getOrCreate

pub fn getOrCreate(self: *Cache, gpa: std.mem.Allocator, font: Font) std.mem.Allocator.Error!*Entry {
        const entry = try self.cache.getOrPut(gpa, font.hash());
        if (entry.found_existing) return entry.value_ptr;

        const fname = font.name(gpa);
        defer gpa.free(fname);

        const exact, const second = self.findSource(font);

        const source = exact orelse blk: {
            if (second) |s| {
                const sname = s.name(gpa);
                defer gpa.free(sname);
                dvui.log.warn("Font {s} not loaded in dvui, using second best {s}", .{ fname, sname });
                break :blk s;
            } else {
                dvui.log.warn("Font {s} not loaded in dvui, using fallback", .{fname});
                break :blk Source.fallback;
            }
        };

        //log.debug("FontCacheGet creating font hash {x} ptr {*} size {d} name \"{s}\"", .{ fontHash, bytes.ptr, font.size, font.name });

        entry.value_ptr.* = Entry.init(gpa, source.bytes, font) catch |err| {
            dvui.log.err("Font {s} init got {any}, using fallback", .{ fname, err });
            // Remove the invalid font cache entry, something went wrong reading the ttf_bytes
            self.cache.map.removeByPtr(entry.key_ptr);
            // Substitute the known good fallback font
            return self.getOrCreate(gpa, Source.fallback.font());
        };
        //log.debug("- size {d} ascent {d} height {d}", .{ font.size, entry.ascent, entry.height });
        return entry.value_ptr;
    }