| err = ESUCCESS, m = m1, m0 = n, 2 * NODE_HEADER_SIZE ≤ m1, n + m1 ≤ # buf, n + NODE_HEADER_SIZE ≤ # buf, err = ESUCCESS → is-encoded(ndhd, subarray(buf, n, NODE_HEADER_SIZE)), err = ESUCCESS ∨ ⌊err⌋ ⊦ ⟪decode_node_headerless#(m0 + NODE_HEADER_SIZE, buf; nd, m; err); if err ≠ ESUCCESS then debug#("persistence: decode_node decoding failed") else if m ≠ ndhd.size then {debug#("persistence: decode_node size of node unexpected"); err := EINVAL}; if err = ESUCCESS ∧ ¬ range=(buf, m0 + NODE_HEADER_SIZE + align↑(ndhd.size, 2 * NODE_HEADER_SIZE), validtrailer, 0, NODE_HEADER_SIZE) then {debug#("persistence: decode_node no validtrailer"); err := EIO}⟫ ( (err = ESUCCESS ∨ ⌊err⌋ ) ∧ ( err = ESUCCESS → (∃ buf0, buf1. subarray(buf, n, 2 * NODE_HEADER_SIZE + nd.alignedsize) = buf0 + buf1 + validtrailer ∧ is-encoded(nodeheader(node-size-headerless(nd), false), buf0) ∧ is-encoded(nd, subarray(buf1, 0, node-size-headerless(nd))) ∧ # buf1 = nd.alignedsize) ∧ m1 = 2 * NODE_HEADER_SIZE + nd.alignedsize)), err = ESUCCESS ∧ align↑(ndhd.size, 2 * NODE_HEADER_SIZE) + 2 * NODE_HEADER_SIZE ≠ m, err = ESUCCESS ∧ ndhd.ispadding |
m = align↑(ndhd.size, 2 * NODE_HEADER_SIZE) + 2 * NODE_HEADER_SIZE, is-encoded(ndhd, subarray(buf, n, NODE_HEADER_SIZE)), n + align↑(ndhd.size, 2 * NODE_HEADER_SIZE) + 2 * NODE_HEADER_SIZE ≤ # buf, n + NODE_HEADER_SIZE ≤ # buf, ¬ ndhd.ispadding ⊦ ⟪decode_node_headerless#(n + NODE_HEADER_SIZE, buf; nd, m; err); if err ≠ ESUCCESS then debug#("persistence: decode_node decoding failed") else if m ≠ ndhd.size then {debug#("persistence: decode_node size of node unexpected"); err := EINVAL}; if err = ESUCCESS ∧ ¬ range=(buf, n + NODE_HEADER_SIZE + align↑(ndhd.size, 2 * NODE_HEADER_SIZE), validtrailer, 0, NODE_HEADER_SIZE) then {debug#("persistence: decode_node no validtrailer"); err := EIO}⟫ ( (err = ESUCCESS ∨ ⌊err⌋ ) ∧ ( err = ESUCCESS → (∃ buf0, buf1. subarray(buf, n, 2 * NODE_HEADER_SIZE + nd.alignedsize) = buf0 + buf1 + validtrailer ∧ is-encoded(nodeheader(node-size-headerless(nd), false), buf0) ∧ is-encoded(nd, subarray(buf1, 0, node-size-headerless(nd))) ∧ # buf1 = nd.alignedsize) ∧ align↑(ndhd.size, 2 * NODE_HEADER_SIZE) = nd.alignedsize))
Used simplifier rules: ⊦ m + n = m + n0 ↔ n = n0; (s)%c: ⊦ m + n = n + m; from specification nat-basic%a: ⊦ (m + n0) + n1 = m + n0 + n1; from specification nat-basic% ⊦ m ≤ m + n; (s)% ⊦ # subarray(buf, m, n) = n; (s)%is-encoded-size: ⊦ is-encoded(ndhd, buf) → # buf = NODE_HEADER_SIZE; (forward) from specification encoding-fixed-size-nonempty[encoding-node-header]