diff --git a/core/strings/intern.odin b/core/strings/intern.odin new file mode 100644 index 000000000..def03d899 --- /dev/null +++ b/core/strings/intern.odin @@ -0,0 +1,54 @@ +package strings + +import "core:mem" + +Intern_Entry :: struct { + len: int, + str: [1]byte, // string is allocated inline with the entry to keep allocations simple +} + +Intern :: struct { + allocator: mem.Allocator, + entries: map[string]^Intern_Entry, +} + +intern_init :: proc(m: ^Intern, allocator := context.allocator, map_allocator := context.allocator) { + m.allocator = allocator; + m.entries = make(map[string]^Intern_Entry, 16, map_allocator); +} + +intern_destroy :: proc(m: ^Intern) { + for _, value in m.entries { + free(value, m.allocator); + } + delete(m.entries); +} + +intern_get :: proc(m: ^Intern, text: string) -> string { + entry := _intern_get_entry(m, text); + return #no_bounds_check string(entry.str[:entry.len]); +} +intern_get_cstring :: proc(m: ^Intern, text: string) -> cstring { + entry := _intern_get_entry(m, text); + return cstring(&entry.str[0]); +} + +_intern_get_entry :: proc(m: ^Intern, text: string) -> ^Intern_Entry #no_bounds_check { + if prev, ok := m.entries[text]; ok { + return prev; + } + if m.allocator.procedure == nil { + m.allocator = context.allocator; + } + + entry_size := int(offset_of(Intern_Entry, str)) + len(text) + 1; + new_entry := (^Intern_Entry)(mem.alloc(entry_size, align_of(Intern_Entry), m.allocator)); + + new_entry.len = len(text); + copy(new_entry.str[:new_entry.len], text); + new_entry.str[new_entry.len] = 0; + + key := string(new_entry.str[:new_entry.len]); + m.entries[key] = new_entry; + return new_entry; +}