freesurferformats (version 1.1.0)

validate_allocation_size: Validate that a requested allocation does not exceed the safety limit.

Description

Given dimension sizes and bytes per element, checks that the total allocation size is safe. Catches negative/NA/Inf dimensions, integer overflow (by converting to double), and enforces the max allocation limit.

Note that bytes_per_elem must be the size of an element in memory, which is not necessarily the size on disk: readBin() into a numeric() vector allocates 8 bytes per element even when the values are stored as 4 byte floats.

Usage

validate_allocation_size(
  dims,
  bytes_per_elem,
  max_bytes = get_max_alloc_bytes(),
  label = NULL
)

Value

the total number of elements (as double), invisibly. The function stops with an error if the allocation would be unsafe.

Arguments

dims

numeric vector of dimension sizes (e.g., c(256, 256, 256)).

bytes_per_elem

single numeric value, the number of bytes per element as stored in memory (e.g., 8 for a numeric() vector).

max_bytes

single numeric value, the maximum allowed allocation in bytes. Defaults to the result of get_max_alloc_bytes(). Pass Inf to disable the limit check (negative/NA/Inf dims are still rejected).

label

character string or NULL, a human-readable description of what is being allocated. Included in the error message to help the user understand which part of a file the limit was hit on.