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Diffstat (limited to 'libgo/go/net/http/response.go')
-rw-r--r-- | libgo/go/net/http/response.go | 236 |
1 files changed, 236 insertions, 0 deletions
diff --git a/libgo/go/net/http/response.go b/libgo/go/net/http/response.go new file mode 100644 index 00000000000..ae314b5ac93 --- /dev/null +++ b/libgo/go/net/http/response.go @@ -0,0 +1,236 @@ +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// HTTP Response reading and parsing. + +package http + +import ( + "bufio" + "errors" + "io" + "net/textproto" + "net/url" + "strconv" + "strings" +) + +var respExcludeHeader = map[string]bool{ + "Content-Length": true, + "Transfer-Encoding": true, + "Trailer": true, +} + +// Response represents the response from an HTTP request. +// +type Response struct { + Status string // e.g. "200 OK" + StatusCode int // e.g. 200 + Proto string // e.g. "HTTP/1.0" + ProtoMajor int // e.g. 1 + ProtoMinor int // e.g. 0 + + // Header maps header keys to values. If the response had multiple + // headers with the same key, they will be concatenated, with comma + // delimiters. (Section 4.2 of RFC 2616 requires that multiple headers + // be semantically equivalent to a comma-delimited sequence.) Values + // duplicated by other fields in this struct (e.g., ContentLength) are + // omitted from Header. + // + // Keys in the map are canonicalized (see CanonicalHeaderKey). + Header Header + + // Body represents the response body. + // + // The http Client and Transport guarantee that Body is always + // non-nil, even on responses without a body or responses with + // a zero-lengthed body. + Body io.ReadCloser + + // ContentLength records the length of the associated content. The + // value -1 indicates that the length is unknown. Unless RequestMethod + // is "HEAD", values >= 0 indicate that the given number of bytes may + // be read from Body. + ContentLength int64 + + // Contains transfer encodings from outer-most to inner-most. Value is + // nil, means that "identity" encoding is used. + TransferEncoding []string + + // Close records whether the header directed that the connection be + // closed after reading Body. The value is advice for clients: neither + // ReadResponse nor Response.Write ever closes a connection. + Close bool + + // Trailer maps trailer keys to values, in the same + // format as the header. + Trailer Header + + // The Request that was sent to obtain this Response. + // Request's Body is nil (having already been consumed). + // This is only populated for Client requests. + Request *Request +} + +// Cookies parses and returns the cookies set in the Set-Cookie headers. +func (r *Response) Cookies() []*Cookie { + return readSetCookies(r.Header) +} + +var ErrNoLocation = errors.New("http: no Location header in response") + +// Location returns the URL of the response's "Location" header, +// if present. Relative redirects are resolved relative to +// the Response's Request. ErrNoLocation is returned if no +// Location header is present. +func (r *Response) Location() (*url.URL, error) { + lv := r.Header.Get("Location") + if lv == "" { + return nil, ErrNoLocation + } + if r.Request != nil && r.Request.URL != nil { + return r.Request.URL.Parse(lv) + } + return url.Parse(lv) +} + +// ReadResponse reads and returns an HTTP response from r. The +// req parameter specifies the Request that corresponds to +// this Response. Clients must call resp.Body.Close when finished +// reading resp.Body. After that call, clients can inspect +// resp.Trailer to find key/value pairs included in the response +// trailer. +func ReadResponse(r *bufio.Reader, req *Request) (resp *Response, err error) { + + tp := textproto.NewReader(r) + resp = new(Response) + + resp.Request = req + resp.Request.Method = strings.ToUpper(resp.Request.Method) + + // Parse the first line of the response. + line, err := tp.ReadLine() + if err != nil { + if err == io.EOF { + err = io.ErrUnexpectedEOF + } + return nil, err + } + f := strings.SplitN(line, " ", 3) + if len(f) < 2 { + return nil, &badStringError{"malformed HTTP response", line} + } + reasonPhrase := "" + if len(f) > 2 { + reasonPhrase = f[2] + } + resp.Status = f[1] + " " + reasonPhrase + resp.StatusCode, err = strconv.Atoi(f[1]) + if err != nil { + return nil, &badStringError{"malformed HTTP status code", f[1]} + } + + resp.Proto = f[0] + var ok bool + if resp.ProtoMajor, resp.ProtoMinor, ok = ParseHTTPVersion(resp.Proto); !ok { + return nil, &badStringError{"malformed HTTP version", resp.Proto} + } + + // Parse the response headers. + mimeHeader, err := tp.ReadMIMEHeader() + if err != nil { + return nil, err + } + resp.Header = Header(mimeHeader) + + fixPragmaCacheControl(resp.Header) + + err = readTransfer(resp, r) + if err != nil { + return nil, err + } + + return resp, nil +} + +// RFC2616: Should treat +// Pragma: no-cache +// like +// Cache-Control: no-cache +func fixPragmaCacheControl(header Header) { + if hp, ok := header["Pragma"]; ok && len(hp) > 0 && hp[0] == "no-cache" { + if _, presentcc := header["Cache-Control"]; !presentcc { + header["Cache-Control"] = []string{"no-cache"} + } + } +} + +// ProtoAtLeast returns whether the HTTP protocol used +// in the response is at least major.minor. +func (r *Response) ProtoAtLeast(major, minor int) bool { + return r.ProtoMajor > major || + r.ProtoMajor == major && r.ProtoMinor >= minor +} + +// Writes the response (header, body and trailer) in wire format. This method +// consults the following fields of resp: +// +// StatusCode +// ProtoMajor +// ProtoMinor +// RequestMethod +// TransferEncoding +// Trailer +// Body +// ContentLength +// Header, values for non-canonical keys will have unpredictable behavior +// +func (resp *Response) Write(w io.Writer) error { + + // RequestMethod should be upper-case + if resp.Request != nil { + resp.Request.Method = strings.ToUpper(resp.Request.Method) + } + + // Status line + text := resp.Status + if text == "" { + var ok bool + text, ok = statusText[resp.StatusCode] + if !ok { + text = "status code " + strconv.Itoa(resp.StatusCode) + } + } + io.WriteString(w, "HTTP/"+strconv.Itoa(resp.ProtoMajor)+".") + io.WriteString(w, strconv.Itoa(resp.ProtoMinor)+" ") + io.WriteString(w, strconv.Itoa(resp.StatusCode)+" "+text+"\r\n") + + // Process Body,ContentLength,Close,Trailer + tw, err := newTransferWriter(resp) + if err != nil { + return err + } + err = tw.WriteHeader(w) + if err != nil { + return err + } + + // Rest of header + err = resp.Header.WriteSubset(w, respExcludeHeader) + if err != nil { + return err + } + + // End-of-header + io.WriteString(w, "\r\n") + + // Write body and trailer + err = tw.WriteBody(w) + if err != nil { + return err + } + + // Success + return nil +} |