Crate pallet_stateful_storage

MSA-centric Storage for [PayloadLocation::Paginated] and [PayloadLocation::Itemized]

Quick Links

• Configuration: Config
• Extrinsics: Call
• Runtime API: StatefulStorageRuntimeApi
• Custom RPC API: StatefulStorageApiServer
• Event Enum: Event
• Error Enum: Error

Stateful Storage Pallet

The Stateful Storage Pallet provides per-MSA functionality for reading and writing stateful data where only the latest state is relevant.

Summary

When a Schema uses Paginated or Itemized, the payload data is stored in this pallet. Data stored is user-centric instead of time-centric as with the Messages Pallet. The pallet storage uses child storage making direct query access complex. Custom RPCs are provided for easy access to data.

Paginated Data (PayloadLocation:Paginated)

Data is stored in multiple pages, each 1_024 bytes in size (as defined by constants::MaxPaginatedPageSizeBytes). Each page contains a single item of the associated schema. Page count is limited to 33 per Schema Id, though there may be holes in that range (limit defined by constants::MaxPaginatedPageId). This is most useful for schemas with a larger per-item size and smaller potential item count.

Itemized Data (PayloadLocation:Itemized)

Data is stored in a single page with a max size of 10_240 bytes (defined by constants::MaxItemizedPageSizeBytes). The page contains multiple items of the associated schema. The maximum size of each items is 1_024 bytes (defined by constants::MaxItemizedBlobSizeBytes) . This is most useful for schemas with a relatively small item size and higher potential item count. The read and write complexity is O(n) when n is the number of bytes for all items.

Actions

The Stateful Storage pallet provides for:

• Per MSA and Schema storage of stateful data
• Read/write access storage cost limited to a single MSA Id and Schema Id pair
• A high write throughput
• A high read throughput
• Data race condition protection

Interactions

Extrinsics

Name/Description	Caller	Payment	Key Events	Runtime Added
apply_item_actions Applies a set of actions to an itemized storage array	Provider or MSA Owner	Capacity or Tokens	ItemizedPageUpdated ItemizedPageDeleted	22
apply_item_actions_with_signature_v2 Applies a set of actions to an itemized storage array with a signature authorization	Provider or MSA Owner	Capacity or Tokens	ItemizedPageUpdated ItemizedPageDeleted	45
upsert_page Sets the data for a specific page index	Provider or MSA Owner	Capacity or Tokens	PaginatedPageUpdated	22
delete_page Deletes a specific page index	Provider or MSA Owner	Capacity or Tokens	PaginatedPageDeleted	22
upsert_page_with_signature_v2 Sets the data for a specific page index with a signature authorization	Provider or MSA Owner	Capacity or Tokens	PaginatedPageUpdated	46
delete_page_with_signature_v2 Deletes a specific page index with a signature authorization	Provider or MSA Owner	Capacity or Tokens	PaginatedPageDeleted	46

See Rust Docs for more details.

RPCs

Note: May be restricted based on node settings and configuration.

Name	Description	Call	Node Version
Get Paginated Storage	Retrieves the paginated storage for the given MSA Id and Schema Id	getPaginatedStorage	v1.4.0+
Get Itemized Storage	Retrieves the itemized storage for the given MSA Id and Schema Id	getItemizedStorage	v1.4.0+

See Rust Docs for more details.

Terminology

• Page: Block of on-chain data of a fixed size, which is the underlying type for Itemized and Paginated storage.
• ItemizedPage: A page containing itemized data
• PaginatedPage: A page containing paginated data

Re-exports

pub use pallet::*;

pub use weights::*;

Modules

migration

Migration module

pallet

The pallet module in each FRAME pallet hosts the most important items needed to construct this pallet.

types

Types for the Stateful Storage Pallet

weights

MODIFIED by ‘benchmark_transform’ tool to replace child trie storage access with their specific DB weights

Structs

BlockDuringMigration

The TransactionExtension trait is implemented on BlockDuringMigration to prevent extrinsics in this pallet from being executed while a migration is in progress

Enums

Pre

The info passed between the prepare and post-dispatch steps for the BlockDuringMigration extension.

Val

The info passed between the validate and prepare steps for the BlockDuringMigration extension.

ValidityError

Errors related to the validity of the BlockDuringMigration signed extension.