/[svn]/linuxsampler/trunk/src/scriptvm/ScriptVM.h
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revision 2581 by schoenebeck, Fri May 30 12:48:05 2014 UTC revision 2727 by schoenebeck, Tue Mar 31 17:46:11 2015 UTC
# Line 1  Line 1 
1  /*  /*
2   * Copyright (c) 2014 Christian Schoenebeck   * Copyright (c) 2014-2015 Christian Schoenebeck
3   *   *
4   * http://www.linuxsampler.org   * http://www.linuxsampler.org
5   *   *
# Line 20  Line 20 
20  namespace LinuxSampler {  namespace LinuxSampler {
21    
22      class ParserContext;      class ParserContext;
23        class ExecContext;
24    
25        /** @brief Core virtual machine for real-time instrument scripts.
26         *
27         * This is the core of the virtual machine and main entry class, used for
28         * running real-time instrument scripts. This VM core encompasses the
29         * instrument script parser, generalized virtual machine and very generic
30         * built-in script functions. Thus this class only provides functionalities
31         * which are yet independent of the actual purpose the virtual machine is
32         * going to be used for.
33         *
34         * The actual use case specific functionalites (i.e. MIDI processing) is
35         * then implemented by sampler engines' VM classes which are derived from
36         * this generalized ScriptVM class.
37         *
38         * Typical usage of this class:
39         *
40         * - 1. Create an instance of this ScriptVM class (or of one of its deriving
41         *      classes).
42         * - 2. Load a script by passing its source code to method loadScript(),
43         *      which will return the parsed represenation of the script.
44         * - 3. Create a VM execution context by calling createExecContext().
45         * - 4. Execute the script by calling method exec().
46         *
47         * This class is re-entrant safe, but not thread safe. So you can share one
48         * instance of this class between multiple (native) threads, but you @b must
49         * @b not execute methods of the same class instance simultaniously from
50         * different (native) threads. If you want to execute scripts simultaniously
51         * multi threaded, then create a separate ScriptVM instance for each
52         * (native) thread. Also note that one VMParserContext instance is tied to
53         * exactly one ScriptVM instance. So you @b must @b not create a
54         * VMParserContext with one ScriptVM instance and run it with a different
55         * ScriptVM instance!
56         */
57      class ScriptVM : public VMFunctionProvider {      class ScriptVM : public VMFunctionProvider {
58      public:      public:
59          ScriptVM();          ScriptVM();
60          virtual ~ScriptVM();          virtual ~ScriptVM();
61          void loadScript(const String& s);  
62          void loadScript(std::istream* is);          /**
63          std::vector<ParserIssue> issues() const;           * Loads a script given by its source code (passed as argument @a s to
64          std::vector<ParserIssue> errors() const;           * this method) and returns the parsed represenation of that script.
65          std::vector<ParserIssue> warnings() const;           * After calling this method you must check the returned VMParserContext
66          void dumpParsedScript();           * object whether there had been any parser errors. If there were no
67          VMExecContext* createExecContext();           * parser errors, you may pass the VMParserContext object to method
68          VMEventHandler* eventHandler(uint index);           * exec() for actually executing the script.
69          VMEventHandler* eventHandlerByName(const String& name);           *
70          VMExecStatus_t exec(VMEventHandler* handler, VMExecContext* execContex);           * @param s - entire source code of the script to be loaded
71          VMExecContext* currentVMExecContext();           * @returns parsed represenation of the script
72          VMFunction* functionByName(const String& name);           */
73            VMParserContext* loadScript(const String& s);
74    
75            /**
76             * Same as above's loadScript() method, but this one reads the script's
77             * source code from an input stream object (i.e. stdin or a file).
78             *
79             * @param is - input stream from which the entire source code of the
80             *             script is to be read and loaded from
81             * @returns parsed represenation of the script
82             */
83            VMParserContext* loadScript(std::istream* is);
84    
85            /**
86             * Dumps the translated tree of the already parsed script, given by
87             * argument @a context, to stdout. This method is for debugging purposes
88             * only.
89             *
90             * @param context - parsed represenation of the script
91             */
92            void dumpParsedScript(VMParserContext* context);
93    
94            /**
95             * Creates a so called VM exceution context for a specific, already
96             * parsed script (provided by argument @a parserContext). Due to the
97             * general real-time design of this virtual machine, the VM execution
98             * context differs for every script. So you must (re)create the
99             * execution context for each script being loaded.
100             */
101            VMExecContext* createExecContext(VMParserContext* parserContext);
102    
103            /**
104             * Execute a script by virtual machine. Since scripts are event-driven,
105             * you actually execute only one specific event handler block (i.e. a
106             * "on note ... end on" code block) by calling this method (not the
107             * entire script), and hence you must provide one precise handler of the
108             * script to be executed by this method.
109             *
110             * This method usually blocks until the entire script event handler
111             * block has been executed completely. It may however also return before
112             * completion if either a) a script runtime error occurred or b) the
113             * script was suspened by the VM (either because script execution
114             * exceeded a certain limit of time or the script called the built-in
115             * wait() function). You must check the return value of this method to
116             * find out which case applies.
117             *
118             * @param parserContext - parsed represenation of the script
119             * @param execContext - VM execution context (see createExecContext())
120             * @param handler - precise event handler (i.e. "on note ... end on"
121             *                  code block) to be executed
122             *                  (see VMParserContext::eventHandlerByName())
123             * @returns current status of the vitual machine (i.e. script succeeded,
124             *          script runtime error occurred or script was suspended for
125             *          some reason).
126             */
127            VMExecStatus_t exec(VMParserContext* parserContext, VMExecContext* execContext, VMEventHandler* handler);
128    
129            /**
130             * Returns built-in script function for the given function @a name. To
131             * get the implementation of the built-in message() script function for
132             * example, you would pass "message" here).
133             *
134             * This method is re-implemented by deriving classes to add more use
135             * case specific built-in functions.
136             *
137             * @param name - name of the function to be retrieved (i.e. "wait" for the
138             *               built-in wait() function).
139             */
140            VMFunction* functionByName(const String& name) OVERRIDE;
141    
142            /**
143             * Returns all built-in integer script variables. This method returns a
144             * STL map, where the map's key is the variable name and the map's value
145             * is the native pointer to the actual built-in variable.
146             *
147             * This method is re-implemented by deriving classes to add more use
148             * case specific built-in variables.
149             */
150            std::map<String,VMIntRelPtr*> builtInIntVariables() OVERRIDE;
151    
152            /**
153             * Returns all built-in (8 bit) integer array script variables. This
154             * method returns a STL map, where the map's key is the array variable
155             * name and the map's value is the native pointer to the actual built-in
156             * array variable.
157             *
158             * This method is re-implemented by deriving classes to add more use
159             * case specific built-in array variables.
160             */
161            std::map<String,VMInt8Array*> builtInIntArrayVariables() OVERRIDE;
162    
163            /**
164             * Returns all built-in constant integer script variables, which can
165             * only be read, but not be altered by scripts. This method returns a
166             * STL map, where the map's key is the variable name and the map's value
167             * is the native pointer to the actual built-in constant variable.
168             *
169             * This method is re-implemented by deriving classes to add more use
170             * case specific built-in constant integers.
171             *
172             * @b Note: the term "constant" is a bit misleading here, since
173             * built-in constant integer variables may indeed change, i.e. for
174             * built-in constant integers which i.e. reflect some kind of status of
175             * the sampler. So rather see them as "read only" variables, not as
176             * being actually consistent in time.
177             */
178            std::map<String,int> builtInConstIntVariables() OVERRIDE;
179    
180            VMParserContext* currentVMParserContext(); //TODO: should be protected (only usable during exec() calls, intended only for VMFunctions)
181            VMExecContext* currentVMExecContext(); //TODO: should be protected (only usable during exec() calls, intended only for VMFunctions)
182    
183      protected:      protected:
184          ParserContext* m_context;          ParserContext* m_parserContext;
185          CoreVMFunction_message fnMessage;          CoreVMFunction_message fnMessage;
186          CoreVMFunction_exit fnExit;          CoreVMFunction_exit fnExit;
187          CoreVMFunction_wait fnWait;          CoreVMFunction_wait fnWait;
188            CoreVMFunction_abs fnAbs;
189            CoreVMFunction_random fnRandom;
190            CoreVMFunction_num_elements fnNumElements;
191      };      };
192    
193  } // namespace LinuxSampler  } // namespace LinuxSampler
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