(#1554) Add support for all common compressions (write and read)

- Remove the context.Context interface and export the *context, the iris.Context now points to the pointer\nSupport compression and rate limiting in the FileServer\nBit of code organisation


Former-commit-id: ad1c61bf968059510c6be9e7f2cceec7da70ba17

cli.go

@@ -0,0 +1,120 @@
+package iris
+
+//  +------------------------------------------------------------+
+//  | Bridge code between iris-cli and iris web application      |
+//  | https://github.com/kataras/iris-cli						 |
+//  +------------------------------------------------------------+
+
+import (
+	"bytes"
+	"fmt"
+	"net/http"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/kataras/iris/v12/context"
+	"github.com/kataras/iris/v12/core/router"
+	"gopkg.in/yaml.v3"
+)
+
+// injectLiveReload tries to check if this application
+// runs under https://github.com/kataras/iris-cli and if so
+// then it checks if the livereload is enabled and then injects
+// the watch listener (js script) on every HTML response.
+// It has a slight performance cost but
+// this (iris-cli with watch and livereload enabled)
+// is meant to be used only in development mode.
+// It does a full reload at the moment and if the port changed
+// at runtime it will fire 404 instead of redirecting to the correct port (that's a TODO).
+//
+// tryInjectLiveReload runs right before Build -> BuildRouter.
+func injectLiveReload(contextPool *context.Pool, router *router.Router) (bool, error) {
+	conf := struct {
+		Running    bool `yaml:"Running,omitempty"`
+		LiveReload struct {
+			Disable bool `yaml:"Disable"`
+			Port    int  `yaml:"Port"`
+		} `yaml:"LiveReload"`
+	}{}
+	// defaults to disabled here.
+	conf.LiveReload.Disable = true
+
+	wd, err := os.Getwd()
+	if err != nil {
+		return false, err
+	}
+
+	for _, path := range []string{".iris.yml" /*, "../.iris.yml", "../../.iris.yml" */} {
+		path = filepath.Join(wd, path)
+
+		if _, err := os.Stat(path); err == nil {
+			inFile, err := os.OpenFile(path, os.O_RDONLY, 0644)
+			if err != nil {
+				return false, err
+			}
+
+			dec := yaml.NewDecoder(inFile)
+			err = dec.Decode(&conf)
+			inFile.Close()
+			if err != nil {
+				return false, err
+			}
+
+			break
+		}
+	}
+
+	if !conf.Running || conf.LiveReload.Disable {
+		return false, nil
+	}
+
+	scriptReloadJS := []byte(fmt.Sprintf(`<script>(function () {
+    const scheme = document.location.protocol == "https:" ? "wss" : "ws";
+    const endpoint = scheme + "://" + document.location.hostname + ":%d/livereload";
+
+    w = new WebSocket(endpoint);
+    w.onopen = function () {
+        console.info("LiveReload: initialization");
+    };
+    w.onclose = function () {
+        console.info("LiveReload: terminated");
+    };
+    w.onmessage = function (message) {
+        // NOTE: full-reload, at least for the moment. Also if backend changed its port then we will get 404 here. 
+        window.location.reload();
+    };
+}());</script>`, conf.LiveReload.Port))
+
+	bodyCloseTag := []byte("</body>")
+
+	wrapper := func(w http.ResponseWriter, r *http.Request, _ http.HandlerFunc) {
+		ctx := contextPool.Acquire(w, r)
+		rec := ctx.Recorder()  // Record everything and write all in once at the Context release.
+		router.ServeHTTPC(ctx) // We directly call request handler with Context.
+
+		if strings.HasPrefix(ctx.GetContentType(), "text/html") {
+			// delete(rec.Header(), context.ContentLengthHeaderKey)
+
+			body := rec.Body()
+
+			if idx := bytes.LastIndex(body, bodyCloseTag); idx > 0 {
+				// add the script right before last </body>.
+				body = append(body[:idx], bytes.Replace(body[idx:], bodyCloseTag, append(scriptReloadJS, bodyCloseTag...), 1)...)
+				rec.SetBody(body)
+			} else {
+				// Just append it.
+				rec.Write(scriptReloadJS) // nolint:errcheck
+			}
+
+			if _, has := rec.Header()[context.ContentLengthHeaderKey]; has {
+				rec.Header().Set(context.ContentLengthHeaderKey, fmt.Sprintf("%d", len(rec.Body())))
+			}
+		}
+
+		contextPool.Release(ctx)
+	}
+
+	router.WrapRouter(wrapper)
+	return true, nil
+}