Data Structure Memory Footprint Estimator

Inspectable records

Ledger state

The current ledger marks this instrument verified clean within the source-bound verification corpus.

Area

Computing & Information

Tranche

tranche-5

Evidence ID

t5-150

Ledger rows

1

No ledger note is attached.

Review findings

The honest-label warning is appropriate and should remain prominent. The array, linked-list, and hash-map expressions are acceptable only as explicitly simplified illustrative models. Add a tree formula, add key_size and bucket_overhead inputs or define them, specify the overhead-percentage formula and zero-denominator behavior, and document whether all sizes are decimal or binary byte units.

Formula and scope findings

• No formula is provided for the claimed tree data structure, so tree estimates cannot be verified or computed.
• The hash map formula requires key_size and bucket_overhead, but these are not listed as inputs.
• The formulas are simplified models: array allocation headers, capacity slack, alignment, linked-list node headers, hash-entry metadata, bucket count, load factor, resizing slack, and allocator overhead are omitted.
• The output definition does not specify the formula for overhead percentage; it should be explicitly defined as (estimated_total_memory - raw_data_size) / raw_data_size × 100%.
• The linked-list formula assumes each element stores only element_size bytes plus one pointer_size and omits node metadata and alignment.

Unit assumptions

• element_size, key_size, pointer_size, bucket_overhead, and all memory outputs are measured in bytes.
• 32-bit pointer width means pointer_size = 4 bytes; 64-bit pointer width means pointer_size = 8 bytes.
• element_count n is a nonnegative integer.
• raw data size is n × element_size.
• Overhead percentage is relative to raw data size: (total memory - raw data size) / raw data size × 100%.
• The hash-map bucket_overhead value is interpreted as bytes per element under the supplied simplified formula, even though real bucket overhead is generally based on bucket count and load factor.

Boundary hardening

BREAK_CLAIMED · SELF_FLAGGED

A zero-sized element makes the overhead percentage undefined through division by zero, and the unspecified unit convention for element_size can change the result substantially.

Errata and corrections

No applied erratum is attached to this unique-name record.

Inspectable example

4 review vectors are recorded. One source-bound sample is shown below.

{
  "inputs": {
    "structure_type": "array",
    "element_count": 1000,
    "element_size_bytes": 8,
    "pointer_width": "64-bit"
  },
  "expected_outputs": {
    "estimated_total_memory_bytes": 8000,
    "overhead_percentage": 0
  },
  "working": "Raw data = n × element_size = 1000 × 8 = 8000 bytes. Array total = n × element_size = 1000 × 8 = 8000 bytes. Overhead = 8000 - 8000 = 0 bytes. Overhead percentage = 0 / 8000 × 100 = 0%."
}

Related workflows

No source-defined multi-instrument workflow membership is recorded.

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

• VERIFIED_LEDGER.json · VERIFIED_CLEAN
• evidence-tranche5/tranche5-results.json
• BOUNDARY_HAZARD_CATALOG.json