::Size`	`u32`

PageReaped¶

This page was reaped.

Attributes¶

Name	Type	Composition
origin	`MessageOriginOf<T>`	`{'Here': None, 'Parent': None, 'Sibling': 'u32'}`
index	`PageIndex`	`u32`

Processed¶

Message is processed.

Attributes¶

Name	Type	Composition
id	`H256`	`scale_info::12`
origin	`MessageOriginOf<T>`	`{'Here': None, 'Parent': None, 'Sibling': 'u32'}`
weight_used	`Weight`	`{'ref_time': 'u64', 'proof_size': 'u64'}`
success	`bool`	`bool`

ProcessingFailed¶

Message discarded due to an error in the MessageProcessor (usually a format error).

Attributes¶

Name	Type	Composition
id	`H256`	`scale_info::12`
origin	`MessageOriginOf<T>`	`{'Here': None, 'Parent': None, 'Sibling': 'u32'}`
error	`ProcessMessageError`	`{'BadFormat': None, 'Corrupt': None, 'Unsupported': None, 'Overweight': {'ref_time': 'u64', 'proof_size': 'u64'}, 'Yield': None}`

Storage functions¶

BookStateFor¶

The index of the first and last (non-empty) pages.

Python¶

result = substrate.query(
    'MessageQueue', 'BookStateFor', [
    {
        'Here': None,
        'Parent': None,
        'Sibling': 'u32',
    },
]
)

Return value¶

{
    'begin': 'u32',
    'count': 'u32',
    'end': 'u32',
    'message_count': 'u64',
    'ready_neighbours': (
        None,
        {
            'next': {'Here': None, 'Parent': None, 'Sibling': 'u32'},
            'prev': {'Here': None, 'Parent': None, 'Sibling': 'u32'},
        },
    ),
    'size': 'u64',
}

Pages¶

The map of page indices to pages.

Python¶

result = substrate.query(
    'MessageQueue', 'Pages', [
    {
        'Here': None,
        'Parent': None,
        'Sibling': 'u32',
    },
    'u32',
]
)

Return value¶

{
    'first': 'u32',
    'first_index': 'u32',
    'heap': 'Bytes',
    'last': 'u32',
    'remaining': 'u32',
    'remaining_size': 'u32',
}

ServiceHead¶

The origin at which we should begin servicing.

Python¶

result = substrate.query(
    'MessageQueue', 'ServiceHead', []
)

Return value¶

{'Here': None, 'Parent': None, 'Sibling': 'u32'}

Constants¶

HeapSize¶

The size of the page; this implies the maximum message size which can be sent.

A good value depends on the expected message sizes, their weights, the weight that is available for processing them and the maximal needed message size. The maximal message size is slightly lower than this as defined by [MaxMessageLenOf].

Value¶

Python¶

constant = substrate.get_constant('MessageQueue', 'HeapSize')

MaxStale¶

The maximum number of stale pages (i.e. of overweight messages) allowed before culling can happen. Once there are more stale pages than this, then historical pages may be dropped, even if they contain unprocessed overweight messages.

Value¶

Python¶

constant = substrate.get_constant('MessageQueue', 'MaxStale')

ServiceWeight¶

The amount of weight (if any) which should be provided to the message queue for servicing enqueued items.

This may be legitimately None in the case that you will call ServiceQueues::service_queues manually.

Value¶

{'proof_size': 1835008, 'ref_time': 175000000000}

Python¶

constant = substrate.get_constant('MessageQueue', 'ServiceWeight')

Errors¶

AlreadyProcessed¶

The message was already processed and cannot be processed again.

InsufficientWeight¶

There is temporarily not enough weight to continue servicing messages.

NoMessage¶

The referenced message could not be found.

NoPage¶

Page to be reaped does not exist.

NotReapable¶

Page is not reapable because it has items remaining to be processed and is not old enough.

QueuePaused¶

The queue is paused and no message can be executed from it.

This can change at any time and may resolve in the future by re-trying.

Queued¶

The message is queued for future execution.

RecursiveDisallowed¶

Another call is in progress and needs to finish before this call can happen.

TemporarilyUnprocessable¶

This message is temporarily unprocessable.

Such errors are expected, but not guaranteed, to resolve themselves eventually through retrying.