Source: https://guthlabs.ai/docs/instruments/data-structure-memory-footprint-estimator/

instrument / verified-clean

# Data Structure Memory Footprint Estimator

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

Status: **VERIFIED_CLEAN**Lifecycle: **verified-clean**

## Inspectable records

[01**Overview**Purpose and lifecycle](<https://guthlabs.ai/docs/instruments/data-structure-memory-footprint-estimator/>)[02**Mechanism**Method and assumptions](<https://guthlabs.ai/docs/instruments/data-structure-memory-footprint-estimator/mechanism/>)[03**Implementation**Binding and validation](<https://guthlabs.ai/docs/instruments/data-structure-memory-footprint-estimator/implementation/>)[04**Qualification**Evidence and errata](<https://guthlabs.ai/docs/instruments/data-structure-memory-footprint-estimator/qualification/>)

## 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`