/** * @file httprequest.h * @brief Public-facing declarations for HttpRequest class * * $LicenseInfo:firstyear=2012&license=viewerlgpl$ * Second Life Viewer Source Code * Copyright (C) 2012-2014, Linden Research, Inc. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; * version 2.1 of the License only. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA * * Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA * $/LicenseInfo$ */ #ifndef _LLCORE_HTTP_REQUEST_H_ #define _LLCORE_HTTP_REQUEST_H_ #include "httpcommon.h" #include "httphandler.h" namespace LLCore { class HttpRequestQueue; class HttpReplyQueue; class HttpService; class HttpOptions; class HttpHeaders; class HttpOperation; class BufferArray; /// HttpRequest supplies the entry into the HTTP transport /// services in the LLCore libraries. Services provided include: /// /// - Some, but not all, global initialization of libcurl. /// - Starting asynchronous, threaded HTTP requests. /// - Definition of policy classes affect request handling. /// - Utilities to control request options and headers /// /// Requests /// /// The class supports the current HTTP request operations: /// /// - requestGetByteRange: GET with Range header for a single range of bytes /// - requestGet: /// - requestPost: /// - requestPut: /// /// Policy Classes /// /// /// /// Usage /// /// /// /// Threading: An instance may only be used by one application/ /// consumer thread. But a thread may have as many instances of /// this as it likes. /// /// Allocation: Not refcounted, may be stack allocated though that /// hasn't been tested. Queued requests can still run and any /// queued replies will keep refcounts to the reply queue leading /// to memory leaks. /// /// @pre Before using this class (static or instances), some global /// initialization is required. See @see httpcommon.h for more information. /// /// @nosubgrouping /// class HttpRequest { public: HttpRequest(); virtual ~HttpRequest(); private: HttpRequest(const HttpRequest &); // Disallowed void operator=(const HttpRequest &); // Disallowed public: typedef unsigned int policy_t; typedef unsigned int priority_t; typedef boost::shared_ptr ptr_t; public: /// @name PolicyMethods /// @{ /// Represents a default, catch-all policy class that guarantees /// eventual service for any HTTP request. static const policy_t DEFAULT_POLICY_ID = 0; static const policy_t INVALID_POLICY_ID = 0xFFFFFFFFU; static const policy_t GLOBAL_POLICY_ID = 0xFFFFFFFEU; /// Create a new policy class into which requests can be made. /// /// All class creation must occur before threads are started and /// transport begins. Policy classes are limited to a small value. /// Currently that limit is the default class + 1. /// /// @return If positive, the policy_id used to reference /// the class in other methods. If 0, requests /// for classes have exceeded internal limits /// or caller has tried to create a class after /// threads have been started. Caller must fallback /// and recover. /// static policy_t createPolicyClass(); enum EPolicyOption { /// Maximum number of connections the library will use to /// perform operations. This is somewhat soft as the underlying /// transport will cache some connections (up to 5). /// A long value setting the maximum number of connections /// allowed over all policy classes. Note that this will be /// a somewhat soft value. There may be an additional five /// connections per policy class depending upon runtime /// behavior. /// /// Both global and per-class PO_CONNECTION_LIMIT, /// Limits the number of connections used for a single /// literal address/port pair within the class. /// /// Per-class only PO_PER_HOST_CONNECTION_LIMIT, /// String containing a system-appropriate directory name /// where SSL certs are stored. /// /// Global only PO_CA_PATH, /// String giving a full path to a file containing SSL certs. /// /// Global only PO_CA_FILE, /// String of host/port to use as simple HTTP proxy. This is /// going to change in the future into something more elaborate /// that may support richer schemes. /// /// Global only PO_HTTP_PROXY, /// Long value that if non-zero enables the use of the /// traditional LLProxy code for http/socks5 support. If /// enabled, has priority over GP_HTTP_PROXY. /// /// Global only PO_LLPROXY, /// Long value setting the logging trace level for the /// library. Possible values are: /// 0 - No tracing (default) /// 1 - Basic tracing of request start, stop and major events. /// 2 - Connection, header and payload size information from /// HTTP transactions. /// 3 - Partial logging of payload itself. /// /// These values are also used in the trace modes for /// individual requests in HttpOptions. Also be aware that /// tracing tends to impact performance of the viewer. /// /// Global only PO_TRACE, /// If greater than 1, suitable requests are allowed to /// pipeline on their connections when they ask for it. /// Value gives the maximum number of outstanding requests /// on a connection. /// /// There is some interaction between PO_CONNECTION_LIMIT, /// PO_PER_HOST_CONNECTION_LIMIT, and PO_PIPELINING_DEPTH. /// When PIPELINING_DEPTH is 0 or 1 (no pipelining), this /// library manages connection lifecycle and honors the /// PO_CONNECTION_LIMIT setting as the maximum in-flight /// request limit. Libcurl itself may be caching additional /// connections under its connection cache policy. /// /// When PIPELINING_DEPTH is 2 or more, libcurl performs /// connection management and both PO_CONNECTION_LIMIT and /// PO_PER_HOST_CONNECTION_LIMIT should be set and non-zero. /// In this case (as of libcurl 7.37.0), libcurl will /// open new connections in preference to pipelining, up /// to the above limits at which time pipelining begins. /// And as usual, an additional cache of open but inactive /// connections may still be maintained within libcurl. /// For SL, a good rule-of-thumb is to set /// PO_PER_HOST_CONNECTION_LIMIT to the user-visible /// concurrency value and PO_CONNECTION_LIMIT to twice /// that for baked texture loads and region crossings where /// additional connection load will be tolerated. If /// either limit is 0, libcurl will prefer pipelining /// over connection creation, which is still interesting, /// but won't be pursued at this time. /// /// Per-class only PO_PIPELINING_DEPTH, /// Controls whether client-side throttling should be /// performed on this policy class. Positive values /// enable throttling and specify the request rate /// (requests per second) that should be targeted. /// A value of zero, the default, specifies no throttling. /// /// Per-class only PO_THROTTLE_RATE, /// Controls the callback function used to control SSL CTX /// certificate verification. /// /// Global only PO_SSL_VERIFY_CALLBACK, PO_LAST // Always at end }; /// Prototype for policy based callbacks. The callback methods will be executed /// on the worker thread so no modifications should be made to the HttpHandler object. typedef HttpStatus(*policyCallback)(const std::string &, HttpHandler const * const, void *); /// Set a policy option for a global or class parameter at /// startup time (prior to thread start). /// /// @param opt Enum of option to be set. /// @param pclass For class-based options, the policy class ID to /// be changed. For globals, specify GLOBAL_POLICY_ID. /// @param value Desired value of option. /// @param ret_value Pointer to receive effective set value /// if successful. May be NULL if effective /// value not wanted. /// @return Standard status code. static HttpStatus setStaticPolicyOption(EPolicyOption opt, policy_t pclass, long value, long * ret_value); static HttpStatus setStaticPolicyOption(EPolicyOption opt, policy_t pclass, const std::string & value, std::string * ret_value); static HttpStatus setStaticPolicyOption(EPolicyOption opt, policy_t pclass, policyCallback value, policyCallback * ret_value);; /// Set a parameter on a class-based policy option. Calls /// made after the start of the servicing thread are /// not honored and return an error status. /// /// @param opt Enum of option to be set. /// @param pclass For class-based options, the policy class ID to /// be changed. Ignored for globals but recommend /// using INVALID_POLICY_ID in this case. /// @param value Desired value of option. /// @return Handle of dynamic request. Use @see getStatus() if /// the returned handle is invalid. HttpHandle setPolicyOption(EPolicyOption opt, policy_t pclass, long value, HttpHandler * handler); HttpHandle setPolicyOption(EPolicyOption opt, policy_t pclass, const std::string & value, HttpHandler * handler); /// @} /// @name RequestMethods /// /// @{ /// Some calls expect to succeed as the normal part of operation and so /// return a useful value rather than a status. When they do fail, the /// status is saved and can be fetched with this method. /// /// @return Status of the failing method invocation. If the /// preceding call succeeded or other HttpStatus /// returning calls immediately preceded this method, /// the returned value may not be reliable. /// HttpStatus getStatus() const; /// Queue a full HTTP GET request to be issued for entire entity. /// The request is queued and serviced by the working thread and /// notification of completion delivered to the optional HttpHandler /// argument during @see update() calls. /// /// With a valid handle returned, it can be used to reference the /// request in other requests (like cancellation) and will be an /// argument when any HttpHandler object is invoked. /// /// Headers supplied by default: /// - Connection: keep-alive /// - Accept: */* /// - Accept-Encoding: deflate, gzip /// - Keep-alive: 300 /// - Host: /// /// Some headers excluded by default: /// - Pragma: /// - Cache-control: /// - Range: /// - Transfer-Encoding: /// - Referer: /// /// @param policy_id Default or user-defined policy class under /// which this request is to be serviced. /// @param priority Standard priority scheme inherited from /// Indra code base (U32-type scheme). /// @param url URL with any encoded query parameters to /// be accessed. /// @param options Optional instance of an HttpOptions object /// to provide additional controls over the request /// function for this request only. Any such /// object then becomes shared-read across threads /// and no code should modify the HttpOptions /// instance. /// @param headers Optional instance of an HttpHeaders object /// to provide additional and/or overridden /// headers for the request. As with options, /// the instance becomes shared-read across threads /// and no code should modify the HttpHeaders /// instance. /// @param handler Optional pointer to an HttpHandler instance /// whose onCompleted() method will be invoked /// during calls to update(). This is a non- /// reference-counted object which would be a /// problem for shutdown and other edge cases but /// the pointer is only dereferenced during /// calls to update(). /// /// @return The handle of the request if successfully /// queued or LLCORE_HTTP_HANDLE_INVALID if the /// request could not be queued. In the latter /// case, @see getStatus() will return more info. /// HttpHandle requestGet(policy_t policy_id, priority_t priority, const std::string & url, HttpOptions * options, HttpHeaders * headers, HttpHandler * handler); /// Queue a full HTTP GET request to be issued with a 'Range' header. /// The request is queued and serviced by the working thread and /// notification of completion delivered to the optional HttpHandler /// argument during @see update() calls. /// /// With a valid handle returned, it can be used to reference the /// request in other requests (like cancellation) and will be an /// argument when any HttpHandler object is invoked. /// /// Headers supplied by default: /// - Connection: keep-alive /// - Accept: */* /// - Accept-Encoding: deflate, gzip /// - Keep-alive: 300 /// - Host: /// - Range: (will be omitted if offset == 0 and len == 0) /// /// Some headers excluded by default: /// - Pragma: /// - Cache-control: /// - Transfer-Encoding: /// - Referer: /// /// @param policy_id @see requestGet() /// @param priority " /// @param url " /// @param offset Offset of first byte into resource to be returned. /// @param len Count of bytes to be returned /// @param options @see requestGet() /// @param headers " /// @param handler " /// @return " /// HttpHandle requestGetByteRange(policy_t policy_id, priority_t priority, const std::string & url, size_t offset, size_t len, HttpOptions * options, HttpHeaders * headers, HttpHandler * handler); /// Queue a full HTTP POST. Query arguments and body may /// be provided. Caller is responsible for escaping and /// encoding and communicating the content types. /// /// Headers supplied by default: /// - Connection: keep-alive /// - Accept: */* /// - Accept-Encoding: deflate, gzip /// - Keep-Alive: 300 /// - Host: /// - Content-Length: /// - Content-Type: application/x-www-form-urlencoded /// /// Some headers excluded by default: /// - Pragma: /// - Cache-Control: /// - Transfer-Encoding: ... chunked ... /// - Referer: /// - Content-Encoding: /// - Expect: /// /// @param policy_id @see requestGet() /// @param priority " /// @param url " /// @param body Byte stream to be sent as the body. No /// further encoding or escaping will be done /// to the content. /// @param options @see requestGet()K(optional) /// @param headers " /// @param handler " /// @return " /// HttpHandle requestPost(policy_t policy_id, priority_t priority, const std::string & url, BufferArray * body, HttpOptions * options, HttpHeaders * headers, HttpHandler * handler); /// Queue a full HTTP PUT. Query arguments and body may /// be provided. Caller is responsible for escaping and /// encoding and communicating the content types. /// /// Headers supplied by default: /// - Connection: keep-alive /// - Accept: */* /// - Accept-Encoding: deflate, gzip /// - Keep-Alive: 300 /// - Host: /// - Content-Length: /// /// Some headers excluded by default: /// - Pragma: /// - Cache-Control: /// - Transfer-Encoding: ... chunked ... /// - Referer: /// - Content-Encoding: /// - Expect: /// - Content-Type: /// /// @param policy_id @see requestGet() /// @param priority " /// @param url " /// @param body Byte stream to be sent as the body. No /// further encoding or escaping will be done /// to the content. /// @param options @see requestGet()K(optional) /// @param headers " /// @param handler " /// @return " /// HttpHandle requestPut(policy_t policy_id, priority_t priority, const std::string & url, BufferArray * body, HttpOptions * options, HttpHeaders * headers, HttpHandler * handler); /// Queue a NoOp request. /// The request is queued and serviced by the working thread which /// immediately processes it and returns the request to the reply /// queue. /// /// @param handler @see requestGet() /// @return " /// HttpHandle requestNoOp(HttpHandler * handler); /// While all the heavy work is done by the worker thread, notifications /// must be performed in the context of the application thread. These /// are done synchronously during calls to this method which gives the /// library control so notification can be performed. Application handlers /// are expected to return 'quickly' and do any significant processing /// outside of the notification callback to onCompleted(). /// /// @param usecs Maximum number of wallclock microseconds to /// spend in the call. As hinted at above, this /// is partly a function of application code so it's /// a soft limit. A '0' value will run without /// time limit until everything queued has been /// delivered. /// /// @return Standard status code. HttpStatus update(long usecs); /// @} /// @name RequestMgmtMethods /// /// @{ HttpHandle requestCancel(HttpHandle request, HttpHandler *); /// Request that a previously-issued request be reprioritized. /// The status of whether the change itself succeeded arrives /// via notification. /// /// @param request Handle of previously-issued request to /// be changed. /// @param priority New priority value. /// @param handler @see requestGet() /// @return " /// HttpHandle requestSetPriority(HttpHandle request, priority_t priority, HttpHandler * handler); /// @} /// @name UtilityMethods /// /// @{ /// Initialization method that needs to be called before queueing any /// requests. Doesn't start the worker thread and may be called befoer /// or after policy setup. static HttpStatus createService(); /// Mostly clean shutdown of services prior to exit. Caller is expected /// to have stopped a running worker thread before calling this. static HttpStatus destroyService(); /// Called once after @see createService() to start the worker thread. /// Stopping the thread is achieved by requesting it via @see requestStopThread(). /// May be called before or after requests are issued. static HttpStatus startThread(); /// Queues a request to the worker thread to have it stop processing /// and exit (without exiting the program). When the operation is /// picked up by the worker thread, it immediately processes it and /// begins detaching from refcounted resources like request and /// reply queues and then returns to the host OS. It *does* queue a /// reply to give the calling application thread a notification that /// the operation has been performed. /// /// @param handler (optional) /// @return The handle of the request if successfully /// queued or LLCORE_HTTP_HANDLE_INVALID if the /// request could not be queued. In the latter /// case, @see getStatus() will return more info. /// As the request cannot be cancelled, the handle /// is generally not useful. /// HttpHandle requestStopThread(HttpHandler * handler); /// Queue a Spin request. /// DEBUG/TESTING ONLY. This puts the worker into a CPU spin for /// test purposes. /// /// @param mode 0 for hard spin, 1 for soft spin /// @return Standard handle return cases. /// HttpHandle requestSpin(int mode); /// @} protected: void generateNotification(HttpOperation * op); private: /// @name InstanceData /// /// @{ HttpStatus mLastReqStatus; HttpReplyQueue * mReplyQueue; HttpRequestQueue * mRequestQueue; /// @} // ==================================== /// @name GlobalState /// /// @{ /// /// Must be established before any threading is allowed to /// start. /// /// @} // End Global State // ==================================== }; // end class HttpRequest } // end namespace LLCore #endif // _LLCORE_HTTP_REQUEST_H_