Create new type and remove un-used code

vendor/github.com/labstack/echo/v4/middleware/decompress.go

@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: MIT
+// SPDX-FileCopyrightText: © 2015 LabStack LLC and Echo contributors
+
+package middleware
+
+import (
+	"compress/gzip"
+	"io"
+	"net/http"
+	"sync"
+
+	"github.com/labstack/echo/v4"
+)
+
+// DecompressConfig defines the config for Decompress middleware.
+type DecompressConfig struct {
+	// Skipper defines a function to skip middleware.
+	Skipper Skipper
+
+	// GzipDecompressPool defines an interface to provide the sync.Pool used to create/store Gzip readers
+	GzipDecompressPool Decompressor
+}
+
+// GZIPEncoding content-encoding header if set to "gzip", decompress body contents.
+const GZIPEncoding string = "gzip"
+
+// Decompressor is used to get the sync.Pool used by the middleware to get Gzip readers
+type Decompressor interface {
+	gzipDecompressPool() sync.Pool
+}
+
+// DefaultDecompressConfig defines the config for decompress middleware
+var DefaultDecompressConfig = DecompressConfig{
+	Skipper:            DefaultSkipper,
+	GzipDecompressPool: &DefaultGzipDecompressPool{},
+}
+
+// DefaultGzipDecompressPool is the default implementation of Decompressor interface
+type DefaultGzipDecompressPool struct {
+}
+
+func (d *DefaultGzipDecompressPool) gzipDecompressPool() sync.Pool {
+	return sync.Pool{New: func() interface{} { return new(gzip.Reader) }}
+}
+
+// Decompress decompresses request body based if content encoding type is set to "gzip" with default config
+func Decompress() echo.MiddlewareFunc {
+	return DecompressWithConfig(DefaultDecompressConfig)
+}
+
+// DecompressWithConfig decompresses request body based if content encoding type is set to "gzip" with config
+func DecompressWithConfig(config DecompressConfig) echo.MiddlewareFunc {
+	// Defaults
+	if config.Skipper == nil {
+		config.Skipper = DefaultGzipConfig.Skipper
+	}
+	if config.GzipDecompressPool == nil {
+		config.GzipDecompressPool = DefaultDecompressConfig.GzipDecompressPool
+	}
+
+	return func(next echo.HandlerFunc) echo.HandlerFunc {
+		pool := config.GzipDecompressPool.gzipDecompressPool()
+
+		return func(c echo.Context) error {
+			if config.Skipper(c) {
+				return next(c)
+			}
+
+			if c.Request().Header.Get(echo.HeaderContentEncoding) != GZIPEncoding {
+				return next(c)
+			}
+
+			i := pool.Get()
+			gr, ok := i.(*gzip.Reader)
+			if !ok || gr == nil {
+				return echo.NewHTTPError(http.StatusInternalServerError, i.(error).Error())
+			}
+			defer pool.Put(gr)
+
+			b := c.Request().Body
+			defer b.Close()
+
+			if err := gr.Reset(b); err != nil {
+				if err == io.EOF { //ignore if body is empty
+					return next(c)
+				}
+				return err
+			}
+
+			// only Close gzip reader if it was set to a proper gzip source otherwise it will panic on close.
+			defer gr.Close()
+
+			c.Request().Body = gr
+
+			return next(c)
+		}
+	}
+}