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const std = @import("std");
const testing = std.testing;
const StartupMessage = @import("startup_message.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 Query = @import("query.zig");
const Conn = @import("conn.zig");
pub const ProtocolError = error{
InvalidProtocolVersion,
InvalidKeyValuePair,
InvalidMessageLength,
InvalidAuthType,
MissingField,
WrongMessageType,
InvalidTransactionStatus,
};
pub const ClientError = error{
UnsupportedAuthType,
};
pub const ServerError = error{
ErrorResponse,
};
// Fallible version of enumFromInt
pub fn enum_from_int(comptime e: type, i: anytype) ?e {
const enum_ti = @typeInfo(e);
if (enum_ti != .Enum) @compileError("e should be an enum but instead it's a " ++ @typeName(e));
const ei = enum_ti.Enum;
if (@TypeOf(i) != ei.tag_type) @compileError("i should be of type " ++ @typeName(e) ++ " but instead it's " ++ @typeName(@TypeOf(i)));
inline for (ei.fields) |field| {
if (field.value == i) {
return @enumFromInt(i);
}
} else {
return null;
}
}
// 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;
_ = AuthenticationRequest;
_ = PasswordMessage;
_ = ErrorResponse;
_ = Conn;
_ = ReadyForQuery;
_ = ParameterStatus;
_ = BackendKeyData;
_ = Query;
}
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