jam-std-common 0.1.16

use super::{Extrinsic, Header};
use core::fmt;
use jam_types::{
	chain_params, max_exports, max_imports, max_input, opaque, val_count, Balance, CoreIndex,
	FixedVec, SegmentSliceLen, Slot, UnsignedGas, ValIndex,
};
use scale::{Decode, Encode};
use std::{sync::atomic::Ordering::Relaxed, time::Duration};

/// Length of a timeslot in nanoseconds.
pub const SLOT_PERIOD_IN_NS: u64 = 6_000_000_000;

/// Length of a timeslot.
pub const SLOT_PERIOD: Duration = Duration::from_nanos(SLOT_PERIOD_IN_NS);

/// Index for an attempt at producing a ticket for the right to produce a block.
pub type TicketAttempt = u8;

#[cfg(feature = "tiny")]
mod defaults {
	use super::{Slot, TicketAttempt};
	pub(super) const EPOCH_PERIOD: Slot = 12;
	pub(super) const ROTATION_PERIOD: Slot = 4;
	pub(super) const MAX_TICKETS_PER_BLOCK: usize = 3;
	pub(super) const TICKETS_ATTEMPTS_NUMBER: TicketAttempt = 3;
}
#[cfg(not(feature = "tiny"))]
mod defaults {
	use super::{Slot, TicketAttempt};
	pub(super) const EPOCH_PERIOD: Slot = 600;
	pub(super) const ROTATION_PERIOD: Slot = 10;
	pub(super) const MAX_TICKETS_PER_BLOCK: usize = 16;
	pub(super) const TICKETS_ATTEMPTS_NUMBER: TicketAttempt = 2;
}

chain_params! {
	/// The rotation period, defined in number of slots.
	static ROTATION_PERIOD: _ = _(defaults::ROTATION_PERIOD);
	pub fn rotation_period() -> Slot;
	pub struct RotationPeriod; impl Get<_> for _ {}

	/// The epoch period, defined in number of slots.
	static EPOCH_PERIOD: _ = _(defaults::EPOCH_PERIOD);
	pub fn epoch_period() -> Slot;
	pub struct EpochPeriod; impl Get<_> for _ {}

	/// Max tickets allowed to be embedded in each block extrinsic.
	static MAX_TICKETS_PER_BLOCK: _ = _(defaults::MAX_TICKETS_PER_BLOCK);
	pub fn max_tickets_per_block() -> usize;
	pub struct MaxTicketsPerBlock; impl Get<_> for _ {}

	/// Maximum number of tickets which each validator may create.
	///
	/// Influences the anonymity of block producers. As all published tickets have a public
	/// attempt number less than `attempts_number` if two tickets share an attempt number
	/// then they must belong to two different validators, which reduces anonymity late as
	/// we approach the epoch tail.
	static TICKETS_ATTEMPTS_NUMBER: _ = _(defaults::TICKETS_ATTEMPTS_NUMBER);
	pub fn tickets_attempts_number() -> TicketAttempt;

	static DEPOSIT_PER_ACCOUNT: _ = _(100);
	pub fn deposit_per_account() -> Balance;

	static DEPOSIT_PER_ITEM: _ = _(10);
	pub fn deposit_per_item() -> Balance;

	static DEPOSIT_PER_BYTE: _ = _(1);
	pub fn deposit_per_byte() -> Balance;

	/// The maximum gas which may be used in a single block. At present this is just the product of
	/// the maximum gas per work-report and the number of cores. In the future it should probably be
	/// more to account for the possibility of always-accumulate services.
	static BLOCK_GAS_LIMIT: _ = _(3_500_000_000);
	pub fn block_gas_limit() -> UnsignedGas;

	/// Maximum gas which may be used to Authorize a single work-package.
	static MAX_IS_AUTHORIZED_GAS: _ = _(50_000_000);
	pub fn max_is_authorized_gas() -> UnsignedGas;

	/// Maximum gas which may be used to Refine a single work-report.
	static MAX_REFINE_GAS: _ = _(5_000_000_000);
	pub fn max_refine_gas() -> UnsignedGas;

	/// Maximum gas which may be used to Accumulate a single work-report.
	static MAX_ACCUMULATE_GAS: _ = _(10_000_000);
	pub fn max_accumulate_gas() -> UnsignedGas;

	static MAX_REFINE_CODE_SIZE: _ = _(10 * 1024 * 1024);
	pub fn max_refine_code_size() -> usize;

	static MAX_IS_AUTHORIZED_CODE_SIZE: _ = _(64 * 1024);
	pub fn max_is_authorized_code_size() -> usize;

	static MAX_REFINE_MEMORY: _ = _(1024 * 1024 * 1024);
	pub fn max_refine_memory() -> usize;

	static MAX_IS_AUTHORIZED_MEMORY: _ = _(256 * 1024);
	pub fn max_is_authorized_memory() -> usize;

	/// The number of blocks which are kept in the recent block cache. We use a `u8` to index into
	/// this and therefore it may be no larger than 255.
	static RECENT_BLOCK_COUNT: _ = _(8);
	pub fn recent_block_count() -> Slot;
	pub struct RecentBlockCount; impl Get<_> for _ {}

	/// The number of validators on each core.
	pub const VALS_PER_CORE: _ = 3;
	pub fn vals_per_core() -> usize;
	pub struct ValsPerCore; impl Get<_> for _ {}

	/// Number of cores in the JAM.
	pub fn core_count() -> CoreIndex {
		(val_count() as usize / VALS_PER_CORE) as CoreIndex
	}
	pub struct CoreCount; impl Get<_> for _ {}

	/// Maximum number of DA segments that a Work Package can produce.
	pub fn max_export_segments() -> u32 {
		max_exports() + max_exports().div_ceil(PROVEN_PER_SEGMENT as u32)
	}
	pub struct MaxExportSegments; impl Get<_> for _ {}

	/// Maximum number of DA segments that a Work Package can require as imports. This is twice the
	/// maximum number of imports because each import may require a proof segment.
	pub fn max_import_segments() -> u32 { max_imports() * 2 }
	pub struct MaxImportSegments; impl Get<_> for _ {}

	/// The period in timeslots after which reported but unavailable work may be replaced.
	static AVAILABILITY_TIMEOUT: _ = _(5);
	pub fn availability_timeout() -> Slot;

	/// Number of items in the authorization window.
	static AUTH_WINDOW: _ = _(8);
	pub fn auth_window() -> usize;
	pub struct AuthWindow; impl Get<_> for _ {}

	/// Maximum age, in blocks, that the lookup anchor may be, taken from the regular anchor.
	static MAX_LOOKUP_ANCHOR_AGE: _ = _(24 * 600);
	pub fn max_lookup_anchor_age() -> Slot;
}

/// The conservative maximum size of a Work Package Bundle. This is basically `MAX_INPUT` plus sone
/// extra for the import proofs.
pub fn max_bundle_size() -> usize {
	max_input() as usize + 1024 * 1024
}

/// Parameters for the JAM protocol.
#[derive(
	Copy, Clone, Eq, PartialEq, Debug, Encode, Decode, serde::Serialize, serde::Deserialize,
)]
pub struct Parameters {
	/// Total number of validators. Must by divisible by guarantor group size (3).
	pub val_count: ValIndex,
	/// Number of octets in a basic piece. Must be even and divide into segment length (4,104).
	pub basic_piece_len: u32,
	/// Number of authorizations in a queue allocated to a core.
	pub auth_queue_len: u32,
	/// Minimum period in blocks between going from becoming `Available` to `Zombie`, and then
	/// again from `Zombie` to non-existent.
	pub min_turnaround_period: Slot,
	/// Maximum number of Work Items in a Work Package.
	pub max_work_items: u32,
	/// Maximum number of imports in a Work Package.
	pub max_imports: u32,
	/// Maximum number of exports in a Work Package.
	pub max_exports: u32,
	/// Maximum number of extrinsics in a Work Package.
	pub max_extrinsics: u32,
	/// Maximum number of dependencies (total of prerequisites and SR lookup entries).
	pub max_dependencies: u32,
	/// Maximum size of a Work Package together with all extrinsic data and imported segments.
	pub max_input: u32,

	/// The epoch period, defined in number of slots.
	pub epoch_period: Slot,
	/// The rotation period, defined in number of slots.
	pub rotation_period: Slot,
	/// Maximum gas which can be processed in a single block.
	pub block_gas_limit: UnsignedGas,
	/// The number of blocks which are kept in the recent block cache.
	pub recent_block_count: Slot,
	/// Max tickets allowed to be embedded in each block extrinsic.
	pub max_tickets_per_block: u32,
	/// The number of distinct tickets which may be created and submitted by each validator on each
	/// epoch.
	pub tickets_attempts_number: TicketAttempt,
	/// The base deposit required to retain an account.
	pub deposit_per_account: Balance,
	/// The additional deposit required for each preimage or storage item in an account.
	pub deposit_per_item: Balance,
	/// The additional deposit required for each byte of each storage item in an account and
	/// preimage of an account.
	pub deposit_per_byte: Balance,
	/// Maximum gas which may be used to Authorize a single work-package.
	pub max_is_authorized_gas: UnsignedGas,
	/// Maximum gas which may be used to Refine a single work-report.
	pub max_refine_gas: UnsignedGas,
	/// Maximum gas which may be used to Accumulate a single work-report.
	pub max_accumulate_gas: UnsignedGas,
	/// The maximum size of Refine/Accumulate code.
	pub max_refine_code_size: u32,
	/// The maximum size of Is-Authorized code.
	pub max_is_authorized_code_size: u32,
	/// The maximum amount of RAM which may be used by Refine/Accumulate code.
	pub max_refine_memory: u32,
	/// The maximum amount of RAM which may be used by IsAuthorized code.
	pub max_is_authorized_memory: u32,
	/// The period in timeslots after which reported but unavailable work may be replaced.
	pub availability_timeout: Slot,
	/// Number of items in the authorization window.
	pub auth_window: u32,
	/// Maximum age, in blocks, that the lookup anchor may be, taken from the regular anchor.
	pub max_lookup_anchor_age: Slot,
}
impl fmt::Display for Parameters {
	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
		write!(
			f,
			"\n\
			val_count: {}\n\
			basic_piece_len: {}\n\
			auth_queue_len: {}\n\
			min_turnaround_period: {}\n\
			max_work_items: {}\n\
			max_imports: {}\n\
			max_exports: {}\n\
			max_extrinsics: {}\n\
			max_dependencies: {}\n\
			max_input: {}\n\
			epoch_period: {}\n\
			rotation_period: {}\n\
			block_gas_limit: {}\n\
			recent_block_count: {}\n\
			max_tickets_per_block: {}\n\
			tickets_attempts_number: {}\n\
			deposit_per_account: {}\n\
			deposit_per_item: {}\n\
			deposit_per_byte: {}\n\
			max_is_authorized_gas: {}\n\
			max_refine_gas: {}\n\
			max_accumulate_gas: {}\n\
			max_refine_code_size: {}\n\
			max_is_authorized_code_size: {}\n\
			max_refine_memory: {}\n\
			max_is_authorized_memory: {}\n\
			availability_timeout: {}\n\
			auth_window: {}\n\
			max_lookup_anchor_age: {}\n\
			",
			self.val_count,
			self.basic_piece_len,
			self.auth_queue_len,
			self.min_turnaround_period,
			self.max_work_items,
			self.max_imports,
			self.max_exports,
			self.max_extrinsics,
			self.max_dependencies,
			self.max_input,
			self.epoch_period,
			self.rotation_period,
			self.block_gas_limit,
			self.recent_block_count,
			self.max_tickets_per_block,
			self.tickets_attempts_number,
			self.deposit_per_account,
			self.deposit_per_item,
			self.deposit_per_byte,
			self.max_is_authorized_gas,
			self.max_refine_gas,
			self.max_accumulate_gas,
			self.max_refine_code_size,
			self.max_is_authorized_code_size,
			self.max_refine_memory,
			self.max_is_authorized_memory,
			self.availability_timeout,
			self.auth_window,
			self.max_lookup_anchor_age,
		)
	}
}

impl Parameters {
	pub fn tiny() -> Self {
		Self {
			val_count: 6,
			basic_piece_len: 4,
			auth_queue_len: 80,
			min_turnaround_period: 28_800,
			max_work_items: 16,
			max_imports: 3072,
			max_exports: 3072,
			max_extrinsics: 128,
			max_dependencies: 8,
			max_input: 12 * 1024 * 1024,
			epoch_period: 12,
			rotation_period: 4,
			block_gas_limit: 20_000_000,
			recent_block_count: 8,
			max_tickets_per_block: 3,
			tickets_attempts_number: 3,
			deposit_per_account: 100,
			deposit_per_item: 10,
			deposit_per_byte: 1,
			max_is_authorized_gas: 50_000_000,
			max_refine_gas: 1_600_000_000,
			max_accumulate_gas: 10_000_000,
			max_refine_code_size: 10 * 1024 * 1024,
			max_is_authorized_code_size: 64 * 1024,
			max_refine_memory: 1024 * 1024 * 1024,
			max_is_authorized_memory: 256 * 1024,
			availability_timeout: 5,
			auth_window: 8,
			max_lookup_anchor_age: 24 * 600,
		}
	}
	pub fn full() -> Self {
		Self {
			val_count: 1023,
			basic_piece_len: 684,
			auth_queue_len: 80,
			min_turnaround_period: 28_800,
			max_work_items: 16,
			max_imports: 3072,
			max_exports: 3072,
			max_extrinsics: 128,
			max_dependencies: 8,
			max_input: 12 * 1024 * 1024,
			epoch_period: 600,
			rotation_period: 10,
			block_gas_limit: 3_500_000_000,
			recent_block_count: 8,
			max_tickets_per_block: 16,
			tickets_attempts_number: 2,
			deposit_per_account: 100,
			deposit_per_item: 10,
			deposit_per_byte: 1,
			max_is_authorized_gas: 50_000_000,
			max_refine_gas: 5_000_000_000,
			max_accumulate_gas: 10_000_000,
			max_refine_code_size: 10 * 1024 * 1024,
			max_is_authorized_code_size: 64 * 1024,
			max_refine_memory: 1024 * 1024 * 1024,
			max_is_authorized_memory: 256 * 1024,
			availability_timeout: 5,
			auth_window: 8,
			max_lookup_anchor_age: 24 * 600,
		}
	}
	pub fn get() -> Self {
		let jam_types::Parameters {
			val_count,
			basic_piece_len,
			auth_queue_len,
			min_turnaround_period,
			max_work_items,
			max_imports,
			max_exports,
			max_extrinsics,
			max_dependencies,
			max_input,
		} = jam_types::Parameters::get();
		Self {
			val_count,
			basic_piece_len,
			auth_queue_len,
			min_turnaround_period,
			max_work_items,
			max_imports,
			max_exports,
			max_extrinsics,
			max_dependencies,
			max_input,
			epoch_period: EPOCH_PERIOD.load(Relaxed),
			rotation_period: ROTATION_PERIOD.load(Relaxed),
			block_gas_limit: BLOCK_GAS_LIMIT.load(Relaxed),
			recent_block_count: RECENT_BLOCK_COUNT.load(Relaxed),
			max_tickets_per_block: MAX_TICKETS_PER_BLOCK.load(Relaxed) as _,
			tickets_attempts_number: TICKETS_ATTEMPTS_NUMBER.load(Relaxed),
			deposit_per_account: DEPOSIT_PER_ACCOUNT.load(Relaxed),
			deposit_per_item: DEPOSIT_PER_ITEM.load(Relaxed),
			deposit_per_byte: DEPOSIT_PER_BYTE.load(Relaxed),
			max_is_authorized_gas: MAX_IS_AUTHORIZED_GAS.load(Relaxed),
			max_refine_gas: MAX_REFINE_GAS.load(Relaxed),
			max_accumulate_gas: MAX_ACCUMULATE_GAS.load(Relaxed),
			max_refine_code_size: MAX_REFINE_CODE_SIZE.load(Relaxed) as _,
			max_is_authorized_code_size: MAX_IS_AUTHORIZED_CODE_SIZE.load(Relaxed) as _,
			max_refine_memory: MAX_REFINE_MEMORY.load(Relaxed) as _,
			max_is_authorized_memory: MAX_IS_AUTHORIZED_MEMORY.load(Relaxed) as _,
			availability_timeout: AVAILABILITY_TIMEOUT.load(Relaxed),
			auth_window: AUTH_WINDOW.load(Relaxed) as _,
			max_lookup_anchor_age: MAX_LOOKUP_ANCHOR_AGE.load(Relaxed),
		}
	}
	pub fn validate(self) -> Result<jam_types::Parameters, &'static str> {
		let r = jam_types::Parameters {
			val_count: self.val_count,
			basic_piece_len: self.basic_piece_len,
			auth_queue_len: self.auth_queue_len,
			min_turnaround_period: self.min_turnaround_period,
			max_work_items: self.max_work_items,
			max_imports: self.max_imports,
			max_exports: self.max_exports,
			max_extrinsics: self.max_extrinsics,
			max_dependencies: self.max_dependencies,
			max_input: self.max_input,
		};
		r.validate()?;
		if self.epoch_period % self.rotation_period != 0 {
			return Err("`rotation_period` does not divide into `epoch_period`")
		}
		if self.val_count as usize % VALS_PER_CORE != 0 {
			return Err("`val_count` does not divide by `VALS_PER_CORE` (3)")
		}
		if recent_block_count() > 255 {
			return Err("`recent_block_count` may be no larger than `BlockIndex::MAX` (255)")
		}
		Ok(r)
	}
	pub fn apply(self) -> Result<(), &'static str> {
		let base = self.validate()?;
		base.apply()?;
		EPOCH_PERIOD.store(self.epoch_period, Relaxed);
		ROTATION_PERIOD.store(self.rotation_period, Relaxed);
		BLOCK_GAS_LIMIT.store(self.block_gas_limit, Relaxed);
		RECENT_BLOCK_COUNT.store(self.recent_block_count, Relaxed);
		MAX_TICKETS_PER_BLOCK.store(self.max_tickets_per_block as _, Relaxed);
		TICKETS_ATTEMPTS_NUMBER.store(self.tickets_attempts_number, Relaxed);
		DEPOSIT_PER_ACCOUNT.store(self.deposit_per_account, Relaxed);
		DEPOSIT_PER_ITEM.store(self.deposit_per_item, Relaxed);
		DEPOSIT_PER_BYTE.store(self.deposit_per_byte, Relaxed);
		MAX_IS_AUTHORIZED_GAS.store(self.max_is_authorized_gas, Relaxed);
		MAX_REFINE_GAS.store(self.max_refine_gas, Relaxed);
		MAX_ACCUMULATE_GAS.store(self.max_accumulate_gas, Relaxed);
		MAX_REFINE_CODE_SIZE.store(self.max_refine_code_size as _, Relaxed);
		MAX_IS_AUTHORIZED_CODE_SIZE.store(self.max_is_authorized_code_size as _, Relaxed);
		MAX_REFINE_MEMORY.store(self.max_refine_memory as _, Relaxed);
		MAX_IS_AUTHORIZED_MEMORY.store(self.max_is_authorized_memory as _, Relaxed);
		RECENT_BLOCK_COUNT.store(self.recent_block_count, Relaxed);
		AVAILABILITY_TIMEOUT.store(self.availability_timeout, Relaxed);
		AUTH_WINDOW.store(self.auth_window as _, Relaxed);
		MAX_LOOKUP_ANCHOR_AGE.store(self.max_lookup_anchor_age, Relaxed);
		Ok(())
	}
}

/// Maximum basic size of a Work Package that we accept.
pub const SANE_MAX_PACKAGE_SIZE: usize = 100 * 1024;

/// Maximum total output blobs which can be in a Work Report. The maximum encoded size of a Work
/// Report is this together with the portions which are constant or based on the (very limited)
/// number of Work Items.
pub const MAX_REPORT_ELECTIVE_DATA: usize = 48 * 1024;

/// The min. no. of signatures required for a guarantee to be valid.
///
/// Equals 2/3 of guarantors assigned to a core.
pub const GUARANTEE_MIN_SIGNATURES: usize = (VALS_PER_CORE * 2).div_ceil(3);

// Entropy required by some protocol's operations.
opaque! { pub struct Entropy(pub [u8; 32]); }

#[derive(Clone, Encode, Decode, Debug)]
pub struct Block {
	pub header: Header,
	pub extrinsic: Extrinsic,
}

/// The maximum number of levels in the implicit tree derived from the segment hashes in a
/// proof-page.
//pub const SUFFIX_SKIP_LEN: usize = (SEGMENT_LEN / 2 / 32).trailing_zeros() as usize;
pub const SUFFIX_SKIP_LEN: usize = 6;

/// The maximum number of segments whose justification can be included in a single segment-sized
/// proof-page. Basically just the highest power of 2 which when multiplied by 32 (the size of a
/// hash) leaves enough room from 4104 (the size of a segment) to fit a partial Merkle proof of
/// 6 branches (6 * 32 = 192) plus the overhead for storing the actual number of hashes (should be
/// one byte for `PROVEN_PER_SEGMENT < 128`). It turns out that this is 2^6 = 64.
///
/// See `max_prefix_proof_len` for the actual formula.
pub const PROVEN_PER_SEGMENT: usize = 1 << SUFFIX_SKIP_LEN;

pub type SegmentSlice = FixedVec<u8, SegmentSliceLen>;

/// Type to represent the index of a tranche.
pub type TrancheIndex = u8;