Elsevier returns the caller's weekly quota and short-term rate-limit status in
response headers. scopus_quota() extracts them into a tidy list so a
workflow can pause, schedule or report on the remaining allowance.
Arguments
- resp
An httr2::response object, typically captured during a request.
Value
A list with elements limit, remaining, reset (a POSIXct time
at which the rate-limit window resets, or NA), status and retry_after
(seconds, or NA). A missing header yields NA.
Details
The relevant headers are X-RateLimit-Limit, X-RateLimit-Remaining,
X-RateLimit-Reset (epoch seconds), X-ELS-Status and Retry-After. When
the API raises a quota or rate-limit error, the parsed quota is also attached
to the resulting condition, where it is available as cnd$quota.
Examples
# Build a fake response to show the shape of the output (no network used).
resp <- httr2::response(
status_code = 200,
headers = list(
`X-RateLimit-Limit` = "20000",
`X-RateLimit-Remaining` = "19987",
`X-RateLimit-Reset` = "1700000000"
)
)
scopus_quota(resp)
#> $limit
#> [1] 20000
#>
#> $remaining
#> [1] 19987
#>
#> $reset
#> [1] "2023-11-14 22:13:20 UTC"
#>
#> $status
#> [1] NA
#>
#> $retry_after
#> [1] NA
#>