http

type CacheControlPublicHandler ¶

type CacheControlPublicHandler struct {
	http.Handler
}

CacheControlPublicHandler is a net/http.Handler implementation that sets the "Cache-Control" header to "public".

It only sets the header if the status code is StatusOK/204 or StatusNotModified/304.

func (h *CacheControlPublicHandler) ServeHTTP(rw http.ResponseWriter, req *http.Request)

type Error ¶

type Error struct {
	Code int
	Text string
}

Error is a HTTP error.

It is supported by Handler.

func NewErrorDefaultText(code int) *Error

func (err *Error) Error() string

type ExpiresHandler ¶

type ExpiresHandler struct {
	http.Handler
	Expires time.Duration
}

ExpiresHandler is a net/http.Handler implementation that sets the "Expires" header.

It only sets the header if the status code is StatusOK/204 or StatusNotModified/304.

func (eh *ExpiresHandler) ServeHTTP(rw http.ResponseWriter, req *http.Request)

type Handler ¶

type Handler struct {
	// Parser parses the HTTP request and fills the Params.
	Parser Parser

	// Server handles the image request.
	Server imageserver.Server

	// ETagFunc is an optional function that returns the ETag value for the given Params.
	// See https://en.wikipedia.org/wiki/HTTP_ETag .
	// The returned value must not be enclosed in quotes (they are added automatically).
	ETagFunc func(params imageserver.Params) string

	// ErrorFunc is an optional function that is called if there is an internal error.
	ErrorFunc func(err error, req *http.Request)
}

Handler is a net/http.Handler implementation that wraps a imageserver.Server.

Supported methods are: GET and HEAD. Other method will return a StatusMethodNotAllowed/405 response.

It supports ETag/If-None-Match headers and returns a StatusNotModified/304 response accordingly. But it doesn't check if the Image really exists (the Server is not called).

Steps:

• Parse the HTTP request, and fill the Params.
• If the given If-None-Match header matches the ETag, return a StatusNotModified/304 response.
• Call the Server and get the Image.
• Return a StatusOK/200 response containing the Image.

Errors (returned by Parser or Server):

• *imageserver/http.Error will return a response with the given status code and message.
• *imageserver.ParamError will return a StatusBadRequest/400 response, with a message including the resolved HTTP param.
• *imageserver.ImageError will return a StatusBadRequest/400 response, with the given message.
• Other error will return a StatusInternalServerError/500 response, and ErrorFunc will be called.

Returned headers:

• Content-Type is set for StatusOK/200 response, and contains "image/{Image.Format}".
• Content-Length is set for StatusOK/200 response, and contains the Image size.
• ETag is set for StatusOK/200 and StatusNotModified/304 response, and contains the ETag value.

func (handler *Handler) ServeHTTP(rw http.ResponseWriter, req *http.Request)

type ListParser ¶

type ListParser []Parser

ListParser is a Parser implementation that wraps a list of Parser.

func (lp ListParser) Parse(req *http.Request, params imageserver.Params) error

func (lp ListParser) Resolve(param string) string

type Parser ¶

type Parser interface {
	// Parse parses a *net/http.Request and fill Params.
	Parse(*http.Request, imageserver.Params) error

	// Resolve resolves an internal param to a HTTP param.
	// It returns the resolved HTTP param, or an empty string if it can not be resolved.
	// It is used by Handler to generate errors messages.
	Resolve(param string) (httpParam string)
}

Parser represents a *net/http.Request parser.

type SourceParser ¶

type SourceParser struct{}

SourceParser is a Parser implementation that takes the "source" param from the HTTP URL query.

func (parser *SourceParser) Parse(req *http.Request, params imageserver.Params) error

func (parser *SourceParser) Resolve(param string) string

type SourcePathParser ¶

type SourcePathParser struct{}

SourcePathParser is a Parser implementation that takes the "source" param from the HTTP URL path.

func (parser *SourcePathParser) Parse(req *http.Request, params imageserver.Params) error

func (parser *SourcePathParser) Resolve(param string) string

type SourcePrefixParser ¶

type SourcePrefixParser struct {
	Parser
	Prefix string
}

SourcePrefixParser is a Parser implementation that adds a prefix to the "source" param.

func (ps *SourcePrefixParser) Parse(req *http.Request, params imageserver.Params) error

type SourceTransformParser ¶

type SourceTransformParser struct {
	Parser
	Transform func(source string) string
}

SourceTransformParser is a Parser implementation that transforms the "source" param.

func (ps *SourceTransformParser) Parse(req *http.Request, params imageserver.Params) error