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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.graal.python.lib;

import static com.oracle.graal.python.nodes.ErrorMessages.DECODING_STR_NOT_SUPPORTED;
import static com.oracle.graal.python.nodes.StringLiterals.T_EMPTY_STRING;
import static com.oracle.graal.python.util.PythonUtils.TS_ENCODING;

import com.oracle.graal.python.builtins.PythonBuiltinClassType;
import com.oracle.graal.python.builtins.objects.buffer.PythonBufferAccessLibrary;
import com.oracle.graal.python.builtins.objects.bytes.PBytes;
import com.oracle.graal.python.builtins.objects.common.SequenceStorageNodes;
import com.oracle.graal.python.builtins.objects.str.PString;
import com.oracle.graal.python.nodes.PNodeWithIndirectCall;
import com.oracle.graal.python.nodes.PRaiseNode;
import com.oracle.truffle.api.Truffle;
import com.oracle.truffle.api.dsl.Cached;
import com.oracle.truffle.api.dsl.Cached.Shared;
import com.oracle.truffle.api.dsl.GenerateUncached;
import com.oracle.truffle.api.dsl.Specialization;
import com.oracle.truffle.api.frame.Frame;
import com.oracle.truffle.api.frame.VirtualFrame;
import com.oracle.truffle.api.library.CachedLibrary;
import com.oracle.truffle.api.profiles.ConditionProfile;
import com.oracle.truffle.api.strings.TruffleString;
import com.oracle.truffle.api.strings.TruffleString.Encoding;

/**
 * Equivalent of CPython's {@code PyUnicode_FromEncodedObject}.
 */
@GenerateUncached
public abstract class PyUnicodeFromEncodedObject extends PNodeWithIndirectCall {
    public abstract Object execute(Frame frame, Object object, Object encoding, Object errors);

    @Specialization
    Object doBytes(VirtualFrame frame, PBytes object, Object encoding, Object errors,
                    @Cached SequenceStorageNodes.LenNode lenNode,
                    @Cached ConditionProfile emptyStringProfile,
                    @Cached PyUnicodeDecode decode) {
        // Decoding bytes objects is the most common case and should be fast
        if (emptyStringProfile.profile(lenNode.execute(object.getSequenceStorage()) == 0)) {
            return T_EMPTY_STRING;
        }
        return decode.execute(frame, object, encoding, errors);
    }

    @Specialization
    @SuppressWarnings("unused")
    Object doString(VirtualFrame frame, TruffleString object, Object encoding, Object errors,
                    @Shared("raiseNode") @Cached PRaiseNode raiseNode) {
        throw raiseNode.raise(PythonBuiltinClassType.TypeError, DECODING_STR_NOT_SUPPORTED);
    }

    @Specialization
    @SuppressWarnings("unused")
    Object doPString(VirtualFrame frame, PString object, Object encoding, Object errors,
                    @Shared("raiseNode") @Cached PRaiseNode raiseNode) {
        throw raiseNode.raise(PythonBuiltinClassType.TypeError, DECODING_STR_NOT_SUPPORTED);
    }

    @Specialization(guards = {"!isPBytes(object)", "!isString(object)"}, limit = "3")
    Object doBuffer(VirtualFrame frame, Object object, Object encoding, Object errors,
                    @Cached ConditionProfile emptyStringProfile,
                    @Cached PyUnicodeDecode decode,
                    @CachedLibrary("object") PythonBufferAccessLibrary bufferLib,
                    @Cached TruffleString.FromByteArrayNode fromByteArrayNode,
                    @Cached TruffleString.SwitchEncodingNode switchEncodingNode) {
        try {
            int len = bufferLib.getBufferLength(object);
            if (emptyStringProfile.profile(len == 0)) {
                return T_EMPTY_STRING;
            }
            // TODO GR-37601: this is probably never executed
            TruffleString utf8 = fromByteArrayNode.execute(bufferLib.getInternalOrCopiedByteArray(object), 0, len, Encoding.UTF_8, true);
            final TruffleString unicode = switchEncodingNode.execute(utf8, TS_ENCODING);
            return decode.execute(frame, unicode, encoding, errors);
        } finally {
            bufferLib.release(object, frame, this);
        }
    }

    public static PyUnicodeFromEncodedObject create() {
        return PyUnicodeFromEncodedObjectNodeGen.create(Truffle.getRuntime().createAssumption(), Truffle.getRuntime().createAssumption());
    }
}
