| //go:build !go1.19 |
| // +build !go1.19 |
| |
| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package triple_protocol |
| |
| import ( |
| "errors" |
| "fmt" |
| "io" |
| "net/http" |
| ) |
| |
| // maxBytesReaderFunc is the same as http.MaxBytesReader for golang version smaller than 1.19 |
| func maxBytesReaderFunc(w http.ResponseWriter, r io.ReadCloser, n int64) io.ReadCloser { |
| if n < 0 { // Treat negative limits as equivalent to 0. |
| n = 0 |
| } |
| return &maxBytesReader{w: w, r: r, i: n, n: n} |
| } |
| |
| // maxBytesReader is the same as http.maxBytesReader for golang version smaller than 1.19. |
| // We need to copy the whole type from http library because we need to return maxBytesError in maxBytesReader.Read |
| type maxBytesReader struct { |
| w http.ResponseWriter |
| r io.ReadCloser // underlying reader |
| i int64 // max bytes initially, for MaxBytesError |
| n int64 // max bytes remaining |
| err error // sticky error |
| } |
| |
| func (l *maxBytesReader) Read(p []byte) (n int, err error) { |
| if l.err != nil { |
| return 0, l.err |
| } |
| if len(p) == 0 { |
| return 0, nil |
| } |
| // If they asked for a 32KB byte read but only 5 bytes are |
| // remaining, no need to read 32KB. 6 bytes will answer the |
| // question of the whether we hit the limit or go past it. |
| // 0 < len(p) < 2^63 |
| if int64(len(p))-1 > l.n { |
| p = p[:l.n+1] |
| } |
| n, err = l.r.Read(p) |
| |
| if int64(n) <= l.n { |
| l.n -= int64(n) |
| l.err = err |
| return n, err |
| } |
| |
| n = int(l.n) |
| l.n = 0 |
| |
| // The server code and client code both use |
| // maxBytesReader. This "requestTooLarge" check is |
| // only used by the server code. To prevent binaries |
| // which only using the HTTP Client code (such as |
| // cmd/go) from also linking in the HTTP server, don't |
| // use a static type assertion to the server |
| // "*response" type. Check this interface instead: |
| type requestTooLarger interface { |
| requestTooLarge() |
| } |
| if res, ok := l.w.(requestTooLarger); ok { |
| res.requestTooLarge() |
| } |
| l.err = &maxBytesError{l.i} |
| return n, l.err |
| } |
| |
| func (l *maxBytesReader) Close() error { |
| return l.r.Close() |
| } |
| |
| // maxBytesError is the same as http.MaxBytesError for golang version smaller than 1.19 |
| type maxBytesError struct { |
| Limit int64 |
| } |
| |
| func (e *maxBytesError) Error() string { |
| // Due to Hyrum's law, this text cannot be changed. |
| return "http: request body too large" |
| } |
| |
| // MaxBytesHandler is the same as http.MaxBytesHandler for golang version smaller than 1.19 |
| func MaxBytesHandler(h http.Handler, n int64) http.Handler { |
| return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { |
| r2 := *r |
| r2.Body = maxBytesReaderFunc(w, r.Body, n) |
| h.ServeHTTP(w, &r2) |
| }) |
| } |
| |
| func asMaxBytesError(err error, tmpl string, args ...interface{}) *Error { |
| var maxBytesErr *maxBytesError |
| if ok := errors.As(err, &maxBytesErr); !ok { |
| return nil |
| } |
| prefix := fmt.Sprintf(tmpl, args...) |
| return errorf(CodeResourceExhausted, "%s: exceeded %d byte http.MaxBytesReader limit", prefix, maxBytesErr.Limit) |
| } |