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mutate users in tests

This commit is contained in:
Motiejus Jakštys 2022-02-27 06:09:46 +02:00 committed by Motiejus Jakštys
parent b4c7cba627
commit 1ef962d64a
1 changed files with 62 additions and 24 deletions
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70
src/user.zig
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@ -4,10 +4,11 @@ const pad = @import("padding.zig");
const assert = std.debug.assert;
const mem = std.mem;
const Allocator = mem.Allocator;
const ArrayList = std.ArrayList;
// ShellIndexFn is a function prototype that, given a shell's index (in
// global shell section), will return a shell string. Matches ShelReader.get.
const ShellIndexFn = fn (u6) []const u8;
// Idx2ShellProto is a function prototype that, given a shell's index (in
// global shell section), will return a shell string. Matches ShellReader.get.
const Idx2ShellProto = fn (u6) []const u8;
// User is a convenient public struct for record construction and
// serialization. Iterator can help retrieve these records.
@ -28,19 +29,19 @@ fn packedUser(immutable: bool) type {
const Self = @This();
const AlignmentBits = 3;
const shellIndexFn = fn ([]const u8) ?u6;
const shell2idxProto = fn ([]const u8) ?u6;
const InnerSize = @divExact(@bitSizeOf(Inner), 8);
const Inner = packed struct {
uid: u32,
gid: u32,
additional_gids_offset: u29,
shell_here: bool,
shell_len_or_idx: u6,
home_len: u6,
name_is_a_suffix: bool,
name_len: u5,
gecos_len: u8,
additional_gids_offset: u29,
fn homeLen(self: *const Inner) usize {
return @as(u32, self.home_len) + 1;
@ -107,7 +108,7 @@ fn packedUser(immutable: bool) type {
};
pub fn fromBytes(bytes: Bytes) Entry {
const inner = std.mem.bytesAsValue(
const inner = mem.bytesAsValue(
Inner,
// Should use InnerSize instead of sizeOf, see
// https://github.com/ziglang/zig/issues/10958
@ -154,7 +155,7 @@ fn packedUser(immutable: bool) type {
pub fn packTo(
arr: *ArrayList(u8),
user: User,
idxFn: shellIndexFn,
idxFn: shell2idxProto,
) packErr!void {
// function arguments are consts. We need to mutate the underlying
// slice, so passing it via pointer instead.
@ -219,6 +220,10 @@ fn packedUser(immutable: bool) type {
return self.inner.gid;
}
pub fn additionalGidsOffset(self: Self) u29 {
return self.inner.additional_gids_offset;
}
pub fn home(self: Self) []const u8 {
return self.userdata[0..self.inner.homeLen()];
}
@ -235,7 +240,7 @@ fn packedUser(immutable: bool) type {
return self.userdata[gecos_pos .. gecos_pos + gecos_len];
}
pub fn shell(self: Self, idxFn: ShellIndexFn) []const u8 {
pub fn shell(self: Self, idxFn: Idx2ShellProto) []const u8 {
if (self.inner.shell_here) {
const shell_pos = self.inner.maybeShellStart();
const shell_len = self.inner.shellLen();
@ -244,9 +249,17 @@ fn packedUser(immutable: bool) type {
return idxFn(self.inner.shell_len_or_idx);
}
pub fn setAdditionalGidsOffset(self: Self, new: u29) void {
// TODO(motiejus) how to not declare function for const PackedUser at all?
if (immutable) {
@compileError("this function is available only for mutable PackedUsers");
}
self.inner.additional_gids_offset = new;
}
pub const Iterator = struct {
section: ?Bytes,
shellIndex: ShellIndexFn,
shellIndex: Idx2ShellProto,
pub fn next(it: *Iterator) ?Self {
if (it.section) |section| {
@ -258,7 +271,7 @@ fn packedUser(immutable: bool) type {
}
};
pub fn iterator(section: Bytes, idxFn: ShellIndexFn) Iterator {
pub fn iterator(section: Bytes, idxFn: Idx2ShellProto) Iterator {
return Iterator{
.section = section,
.shellIndex = idxFn,
@ -268,7 +281,6 @@ fn packedUser(immutable: bool) type {
}
const testing = std.testing;
const ArrayList = std.ArrayList;
test "PackedUser internal and external alignment" {
// External padding (AlignmentBits) must be higher or equal to
@ -277,7 +289,7 @@ test "PackedUser internal and external alignment" {
// cannot be converted from/to [@bitSizeOf(PackedUser)/8]u8;
// asBytes/bytesAsValue use @sizeOf, which is larger. Now we are putting no
// more than 1, but it probably could be higher.
try testing.expect(@sizeOf(PackedUserMut.Inner) * 8 - @bitSizeOf(PackedUserMut.Inner) <= 8);
try testing.expectEqual(8, @sizeOf(PackedUserConst.Inner) * 8 - @bitSizeOf(PackedUserConst.Inner));
}
fn testShellIndex(shell: []const u8) ?u6 {
@ -331,15 +343,20 @@ test "construct PackedUser section" {
.shell = "/",
} };
for (users) |user| {
try buf.ensureUnusedCapacity(PackedUserMut.maxSize());
try PackedUserMut.packTo(&buf, user, testShellIndex);
try PackedUserConst.packTo(&buf, user, testShellIndex);
}
var it = PackedUserMut.iterator(buf.items, testShell);
var i: u32 = 0;
var i: u29 = 0;
{
var it = PackedUserConst.iterator(buf.items, testShell);
i = 0;
while (it.next()) |user| : (i += 1) {
try testing.expectEqual(users[i].uid, user.uid());
try testing.expectEqual(users[i].gid, user.gid());
try testing.expectEqual(
@as(u29, std.math.maxInt(u29)),
user.additionalGidsOffset(),
);
try testing.expectEqualStrings(users[i].name, user.name());
try testing.expectEqualStrings(users[i].gecos, user.gecos());
try testing.expectEqualStrings(users[i].home, user.home());
@ -348,6 +365,27 @@ test "construct PackedUser section" {
try testing.expectEqual(users.len, i);
}
{
var it = PackedUserMut.iterator(buf.items, testShell);
i = 0;
while (it.next()) |user| : (i += 1) {
user.setAdditionalGidsOffset(i);
}
try testing.expectEqual(users.len, i);
}
{
var it = PackedUserConst.iterator(buf.items, testShell);
i = 0;
while (it.next()) |user| : (i += 1) {
try testing.expectEqual(users[i].gid, user.gid());
try testing.expectEqual(i, user.additionalGidsOffset());
try testing.expectEqualStrings(users[i].name, user.name());
}
try testing.expectEqual(users.len, i);
}
}
test "PackedUser.maxSize()" {
// TODO(motiejus) try using a slice that points to an array in stack.
// As of writing, I am getting a stack smashing error.