1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
|
//! `NullStore`: a no-op `SessionStore` for embedders who opt out of
//! persistence (and the default backing for an `Agent` constructed without
//! a real store).
//!
//! Every append is dropped (but its messages are freed, honoring the store
//! ownership contract — appends consume their messages). `loadConversation`
//! returns an empty conversation with no dangling prompt. `activeModel` is
//! null and the session id is the empty string.
//!
//! Because freeing the dropped messages needs an allocator, `NullStore`
//! carries one. Construct it with `init(alloc)` and call `.store()` for the
//! interface handle. The struct is trivially copyable and holds no other
//! state, so the handle may borrow it for the agent's lifetime.
const std = @import("std");
const Allocator = std.mem.Allocator;
const session_store_mod = @import("session_store.zig");
const conversation_mod = @import("conversation.zig");
const SessionStore = session_store_mod.SessionStore;
const LoadedSession = session_store_mod.LoadedSession;
const DiskMessage = session_store_mod.DiskMessage;
const ActiveModel = session_store_mod.ActiveModel;
pub const NullStore = struct {
allocator: Allocator,
pub fn init(allocator: Allocator) NullStore {
return .{ .allocator = allocator };
}
fn appendMessagesVT(
ctx: *anyopaque,
messages: []DiskMessage,
_: []const ?[]const u8,
_: []const ?[]const u8,
) anyerror!void {
const self: *NullStore = @ptrCast(@alignCast(ctx));
// Appends consume their messages; we drop them, so free them.
for (messages) |m| m.deinit(self.allocator);
}
fn loadConversationVT(ctx: *anyopaque, alloc: Allocator) anyerror!LoadedSession {
_ = ctx;
return .{
.conversation = conversation_mod.Conversation.init(alloc),
.dangling_user = null,
};
}
fn sessionIdVT(_: *anyopaque) []const u8 {
return "";
}
fn activeModelVT(_: *anyopaque) ?ActiveModel {
return null;
}
const vtable: SessionStore.VTable = .{
.appendMessages = appendMessagesVT,
.loadConversation = loadConversationVT,
.sessionId = sessionIdVT,
.activeModel = activeModelVT,
};
/// Wrap this `NullStore` as a `SessionStore`. The handle borrows
/// `self`; `self` must outlive it.
pub fn store(self: *NullStore) SessionStore {
return .{ .ptr = self, .vtable = &vtable };
}
};
const testing = std.testing;
test "NullStore: appends are dropped (and freed) and load returns empty" {
var ns = NullStore.init(testing.allocator);
const s = ns.store();
var msg_content = try testing.allocator.alloc(session_store_mod.DiskContentBlock, 1);
msg_content[0] = .{ .text = .{ .text = try testing.allocator.dupe(u8, "hi") } };
var messages = [_]DiskMessage{.{ .role = .user, .content = msg_content }};
// No defer-free: the store consumes (frees) the message.
try s.appendMessages(&messages, &.{null}, &.{null});
var loaded = try s.loadConversation(testing.allocator);
defer loaded.deinit(testing.allocator);
try testing.expectEqual(@as(usize, 0), loaded.conversation.messages.items.len);
try testing.expect(loaded.dangling_user == null);
try testing.expect(s.activeModel() == null);
try testing.expectEqualStrings("", s.sessionId());
}
|
