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 * (a) the Software, and
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 * (b) any piece of software and/or hardware listed in the lrgrwrks.txt file if
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package com.oracle.truffle.nfi;

import com.oracle.truffle.api.CompilerDirectives.TruffleBoundary;
import org.graalvm.collections.EconomicMap;

import com.oracle.truffle.api.TruffleLanguage.Env;
import com.oracle.truffle.api.nodes.LanguageInfo;
import com.oracle.truffle.nfi.spi.NFIBackend;
import com.oracle.truffle.nfi.spi.NFIBackendFactory;
import com.oracle.truffle.nfi.spi.NFIBackendTools;

final class NFIContext {

    private static final class NFIBackendToolsImpl extends NFIBackendTools {

        private final String backend;

        NFIBackendToolsImpl(String backend) {
            this.backend = backend.intern();
        }

        @Override
        public Object createBindableSymbol(Object symbol) {
            return NFISymbol.createBindable(backend, symbol);
        }
    }

    Env env;
    final EconomicMap<String, API> apiCache = EconomicMap.create();

    NFIContext(Env env) {
        this.env = env;
    }

    void patch(Env newEnv) {
        this.env = newEnv;
        this.apiCache.clear();
    }

    NFIBackend getBackend(String id) {
        return getAPI(id).backend;
    }

    @TruffleBoundary
    API getAPI(String backendId) {
        API ret = apiCache.get(backendId);
        if (ret != null) {
            return ret;
        }

        synchronized (apiCache) {
            ret = apiCache.get(backendId);
            if (ret != null) {
                return ret;
            }

            for (LanguageInfo language : env.getInternalLanguages().values()) {
                if ("nfi".equals(language.getId())) {
                    continue;
                }

                NFIBackendFactory backendFactory = env.lookup(language, NFIBackendFactory.class);
                if (backendFactory != null && backendFactory.getBackendId().equals(backendId)) {
                    // force initialization of the backend language
                    env.initializeLanguage(language);

                    NFIBackend backend = backendFactory.createBackend(new NFIBackendToolsImpl(backendId));
                    API api = new API(backendId, backend);
                    apiCache.put(backendFactory.getBackendId(), api);
                    return api;
                }
            }
        }

        return null;
    }
}