Checkpoint

---

Calls

---

create_checkpoint

Creates a single checkpoint at the current time.

# Arguments - origin is a signer that has permissions to act as an agent of ticker. - ticker to create the checkpoint for.

# Errors - UnauthorizedAgent if the DID of origin isn't a permissioned agent for ticker. - CounterOverflow if the total checkpoint counter would overflow.

Attributes

Name	Type
ticker	Ticker

Python

call = substrate.compose_call(
    'Checkpoint', 'create_checkpoint', {'ticker': '[u8; 12]'}
)

---

create_schedule

Creates a schedule generating checkpoints in the future at either a fixed time or at intervals.

The schedule starts out with strong_ref_count(schedule_id) <- 0.

# Arguments - origin is a signer that has permissions to act as owner of ticker. - ticker to create the schedule for. - schedule that will generate checkpoints.

# Errors - UnauthorizedAgent if the DID of origin isn't a permissioned agent for ticker. - InsufficientAccountBalance if the protocol fee could not be charged. - CounterOverflow if the schedule ID or total checkpoint counters would overflow.

# Permissions * Asset

Attributes

Name	Type
ticker	Ticker
schedule	ScheduleCheckpoints

Python

call = substrate.compose_call(
    'Checkpoint', 'create_schedule', {
    'schedule': {
        'pending': 'scale_info::173',
    },
    'ticker': '[u8; 12]',
}
)

---

remove_schedule

Removes the checkpoint schedule of an asset identified by id.

# Arguments - origin is a signer that has permissions to act as owner of ticker. - ticker to remove the schedule from. - id of the schedule, when it was created by created_schedule.

# Errors - UnauthorizedAgent if the DID of origin isn't a permissioned agent for ticker. - NoCheckpointSchedule if id does not identify a schedule for this ticker. - ScheduleNotRemovable if id exists but is not removable.

# Permissions * Asset

Attributes

Name	Type
ticker	Ticker
id	ScheduleId

Python

call = substrate.compose_call(
    'Checkpoint', 'remove_schedule', {'id': 'u64', 'ticker': '[u8; 12]'}
)

---

set_schedules_max_complexity

Sets the max complexity of a schedule set for an arbitrary ticker to max_complexity. The new maximum is not enforced retroactively, and only applies once new schedules are made.

Must be called as a PIP (requires "root").

# Arguments - origin is the root origin. - max_complexity allowed for an arbitrary ticker's schedule set.

Attributes

Name	Type
max_complexity	u64

Python

call = substrate.compose_call(
    'Checkpoint', 'set_schedules_max_complexity', {'max_complexity': 'u64'}
)

---

Events

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CheckpointCreated

A checkpoint was created.

(caller DID, ticker, checkpoint ID, total supply, checkpoint timestamp)

Attributes

Name	Type	Composition
None	Option<IdentityId>	(None, '[u8; 32]')
None	Ticker	[u8; 12]
None	CheckpointId	u64
None	Balance	u128
None	Moment	u64

---

MaximumSchedulesComplexityChanged

The maximum complexity for an arbitrary ticker's schedule set was changed.

(GC DID, the new maximum)

Attributes

Name	Type	Composition
None	IdentityId	[u8; 32]
None	u64	u64

---

ScheduleCreated

A checkpoint schedule was created.

(caller DID, ticker, schedule id, schedule)

Attributes

Name	Type	Composition
None	IdentityId	[u8; 32]
None	Ticker	[u8; 12]
None	ScheduleId	u64
None	ScheduleCheckpoints	{'pending': 'scale_info::173'}

---

ScheduleRemoved

A checkpoint schedule was removed.

(caller DID, ticker, schedule id, schedule)

Attributes

Name	Type	Composition
None	IdentityId	[u8; 32]
None	Ticker	[u8; 12]
None	ScheduleId	u64
None	ScheduleCheckpoints	{'pending': 'scale_info::173'}

---

Storage functions

---

Balance

Balance of a DID at a checkpoint.

(ticker, did, checkpoint ID) -> Balance of a DID at a checkpoint

Python

result = substrate.query(
    'Checkpoint', 'Balance', [('[u8; 12]', 'u64'), '[u8; 32]']
)

Return value

'u128'

---

BalanceUpdates

Checkpoints where a DID's balance was updated. (ticker, did) -> [checkpoint ID where user balance changed]

Python

result = substrate.query(
    'Checkpoint', 'BalanceUpdates', ['[u8; 12]', '[u8; 32]']
)

Return value

['u64']

---

CachedNextCheckpoints

Cached next checkpoint for each schedule.

This is used to quickly find the next checkpoint from a ticker's schedules.

(ticker) -> next checkpoints

Python

result = substrate.query(
    'Checkpoint', 'CachedNextCheckpoints', ['[u8; 12]']
)

Return value

{'next_at': 'u64', 'schedules': 'scale_info::636', 'total_pending': 'u64'}

---

CheckpointIdSequence

Checkpoints ID generator sequence. ID of first checkpoint is 1 instead of 0.

(ticker) -> no. of checkpoints

Python

result = substrate.query(
    'Checkpoint', 'CheckpointIdSequence', ['[u8; 12]']
)

Return value

'u64'

---

ScheduleIdSequence

Checkpoint schedule ID sequence for tickers.

(ticker) -> schedule ID

Python

result = substrate.query(
    'Checkpoint', 'ScheduleIdSequence', ['[u8; 12]']
)

Return value

'u64'

---

SchedulePoints

All the checkpoints a given schedule originated.

(ticker, schedule ID) -> [checkpoint ID]

Python

result = substrate.query(
    'Checkpoint', 'SchedulePoints', ['[u8; 12]', 'u64']
)

Return value

['u64']

---

ScheduleRefCount

How many "strong" references are there to a given ScheduleId?

The presence of a "strong" reference, in the sense of Rc<T>, entails that the referenced schedule cannot be removed. Thus, as long as strong_ref_count(schedule_id) > 0, remove_schedule(schedule_id) will error.

(ticker, schedule ID) -> strong ref count

Python

result = substrate.query(
    'Checkpoint', 'ScheduleRefCount', ['[u8; 12]', 'u64']
)

Return value

'u32'

---

ScheduledCheckpoints

Scheduled checkpoints.

(ticker, schedule ID) -> schedule checkpoints

Python

result = substrate.query(
    'Checkpoint', 'ScheduledCheckpoints', ['[u8; 12]', 'u64']
)

Return value

{'pending': 'scale_info::173'}

---

SchedulesMaxComplexity

The maximum complexity allowed for a ticker's schedules.

Python

result = substrate.query(
    'Checkpoint', 'SchedulesMaxComplexity', []
)

Return value

'u64'

---

StorageVersion

Storage version.

Python

result = substrate.query(
    'Checkpoint', 'StorageVersion', []
)

Return value

'u8'

---

Timestamps

Checkpoint timestamps.

Every schedule-originated checkpoint maps its ID to its due time. Every checkpoint manually created maps its ID to the time of recording.

(ticker) -> (checkpoint ID) -> checkpoint timestamp

Python

result = substrate.query(
    'Checkpoint', 'Timestamps', ['[u8; 12]', 'u64']
)

Return value

'u64'

---

TotalSupply

Total supply of the token at the checkpoint.

(ticker, checkpointId) -> total supply at given checkpoint

Python

result = substrate.query(
    'Checkpoint', 'TotalSupply', ['[u8; 12]', 'u64']
)

Return value

'u128'

---

Errors

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NoSuchSchedule

A checkpoint schedule does not exist for the asset.

---

ScheduleFinished

The schedule has no more checkpoints.

---

ScheduleHasExpiredCheckpoints

The schedule has expired checkpoints.

---

ScheduleIsEmpty

Can't create an empty schedule.

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ScheduleNotRemovable

A checkpoint schedule is not removable as ref_count(schedule_id) > 0.

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SchedulesOverMaxComplexity

The new schedule would put the ticker over the maximum complexity allowed.

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