clone.go

     1  // Copyright 2019 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package http
     6  
     7  import (
     8  	"mime/multipart"
     9  	"net/textproto"
    10  	"net/url"
    11  	_ "unsafe" // for linkname
    12  )
    13  
    14  // cloneURLValues should be an internal detail,
    15  // but widely used packages access it using linkname.
    16  // Notable members of the hall of shame include:
    17  //   - github.com/searKing/golang
    18  //
    19  // Do not remove or change the type signature.
    20  // See go.dev/issue/67401.
    21  //
    22  //go:linkname cloneURLValues
    23  func cloneURLValues(v url.Values) url.Values {
    24  	if v == nil {
    25  		return nil
    26  	}
    27  	// http.Header and url.Values have the same representation, so temporarily
    28  	// treat it like http.Header, which does have a clone:
    29  	return url.Values(Header(v).Clone())
    30  }
    31  
    32  // cloneURL should be an internal detail,
    33  // but widely used packages access it using linkname.
    34  // Notable members of the hall of shame include:
    35  //   - github.com/searKing/golang
    36  //
    37  // Do not remove or change the type signature.
    38  // See go.dev/issue/67401.
    39  //
    40  //go:linkname cloneURL
    41  func cloneURL(u *url.URL) *url.URL {
    42  	if u == nil {
    43  		return nil
    44  	}
    45  	u2 := new(url.URL)
    46  	*u2 = *u
    47  	if u.User != nil {
    48  		u2.User = new(url.Userinfo)
    49  		*u2.User = *u.User
    50  	}
    51  	return u2
    52  }
    53  
    54  // cloneMultipartForm should be an internal detail,
    55  // but widely used packages access it using linkname.
    56  // Notable members of the hall of shame include:
    57  //   - github.com/searKing/golang
    58  //
    59  // Do not remove or change the type signature.
    60  // See go.dev/issue/67401.
    61  //
    62  //go:linkname cloneMultipartForm
    63  func cloneMultipartForm(f *multipart.Form) *multipart.Form {
    64  	if f == nil {
    65  		return nil
    66  	}
    67  	f2 := &multipart.Form{
    68  		Value: (map[string][]string)(Header(f.Value).Clone()),
    69  	}
    70  	if f.File != nil {
    71  		m := make(map[string][]*multipart.FileHeader)
    72  		for k, vv := range f.File {
    73  			vv2 := make([]*multipart.FileHeader, len(vv))
    74  			for i, v := range vv {
    75  				vv2[i] = cloneMultipartFileHeader(v)
    76  			}
    77  			m[k] = vv2
    78  		}
    79  		f2.File = m
    80  	}
    81  	return f2
    82  }
    83  
    84  // cloneMultipartFileHeader should be an internal detail,
    85  // but widely used packages access it using linkname.
    86  // Notable members of the hall of shame include:
    87  //   - github.com/searKing/golang
    88  //
    89  // Do not remove or change the type signature.
    90  // See go.dev/issue/67401.
    91  //
    92  //go:linkname cloneMultipartFileHeader
    93  func cloneMultipartFileHeader(fh *multipart.FileHeader) *multipart.FileHeader {
    94  	if fh == nil {
    95  		return nil
    96  	}
    97  	fh2 := new(multipart.FileHeader)
    98  	*fh2 = *fh
    99  	fh2.Header = textproto.MIMEHeader(Header(fh.Header).Clone())
   100  	return fh2
   101  }
   102  
   103  // cloneOrMakeHeader invokes Header.Clone but if the
   104  // result is nil, it'll instead make and return a non-nil Header.
   105  //
   106  // cloneOrMakeHeader should be an internal detail,
   107  // but widely used packages access it using linkname.
   108  // Notable members of the hall of shame include:
   109  //   - github.com/searKing/golang
   110  //
   111  // Do not remove or change the type signature.
   112  // See go.dev/issue/67401.
   113  //
   114  //go:linkname cloneOrMakeHeader
   115  func cloneOrMakeHeader(hdr Header) Header {
   116  	clone := hdr.Clone()
   117  	if clone == nil {
   118  		clone = make(Header)
   119  	}
   120  	return clone
   121  }
   122
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