115 lines
2.7 KiB
Go
115 lines
2.7 KiB
Go
/*
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* lrpc allows for clients to call functions on a server remotely.
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* Copyright (C) 2022 Arsen Musayelyan
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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package server
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import (
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"context"
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"time"
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"go.arsenm.dev/lrpc/codec"
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"github.com/gofrs/uuid"
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)
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// Context is a connection context for RPC calls
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type Context struct {
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isChannel bool
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channelID string
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channel chan any
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codec codec.Codec
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doneCh chan struct{}
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canceled bool
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ctx context.Context
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}
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func newContext(ctx context.Context, codec codec.Codec) *Context {
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out := &Context{
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doneCh: make(chan struct{}),
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codec: codec,
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ctx: ctx,
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}
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if ctx == nil {
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out.ctx = context.Background()
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}
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go func() {
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<-out.ctx.Done()
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out.cancel()
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}()
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return out
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}
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// MakeChannel changes the function it's called in into a
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// channel function, and returns a channel which can be used
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// to send information to the client.
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//
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// This will ovewrite any return value of the function with
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// a channel ID.
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func (ctx *Context) MakeChannel() (chan<- any, error) {
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ctx.isChannel = true
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chID, err := uuid.NewV4()
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ctx.channelID = chID.String()
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ctx.channel = make(chan any, 5)
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return ctx.channel, err
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}
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// GetCodec returns a codec bound to the connection
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// that called this function
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func (ctx *Context) GetCodec() codec.Codec {
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return ctx.codec
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}
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// Deadline always returns the current time and false
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// as this context does not support deadlines
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func (ctx *Context) Deadline() (time.Time, bool) {
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return time.Now(), false
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}
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// Value always returns nil as this context stores no values
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func (ctx *Context) Value(_ any) any {
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return nil
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}
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// Err returns context.Canceled if the context was canceled,
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// otherwise nil
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func (ctx *Context) Err() error {
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if ctx.canceled {
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return context.Canceled
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}
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return nil
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}
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// Done returns a channel that will be closed when
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// the context is canceled, such as when ChannelDone
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// is called by the client
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func (ctx *Context) Done() <-chan struct{} {
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return ctx.doneCh
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}
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// Cancel cancels the context
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func (ctx *Context) cancel() {
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if ctx.canceled {
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return
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}
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ctx.canceled = true
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close(ctx.doneCh)
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}
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