http

type Client struct {
	// Transport specifies the mechanism by which individual
	// HTTP requests are made.
	// If nil, DefaultTransport is used.
	Transport RoundTripper

	// CheckRedirect specifies the policy for handling redirects.
	// If CheckRedirect is not nil, the client calls it before
	// following an HTTP redirect. The arguments req and via are
	// the upcoming request and the requests made already, oldest
	// first. If CheckRedirect returns an error, the Client's Get
	// method returns both the previous Response and
	// CheckRedirect's error (wrapped in a url.Error) instead of
	// issuing the Request req.
	//
	// If CheckRedirect is nil, the Client uses its default policy,
	// which is to stop after 10 consecutive requests.
	CheckRedirect func(req *Request, via []*Request) error

	// Jar specifies the cookie jar.
	// If Jar is nil, cookies are not sent in requests and ignored
	// in responses.
	Jar http.CookieJar

	// Timeout specifies a time limit for requests made by this
	// Client. The timeout includes connection time, any
	// redirects, and reading the response body. The timer remains
	// running after Get, Head, Post, or Do return and will
	// interrupt reading of the Response.Body.
	//
	// A Timeout of zero means no timeout.
	//
	// The Client's Transport must support the CancelRequest
	// method or Client will return errors when attempting to make
	// a request with Get, Head, Post, or Do. Client's default
	// Transport (DefaultTransport) supports CancelRequest.
	Timeout time.Duration
}

type ProtocolError struct {
	ErrorString string
}

type Request struct {
	// Method specifies the HTTP method (GET, POST, PUT, etc.).
	// For client requests an empty string means GET.
	Method string

	// URL specifies either the URI being requested (for server
	// requests) or the URL to access (for client requests).
	//
	// For server requests the URL is parsed from the URI
	// supplied on the Request-Line as stored in RequestURI.  For
	// most requests, fields other than Path and RawQuery will be
	// empty. (See RFC 2616, Section 5.1.2)
	//
	// For client requests, the URL's Host specifies the server to
	// connect to, while the Request's Host field optionally
	// specifies the Host header value to send in the HTTP
	// request.
	URL *url.URL

	// The protocol version for incoming requests.
	// Client requests always use HTTP/1.1.
	Proto      string // "HTTP/1.0"
	ProtoMajor int    // 1
	ProtoMinor int    // 0

	// A header maps request lines to their values.
	// If the header says
	//
	//	accept-encoding: gzip, deflate
	//	Accept-Language: en-us
	//	Connection: keep-alive
	//
	// then
	//
	//	Header = map[string][]string{
	//		"Accept-Encoding": {"gzip, deflate"},
	//		"Accept-Language": {"en-us"},
	//		"Connection": {"keep-alive"},
	//	}
	//
	// HTTP defines that header names are case-insensitive.
	// The request parser implements this by canonicalizing the
	// name, making the first character and any characters
	// following a hyphen uppercase and the rest lowercase.
	//
	// For client requests certain headers are automatically
	// added and may override values in Header.
	//
	// See the documentation for the Request.Write method.
	Header http.Header

	// Body is the request's body.
	//
	// For client requests a nil body means the request has no
	// body, such as a GET request. The HTTP Client's Transport
	// is responsible for calling the Close method.
	//
	// For server requests the Request Body is always non-nil
	// but will return EOF immediately when no body is present.
	// The Server will close the request body. The ServeHTTP
	// Handler does not need to.
	Body io.ReadCloser

	// ContentLength records the length of the associated content.
	// The value -1 indicates that the length is unknown.
	// Values >= 0 indicate that the given number of bytes may
	// be read from Body.
	// For client requests, a value of 0 means unknown if Body is not nil.
	ContentLength int64

	// TransferEncoding lists the transfer encodings from outermost to
	// innermost. An empty list denotes the "identity" encoding.
	// TransferEncoding can usually be ignored; chunked encoding is
	// automatically added and removed as necessary when sending and
	// receiving requests.
	TransferEncoding []string

	// Close indicates whether to close the connection after
	// replying to this request (for servers) or after sending
	// the request (for clients).
	Close bool

	// For server requests Host specifies the host on which the
	// URL is sought. Per RFC 2616, this is either the value of
	// the "Host" header or the host name given in the URL itself.
	// It may be of the form "host:port".
	//
	// For client requests Host optionally overrides the Host
	// header to send. If empty, the Request.Write method uses
	// the value of URL.Host.
	Host string

	// Form contains the parsed form data, including both the URL
	// field's query parameters and the POST or PUT form data.
	// This field is only available after ParseForm is called.
	// The HTTP client ignores Form and uses Body instead.
	Form url.Values

	// PostForm contains the parsed form data from POST or PUT
	// body parameters.
	// This field is only available after ParseForm is called.
	// The HTTP client ignores PostForm and uses Body instead.
	PostForm url.Values

	// MultipartForm is the parsed multipart form, including file uploads.
	// This field is only available after ParseMultipartForm is called.
	// The HTTP client ignores MultipartForm and uses Body instead.
	MultipartForm *multipart.Form

	// Trailer specifies additional headers that are sent after the request
	// body.
	//
	// For server requests the Trailer map initially contains only the
	// trailer keys, with nil values. (The client declares which trailers it
	// will later send.)  While the handler is reading from Body, it must
	// not reference Trailer. After reading from Body returns EOF, Trailer
	// can be read again and will contain non-nil values, if they were sent
	// by the client.
	//
	// For client requests Trailer must be initialized to a map containing
	// the trailer keys to later send. The values may be nil or their final
	// values. The ContentLength must be 0 or -1, to send a chunked request.
	// After the HTTP request is sent the map values can be updated while
	// the request body is read. Once the body returns EOF, the caller must
	// not mutate Trailer.
	//
	// Few HTTP clients, servers, or proxies support HTTP trailers.
	Trailer http.Header

	// RemoteAddr allows HTTP servers and other software to record
	// the network address that sent the request, usually for
	// logging. This field is not filled in by ReadRequest and
	// has no defined format. The HTTP server in this package
	// sets RemoteAddr to an "IP:port" address before invoking a
	// handler.
	// This field is ignored by the HTTP client.
	RemoteAddr string

	// RequestURI is the unmodified Request-URI of the
	// Request-Line (RFC 2616, Section 5.1) as sent by the client
	// to a server. Usually the URL field should be used instead.
	// It is an error to set this field in an HTTP client request.
	RequestURI string

	// TLS allows HTTP servers and other software to record
	// information about the TLS connection on which the request
	// was received. This field is not filled in by ReadRequest.
	// The HTTP server in this package sets the field for
	// TLS-enabled connections before invoking a handler;
	// otherwise it leaves the field nil.
	// This field is ignored by the HTTP client.
	TLS *tls.ConnectionState
}

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 may 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 http.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-length body. It is the caller's responsibility to
	// close Body.
	//
	// The Body is automatically dechunked if the server replied
	// with a "chunked" Transfer-Encoding.
	Body io.ReadCloser

	// ContentLength records the length of the associated content.  The
	// value -1 indicates that the length is unknown.  Unless Request.Method
	// 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 http.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

	// TLS contains information about the TLS connection on which the
	// response was received. It is nil for unencrypted responses.
	// The pointer is shared between responses and should not be
	// modified.
	TLS *tls.ConnectionState
}

type RoundTripper interface {
	// RoundTrip executes a single HTTP transaction, returning
	// the Response for the request req.  RoundTrip should not
	// attempt to interpret the response.  In particular,
	// RoundTrip must return err == nil if it obtained a response,
	// regardless of the response's HTTP status code.  A non-nil
	// err should be reserved for failure to obtain a response.
	// Similarly, RoundTrip should not attempt to handle
	// higher-level protocol details such as redirects,
	// authentication, or cookies.
	//
	// RoundTrip should not modify the request, except for
	// consuming and closing the Body, including on errors. The
	// request's URL and Header fields are guaranteed to be
	// initialized.
	RoundTrip(*Request) (*Response, error)
}

type Transport struct {

	// Proxy specifies a function to return a proxy for a given
	// Request. If the function returns a non-nil error, the
	// request is aborted with the provided error.
	// If Proxy is nil or returns a nil *URL, no proxy is used.
	Proxy func(*Request) (*url.URL, error)

	// Dial specifies the dial function for creating TCP
	// connections.
	// If Dial is nil, net.Dial is used.
	Dial func(network, addr string) (net.Conn, error)

	// TLSClientConfig specifies the TLS configuration to use with
	// tls.Client. If nil, the default configuration is used.
	TLSClientConfig *tls.Config

	// TLSHandshakeTimeout specifies the maximum amount of time waiting to
	// wait for a TLS handshake. Zero means no timeout.
	TLSHandshakeTimeout time.Duration

	// DisableKeepAlives, if true, prevents re-use of TCP connections
	// between different HTTP requests.
	DisableKeepAlives bool

	// DisableCompression, if true, prevents the Transport from
	// requesting compression with an "Accept-Encoding: gzip"
	// request header when the Request contains no existing
	// Accept-Encoding value. If the Transport requests gzip on
	// its own and gets a gzipped response, it's transparently
	// decoded in the Response.Body. However, if the user
	// explicitly requested gzip it is not automatically
	// uncompressed.
	DisableCompression bool

	// MaxIdleConnsPerHost, if non-zero, controls the maximum idle
	// (keep-alive) to keep per-host.  If zero,
	// DefaultMaxIdleConnsPerHost is used.
	MaxIdleConnsPerHost int

	// ResponseHeaderTimeout, if non-zero, specifies the amount of
	// time to wait for a server's response headers after fully
	// writing the request (including its body, if any). This
	// time does not include the time to read the response body.
	ResponseHeaderTimeout time.Duration
	// contains filtered or unexported fields
}