gecko-dev/netwerk/base/public/nsIChannel.idl

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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
*
* The contents of this file are subject to the Netscape Public
* License Version 1.1 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.mozilla.org/NPL/
*
* Software distributed under the License is distributed on an "AS
* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
* implied. See the License for the specific language governing
* rights and limitations under the License.
*
* The Original Code is mozilla.org code.
*
* The Initial Developer of the Original Code is Netscape
* Communications Corporation. Portions created by Netscape are
* Copyright (C) 1998 Netscape Communications Corporation. All
* Rights Reserved.
*
* Contributor(s):
*/
#include "nsIRequest.idl"
interface nsIURI;
interface nsIInputStream;
interface nsIOutputStream;
interface nsIStreamObserver;
interface nsIStreamListener;
interface nsIStreamProvider;
interface nsILoadGroup;
interface nsIInterfaceRequestor;
interface nsIStreamIO;
typedef unsigned long nsLoadFlags;
/**
* The nsIChannel interface allows the user to construct get requests for
* specific protocols, and manage them in a uniform way. Once a channel
* is created (via nsIIOService::NewChannel), parameters for that request
* may be set by using the channel attributes, or by QueryInterfacing to a
* subclass of nsIChannel for protocol-specific parameters. Then the actual
* request can be issued in one of several ways:
*
* - AsyncOpen is used for asynchronous reading, calling back the
* user's stream listener.
* - Open is used for synchronous read on the underlying channel.
*
* After a request has been completed, the channel is still valid for
* accessing protocol-specific results. For example, QueryInterfacing to
* nsIHTTPChannel allows response headers to be retrieved that result from
* http transactions.
*
*/
[scriptable, uuid(1788e79e-f947-11d3-8cda-0060b0fc14a3)]
interface nsIChannel : nsIRequest
{
////////////////////////////////////////////////////////////////////////////
// nsIChannel accessors
////////////////////////////////////////////////////////////////////////////
/**
* Returns the original URL used to construct the channel.
* This is used in the case of a redirect or URI "resolution" (e.g.
* resolving a resource: URI to a file: URI) so that the original
* pre-redirect URI can still be obtained.
*
* Note that this is distinctly different from the http referrer
* (referring URI) which is typically the page that contained the
* original URI (accessible from nsIHTTPChannel).
*/
attribute nsIURI originalURI;
/**
* Returns the URL to which the channel currently refers. If a redirect
* or URI resolution occurs, this accessor returns the current location
* to which the channel is referring.
*/
attribute nsIURI URI;
/**
* Accesses the owner corresponding to the entity that is
* responsible for this channel. Used by security code to grant
* or deny privileges to mobile code loaded from this channel.
*
* Note: This is a strong reference to the owner, so if the owner is also
* holding a pointer to the channel, care must be taken to explicitly drop
* its reference to the channel -- otherwise a leak will result.
*/
attribute nsISupports owner;
/**
* Accesses the load group in which the channel is a currently a member.
*/
attribute nsILoadGroup loadGroup;
/**
* Accesses the load attributes for the channel. E.g. setting the load
* attributes with the LOAD_QUIET bit set causes the loading process to
* not deliver status notifications to the program performing the load,
* and to not contribute to keeping any nsILoadGroup it may be contained
* in from firing its OnLoadComplete notification.
*/
attribute nsLoadFlags loadAttributes;
/**
* Accesses the capabilities callbacks of the channel. This is set by clients
* who wish to provide a means to receive progress, status and protocol-specific
* notifications.
*/
attribute nsIInterfaceRequestor notificationCallbacks;
/**
* Any security information about this channel. This can be null.
*/
readonly attribute nsISupports securityInfo;
/**
* Returns the content MIME type of the channel if available. Note that the
* content type can often be wrongly specified (wrong file extension, wrong
* MIME type, wrong document type stored on a server, etc.) and the caller
* most likely wants to verify with the actual data.
*/
attribute string contentType;
/**
* Returns the length of the data associated with the channel if available.
* If the length is unknown then -1 is returned.
*/
attribute long contentLength;
/**
* Open is used for synchronous read on the channel.
**/
nsIInputStream open();
/** AsyncOpen is used for asynchronous reading, calling back the
* user's stream listener.
**/
void asyncOpen(in nsIStreamListener listener, in nsISupports ctxt);
////////////////////////////////////////////////////////////////////////////
// Below are Load attribute flags which may be or'd together.
////////////////////////////////////////////////////////////////////////////
/**
* Note that more will follow for each protocol's implementation of a channel,
* although channel writers have to be careful to not let the flag bits
* overlap. Otherwise, users won't be able to create a single flag word
* of load attributes that applies to a number of different channel types.
*/
/**
* No special load attributes -- use defaults:
*/
const unsigned long LOAD_NORMAL = 0;
/**
* Don't deliver status notifications to the nsIProgressEventSink, or keep
* this load from completing the nsILoadGroup it may belong to:
*/
const unsigned long LOAD_BACKGROUND = 1 << 0;
/**
* Used exclusively by the uriloader and docshell to indicate whether or
* not this channel corresponds to the toplevel document.
*/
const unsigned long LOAD_DOCUMENT_URI = 1 << 1;
/**
* If the end consumer for this load has been retargeted after discovering
* it's content, this flag will be set:
*/
const unsigned long LOAD_RETARGETED_DOCUMENT_URI = 1 << 2;
////////////////////////////////////////////////////////////////////////////
/**
* The following flags control caching behavior. Not all protocols pay
* attention to all these flags, but they are applicable to more than one
* protocol, so they are defined here.
*/
/**
* Don't store data in the disk cache. This can be used to preserve
* privacy, e.g. so that no https transactions are recorded, or to avoid
* caching a stream to disk that is already stored in a local file,
* e.g. the mailbox: protocol.
*/
const unsigned long INHIBIT_PERSISTENT_CACHING = 1 << 8;
/**
* Force an end-to-end download of content data from the origin server (and
* any intervening proxies that sit between it and the client), e.g. this
* flag is used for a shift-reload.
*/
const unsigned long FORCE_RELOAD = 1 << 9;
/**
* Force revalidation with server (or proxy) to verify that cached content
* is up-to-date, e.g. by comparing last-modified date on server with that
* of the cached version. For example, this flag is used when the reload
* button is pressed.
*/
const unsigned long FORCE_VALIDATION = 1 << 10;
/**
* If the CACHE_AS_FILE flag is set, any stream content is stored in the
* cache as a single disk file. Content will not be cached in the memory
* cache nor will it be stored in any other type of cache, e.g. a flat-file
* cache database. This is used to implement the jar protocol handler and
* to provide the stream-as-file semantics required by the classic browser
* plugin API.
*/
const unsigned long CACHE_AS_FILE = 1 << 11;
/**
* When cache data is potentially out of date, it can be revalidated with
* the origin server to see if the content needs to be reloaded. The
* following four flags control how often this validation occurs.
* These flags are commonly used for "normal" loading. Note that
* the VALIDATE_HEURISTICALLY and VALIDATE_ONCE_PER_SESSION flags can be
* combined to validate heuristically but no more than once per session.
*/
const unsigned long VALIDATE_NEVER = 1 << 12;
const unsigned long VALIDATE_ALWAYS = 1 << 13;
const unsigned long VALIDATE_ONCE_PER_SESSION = 1 << 14;
const unsigned long VALIDATE_HEURISTICALLY = 1 << 15;
/**
* This flag is used to tell the webshell not to cancel the load in cases
* when the channel is receiving multipart/replace document
*/
const unsigned long LOAD_REPLACE = 1 << 16;
};