objsize 0.18 (latest) · OCaml Package

Compute memory usage of OCaml heap values (by recursively inspecting runtime representation)

type tag_info = {

tag : int;
(*
heap value tag
*)
count : int;
(*
number of values with this tag (eq. words used for headers)
*)
words : int;
(*
heap words used for data
*)

}

type info = {

data : int;
headers : int;
depth : int;
tags : tag_info array;
(*
counts grouped by tags
- since 0.17
*)

}

Information gathered while walking through values.

val objsize : 'a -> info

Returns information for first argument.

val objsize_limit : int -> 'a -> info

objsize_limit limit v

returns
memory usage information for v. limit limits the maximum depth to follow (to prevent excess stack usage). If maximum depth is reached during heap traversal then the returned result may be less than actual. One can detect this situation by comparing returned depth against the limit.

since 0.17

val size_with_headers : info -> int

Calculate size in bytes

val size_without_headers : info -> int

val objsize_roots : unit -> info

Walk through all the roots and return information for the whole heap.

since 0.17

val objsize_roots_limit : int -> info

Walk through all the roots and return information for the whole heap. Integer parameter limits the maximum depth to follow (to prevent excess stack usage). If maximum depth is reached during heap traversal then the returned result may be less than actual. One can detect this situation by comparing returned depth against the limit.

since 0.17

val sub : ?tweak:bool -> info -> info -> info

sub next base calculate next - base, i.e. the changes from base to next.

parameter tweak
account for the memory occupied by one info structure, default true

since 0.17

val string_of_tag : int -> string

returns
human readable name for the tag number

since 0.17

val show_info : ?map:(int -> string) -> info -> string

returns
human readable representation of memory usage in general

parameter map
convert number of words to string

since 0.17

val show_tags : ?map:(int -> string) -> info -> string list

returns
human readable representation of memory usage grouped by tags

parameter map
convert number of words to string

since 0.17

package objsize