Implement base 9P2000 sessions, shared transports, and conformance probes

1 files changed, 82 insertions, 0 deletions

diff --git a/test/differential/session.zig b/test/differential/session.zig
new file mode 100644
index 0000000..3c5d2de
--- /dev/null
+++ b/test/differential/session.zig
@@ -0,0 +1,82 @@
+//! Local interoperability client. The parent connects stdio to a reference server.
+const std = @import("std");
+const c9 = @import("cloud9");
+const libc = std.c;
+const Session = struct {
+    client: c9.Client,
+    requests: usize = 0,
+    bytes_read: usize = 0,
+    bytes_written: usize = 0,
+    read_calls: usize = 0,
+    write_calls: usize = 0,
+
+    fn ask(s: *Session, request: c9.Client.Request) !c9.Client.Result {
+        const tag = try s.client.submit(request);
+        s.requests += 1;
+        while (s.client.output().len != 0) {
+            const output = s.client.output();
+            s.write_calls += 1;
+            // Fragment requests across their header and body fields.
+            const n = libc.write(1, output.ptr, @min(output.len, 3));
+            if (n <= 0) return error.Write;
+            s.bytes_written += @intCast(n);
+            s.client.wrote(@intCast(n));
+        }
+        while (true) {
+            if (s.client.take()) |done| {
+                if (done.tag != tag) return error.Tag;
+                if (done.result == .fail) {
+                    std.debug.print("remote error: {s}\n", .{done.result.fail});
+                    return error.Remote;
+                }
+                return done.result;
+            }
+            if (s.client.dead) return error.Protocol;
+            var buffer: [7]u8 = undefined;
+            s.read_calls += 1;
+            const n = libc.read(0, &buffer, buffer.len);
+            if (n <= 0) return error.Read;
+            s.bytes_read += @intCast(n);
+            if (s.client.push(buffer[0..@intCast(n)]) != n) return error.InputFull;
+        }
+    }
+};
+
+pub fn main(init: std.process.Init) !void {
+    const args = try init.minimal.args.toSlice(init.arena.allocator());
+    if (args.len != 3) return error.Arguments;
+    const seed = try std.fmt.parseInt(u64, args[1], 10);
+    const rounds = try std.fmt.parseInt(usize, args[2], 10);
+    if (rounds == 0 or rounds > 10000) return error.Arguments;
+    var random: std.Random.DefaultPrng = .init(seed);
+    var input: [8192]u8 = undefined;
+    var output: [8192]u8 = undefined;
+    var session: Session = .{ .client = .init(.{ .in = &input, .out = &output }) };
+    const version = (try session.ask(.{ .version = .{} })).version;
+    if (version.msize > input.len or !std.mem.eql(u8, version.version, "9P2000")) return error.Version;
+    _ = try session.ask(.{ .attach = .{ .fid = 0, .uname = "user" } });
+    var expected: [4096]u8 = @splat(0);
+    var length: usize = 0;
+    for (0..rounds) |_| {
+        const walk = (try session.ask(.{ .walk = .{ .fid = 0, .newfid = 1, .names = &.{"file"} } })).walk;
+        if (walk.nwqid != 1 or walk.wqid[0].type & c9.qtdir != 0) return error.Walk;
+        _ = try session.ask(.{ .open = .{ .fid = 1, .mode = c9.ordwr } });
+        const offset = random.random().uintLessThan(usize, 2048);
+        const count = random.random().uintLessThan(usize, 1024) + 1;
+        var data: [1024]u8 = undefined;
+        random.random().bytes(data[0..count]);
+        const written = (try session.ask(.{ .write = .{ .fid = 1, .offset = offset, .data = data[0..count] } })).write;
+        if (written != count) return error.WriteCount;
+        @memcpy(expected[offset..][0..count], data[0..count]);
+        length = @max(length, offset + count);
+        const result = (try session.ask(.{ .read = .{ .fid = 1, .offset = 0, .count = expected.len } })).read;
+        if (!std.mem.eql(u8, result, expected[0..length])) return error.Contents;
+        const stat = (try session.ask(.{ .stat = .{ .fid = 1 } })).stat;
+        if (stat.length != length or !std.mem.eql(u8, stat.name, "file")) return error.Stat;
+        const eof = (try session.ask(.{ .read = .{ .fid = 1, .offset = length, .count = 1 } })).read;
+        if (eof.len != 0) return error.Eof;
+        _ = try session.ask(.{ .clunk = .{ .fid = 1 } });
+    }
+    _ = try session.ask(.{ .clunk = .{ .fid = 0 } });
+    std.debug.print("{{\"requests\":{d},\"bytes_read\":{d},\"bytes_written\":{d},\"read_calls\":{d},\"write_calls\":{d},\"seed\":{d},\"rounds\":{d}}}\n", .{ session.requests, session.bytes_read, session.bytes_written, session.read_calls, session.write_calls, seed, rounds });
+}