Module hdi::prelude

Exports common types and functions according to the Rust prelude pattern.

Re-exports

• pub use crate::chain::must_get_agent_activity;
• pub use crate::ed25519::verify_signature;
• pub use crate::ed25519::verify_signature_raw;
• pub use crate::entry::must_get_action;
• pub use crate::entry::must_get_entry;
• pub use crate::entry::must_get_valid_record;
• pub use crate::entry_types;
• pub use crate::hash_path::anchor::Anchor;
• pub use crate::hash_path::path::Component;
• pub use crate::hash_path::path::Path;
• pub use crate::hash_path::path::TypedPath;
• pub use crate::hash_path::shard::ShardStrategy;
• pub use crate::info::dna_info;
• pub use crate::info::zome_info;
• pub use crate::link::LinkTypeFilterExt;
• pub use crate::map_extern;
• pub use crate::map_extern;
• pub use crate::map_extern::ExternResult;
• pub use crate::map_extern_infallible;
• pub use crate::map_extern_preamble;
• pub use crate::x_salsa20_poly1305::ed_25519_x_salsa20_poly1305_decrypt;
• pub use crate::x_salsa20_poly1305::x_25519_x_salsa20_poly1305_decrypt;
• pub use crate::x_salsa20_poly1305::x_salsa20_poly1305_decrypt;
• pub use crate::error;
• pub use hdk_derive;
• pub use holo_hash;
• pub use holochain_integrity_types;
• pub use crate::flat_op::*;
• pub use crate::hash::*;
• pub use crate::hdi::*;
• pub use crate::op::*;

Modules

• allocation
• builder
• conversions
• data
• encode_raw
  By default, disable string encoding and just display raw bytes
• encrypted_data
• hash_type
  Defines the prefixes for the various HashTypes, as well as the traits which unify them
• holochain_serialized_bytes
• key_ref
• nonce
• result
• serde_bytes
  Wrapper types to enable optimized handling of &[u8] and Vec<u8>.
• x25519

Macros

• app_entry
  Implements conversion traits to allow a struct to be handled as an app entry. If you have some need to implement custom serialization logic or metadata injection you can do so by implementing these traits manually instead.
• assert_length
  Helper for ensuring the the proper number of bytes is used in various situations
• holochain_serial
  unidiomatic way to derive default trait implementations of TryFrom in/out of SerializedBytes
• host_externs
• impl_hashable_content
  A default HashableContent implementation, suitable for content which is already TryInto<SerializedBytes>, and uses a PrimitiveHashType
• paste
• try_ptr
  A simple macro to wrap return_err_ptr in an analogy to the native rust ?.
• wasm_error
  Helper macro for returning an error from a WASM.

Structs

• AgentValidationPkg
  Action for an agent validation package, used to determine whether an agent is allowed to participate in this DNA
• AppEntryBytes
  Newtype for the bytes comprising an App entry
• AppEntryDef
  Information about a class of Entries provided by the DNA
• AppEntryName
  Identifier for an entry definition. This may be removed.
• BTreeSet
  An ordered set based on a B-Tree.
• CapClaim
  System entry to hold a capability token claim for use as a caller. Stored by a claimant so they can remember what’s necessary to exercise this capability by sending the secret to the grantor.
• CapSecret
  A CapSecret is used by a caller to prove to a callee access to a committed CapGrant.
• ChainFilter
  Filter source chain items. Starting from some chain position given as an ActionHash the chain is walked backwards to genesis. The filter can stop early by specifying the number of chain items to take and / or an ActionHash to consume until.
• CloseChain
  When migrating to a new version of a DNA, this action is committed to the old chain to declare the migration path taken.
• CloseChainInput
  Input to close a chain.
• CompositeHashConversionError
  Error converting a composite hash into a subset composite hash, due to type mismatch
• CounterSigningAgentState
  Every countersigning agent must sign against their chain state. The chain must be frozen until each agent decides to sign or exit the session.
• CounterSigningSessionData
  All the data required for a countersigning session.
• CounterSigningSessionTimes
  Every countersigning session must complete a full set of actions between the start and end times to be valid.
• Create
  An action which “speaks” Entry content into being. The same content can be referenced by multiple such actions.
• CreateBase
  Base data for Create actions.
• CreateLink
  Declares that a metadata Link should be made between two EntryHashes
• Delete
  Declare that a previously published Action should be nullified and considered deleted.
• DeleteAction
  Placeholder for future when we want to have deletes on actions Not currently in use.
• DeleteLink
  Declares that a previously made Link should be nullified and considered removed.
• Dna
  The Dna Action is always the first action in a source chain
• DnaInfoV1
  Information about the current DNA.
• DnaInfoV2
  Information about the current DNA.
• DnaModifiers
  Modifiers of this DNA - the network seed, properties and origin time - as opposed to the actual DNA code. These modifiers are included in the DNA hash computation.
• DnaModifiersOpt
  DnaModifiers options of which all are optional.
• Ed25519XSalsa20Poly1305Decrypt
• EntryDef
• EntryDefIndex
• EntryDefs
  All definitions for all entry types in an integrity zome.
• EntryHashes
  A newtype for a collection of EntryHashes, needed for some wasm return types.
• EntryRateWeight
  Combination of the three main rate limiting data types, for convenience
• EphemeralSignatures
  The output of ephemeral signing. The private key for this public key has been discarded by this point. The signatures match the public key provided but cannot be reproduced or forged because the private key no longer exists. The signatures match the input items positionally in the vector, it is up to the caller to reconstruct/align/zip them back together.
• ExternIO
• FunctionName
  A single function name.
• GenesisSelfCheckDataV1
  Data passed into the genesis_self_check callback for verifying the initial chain entries
• GenesisSelfCheckDataV2
  Data passed into the genesis_self_check callback for verifying the initial chain entries. DnaInfo can be read with a call to dna_info within the self check callback, it is elided here to minimise/stabilise the callback function signature.
• Hash256Bits
  256 Bit generic hash.
• Hash512Bits
  512 Bit generic hash.
• HashConversionError
  Error converting a composite hash into a primitive one, due to type mismatch
• HashSet
  A hash set implemented as a HashMap where the value is ().
• HoloHash
  A HoloHash contains a vector of 36 bytes representing a 32-byte blake2b hash plus 4 bytes representing a DHT location. It also contains a zero-sized type which specifies what it is a hash of.
• HoloHashed
  Represents some piece of content along with its hash representation, so that hashes need not be calculated multiple times. Provides an easy constructor which consumes the content.
• InclusiveTimestampInterval
  It’s an interval bounded by timestamps that are not infinite.
• InitZomesComplete
  An action which declares that all zome init functions have successfully completed, and the chain is ready for commits. Contains no explicit data.
• LinkTag
  Opaque tag for the link applied at the app layer, used to differentiate between different semantics and validation rules for different links
• LinkType
• MustGetActionInput
  Zome input for must_get_action.
• MustGetAgentActivityInput
  Input to the must_get_agent_activity call.
• MustGetEntryInput
  Zome input for must_get_entry.
• MustGetValidRecordInput
  Zome input for must_get_valid_record.
• OpenChain
  When migrating to a new version of a DNA, this action is committed to the new chain to declare the migration path taken.
• OpenChainInput
  Input to open a chain.
• PreflightBytes
  Every preflight request can have optional arbitrary bytes that can be agreed to.
• PreflightRequest
  The same PreflightRequest is sent to every agent. Each agent signs this data as part of their PreflightResponse. Every preflight must be identical and signed by every agent for a session to be valid.
• PreflightResponse
  Every agent must send back a preflight response. All the preflight response data is signed by each agent and included in the session data.
• RateWeight
  Combination of two rate limiting data types, for convenience
• Record
  a chain record containing the signed action along with the entry if the action type has one.
• RegisterAgentActivity
  Registers a new Action on an agent source chain. This is the act of creating any Action and publishing it to the DHT.
• RegisterCreateLink
  Registers a link between two Entrys. This is the act of creating a Action::CreateLink and publishing it to the DHT. The authority is the entry authority for the base Entry.
• RegisterDelete
  Registers a deletion of an instance of an Entry in the DHT. This is the act of creating a Action::Delete and publishing it to the DHT.
• RegisterDeleteLink
  Deletes a link between two Entrys. This is the act of creating a Action::DeleteLink and publishing it to the DHT. The delete always references a specific Action::CreateLink.
• RegisterUpdate
  Registers an update from an instance of an Entry in the DHT. This is the act of creating a Action::Update and publishing it to the DHT. Note that the Action::Update stores an new instance of an Entry and registers it as an update to the original Entry. This operation is only concerned with registering the update.
• RequiredValidations
  The number of validations required for an entry to be considered published.
• Role
  Agents can have a role specific to each countersigning session. The role is app defined and opaque to the subconscious.
• ScopedZomeType
  A type with the zome that it is defined in.
• ScopedZomeTypes
  zome types that are in scope for the calling zome.
• ScopedZomeTypesSet
  The set of EntryDefIndex and LinkTypes in scope for the calling zome.
• SerializedBytes
  A Canonical Serialized Bytes representation for data If you have a data structure that needs a canonical byte representation use this Always round-trip through SerializedBytes via. a single TryFrom implementation. This ensures that the internal bytes of SerializedBytes are indeed canonical. The corrolary is that if bytes are NOT wrapped in SerializedBytes we can assume they are NOT canonical. Typically we need a canonical serialization when data is to be handled at the byte level by independently implemented and maintained systems.
• Signature
  The raw bytes of a signature.
• SignedHashed
  Any content that has been hashed and signed.
• StoreEntry
  Stores a new Entry in the DHT. This is the act of creating a either a Action::Create or a Action::Update and publishing it to the DHT. These actions create a new instance of an Entry.
• StoreRecord
  Stores a new Record in the DHT. This is the act of creating a new Action and publishing it to the DHT. Note that not all Actions contain an Entry.
• Timestamp
  A microsecond-precision UTC timestamp for use in Holochain’s actions.
• TraceMsg
  Representation of message to be logged via the debug host function
• UnsafeBytes
  UnsafeBytes the only way to implement a custom round trip through bytes for SerializedBytes It is intended to be an internal implementation in TryFrom implementations The assumption is that any code using UnsafeBytes is NOT valid messagepack data This allows us to enforce that all data round-tripping through SerializedBytes is via TryFrom and also allow for custom non-messagepack canonical representations of data types.
• Update
  An action which specifies that some new Entry content is intended to be an update to some old Entry.
• UpdateAction
  Placeholder for future when we want to have updates on actions Not currently in use.
• UpdateBase
  Base data for Update actions.
• VerifySignature
  Mirror struct for Sign that includes a signature to verify against a key and data.
• WasmError
  Wraps a WasmErrorInner with a file and line number. The easiest way to generate this is with the wasm_error! macro that will insert the correct file/line and can create strings by forwarding args to the format! macro.
• WrongActionError
• X25519PubKey
• X25519XSalsa20Poly1305Decrypt
• XSalsa20Poly1305Data
  Data that can be encrypted with secretbox.
• XSalsa20Poly1305Decrypt
• XSalsa20Poly1305EncryptedData
• XSalsa20Poly1305KeyRef
  Key refs represent shared secrets stored in the keystore. They can either be user-specified, or auto-generated at time of secret creation, or ingestion.
• ZomeCallCapGrant
  The entry for the ZomeCall capability grant. This data is committed to the callee’s source chain as a private entry. The remote calling agent must provide a secret and we source their pubkey from the active network connection. This must match the strictness of the CapAccess.
• ZomeDependencyIndex
  The index into the ZomeIndex vec.
• ZomeIndex
  this id is an internal reference, which also serves as a canonical ordering for zome initialization. The value should be auto-generated from the Zome Bundle def
• ZomeInfo
  The properties of the current dna/zome being called.
• ZomeName
  ZomeName as a String.
• ZomeTypesKey
  A key to the ScopedZomeTypes container.

Enums

• Action
  Action contains variants for each type of action.
• ActionBase
  Enum to mirror Action for all the shared data required to build session actions. Does NOT hold any agent specific information.
• ActionType
  A unit enum which just maps onto the different Action variants, without containing any extra data
• AnyDhtHashPrimitive
  The primitive hash types represented by this composite hash
• AnyLinkableHashPrimitive
  The primitive hash types represented by this composite hash
• CapAccess
  Represents access requirements for capability grants.
• CapGrant
  Represents a potentially valid access grant to a zome call. Zome call response will be Unauthorized without a valid grant.
• ChainFilters
  Specify which Actions to allow through this filter.
• CounterSigningError
  Errors related to the secure primitive macro.
• Entry
  Structure holding the entry portion of a chain record.
• EntryCreationAction
  Either a Action::Create or a Action::Update. These actions both create a new instance of an Entry.
• EntryDefId
• EntryDefsCallbackResult
• EntryError
  Errors involving app entry creation
• EntryType
  Allows Actions which reference Entries to know what type of Entry it is referencing. Useful for examining Actions without needing to fetch the corresponding Entries.
• EntryVisibility
• GrantedFunctions
  A collection of zome/function pairs
• HashInput
  Input to holochain hash function.
• HashOutput
  Output from the holochain hashing host function.
• HashableContentBytes
  HashableContent can be expressed as “content”, or “prehashed”, which affects how a HoloHashed type will be constructed from it.
• HoloHashError
  HoloHash Error Type.
• HumanTimestamp
  A human-readable timestamp which is represented/serialized as an RFC3339 when possible, and a microsecond integer count otherwise. Both representations can be deserialized to this type.
• Level
  Maps directly to the tracing Levels but here to define the interface. See https://docs.rs/tracing-core/0.1.17/tracing_core/struct.Level.html
• LinkTypeFilter
  Filter on a set of LinkTypes.
• Op
  These are the operations that can be applied to Holochain data. Every Action produces a set of operations. These operations are each sent to an authority for validation.
• PreflightRequestAcceptance
  A preflight request can be accepted, or invalid, or valid but the local agent cannot accept it.
• RecordEntry
  Represents the different ways the entry_address reference within an action can be interpreted
• RequiredValidationType
  The level of validation package required by an entry.
• SerializedBytesError
• TimestampError
• UnitEnumEither
  A full UnitEnum, or just the unit type of that UnitEnum
• UnresolvedDependencies
  Unresolved dependencies that are either a set of hashes or an agent activity query.
• ValidateCallbackResult
• WasmErrorInner
  Enum of all possible ERROR states that wasm can encounter.
• WeighInput
  Input to the weigh callback. Includes an “unweighed” action, and Entry if applicable.

Constants

• CAP_SECRET_BITS
  The number of bits we want for a comfy secret.
• CAP_SECRET_BYTES
  The number of bytes we want for a comfy secret.
• ENTRY_SIZE_LIMIT
  Entries larger than this number of bytes cannot be created
• HOLO_HASH_CORE_LEN
  Length of the core bytes (32)
• HOLO_HASH_FULL_LEN
  Length of the full HoloHash bytes (39 = 3 + 32 + 4)
• HOLO_HASH_LOC_LEN
  Length of the location bytes (4)
• HOLO_HASH_PREFIX_LEN
  Length of the prefix bytes (3)
• HOLO_HASH_UNTYPED_LEN
  Length of the core bytes + the loc bytes (36 = 32 + 4), i.e. everything except the type prefix
• MAX_COUNTERSIGNING_AGENTS
  8 seems like a reasonable limit of agents to countersign.
• MIN_COUNTERSIGNING_AGENTS
  Need at least two to countersign.
• MM
  One million
• POST_GENESIS_SEQ_THRESHOLD
  Any action with a action_seq less than this value is part of a record created during genesis. Anything with this seq or higher was created after genesis.
• SESSION_ACTION_TIME_OFFSET
  The timestamps on actions for a session use this offset relative to the session start time. This makes it easier for agents to accept a preflight request with actions that are after their current chain top, after network latency.
• SESSION_TIME_FUTURE_MAX
  Maximum time in the future the session start can be in the opinion of the participating agent. As the action will be SESSION_ACTION_TIME_OFFSET after the session start we include that here.
• SIGNATURE_BYTES
  Ed25519 signatures are always the same length, 64 bytes.
• X25519_PUB_KEY_BYTES

Traits

• ActionUnweighed
  A trait to unify the “inner” parts of an Action, i.e. the structs inside the Action enum’s variants. This trait is used for the “unweighed” version of each struct, i.e. the version with weight information erased.
• ActionWeighed
  A trait to unify the “inner” parts of an Action, i.e. the structs inside the Action enum’s variants. This trait is used for the “weighed” version of each struct, i.e. the version without weight information erased.
• Deserialize
  A data structure that can be deserialized from any data format supported by Serde.
• EntryDefRegistration
  Trait for binding static EntryDef property access for a type. This trait maps a type to its corresponding EntryDef property at compile time.
• EntryTypesHelper
  Helper trait for deserializing Entrys to the correct type.
• HasHash
  Anything which has an owned HoloHashOf.
• HashType
  Every HoloHash is generic over HashType. Additionally, every HashableContent has an associated HashType. The HashType is the glue that binds together HashableContent with its hash.
• HashableContent
  Any implementor of HashableContent may be used in a HoloHashed to pair data with its HoloHash representation. It also has an associated HashType.
• LinkTypesHelper
  A helper trait for finding the app defined link type from a ZomeIndex and LinkType.
• PrimitiveHashType
  A PrimitiveHashType is one with a multihash prefix. In contrast, a non-primitive hash type could be one of several primitive types, e.g. an AnyDhtHash can represent one of three primitive types.
• Serialize
  A data structure that can be serialized into any data format supported by Serde.
• TryFrom
  Simple and safe type conversions that may fail in a controlled way under some circumstances. It is the reciprocal of TryInto.
• TryFromDnaProperties
  Trait to convert from dna properties into specified type
• TryInto
  An attempted conversion that consumes self, which may or may not be expensive.
• U8Index
  Helper trait for types that are internally represented as u8 but need to be used as indicies into containers.
• UnitEnum
  A utility trait for associating a data enum with a unit enum that has the same variants.

Functions

• __hc__dna_info_1^⚠
• __hc__dna_info_2^⚠
• __hc__ed_25519_x_salsa20_poly1305_decrypt_1^⚠
• __hc__hash_1^⚠
• __hc__must_get_action_1^⚠
• __hc__must_get_agent_activity_1^⚠
• __hc__must_get_entry_1^⚠
• __hc__must_get_valid_record_1^⚠
• __hc__trace_1^⚠
• __hc__unreachable_1^⚠
• __hc__verify_signature_1^⚠
• __hc__x_25519_x_salsa20_poly1305_decrypt_1^⚠
• __hc__x_salsa20_poly1305_decrypt_1^⚠
• __hc__zome_info_1^⚠
• decode
• encode
• host_args
  Receive arguments from the host. The guest sets the type O that the host needs to match. If deserialization fails then a GuestPtr to a WasmError::Deserialize is returned. The guest should immediately return an Err back to the host. The WasmError::Deserialize enum contains the bytes that failed to deserialize so the host can unambiguously provide debug information.
• host_call
  Given an extern that we expect the host to provide:
• merge_u32
• merge_u64
• merge_usize
  Given 2x u32, return a DoubleUSize merged. Works via a simple bitwise shift to move the pointer to high bits then OR the length into the low bits.
• return_err_ptr
  Convert a WasmError to a GuestPtrLen as best we can. This is not necessarily straightforward as the serialization process can error recursively. In the worst case we can’t even serialize an enum variant, in which case we panic. The casts from usize to u32 are safe as long as the guest code is compiled for wasm32-unknown-unknown target.
• return_ptr
  Convert any serializable value into a GuestPtr that can be returned to the host. The host is expected to know how to consume and deserialize it.
• split_u64
• split_u128
• split_usize
  Given 2x merged usize, split out two usize. Performs the inverse of merge_usize.

Type Aliases

• ActionHash
  The hash of an action
• ActionHashed
• AgentPubKey
  An Agent public signing key. Not really a hash, more of an “identity hash”.
• AnyDhtHash
  The hash of anything referrable in the DHT. This is a composite of either an EntryHash or a ActionHash
• AnyLinkableHash
  The hash of anything linkable.
• BoxData
• CapClaimEntry
  The data type written to the source chain to denote a capability claim
• CapGrantEntry
  The data type written to the source chain when explicitly granting a capability. NB: this is not simply CapGrant, because the CapGrant::ChainAuthor grant is already implied by Entry::Agent, so that should not be committed to a chain. This is a type alias because if we add other capability types in the future, we may want to include them
• CapSecretBytes
  A fixed size array of bytes that a secret must be.
• CounterSigningAgents
  Alias for a list of agents and their roles.
• DhtOpHash
  The hash of a DhtOp’s “unique form” representation
• DnaHash
  The hash of a DnaDef
• DnaInfo
  Convenience alias to the latest DnaInfoN.
• DoubleUSize
• EntryHash
  The hash of an Entry.
• EntryHashed
  An Entry paired with its EntryHash
• ExternalHash
  The hash of some external data that can’t or doesn’t exist on the DHT.
• GenesisSelfCheckData
  Alias to the current version of GenesisSelfCheckData.
• GrantedFunction
  a single zome/function pair
• GuestPtr
  A WasmSize that points to a position in wasm linear memory that the host and guest are sharing to communicate across function calls.
• GuestPtrLen
  Enough bits to fit a pointer and length into so we can return it. The externs defined as “C” don’t support multiple return values (unlike wasm). The native Rust support for wasm externs is not stable at the time of writing.
• HoloHashOf
  A convenience type, for specifying a hash by HashableContent rather than by its HashType
• HoloHashResult
  HoloHash Result type
• Len
  A WasmSize integer that represents the size of bytes to read/write to memory.
• MembraneProof
  App-specific payload for proving membership in the membrane of the app
• NetIdHash
  The hash of a network ID
• NetworkSeed
  Placeholder for a real network seed type. See DnaModifiers.
• OpBasis
  Alias for AnyLinkableHash. This hash forms the notion of the “basis hash” of an op.
• RateBucketCapacity
  The amount that a bucket is “filled”
• RateBucketId
  A bucket ID, for rate limiting
• RateBytes
  The normalized total size of this action, for rate limiting
• RateUnits
  The weight of this action, for rate limiting
• RecordEntryRef
  Alias for record with ref entry
• ScopedEntryDefIndex
  An EntryDefIndex within the scope of the zome where it’s defined.
• ScopedLinkType
  A LinkType within the scope of the zome where it’s defined.
• SecretBoxData
• SignedActionHashed
  The hashed action and the signature that signed it
• TimestampResult
• WasmHash
  The hash of some wasm bytecode
• WasmSize
  Something like usize for wasm. Wasm has a memory limit of 4GB so offsets and lengths fit in u32.
• ZomeCallSigningKey
  A public key of a pair of signing keys for signing zome calls.
• ZomeEntryTypesKey
  A key to the ScopedZomeTypes<EntryDefIndex> container.
• ZomeLinkTypesKey
  A key to the ScopedZomeTypes<LinkType> container.

Attribute Macros

• dna_properties
• hdk_entry_helper
  Helper for entry data types.
• hdk_entry_types
  Declares the integrity zome’s entry types.
• hdk_entry_types_conversions
• hdk_extern
• hdk_link_types
  Implements all the required types needed for a LinkTypes enum.
• hdk_to_coordinates

Derive Macros

• Deserialize
• EntryDefRegistration
• Serialize
• SerializedBytes
• UnitEnum