88 lines
2 KiB
Go
88 lines
2 KiB
Go
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package httputil
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import (
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"fmt"
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"net/http"
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"time"
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)
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// Prm groups the required parameters of the Server's constructor.
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//
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// All values must comply with the requirements imposed on them.
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// Passing incorrect parameter values will result in constructor
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// failure (error or panic depending on the implementation).
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type Prm struct {
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// TCP address for the server to listen on.
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//
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// Must be a valid TCP address.
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Address string
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// Must not be nil.
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Handler http.Handler
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}
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// Server represents a wrapper over http.Server
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// that provides interface to start and stop
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// listening routine.
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//
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// For correct operation, Server must be created
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// using the constructor (New) based on the required parameters
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// and optional components. After successful creation,
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// Server is immediately ready to work through API.
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type Server struct {
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shutdownTimeout time.Duration
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srv *http.Server
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}
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const invalidValFmt = "invalid %s %s (%T): %v"
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func panicOnPrmValue(n string, v interface{}) {
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panicOnValue("parameter", n, v)
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}
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func panicOnOptValue(n string, v interface{}) {
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panicOnValue("option", n, v)
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}
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func panicOnValue(t, n string, v interface{}) {
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panic(fmt.Sprintf(invalidValFmt, t, n, v, v))
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}
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// New creates a new instance of the Server.
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//
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// Panics if at least one value of the parameters is invalid.
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//
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// Panics if at least one of next optinal parameters is invalid:
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// * shutdown timeout is non-positive.
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//
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// The created Server does not require additional
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// initialization and is completely ready for work.
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func New(prm Prm, opts ...Option) *Server {
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switch {
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case prm.Address == "":
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panicOnPrmValue("Address", prm.Address)
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case prm.Handler == nil:
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panicOnPrmValue("Handler", prm.Handler)
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}
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c := defaultCfg()
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for _, o := range opts {
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o(c)
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}
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switch {
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case c.shutdownTimeout <= 0:
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panicOnOptValue("shutdown timeout", c.shutdownTimeout)
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}
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return &Server{
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shutdownTimeout: c.shutdownTimeout,
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srv: &http.Server{
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Addr: prm.Address,
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Handler: prm.Handler,
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},
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}
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}
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