Update vendor (#1414)

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

@@ -0,0 +1,120 @@
+package middleware
+
+import (
+	"bytes"
+	"compress/gzip"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"sync"
+
+	"github.com/labstack/echo/v4"
+)
+
+type (
+	// DecompressConfig defines the config for Decompress middleware.
+	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
+}
+
+var (
+	//DefaultDecompressConfig defines the config for decompress middleware
+	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{} {
+			// create with an empty reader (but with GZIP header)
+			w, err := gzip.NewWriterLevel(ioutil.Discard, gzip.BestSpeed)
+			if err != nil {
+				return err
+			}
+
+			b := new(bytes.Buffer)
+			w.Reset(b)
+			w.Flush()
+			w.Close()
+
+			r, err := gzip.NewReader(bytes.NewReader(b.Bytes()))
+			if err != nil {
+				return err
+			}
+			return r
+		},
+	}
+}
+
+//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)
+			}
+			switch c.Request().Header.Get(echo.HeaderContentEncoding) {
+			case GZIPEncoding:
+				b := c.Request().Body
+
+				i := pool.Get()
+				gr, ok := i.(*gzip.Reader)
+				if !ok {
+					return echo.NewHTTPError(http.StatusInternalServerError, i.(error).Error())
+				}
+
+				if err := gr.Reset(b); err != nil {
+					pool.Put(gr)
+					if err == io.EOF { //ignore if body is empty
+						return next(c)
+					}
+					return err
+				}
+				var buf bytes.Buffer
+				io.Copy(&buf, gr)
+
+				gr.Close()
+				pool.Put(gr)
+
+				b.Close() // http.Request.Body is closed by the Server, but because we are replacing it, it must be closed here
+
+				r := ioutil.NopCloser(&buf)
+				c.Request().Body = r
+			}
+			return next(c)
+		}
+	}
+}