forked from ekanite/ekanite
/
server.go
93 lines (79 loc) · 1.66 KB
/
server.go
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package ekanite
import (
"bufio"
"log"
"net"
"os"
"strings"
)
type Searcher interface {
Search(query string) (<-chan string, error)
}
// Server serves query client connections.
type Server struct {
iface string
searcher Searcher
addr net.Addr
Logger *log.Logger
}
// NewServer returns a new Server instance.
func NewServer(iface string, searcher Searcher) *Server {
return &Server{
iface: iface,
searcher: searcher,
Logger: log.New(os.Stderr, "[server] ", log.LstdFlags),
}
}
// Start instructs the Server to bind to the interface and accept connections.
func (s *Server) Start() error {
ln, err := net.Listen("tcp", s.iface)
if err != nil {
return err
}
s.addr = ln.Addr()
go func() {
for {
conn, err := ln.Accept()
if err != nil {
continue
}
go s.handleConnection(conn)
}
}()
return nil
}
// Addr returns the address to which the Server is bound.
func (s *Server) Addr() net.Addr {
return s.addr
}
func (s *Server) handleConnection(conn net.Conn) {
defer func() {
conn.Close()
s.Logger.Printf("connection from %s closed", conn.RemoteAddr())
}()
s.Logger.Printf("new connection from %s", conn.RemoteAddr())
reader := bufio.NewReader(conn)
for {
b, err := reader.ReadString('\n')
if err != nil {
conn.Close()
return
} else {
query := strings.Trim(b, "\r\n")
if query == "" {
continue
}
s.Logger.Printf("executing query '%s'", query)
c, err := s.searcher.Search(query)
if err != nil {
conn.Write([]byte(err.Error()))
} else {
for s := range c {
conn.Write([]byte(s + "\n"))
}
}
// Send two newlines to indicate end-of-results.
conn.Write([]byte("\n\n"))
}
}
}