svn merge -r114679:114681 svn+ssh://svn.lindenlab.com/svn/linden/branches/event-system/event-system-7 svn+ssh://svn.lindenlab.com/svn/linden/branches/event-system/event-system-8

1 files changed, 146 insertions, 0 deletions

diff --git a/indra/llmessage/llsdmessage.h b/indra/llmessage/llsdmessage.h
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+++ b/indra/llmessage/llsdmessage.h
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+/**
+ * @file   llsdmessage.h
+ * @author Nat Goodspeed
+ * @date   2008-10-30
+ * @brief  API intended to unify sending capability, UDP and TCP messages:
+ *         https://wiki.lindenlab.com/wiki/Viewer:Messaging/Messaging_Notes
+ * 
+ * $LicenseInfo:firstyear=2008&license=viewergpl$
+ * Copyright (c) 2008, Linden Research, Inc.
+ * $/LicenseInfo$
+ */
+
+#if ! defined(LL_LLSDMESSAGE_H)
+#define LL_LLSDMESSAGE_H
+
+#include "llerror.h"                // LOG_CLASS()
+#include "llevents.h"               // LLEventPumps
+#include "llhttpclient.h"
+#include <string>
+#include <stdexcept>
+
+class LLSD;
+
+/**
+ * Class managing the messaging API described in
+ * https://wiki.lindenlab.com/wiki/Viewer:Messaging/Messaging_Notes
+ */
+class LLSDMessage
+{
+    LOG_CLASS(LLSDMessage);
+
+public:
+    LLSDMessage();
+
+    /// Exception if you specify arguments badly
+    struct ArgError: public std::runtime_error
+    {
+        ArgError(const std::string& what):
+            std::runtime_error(std::string("ArgError: ") + what) {}
+    };
+
+    /**
+     * The response idiom used by LLSDMessage -- LLEventPump names on which to
+     * post reply or error -- is designed for the case in which your
+     * reply/error handlers are methods on the same class as the method
+     * sending the message. Any state available to the sending method that
+     * must be visible to the reply/error methods can conveniently be stored
+     * on that class itself, if it's not already.
+     *
+     * The LLHTTPClient::Responder idiom requires a separate instance of a
+     * separate class so that it can dispatch to the code of interest by
+     * calling canonical virtual methods. Interesting state must be copied
+     * into that new object. 
+     *
+     * With some trepidation, because existing response code is packaged in
+     * LLHTTPClient::Responder subclasses, we provide this adapter class
+     * <i>for transitional purposes only.</i> Instantiate a new heap
+     * ResponderAdapter with your new LLHTTPClient::ResponderPtr. Pass
+     * ResponderAdapter::getReplyName() and/or getErrorName() in your
+     * LLSDMessage (or LLViewerRegion::getCapAPI()) request event. The
+     * ResponderAdapter will call the appropriate Responder method, then
+     * @c delete itself.
+     */
+    class ResponderAdapter
+    {
+    public:
+        /**
+         * Bind the new LLHTTPClient::Responder subclass instance.
+         *
+         * Passing the constructor a name other than the default is only
+         * interesting if you suspect some usage will lead to an exception or
+         * log message.
+         */
+        ResponderAdapter(LLHTTPClient::ResponderPtr responder,
+                         const std::string& name="ResponderAdapter");
+
+        /// EventPump name on which LLSDMessage should post reply event
+        std::string getReplyName() const { return mReplyPump.getName(); }
+        /// EventPump name on which LLSDMessage should post error event
+        std::string getErrorName() const { return mErrorPump.getName(); }
+
+    private:
+        // We have two different LLEventStreams, though we route them both to
+        // the same listener, so that we can bind an extra flag identifying
+        // which case (reply or error) reached that listener.
+        bool listener(const LLSD&, bool success);
+
+        LLHTTPClient::ResponderPtr mResponder;
+        LLEventStream mReplyPump, mErrorPump;
+    };
+
+    /**
+     * Force our implementation file to be linked with caller. The .cpp file
+     * contains a static instance of this class, which must be linked into the
+     * executable to support the canonical listener. But since the primary
+     * interface to that static instance is via a named LLEventPump rather
+     * than by direct reference, the linker doesn't necessarily perceive the
+     * necessity to bring in the translation unit. Referencing this dummy
+     * method forces the issue.
+     */
+    static void link();
+
+private:
+    friend class LLCapabilityListener;
+    /// Responder used for internal purposes by LLSDMessage and
+    /// LLCapabilityListener. Others should use higher-level APIs.
+    class EventResponder: public LLHTTPClient::Responder
+    {
+    public:
+        /**
+         * LLHTTPClient::Responder that dispatches via named LLEventPump instances.
+         * We bind LLEventPumps, even though it's an LLSingleton, for testability.
+         * We bind the string names of the desired LLEventPump instances rather
+         * than actually obtain()ing them so we only obtain() the one we're going
+         * to use. If the caller doesn't bother to listen() on it, the other pump
+         * may never materialize at all.
+         * @a target and @a message are only to clarify error processing.
+         * For a capability message, @a target should be the region description,
+         * @a message should be the capability name.
+         * For a service with a visible URL, pass the URL as @a target and the HTTP verb
+         * (e.g. "POST") as @a message.
+         */
+        EventResponder(LLEventPumps& pumps,
+                       const std::string& target, const std::string& message,
+                       const std::string& replyPump, const std::string& errorPump):
+            mPumps(pumps),
+            mTarget(target),
+            mMessage(message),
+            mReplyPump(replyPump),
+            mErrorPump(errorPump)
+        {}
+    
+        virtual void result(const LLSD& data);
+        virtual void error(U32 status, const std::string& reason, const LLSD& content);
+    
+    private:
+        LLEventPumps& mPumps;
+        const std::string mTarget, mMessage, mReplyPump, mErrorPump;
+    };
+
+private:
+    bool httpListener(const LLSD&);
+    LLEventStream mEventPump;
+};
+
+#endif /* ! defined(LL_LLSDMESSAGE_H) */