lib/mcollective/vendor/json/java/src/json/ext/RuntimeInfo.java

   1 /*
   2  * This code is copyrighted work by Daniel Luz <dev at mernen dot com>.
   3  *
   4  * Distributed under the Ruby and GPLv2 licenses; see COPYING and GPL files
   5  * for details.
   6  */
   7 package json.ext;
   8
   9 import java.lang.ref.WeakReference;
  10 import java.util.HashMap;
  11 import java.util.Map;
  12 import java.util.WeakHashMap;
  13 import org.jruby.Ruby;
  14 import org.jruby.RubyClass;
  15 import org.jruby.RubyEncoding;
  16 import org.jruby.RubyModule;
  17 import org.jruby.runtime.ThreadContext;
  18 import org.jruby.runtime.builtin.IRubyObject;
  19
  20
  21 final class RuntimeInfo {
  22     // since the vast majority of cases runs just one runtime,
  23     // we optimize for that
  24     private static WeakReference<Ruby> runtime1 = new WeakReference<Ruby>(null);
  25     private static RuntimeInfo info1;
  26     // store remaining runtimes here (does not include runtime1)
  27     private static Map<Ruby, RuntimeInfo> runtimes;
  28
  29     // these fields are filled by the service loaders
  30     // Use WeakReferences so that RuntimeInfo doesn't indirectly hold a hard reference to
  31     // the Ruby runtime object, which would cause memory leaks in the runtimes map above.
  32     /** JSON */
  33     WeakReference<RubyModule> jsonModule;
  34     /** JSON::Ext::Generator::GeneratorMethods::String::Extend */
  35     WeakReference<RubyModule> stringExtendModule;
  36     /** JSON::Ext::Generator::State */
  37     WeakReference<RubyClass> generatorStateClass;
  38     /** JSON::SAFE_STATE_PROTOTYPE */
  39     WeakReference<GeneratorState> safeStatePrototype;
  40
  41     final WeakReference<RubyEncoding> utf8;
  42     final WeakReference<RubyEncoding> ascii8bit;
  43     // other encodings
  44     private final Map<String, WeakReference<RubyEncoding>> encodings;
  45
  46     private RuntimeInfo(Ruby runtime) {
  47         RubyClass encodingClass = runtime.getEncoding();
  48         if (encodingClass == null) { // 1.8 mode
  49             utf8 = ascii8bit = null;
  50             encodings = null;
  51         } else {
  52             ThreadContext context = runtime.getCurrentContext();
  53
  54             utf8 = new WeakReference<RubyEncoding>((RubyEncoding)RubyEncoding.find(context,
  55                     encodingClass, runtime.newString("utf-8")));
  56             ascii8bit = new WeakReference<RubyEncoding>((RubyEncoding)RubyEncoding.find(context,
  57                     encodingClass, runtime.newString("ascii-8bit")));
  58             encodings = new HashMap<String, WeakReference<RubyEncoding>>();
  59         }
  60     }
  61
  62     static RuntimeInfo initRuntime(Ruby runtime) {
  63         synchronized (RuntimeInfo.class) {
  64             if (runtime1.get() == runtime) {
  65                 return info1;
  66             } else if (runtime1.get() == null) {
  67                 runtime1 = new WeakReference<Ruby>(runtime);
  68                 info1 = new RuntimeInfo(runtime);
  69                 return info1;
  70             } else {
  71                 if (runtimes == null) {
  72                     runtimes = new WeakHashMap<Ruby, RuntimeInfo>(1);
  73                 }
  74                 RuntimeInfo cache = runtimes.get(runtime);
  75                 if (cache == null) {
  76                     cache = new RuntimeInfo(runtime);
  77                     runtimes.put(runtime, cache);
  78                 }
  79                 return cache;
  80             }
  81         }
  82     }
  83
  84     public static RuntimeInfo forRuntime(Ruby runtime) {
  85         synchronized (RuntimeInfo.class) {
  86             if (runtime1.get() == runtime) return info1;
  87             RuntimeInfo cache = null;
  88             if (runtimes != null) cache = runtimes.get(runtime);
  89             assert cache != null : "Runtime given has not initialized JSON::Ext";
  90             return cache;
  91         }
  92     }
  93
  94     public boolean encodingsSupported() {
  95         return utf8 != null && utf8.get() != null;
  96     }
  97
  98     public RubyEncoding getEncoding(ThreadContext context, String name) {
  99         synchronized (encodings) {
 100             WeakReference<RubyEncoding> encoding = encodings.get(name);
 101             if (encoding == null) {
 102                 Ruby runtime = context.getRuntime();
 103                 encoding = new WeakReference<RubyEncoding>((RubyEncoding)RubyEncoding.find(context,
 104                         runtime.getEncoding(), runtime.newString(name)));
 105                 encodings.put(name, encoding);
 106             }
 107             return encoding.get();
 108         }
 109     }
 110
 111     public GeneratorState getSafeStatePrototype(ThreadContext context) {
 112         if (safeStatePrototype == null) {
 113             IRubyObject value = jsonModule.get().getConstant("SAFE_STATE_PROTOTYPE");
 114             if (!(value instanceof GeneratorState)) {
 115                 throw context.getRuntime().newTypeError(value, generatorStateClass.get());
 116             }
 117             safeStatePrototype = new WeakReference<GeneratorState>((GeneratorState)value);
 118         }
 119         return safeStatePrototype.get();
 120     }
 121 }