rpcgen.py

from dataclasses import dataclass
from os import makedirs
from typing import Literal, Tuple

@dataclass
class t:
    string = 'string'
    int = 'int'
    uint = 'uint'
    void = 'void'
    fallible_void = 'falliblevoid'
    event = 'event'
    iohandle = 'handle'
    offset = 'ulong'
    size = 'ulong'
    buffer = 'buffer'
    def fallible(t: str) -> Tuple[Literal['fallible'], str]:
        return ['fallible', t]


rpc_services = {
  'logger': {
    'LogLine': [[t.string], t.event],
  },
  'svcdiscovery': {
    'Find': [[t.string], t.int],
    'Declare': [[t.int, t.string], t.void],
  },
  'ioprovider': {
    'Read': [[t.iohandle, t.offset, t.size], t.fallible(t.buffer)],
    'Write': [[t.iohandle, t.offset, t.size], t.fallible(t.buffer)],
    'Close': [[t.iohandle], t.event],
  },
  'filesystem': {
    'OpenFile': [[t.string, t.uint], t.fallible(t.iohandle)],
    'OpenDir': [[t.string], t.fallible(t.iohandle)],
    'MakeDir': [[t.string], t.fallible_void],
    'RemoveDir': [[t.string], t.fallible_void],
    'Unlink': [[t.string], t.fallible_void],
    'GetStatbuf': [[t.string], t.fallible(t.buffer)],
  },
}

funcid = 1

for k, v in rpc_services.items():
    code = [
        '// Autogenerated by rpcgen.py. Do not edit!',
        'module xtrix_rpc.{};'.format(k),
        'import libxtrix.events;',
        'import libxk.bytebuffer;',
        'import libxtrix.rpcutil;',
        'struct {}_client {{'.format(k),
        '\tulong pid;'
    ]
    nam2id = {}
    for fnid, (args, ret) in v.items():
        for arg in args:
            if arg == t.event:
                print('ERROR: argument to {}/{} cannot be an event, only return types can be!'.format(k, fnid))
        nam2id[fnid] = funcid
        funcid += 1

    for fnid, (args, ret) in v.items():
        if ret == t.event:
            dret = 'void'
        elif ret == t.void:
            dret = 'Signal'
        else:
            dret = 'Future!({})'.format(ret)

        code.append('\t{} {}(int _stub = 0)({}) {{'.format(dret, fnid, ', '.join([
            '{} a_{}'.format(aty, aid)
            for aid, aty
            in enumerate(args)
        ])))
        code.append('\t\tByteBuffer buf;')
        code.append('\t\trpcutil_prepare(buf, {});'.format(nam2id[fnid]))
        for aid, aty in enumerate(args):
            code.append('\t\trpcutil_encode_{}(buf, a_{});'.format(aty, aid))
        if ret == t.event:
            code.append('\t\trpcutil_submit_ev(this.pid, buf);')
        elif ret == t.void:
            code.append('\t\treturn rpcutil_submit_sig(this.pid, buf);')
        else:
            code.append('\t\tFuture!(ubyte[]) buffer_future = rpcutil_submit(this.pid, buf);')
            code.append('\t\treturn buffer_future.then((ref ubyte[] newbuf) {{ ulong o = 0; return rpcutil_decode_{}(newbuf, o); }});'.format(ret))
        code.append('\t}')
    code.append('}')
    code.append('struct {}_server {{'.format(k))
    code.append('\tthis() @disable;')
    
    for fnid, (args, ret) in v.items():
        if ret == t.event:
            dret = 'void'
        elif ret == t.void:
            dret = 'Signal'
        else:
            dret = 'Future!({})'.format(ret)

        dlty = '{} delegate({})'.format(dret, ', '.join(args))
        code.append('\tstatic void on{}(int _stub = 0)({} handler) {{'.format(fnid, dlty))
        code.append('\t\trpcutil_handle({}, (pid, rid, buf) {{'.format(nam2id[fnid]))
        code.append('\t\t\tulong off = 0;')
        for aid, aty in enumerate(args):
            code.append('\t\t\t{} a_{} = rpcutil_decode_{}(buf, off);'.format(aty, aid, aty, aid))
        # code.append('\t\t\t')
        if ret == t.event:
            code.append('\t\t\thandler({});'.format(', '.join([
                'a_{}'.format(i)
                for i in range(len(args))
            ])))
        elif ret == t.void:
            code.append('\t\t\trpcutil_sigrespond(pid, rid, handler({}));'.format(', '.join([
                'a_{}'.format(i)
                for i in range(len(args))
            ])))
        else:
            code.append('\t\t\trpcutil_respond_{}(pid, rid, rpcutil_as_future(handler({})));'.format(
                ret, ', '.join([
                    'a_{}'.format(i)
                    for i in range(len(args))
                ]
            )))
            

        code.append('\t\t});')
        code.append('\t}')

    code.append('}')

    makedirs('build/rsc/xtrix_rpc', exist_ok=True)
    with open("build/rsc/xtrix_rpc/{}.d".format(k), 'w') as file:
        file.write('\n'.join(code))