Zig 0.17.0-dev (Split by item)

This is an example of documentation generated by ZigDoc, an alternative to Zig's built-in Auto Doc feature. See also examples in other modes/formats. The project being documented here (as the example) is the Zig library itself.

cf_alloc_callbacks

FsEvents.cf_alloc_callbacks

const cf_alloc_callbacks = struct

File

lib/compiler/Maker/Watch/FsEvents.zig:294

Code

const cf_alloc_callbacks = struct {
    const log = std.log.scoped(.cf_alloc);
    fn allocate(size: CFIndex, hint: CFOptionFlags, info: ?*const anyopaque) callconv(.c) ?*const anyopaque {
        if (enable_debug_logs) log.debug("allocate {d}", .{size});
        _ = hint;
        const gpa: *const Allocator = @ptrCast(@alignCast(info));
        const mem = gpa.alignedAlloc(u8, .of(usize), @intCast(size + @sizeOf(usize))) catch return null;
        const metadata: *usize = @ptrCast(mem);
        metadata.* = @intCast(size);
        return mem[@sizeOf(usize)..].ptr;
    }
    fn reallocate(ptr: ?*anyopaque, new_size: CFIndex, hint: CFOptionFlags, info: ?*const anyopaque) callconv(.c) ?*const anyopaque {
        if (enable_debug_logs) log.debug("reallocate @{*} {d}", .{ ptr, new_size });
        _ = hint;
        if (ptr == null or new_size == 0) return null; // not a bug: documentation explicitly states that realloc on NULL should return NULL
        const gpa: *const Allocator = @ptrCast(@alignCast(info));
        const old_base: [*]align(@alignOf(usize)) u8 = @alignCast(@as([*]u8, @ptrCast(ptr)) - @sizeOf(usize));
        const old_size = @as(*const usize, @ptrCast(old_base)).*;
        const old_mem = old_base[0 .. old_size + @sizeOf(usize)];
        const new_mem = gpa.realloc(old_mem, @intCast(new_size + @sizeOf(usize))) catch return null;
        const metadata: *usize = @ptrCast(new_mem);
        metadata.* = @intCast(new_size);
        return new_mem[@sizeOf(usize)..].ptr;
    }
    fn deallocate(ptr: *anyopaque, info: ?*const anyopaque) callconv(.c) void {
        if (enable_debug_logs) log.debug("deallocate @{*}", .{ptr});
        const gpa: *const Allocator = @ptrCast(@alignCast(info));
        const old_base: [*]align(@alignOf(usize)) u8 = @alignCast(@as([*]u8, @ptrCast(ptr)) - @sizeOf(usize));
        const old_size = @as(*const usize, @ptrCast(old_base)).*;
        const old_mem = old_base[0 .. old_size + @sizeOf(usize)];
        gpa.free(old_mem);
    }
}