Aleph::CA::Checkpoint_Header Struct Reference

Public on-disk header surfaced by inspect_checkpoint. More...

#include <ca-checkpoint.H>

Collaboration diagram for Aleph::CA::Checkpoint_Header:

Public Attributes
std::array< char, 8 >	magic {}
	Stream magic ("ALEPHCA1").
std::uint32_t	format_version = 0
	Format version (1 = Phase 15, 2 = Phase 17).
std::uint64_t	engine_type_hash = 0
	Stable type hash of the engine type that produced this snapshot.
std::uint32_t	state_type_size = 0
	sizeof(state_type) recorded at save time, for sanity checks.
std::uint32_t	rank = 0
	Lattice rank (1, 2 or 3 in the bundled lattices).
std::array< std::uint64_t, 4 >	extents {}
	Per-axis extents (only the first rank entries are meaningful).
std::uint64_t	step_count = 0
	Number of completed steps at save time.
std::uint8_t	has_rng = 0
	1 when the snapshot carries a master RNG seed.
std::uint64_t	master_seed = 0
	Recorded master RNG seed (only valid when has_rng == 1).
std::uint64_t	cell_count = 0
	Number of cells stored in the frame payload (uncompressed view).
std::uint32_t	flags = 0
	Bitmask of ca_checkpoint_flags::* values.
std::uint32_t	compression_level = 0
	DEFLATE compression level used when flags & compressed.
std::uint64_t	payload_size = 0
	Actual payload byte count on disk (compressed size when flags & compressed, or (cell_count * state_type_size) for raw snapshots; delta layout when flags & delta).
std::uint64_t	delta_base_step = 0
	Step number of the baseline snapshot this delta references (meaningful only when flags & delta).

Detailed Description

Public on-disk header surfaced by inspect_checkpoint.

Mirrors the layout serialised at the start of every checkpoint file. Useful for tooling: inspect_checkpoint(path) returns this struct without touching the frame payload.

v1 fields are populated from both v1 and v2 files; v2-only fields default to zero when the source file is v1.

Definition at line 368 of file ca-checkpoint.H.

Member Data Documentation

cell_count

std::uint64_t Aleph::CA::Checkpoint_Header::cell_count = 0

Number of cells stored in the frame payload (uncompressed view).

Definition at line 389 of file ca-checkpoint.H.

Referenced by Aleph::CA::apply_delta_checkpoint().

compression_level

std::uint32_t Aleph::CA::Checkpoint_Header::compression_level = 0

DEFLATE compression level used when flags & compressed.

Definition at line 396 of file ca-checkpoint.H.

delta_base_step

std::uint64_t Aleph::CA::Checkpoint_Header::delta_base_step = 0

Step number of the baseline snapshot this delta references (meaningful only when flags & delta).

Definition at line 403 of file ca-checkpoint.H.

engine_type_hash

std::uint64_t Aleph::CA::Checkpoint_Header::engine_type_hash = 0

Stable type hash of the engine type that produced this snapshot.

Definition at line 375 of file ca-checkpoint.H.

Referenced by Aleph::CA::apply_delta_checkpoint(), and Aleph::CA::load_checkpoint_into().

extents

std::array<std::uint64_t, 4> Aleph::CA::Checkpoint_Header::extents {}

Per-axis extents (only the first rank entries are meaningful).

Definition at line 381 of file ca-checkpoint.H.

Referenced by Aleph::CA::apply_delta_checkpoint(), and Aleph::CA::load_checkpoint_into().

flags

std::uint32_t Aleph::CA::Checkpoint_Header::flags = 0

Bitmask of ca_checkpoint_flags::* values.

Definition at line 394 of file ca-checkpoint.H.

Referenced by Aleph::CA::apply_delta_checkpoint(), and Aleph::CA::load_checkpoint_into().

format_version

std::uint32_t Aleph::CA::Checkpoint_Header::format_version = 0

Format version (1 = Phase 15, 2 = Phase 17).

Definition at line 373 of file ca-checkpoint.H.

Referenced by Aleph::CA::inspect_checkpoint().

has_rng

std::uint8_t Aleph::CA::Checkpoint_Header::has_rng = 0

1 when the snapshot carries a master RNG seed.

Definition at line 385 of file ca-checkpoint.H.

Referenced by Aleph::CA::apply_delta_checkpoint(), and Aleph::CA::load_checkpoint_into().

magic

std::array<char, 8> Aleph::CA::Checkpoint_Header::magic {}

Stream magic ("ALEPHCA1").

Definition at line 371 of file ca-checkpoint.H.

master_seed

std::uint64_t Aleph::CA::Checkpoint_Header::master_seed = 0

Recorded master RNG seed (only valid when has_rng == 1).

Definition at line 387 of file ca-checkpoint.H.

Referenced by Aleph::CA::apply_delta_checkpoint(), and Aleph::CA::load_checkpoint_into().

payload_size

std::uint64_t Aleph::CA::Checkpoint_Header::payload_size = 0

Actual payload byte count on disk (compressed size when flags & compressed, or (cell_count * state_type_size) for raw snapshots; delta layout when flags & delta).

Definition at line 400 of file ca-checkpoint.H.

Referenced by Aleph::CA::apply_delta_checkpoint().

rank

std::uint32_t Aleph::CA::Checkpoint_Header::rank = 0

Lattice rank (1, 2 or 3 in the bundled lattices).

Definition at line 379 of file ca-checkpoint.H.

Referenced by Aleph::CA::apply_delta_checkpoint(), and Aleph::CA::load_checkpoint_into().

state_type_size

std::uint32_t Aleph::CA::Checkpoint_Header::state_type_size = 0

sizeof(state_type) recorded at save time, for sanity checks.

Definition at line 377 of file ca-checkpoint.H.

Referenced by Aleph::CA::apply_delta_checkpoint(), and Aleph::CA::load_checkpoint_into().

step_count

std::uint64_t Aleph::CA::Checkpoint_Header::step_count = 0

Number of completed steps at save time.

Definition at line 383 of file ca-checkpoint.H.

Referenced by Aleph::CA::apply_delta_checkpoint(), Aleph::CA::load_checkpoint_into(), and main().

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

• ca-checkpoint.H