signet::forge::AuditChainWriter Class Reference

Builds SHA-256 hash chains during Parquet writes. More...

#include <audit_chain.hpp>

Public Member Functions
	AuditChainWriter ()
	Construct a new writer with an empty chain.
HashChainEntry	append (const uint8_t *record_data, size_t record_size, int64_t timestamp_ns)
	Append a record to the chain with an explicit timestamp.
HashChainEntry	append (const uint8_t *record_data, size_t record_size)
	Append a record with auto-generated timestamp from the system clock.
int64_t	length () const
	Return the number of entries in the chain.
std::array< uint8_t, 32 >	last_hash () const
	Return the entry_hash of the last entry in the chain.
const std::vector< HashChainEntry > &	entries () const
	Return a const reference to the internal entry list.
std::vector< uint8_t >	serialize_chain () const
	Serialize the entire chain to bytes.
void	reset (std::array< uint8_t, 32 > initial_prev_hash={}, int64_t initial_seq=0)
	Clear the chain and optionally set an initial prev_hash.

Detailed Description

Builds SHA-256 hash chains during Parquet writes.

AuditChainWriter writer;
for (const auto& record : records) {
    auto bytes = serialize_record(record);
    auto entry = writer.append(bytes.data(), bytes.size());
}
auto chain_bytes = writer.serialize_chain();
// Store chain_bytes in Parquet metadata or a sidecar file

To continue a chain across files, save last_hash() from the previous file and pass it to the new writer's reset():

AuditChainWriter writer2;
writer2.reset(previous_writer.last_hash());

Note

NOT thread-safe. Callers must synchronize externally if appending from multiple threads.

Definition at line 408 of file audit_chain.hpp.

Constructor & Destructor Documentation

AuditChainWriter()

signet::forge::AuditChainWriter::AuditChainWriter ( )

inline

Construct a new writer with an empty chain.

The first entry's prev_hash will be all zeros.

Exceptions

std::runtime_error

if the commercial license is required but missing.

Definition at line 413 of file audit_chain.hpp.

Member Function Documentation

append() [1/2]

HashChainEntry signet::forge::AuditChainWriter::append ( const uint8_t *  record_data, size_t  record_size  )

inline

Append a record with auto-generated timestamp from the system clock.

Parameters

record_data	Raw bytes of the record being audited.
record_size	Size of record_data in bytes.

Returns

The newly created HashChainEntry (by value).

See also

append(const uint8_t*, size_t, int64_t) for explicit timestamps.

Definition at line 453 of file audit_chain.hpp.

append() [2/2]

HashChainEntry signet::forge::AuditChainWriter::append ( const uint8_t *  record_data, size_t  record_size, int64_t  timestamp_ns  )

inline

Append a record to the chain with an explicit timestamp.

Hashes record_data to produce data_hash, sets prev_hash from the last entry (or zeros for the first), computes entry_hash, and appends the new entry to the internal list.

Parameters

record_data	Raw bytes of the record being audited.
record_size	Size of record_data in bytes.
timestamp_ns	Nanosecond timestamp for this entry.

Returns

The newly created HashChainEntry (by value).

Definition at line 430 of file audit_chain.hpp.

entries()

const std::vector< HashChainEntry > & signet::forge::AuditChainWriter::entries ( ) const

inline

Return a const reference to the internal entry list.

Definition at line 470 of file audit_chain.hpp.

last_hash()

std::array< uint8_t, 32 > signet::forge::AuditChainWriter::last_hash ( ) const

inline

Return the entry_hash of the last entry in the chain.

If the chain is empty, returns all zeros (or the initial prev_hash if set via reset()).

Definition at line 465 of file audit_chain.hpp.

length()

int64_t signet::forge::AuditChainWriter::length ( ) const

inline

Return the number of entries in the chain.

Definition at line 458 of file audit_chain.hpp.

reset()

void signet::forge::AuditChainWriter::reset ( std::array< uint8_t, 32 >  initial_prev_hash = {}, int64_t  initial_seq = 0  )

inline

Clear the chain and optionally set an initial prev_hash.

Call this to start a new chain. If initial_prev_hash is provided, the first entry's prev_hash will be set to that value instead of all zeros. This is used to continue a chain from a previous file.

Parameters

initial_prev_hash

The prev_hash for the next appended entry (default: all zeros).

Definition at line 511 of file audit_chain.hpp.

serialize_chain()

std::vector< uint8_t > signet::forge::AuditChainWriter::serialize_chain ( ) const

inline

Serialize the entire chain to bytes.

Format: 4-byte entry count (uint32_t LE) followed by N * 112-byte entries. Total size = 4 + N * 112 bytes.

Returns

The serialized chain as a byte vector.

Definition at line 480 of file audit_chain.hpp.

---

The documentation for this class was generated from the following file:

• include/signet/ai/audit_chain.hpp