Cache Expiration Sweep Records

Description

Sweep explicit stored-response age components at a supplied clock instant, classifying equality with lifetime as stale; no eviction, revalidation or stale-serving authorization.

HTTP caches distinguish storage policy, freshness and validation. Age and freshness lifetime are durations in seconds; an entity tag is an opaque validator that can be marked weak. Vary identifies request fields relevant to representation selection. A focused arithmetic or token check alone does not decide whether a stored response may be reused.

Sweep explicit stored-response age components at a supplied clock instant, classifying equality with lifetime as stale; no eviction, revalidation or stale-serving authorization.

When to use this tool

Use this tool to sweep explicit stored-response age components at a supplied clock instant, classifying equality with lifetime as stale; no eviction, revalidation or stale-serving authorization.

How to use the tool and how it works

Enter recordsJson, now using the input definitions below. Serialize the JSON text fields in the decoded shape shown below.
Run the operation. Resolve malformed-input errors before interpreting the result.
Read result.records. Interpret signs, units, ordering and null values using the rules below.

Require nonnegative initialAge/lifetime and now≥storedAt for each record. Calculate age = initialAge + now−storedAt and fresh = age<lifetime, retaining original age components and IDs.^{[1, 2]}

Input field	Meaning and units	Accepted input
recordsJson	JSON array of {id,initialAge,storedAt,lifetime} records. id is a string; age/lifetime are nonnegative seconds and storedAt is a timestamp in the same scale as now.	Text, at most 8,192 UTF-16 code units; the stated grammar and narrower limits also apply.
now	Current supplied timestamp, at least every storedAt, in seconds on the same clock origin.	Finite number satisfying the stated comparisons.

These decoded examples show the structure of the JSON text fields. Supply each as its corresponding serialized JSON string.

json

{
  "recordsJson": [
    {
      "id": "a",
      "initialAge": 2,
      "storedAt": 10,
      "lifetime": 5
    }
  ]
}

Output field	Interpretation
result	Object containing the fields below.
result.records	Original stored-response components plus calculated age and strict fresh flag.

json

{
  "input": {
    "recordsJson": "[{\"id\":\"a\",\"initialAge\":2,\"storedAt\":10,\"lifetime\":5}]",
    "now": 13
  },
  "output": {
    "result": {
      "records": [
        {
          "id": "a",
          "initialAge": 2,
          "storedAt": 10,
          "lifetime": 5,
          "age": 5,
          "fresh": false
        }
      ]
    }
  }
}

Limitations and assumptions

Use seconds for HTTP age semantics and a common timestamp origin. Equality is stale; this does not evict entries or authorize stale serving.
No HTTP exchange, cache store, clock or server is accessed. Header/directive occurrences and timestamps are supplied explicitly. Durations use seconds for HTTP semantics; timestamps must share an origin and unit.
Every declared top-level input is required and unknown fields are rejected. Ordinary strings are limited to 8,192 UTF-16 code units and lists to 128 entries, with tighter operation-specific bounds where stated. JSON text has bounded nesting and node counts.
Numeric outputs must be finite and within the absolute safe-integer magnitude; exact larger integers use decimal text. Source positions are zero-based UTF-16 offsets and span ends are exclusive unless a different convention is explicitly stated.

Alternative or Complementary methods

Combine these focused results with the request/response caching rules applicable to the actual exchange. Preserve field occurrences and distinguish freshness calculations, validator comparison and complete cache-reuse authorization.

References

RFC 9111: HTTP Caching — RFC Editor
Tool behavior and example: Cache Expiration Sweep Records — tool.io

Similar or alternative tools

Cache Corrected Initial Age
Compute RFC 9111 corrected initial cache age from explicit same-unit timestamps and Age value; no actual network observation or clock synchronization assumed.
Cache Age Saturation Formatter
Format a nonnegative exact cache Age integer with RFC delta-seconds overflow saturation at 2^31; does not read response timing.