Got a working test connecting to postgres server and reading data.

Added a couple more message types to facilitate this.

1 files changed, 78 insertions, 7 deletions

diff --git a/src/main.zig b/src/main.zig
index e540256..e539f2f 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -1,10 +1,13 @@
 const std = @import("std");
 const testing = std.testing;
 const StartupMessage = @import("startup_message.zig");
-const AuthenticationOk = @import("authentication_ok.zig");
-const AuthenticationCleartextPassword = @import("authentication_cleartext_password.zig");
+const AuthenticationRequest = @import("authentication_request.zig");
 const PasswordMessage = @import("password_message.zig");
 const ErrorResponse = @import("error_response.zig");
+const ReadyForQuery = @import("ready_for_query.zig");
+const ParameterStatus = @import("parameter_status.zig");
+const BackendKeyData = @import("backend_key_data.zig");
+const Conn = @import("conn.zig");
 
 pub const ProtocolError = error{
     InvalidProtocolVersion,
@@ -12,15 +15,16 @@ pub const ProtocolError = error{
     InvalidMessageLength,
     InvalidAuthType,
     MissingField,
+    WrongMessageType,
+    InvalidTransactionStatus,
 };
 
 pub const ClientError = error{
     UnsupportedAuthType,
 };
 
-pub const AuthType = enum(u32) {
-    AuthTypeOk = 0,
-    AuthTypeCleartextPassword = 3,
+pub const ServerError = error{
+    ErrorResponse,
 };
 
 // Fallible version of enumFromInt
@@ -38,10 +42,77 @@ pub fn enum_from_int(comptime e: type, i: anytype) ?e {
     }
 }
 
+// Tag should already have been read in order to determine msg_type!
+pub fn read_message(comptime msg_type: type, allocator: std.mem.Allocator, stream_reader: anytype) !msg_type {
+    if (!@hasDecl(msg_type, "Tag")) @compileError("msg_type must have a Tag declaration!");
+    if (!@hasDecl(msg_type, "read")) @compileError("msg_type must have a read() function!");
+    const len = try stream_reader.readIntBig(u32);
+    const buf = try allocator.alloc(u8, @as(u32, @intCast(len-4)));
+    defer allocator.free(buf);
+    try stream_reader.readNoEof(buf);
+    return try msg_type.read(allocator, buf);
+}
+
+
+pub fn diagnosticReader(comptime n: usize, base_reader: anytype) DiagnosticReader(n, @TypeOf(base_reader)) {
+    return .{.child_reader = base_reader};
+}
+
+// keeps a buffer of the last n bytes read
+pub fn DiagnosticReader(comptime n: usize, comptime ReaderType: anytype) type {
+    return struct {
+        child_reader: ReaderType,
+        ring: [n]u8 = [_]u8{0}**n,
+        pos: usize = 0,
+
+        pub const Error = ReaderType.Error;
+        pub const Reader = std.io.Reader(*@This(), Error, read);
+
+        pub fn read(self: *@This(), buf: []u8) Error!usize {
+            const amt = try self.child_reader.read(buf);
+            for (0..amt) |i| {
+                self.ring[self.pos] = buf[i];
+                self.pos += 1;
+                self.pos %= n;
+            }
+            return amt;
+        }
+
+        pub fn reader(self: *@This()) Reader {
+            return .{ .context = self };
+        }
+
+        // Caller frees
+        pub fn get(self: @This(), allocator: std.mem.Allocator) ![]const u8 {
+            var buf = try allocator.alloc(u8, n);
+            errdefer allocator.free(buf);
+            @memcpy(buf[0..(n-self.pos)], self.ring[self.pos..n]);
+            @memcpy(buf[(n-self.pos)..n], self.ring[0..self.pos]);
+            return buf;
+        }
+    };
+}
+
+test "diagnostc reader" {
+    const a = std.testing.allocator;
+    const string = "The quick brown fox jumped over the lazy dog";
+    var fbs = std.io.fixedBufferStream(string);
+    var dr = diagnosticReader(15, fbs.reader());
+    var reader = dr.reader();
+    var buf = [_]u8{0}**20;
+    try reader.readNoEof(&buf);
+    const diag = try dr.get(a);
+    defer a.free(diag);
+    try std.testing.expectEqualStrings("uick brown fox ", diag);
+}
+
 test {
     _ = StartupMessage;
-    _ = AuthenticationOk;
-    _ = AuthenticationCleartextPassword;
+    _ = AuthenticationRequest;
     _ = PasswordMessage;
     _ = ErrorResponse;
+    _ = Conn;
+    _ = ReadyForQuery;
+    _ = ParameterStatus;
+    _ = BackendKeyData;
 }