--- /dev/null
+#include <string.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include <plib/ul.h>
+
+#include <simgear/nasal/nasal.h>
+#include <simgear/props/props.hxx>
+#include <simgear/misc/sg_path.hxx>
+#include <simgear/structure/commands.hxx>
+
+#include <Main/globals.hxx>
+
+#include "NasalSys.hxx"
+
+// Read and return file contents in a single buffer. Note use of
+// stat() to get the file size. This is a win32 function, believe it
+// or not. :) Note the REALLY IMPORTANT use of the "b" flag to fopen.
+// Text mode brain damage will kill us if we're trying to do bytewise
+// I/O.
+static char* readfile(const char* file, int* lenOut)
+{
+ struct stat data;
+ if(stat(file, &data) != 0) return 0;
+ FILE* f = fopen(file, "rb");
+ if(!f) return 0;
+ char* buf = new char[data.st_size];
+ *lenOut = fread(buf, 1, data.st_size, f);
+ fclose(f);
+ if(*lenOut != data.st_size) {
+ // Shouldn't happen, but warn anyway since it represents a
+ // platform bug and not a typical runtime error (missing file,
+ // etc...)
+ SG_LOG(SG_NASAL, SG_ALERT,
+ "ERROR in Nasal initialization: " <<
+ "short count returned from fread(). Check your C library!");
+ delete[] buf;
+ return 0;
+ }
+ return buf;
+}
+
+FGNasalSys::FGNasalSys()
+{
+ _context = 0;
+ _globals = naNil();
+ _timerHash = naNil();
+ _nextTimerHashKey = 0; // Any value will do
+}
+
+FGNasalSys::~FGNasalSys()
+{
+ // Nasal doesn't have a "destroy context" API yet. :(
+ // Not a problem for a global subsystem that will never be
+ // destroyed. And the context is actually a global, so no memory
+ // is technically leaked (although the GC pool memory obviously
+ // won't be freed).
+ _context = 0;
+ _globals = naNil();
+}
+
+// Utility. Sets a named key in a hash by C string, rather than nasal
+// string object.
+void FGNasalSys::hashset(naRef hash, const char* key, naRef val)
+{
+ naRef s = naNewString(_context);
+ naStr_fromdata(s, (char*)key, strlen(key));
+ naHash_set(hash, s, val);
+}
+
+// The get/setprop functions accept a *list* of strings and walk
+// through the property tree with them to find the appropriate node.
+// This allows a Nasal object to hold onto a property path and use it
+// like a node object, e.g. setprop(ObjRoot, "size-parsecs", 2.02). This
+// is the utility function that walks the property tree.
+// Future enhancement: support integer arguments to specify array
+// elements.
+static SGPropertyNode* findnode(naContext c, naRef vec, int len)
+{
+ SGPropertyNode* p = globals->get_props();
+ for(int i=0; i<len; i++) {
+ naRef a = naVec_get(vec, i);
+ if(!naIsString(a)) return 0;
+ p = p->getNode(naStr_data(a));
+ if(p == 0) return 0;
+ }
+ return p;
+}
+
+// getprop() extension function. Concatenates its string arguments as
+// property names and returns the value of the specified property. Or
+// nil if it doesn't exist.
+static naRef f_getprop(naContext c, naRef args)
+{
+ const SGPropertyNode* p = findnode(c, args, naVec_size(args));
+ if(!p) return naNil();
+
+ switch(p->getType()) {
+ case SGPropertyNode::BOOL: case SGPropertyNode::INT:
+ case SGPropertyNode::LONG: case SGPropertyNode::FLOAT:
+ case SGPropertyNode::DOUBLE:
+ return naNum(p->getDoubleValue());
+
+ case SGPropertyNode::STRING:
+ {
+ naRef nastr = naNewString(c);
+ const char* val = p->getStringValue();
+ naStr_fromdata(nastr, (char*)val, strlen(val));
+ return nastr;
+ }
+ default:
+ return naNil();
+ }
+}
+
+// setprop() extension function. Concatenates its string arguments as
+// property names and sets the value of the specified property to the
+// final argument.
+static naRef f_setprop(naContext c, naRef args)
+{
+#define BUFLEN 1024
+ int argc = naVec_size(args);
+ char buf[BUFLEN + 1];
+ buf[BUFLEN] = 0;
+ char* p = buf;
+ int buflen = BUFLEN;
+ for(int i=0; i<argc-1; i++) {
+ naRef s = naStringValue(c, naVec_get(args, i));
+ if(naIsNil(s)) return naNil();
+ strncpy(p, naStr_data(s), buflen);
+ p += naStr_len(s);
+ buflen = BUFLEN - (p - buf);
+ if(i < (argc-2) && buflen > 0) {
+ *p++ = '/';
+ buflen--;
+ }
+ }
+
+ SGPropertyNode* props = globals->get_props();
+ naRef val = naVec_get(args, argc-1);
+ if(naIsString(val)) props->setStringValue(buf, naStr_data(val));
+ else props->setDoubleValue(buf, naNumValue(val).num);
+ return naNil();
+#undef BUFLEN
+}
+
+// print() extension function. Concatenates and prints its arguments
+// to the FlightGear log. Uses the highest log level (SG_ALERT), to
+// make sure it appears. Is there better way to do this?
+static naRef f_print(naContext c, naRef args)
+{
+#define BUFLEN 1024
+ char buf[BUFLEN + 1];
+ buf[BUFLEN] = 0; // extra nul to handle strncpy brain damage
+ char* p = buf;
+ int buflen = BUFLEN;
+ int n = naVec_size(args);
+ for(int i=0; i<n; i++) {
+ naRef s = naStringValue(c, naVec_get(args, i));
+ if(naIsNil(s)) continue;
+ strncpy(p, naStr_data(s), buflen);
+ p += naStr_len(s);
+ buflen = BUFLEN - (p - buf);
+ if(buflen <= 0) break;
+ }
+ SG_LOG(SG_GENERAL, SG_ALERT, buf);
+ return naNil();
+#undef BUFLEN
+}
+
+// fgcommand() extension function. Executes a named command via the
+// FlightGear command manager. Takes a single property node name as
+// an argument.
+static naRef f_fgcommand(naContext c, naRef args)
+{
+ naRef cmd = naVec_get(args, 0);
+ naRef props = naVec_get(args, 1);
+ if(!naIsString(cmd) || !naIsString(props)) return naNil();
+
+ SGPropertyNode* pnode =
+ globals->get_props()->getNode(naStr_data(props));
+ if(pnode)
+ globals->get_commands()->execute(naStr_data(cmd), pnode);
+ return naNil();
+}
+
+// settimer(func, dt, simtime) extension function. Falls through to
+// FGNasalSys::setTimer(). See there for docs.
+static naRef f_settimer(naContext c, naRef args)
+{
+ FGNasalSys* nasal = (FGNasalSys*)globals->get_subsystem("nasal");
+ nasal->setTimer(args);
+ return naNil();
+}
+
+// Table of extension functions. Terminate with zeros.
+static struct { char* name; naCFunction func; } funcs[] = {
+ { "getprop", f_getprop },
+ { "setprop", f_setprop },
+ { "print", f_print },
+ { "fgcommand", f_fgcommand },
+ { "settimer", f_settimer },
+ { 0, 0 }
+};
+
+void FGNasalSys::init()
+{
+ _context = naNewContext();
+
+ // Start with globals. Add it to itself as a recursive
+ // sub-reference under the name "globals". This gives client-code
+ // write access to the namespace if someone wants to do something
+ // fancy.
+ _globals = naStdLib(_context);
+ naSave(_context, _globals);
+ hashset(_globals, "globals", _globals);
+
+ // Add in the math library under "math"
+ hashset(_globals, "math", naMathLib(_context));
+
+ // Add our custom extension functions:
+ for(int i=0; funcs[i].name; i++)
+ hashset(_globals, funcs[i].name,
+ naNewFunc(_context, naNewCCode(_context, funcs[i].func)));
+
+ // Make a "__timers" hash to hold the settimer() handlers (to
+ // protect them from begin garbage-collected).
+ _timerHash = naNewHash(_context);
+ hashset(_globals, "__timers", _timerHash);
+
+ // Now load the various source files in the Nasal directory
+ SGPath p(globals->get_fg_root());
+ p.append("Nasal");
+ ulDirEnt* dent;
+ ulDir* dir = ulOpenDir(p.c_str());
+ while(dir && (dent = ulReadDir(dir)) != 0) {
+ SGPath fullpath(p);
+ fullpath.append(dent->d_name);
+ SGPath file(dent->d_name);
+ if(file.extension() != "nas") continue;
+ readScriptFile(fullpath, file.base().c_str());
+ }
+}
+
+// Logs a runtime error, with stack trace, to the FlightGear log stream
+void FGNasalSys::logError()
+{
+ SG_LOG(SG_NASAL, SG_ALERT,
+ "Nasal runtime error: " << naGetError(_context));
+ SG_LOG(SG_NASAL, SG_ALERT,
+ " at " << naStr_data(naGetSourceFile(_context, 0)) <<
+ ", line " << naGetLine(_context, 0));
+ for(int i=1; i<naStackDepth(_context); i++)
+ SG_LOG(SG_NASAL, SG_ALERT,
+ " called from: " << naStr_data(naGetSourceFile(_context, i)) <<
+ ", line " << naGetLine(_context, i));
+}
+
+// Reads a script file, executes it, and places the resulting
+// namespace into the global namespace under the specified module
+// name.
+void FGNasalSys::readScriptFile(SGPath file, const char* lib)
+{
+ int len = 0;
+ char* buf = readfile(file.c_str(), &len);
+ if(!buf) return;
+
+ // Parse and run. Save the local variables namespace, as it will
+ // become a sub-object of globals.
+ naRef code = parse(file.c_str(), buf, len);
+ delete[] buf;
+ if(naIsNil(code))
+ return;
+
+ naRef locals = naNewHash(_context);
+ naCall(_context, code, naNil(), naNil(), locals);
+ if(naGetError(_context)) {
+ logError();
+ return;
+ }
+
+ hashset(_globals, lib, locals);
+}
+
+naRef FGNasalSys::parse(const char* filename, const char* buf, int len)
+{
+ int errLine = -1;
+ naRef srcfile = naNewString(_context);
+ naStr_fromdata(srcfile, (char*)filename, strlen(filename));
+ naRef code = naParseCode(_context, srcfile, 1, (char*)buf, len, &errLine);
+ if(naIsNil(code)) {
+ SG_LOG(SG_NASAL, SG_ALERT,
+ "Nasal parse error: " << naGetError(_context) <<
+ " in "<< filename <<", line " << errLine);
+ return naNil();
+ }
+
+ // Bind to the global namespace before returning
+ return naBindFunction(_context, code, _globals);
+}
+
+bool FGNasalSys::handleCommand(const SGPropertyNode* arg)
+{
+ // Parse the Nasal source. I'd love to use the property name of
+ // the argument, but it's actually a *clone* of the original
+ // location in the property tree. arg->getPath() returns an empty
+ // string.
+ const char* nasal = arg->getStringValue("script");
+ naRef code = parse("<command>", nasal, strlen(nasal));
+ if(naIsNil(code)) return false;
+
+ // FIXME: Cache the just-created code object somewhere, but watch
+ // for changes to the source in the property tree. Maybe store an
+ // integer index into a Nasal vector in the original property
+ // location?
+
+ // Extract the "value" or "offset" arguments if present
+ naRef locals = naNil();
+ if(arg->hasValue("value")) {
+ locals = naNewHash(_context);
+ hashset(locals, "value", naNum(arg->getDoubleValue("value")));
+ } else if(arg->hasValue("offset")) {
+ locals = naNewHash(_context);
+ hashset(locals, "offset", naNum(arg->getDoubleValue("offset")));
+ }
+
+ // Call it!
+ naRef result = naCall(_context, code, naNil(), naNil(), locals);
+ if(!naGetError(_context)) return true;
+ logError();
+ return false;
+}
+
+// settimer(func, dt, simtime) extension function. The first argument
+// is a Nasal function to call, the second is a delta time (from now),
+// in seconds. The third, if present, is a boolean value indicating
+// that "simulator" time (rather than real time) is to be used.
+//
+// Implementation note: the FGTimer objects don't live inside the
+// garbage collector, so the Nasal handler functions have to be
+// "saved" somehow lest they be inadvertently cleaned. In this case,
+// they are inserted into a globals._timers hash and removed on
+// expiration.
+void FGNasalSys::setTimer(naRef args)
+{
+ // Extract the handler, delta, and simtime arguments:
+ naRef handler = naVec_get(args, 0);
+ if(!(naIsCode(handler) || naIsCCode(handler) || naIsFunc(handler)))
+ return;
+
+ naRef delta = naNumValue(naVec_get(args, 1));
+ if(naIsNil(delta)) return;
+
+ bool simtime = naTrue(naVec_get(args, 2)) ? true : false;
+
+ // Generate and register a C++ timer handler
+ NasalTimer* t = new NasalTimer;
+ t->handler = handler;
+ t->hashKey = _nextTimerHashKey++;
+ t->nasal = this;
+
+ globals->get_event_mgr()->addEvent("NasalTimer",
+ t, &NasalTimer::timerExpired,
+ delta.num, simtime);
+
+
+ // Save the handler in the globals.__timers hash to prevent
+ // garbage collection.
+ naHash_set(_timerHash, naNum(t->hashKey), handler);
+}
+
+void FGNasalSys::handleTimer(NasalTimer* t)
+{
+ naCall(_context, t->handler, naNil(), naNil(), naNil());
+ naHash_delete(_timerHash, naNum(t->hashKey));
+}
+
+void FGNasalSys::NasalTimer::timerExpired()
+{
+ nasal->handleTimer(this);
+ delete this;
+}
projects / flightgear.git / commitdiff