github.com/mdempsky/go@v0.0.0-20151201204031-5dd372bd1e70/src/cmd/go/http.go (about)

     1  // Copyright 2012 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  // +build !cmd_go_bootstrap
     6  
     7  // This code is compiled into the real 'go' binary, but it is not
     8  // compiled into the binary that is built during all.bash, so as
     9  // to avoid needing to build net (and thus use cgo) during the
    10  // bootstrap process.
    11  
    12  package main
    13  
    14  import (
    15  	"fmt"
    16  	"io"
    17  	"io/ioutil"
    18  	"log"
    19  	"net/http"
    20  	"net/url"
    21  	"time"
    22  )
    23  
    24  // httpClient is the default HTTP client, but a variable so it can be
    25  // changed by tests, without modifying http.DefaultClient.
    26  var httpClient = http.DefaultClient
    27  var impatientHTTPClient = &http.Client{
    28  	Timeout: time.Duration(5 * time.Second),
    29  }
    30  
    31  type httpError struct {
    32  	status     string
    33  	statusCode int
    34  	url        string
    35  }
    36  
    37  func (e *httpError) Error() string {
    38  	return fmt.Sprintf("%s: %s", e.url, e.status)
    39  }
    40  
    41  // httpGET returns the data from an HTTP GET request for the given URL.
    42  func httpGET(url string) ([]byte, error) {
    43  	resp, err := httpClient.Get(url)
    44  	if err != nil {
    45  		return nil, err
    46  	}
    47  	defer resp.Body.Close()
    48  	if resp.StatusCode != 200 {
    49  		err := &httpError{status: resp.Status, statusCode: resp.StatusCode, url: url}
    50  
    51  		return nil, err
    52  	}
    53  	b, err := ioutil.ReadAll(resp.Body)
    54  	if err != nil {
    55  		return nil, fmt.Errorf("%s: %v", url, err)
    56  	}
    57  	return b, nil
    58  }
    59  
    60  // httpsOrHTTP returns the body of either the importPath's
    61  // https resource or, if unavailable, the http resource.
    62  func httpsOrHTTP(importPath string, security securityMode) (urlStr string, body io.ReadCloser, err error) {
    63  	fetch := func(scheme string) (urlStr string, res *http.Response, err error) {
    64  		u, err := url.Parse(scheme + "://" + importPath)
    65  		if err != nil {
    66  			return "", nil, err
    67  		}
    68  		u.RawQuery = "go-get=1"
    69  		urlStr = u.String()
    70  		if buildV {
    71  			log.Printf("Fetching %s", urlStr)
    72  		}
    73  		if security == insecure && scheme == "https" { // fail earlier
    74  			res, err = impatientHTTPClient.Get(urlStr)
    75  		} else {
    76  			res, err = httpClient.Get(urlStr)
    77  		}
    78  		return
    79  	}
    80  	closeBody := func(res *http.Response) {
    81  		if res != nil {
    82  			res.Body.Close()
    83  		}
    84  	}
    85  	urlStr, res, err := fetch("https")
    86  	if err != nil || res.StatusCode != 200 {
    87  		if buildV {
    88  			if err != nil {
    89  				log.Printf("https fetch failed.")
    90  			} else {
    91  				log.Printf("ignoring https fetch with status code %d", res.StatusCode)
    92  			}
    93  		}
    94  		closeBody(res)
    95  		if security == insecure {
    96  			urlStr, res, err = fetch("http")
    97  		}
    98  	}
    99  	if err != nil {
   100  		closeBody(res)
   101  		return "", nil, err
   102  	}
   103  	// Note: accepting a non-200 OK here, so people can serve a
   104  	// meta import in their http 404 page.
   105  	if buildV {
   106  		log.Printf("Parsing meta tags from %s (status code %d)", urlStr, res.StatusCode)
   107  	}
   108  	return urlStr, res.Body, nil
   109  }