Open a shared memory region identified by a name string and return an ALTREP-backed R object that reads directly from shared memory.
Arguments
- name
a character string as returned by
shared_name(): either a bare shared memory name (opens the root) or a name with a 1-based bracketed index path (e.g."/mori_abc_1[2,3]", opens the addressed sub-list or element directly).
Value
The R object stored at the named region (or sub-object at the
given path), or NULL if name is not a valid shared memory name
(wrong type, length, NA, missing or malformed prefix, or malformed
bracketed path). If name parses as valid but the region is absent or
corrupted — or the path doesn't address a valid sub-object — an error
is raised.
See also
share() to create a shared object, shared_name() to extract
the shared memory name.
Examples
x <- share(1:100)
nm <- shared_name(x)
map_shared(nm)
#> [1] 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
#> [17] 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32
#> [33] 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48
#> [49] 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64
#> [65] 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80
#> [81] 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96
#> [97] 97 98 99 100
# A bracketed index path opens the addressed sub-object directly:
lst <- share(list(a = 1:3, b = letters))
map_shared(shared_name(lst[[2]]))
#> [1] "a" "b" "c" "d" "e" "f" "g" "h" "i" "j" "k" "l" "m" "n" "o" "p"
#> [17] "q" "r" "s" "t" "u" "v" "w" "x" "y" "z"