group members are now slices

lib/Corpus.zig

@@ -82,12 +82,11 @@ pub fn init(
     mem.set(ArrayListUnmanaged(u32), user2groups, ArrayListUnmanaged(u32){});
 
     for (groups.items(.members)) |groupmembers, i| {
-        var members = try allocator.alloc(u32, groupmembers.count());
+        var members = try allocator.alloc(u32, groupmembers.len);
         members.len = 0;
 
-        var it = groupmembers.iterator();
-        while (it.next()) |member_name| {
-            if (name2user.get(member_name.*)) |user_idx| {
+        for (groupmembers) |member_name| {
+            if (name2user.get(member_name)) |user_idx| {
                 members.len += 1;
                 members[members.len - 1] = user_idx;
                 try user2groups[user_idx].append(allocator, @intCast(u32, i));
@@ -204,29 +203,10 @@ pub fn testCorpus(allocator: Allocator) !Corpus {
         .shell = "/usr/sbin/nologin",
     } };
 
-    var members0 = try someMembers(
-        allocator,
-        &[_][]const u8{"root"},
-    );
-    defer members0.deinit();
-
-    var members1 = try someMembers(
-        allocator,
-        &[_][]const u8{"vidmantas"},
-    );
-    defer members1.deinit();
-
-    var members2 = try someMembers(
-        allocator,
-        &[_][]const u8{ "svc-bar", "vidmantas" },
-    );
-    defer members2.deinit();
-
-    var members3 = try someMembers(
-        allocator,
-        &[_][]const u8{ "svc-bar", "Name" ** 8, "vidmantas", "root" },
-    );
-    defer members3.deinit();
+    var members0 = &[_][]const u8{"root"};
+    var members1 = &[_][]const u8{"vidmantas"};
+    var members2 = &[_][]const u8{ "svc-bar", "vidmantas" };
+    var members3 = &[_][]const u8{ "svc-bar", "Name" ** 8, "vidmantas", "root" };
 
     const groups = [_]Group{
         Group{ .gid = 0, .name = "root", .members = members0 },

lib/DB.zig

@@ -218,6 +218,21 @@ pub fn fromBytes(buf: []align(8) const u8) InvalidHeader!DB {
     return result;
 }
 
+// getgrtnam returns a Group entry by name
+fn getgrnam(self: *const DB, name: []const u8) ?Group {
+    const idx = bdz.search(self.bdz_groupname);
+    const offset = self.idx_groupname2group[idx];
+    const entry = PackedGroup.fromBytes(self.groups[offset..]);
+    if (!mem.eql(name, entry.group.name()))
+        return null;
+
+    return Group{
+        .name = name,
+        .gid = entry.group.gid(),
+        .members = null,
+    };
+}
+
 fn shellSections(
     allocator: Allocator,
     corpus: *const Corpus,

lib/Group.zig

@@ -2,79 +2,70 @@ const std = @import("std");
 
 const mem = std.mem;
 const Allocator = mem.Allocator;
-const BufSet = std.BufSet;
 
 const Group = @This();
 
 gid: u32,
 name: []const u8,
-members: BufSet,
+members: []const []const u8,
+_members_buf: []const u8 = undefined,
 
 pub fn clone(self: *const Group, allocator: Allocator) Allocator.Error!Group {
-    var name = try allocator.dupe(u8, self.name);
+    const total_members_len = blk: {
+        var sum: usize = 0;
+        for (self.members) |member| sum += member.len;
+        break :blk sum;
+    };
+    var members = try allocator.alloc([]const u8, self.members.len);
+    errdefer allocator.free(members);
+    members.len = self.members.len;
+
+    var buf = try allocator.alloc(u8, total_members_len);
+    errdefer allocator.free(buf);
+    buf.len = 0;
+
+    for (self.members) |member, i| {
+        const old_len = buf.len;
+        buf.len += member.len;
+        mem.copy(u8, buf[old_len..], member);
+        members[i] = buf[old_len..buf.len];
+    }
+
     return Group{
         .gid = self.gid,
-        .name = name,
-        .members = try self.members.cloneWithAllocator(allocator),
+        .name = try allocator.dupe(u8, self.name),
+        .members = members,
+        ._members_buf = buf,
     };
 }
 
 pub fn deinit(self: *Group, allocator: Allocator) void {
     allocator.free(self.name);
-    self.members.deinit();
+    allocator.free(self.members);
+    allocator.free(self._members_buf);
     self.* = undefined;
 }
 
-// someMembers constructs a bufset from an allocator and a list of strings.
-pub fn someMembers(
-    allocator: Allocator,
-    members: []const []const u8,
-) Allocator.Error!BufSet {
-    var bufset = BufSet.init(allocator);
-    errdefer bufset.deinit();
-    for (members) |member|
-        try bufset.insert(member);
-    return bufset;
-}
-
-// cloneArray clones an array of strings. This may be needed
-// to change members to []const []const u8
-fn cloneArray(allocator: Allocator, arr: []const []const u8) error{OutOfMemory}![]const []const u8 {
-    const total_len = blk: {
-        var sum: usize = 0;
-        for (arr) |elem| sum += elem.len;
-        break :blk sum;
-    };
-    var buf = try allocator.alloc(u8, total_len);
-    var ret = try allocator.alloc([]const u8, arr.len);
-    ret.len = arr.len;
-    for (arr) |elem, i| {
-        const old_len = buf.len;
-        mem.copy(u8, buf[old_len..], elem);
-        ret[i] = buf[old_len .. old_len + elem.len];
-    }
-    return ret;
-}
-
 const testing = std.testing;
 
 test "Group.clone" {
-    var allocator = testing.allocator;
-    var arena = std.heap.ArenaAllocator.init(allocator);
-    defer arena.deinit();
+    // TODO: how to do this on stack?
+    var member1 = try testing.allocator.dupe(u8, "member1");
+    defer testing.allocator.free(member1);
 
-    var members = BufSet.init(allocator);
-    try members.insert("member1");
-    try members.insert("member2");
-    defer members.deinit();
+    var group = Group{
+        .gid = 1,
+        .name = "foo",
+        .members = &[_][]const u8{ member1, "member2" },
+    };
 
-    var cloned = try members.cloneWithAllocator(arena.allocator());
+    var cloned = try group.clone(testing.allocator);
+    defer cloned.deinit(testing.allocator);
 
-    cloned.remove("member1");
-    try cloned.insert("member4");
-    try testing.expect(members.contains("member1"));
-    try testing.expect(!members.contains("member4"));
-
-    try testing.expect(!cloned.contains("member1"));
-    try testing.expect(cloned.contains("member4"));
+    group.gid = 2;
+    group.name = "bar";
+    member1[0] = 'x';
+    try testing.expectEqual(cloned.gid, 1);
+    try testing.expectEqualSlices(u8, cloned.name, "foo");
+    try testing.expectEqualSlices(u8, cloned.members[0], "member1");
 }