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/*
* Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
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*/
package com.oracle.truffle.api.interop;
/**
* This class represents {@link Message#KEY_INFO key info} bit flags. Use this class as a utility to
* get or set the bit flags when dealing with {@link Message#KEY_INFO} message.
*
* The bit flags have following meaning:
*
* - {@link #READABLE}: if {@link Message#READ reading} an existing key is supported.
*
- {@link #MODIFIABLE}: if {@link Message#WRITE writing} an existing key is supported.
*
- {@link #INSERTABLE} if {@link Message#WRITE writing} a new key is supported.
*
- {@link #INVOCABLE}: if {@link Message#createInvoke(int) invoking} an existing key is
* supported.
*
- {@link #REMOVABLE} if {@link Message#REMOVE removing} an existing key is supported.
*
- {@link #INTERNAL} if an existing key is internal.
*
* When a {@link #isReadable(int) readable} or {@link #isWritable(int) writable} flag is
* true, it does not necessarily guarantee that subsequent {@link Message#READ} or
* {@link Message#WRITE} message will succeed. Read or write can fail due to some momentary bad
* state. An object field is expected not to be readable resp. writable when it's known that the
* field can not be read (e.g. a bean property without a getter) resp. can not be written to (e.g. a
* bean property without a setter). The same applies to invocable flag and
* {@link Message#createInvoke(int) invoke} message.
*
*
* @since 0.26
*/
public final class KeyInfo {
/**
* Value of the key info if the key has no capability.
*
* @since 0.33
*/
public static final int NONE = 0;
/**
* Single bit that is set if {@link Message#READ reading} an existing key is supported.
*
* @since 0.33
*/
public static final int READABLE = 1 << 1;
/**
* Single bit that is set if {@link Message#WRITE writing} an existing key is supported.
*
* @since 0.33
*/
public static final int MODIFIABLE = 1 << 2;
/**
* Single bit that is set if {@link Message#createInvoke(int) invoking} an existing key is
* supported.
*
* @since 0.33
*/
public static final int INVOCABLE = 1 << 3;
/**
* Single bit that is set if an existing key is internal.
*
* @since 0.33
*/
public static final int INTERNAL = 1 << 4;
/**
* Single bit that is set if {@link Message#REMOVE removing} an existing key is supported.
*
* @since 0.33
*/
public static final int REMOVABLE = 1 << 5;
/**
* Single bit that is set if {@link Message#WRITE writing} a new key is supported.
*
* @since 0.33
*/
public static final int INSERTABLE = 1 << 6;
private static final int WRITABLE = INSERTABLE | MODIFIABLE;
private static final int EXISTING = READABLE | MODIFIABLE | INVOCABLE | INTERNAL | REMOVABLE;
private KeyInfo() {
}
/**
* Test if the bits represent an existing key.
*
* @since 0.26
*/
public static boolean isExisting(int infoBits) {
return (infoBits & EXISTING) != 0;
}
/**
* Test if {@link Message#READ reading} an existing key is supported.
*
* @since 0.26
*/
public static boolean isReadable(int infoBits) {
return (infoBits & READABLE) != 0;
}
/**
* Test if {@link Message#READ writing} an existing or new key is supported.
*
* @since 0.26
*/
public static boolean isWritable(int infoBits) {
return (infoBits & WRITABLE) != 0;
}
/**
* Test if {@link Message#createInvoke(int) invoking} an existing key is supported.
*
* @since 0.26
*/
public static boolean isInvocable(int infoBits) {
return (infoBits & INVOCABLE) != 0;
}
/**
* Test if an existing key is internal.
*
* @since 0.26
*/
public static boolean isInternal(int infoBits) {
return (infoBits & INTERNAL) != 0;
}
/**
* Test if {@link Message#WRITE writing} a new key is supported.
*
* @since 0.33
*/
public static boolean isRemovable(int infoBits) {
return (infoBits & REMOVABLE) != 0;
}
/**
* Test if {@link Message#WRITE writing} an existing key is supported.
*
* @since 0.33
*/
public static boolean isModifiable(int infoBits) {
return (infoBits & MODIFIABLE) != 0;
}
/**
* Test if {@link Message#WRITE writing} a new key is supported.
*
* @since 0.33
*/
public static boolean isInsertable(int infoBits) {
return (infoBits & INSERTABLE) != 0;
}
/**
* @since 0.26
* @deprecated in 0.33 use integer constants in {@link KeyInfo} instead. For example
* KeyInfo.newBuilder().setWritable(true).setReadable(true).build()
* becomes
* {@link #READABLE READABLE} | {@link #MODIFIABLE MODIFIABLE} | {@link #INSERTABLE
* INSERTABLE}
*/
@Deprecated
public static Builder newBuilder() {
return new KeyInfo().new Builder();
}
/**
* A builder of bit flags. An instance of this class can be reused for multiple key info bits
* {@link #build() creation}.
*
* @since 0.26
* @deprecated in 0.33 use integer constants in {@link KeyInfo} instead. For example
* KeyInfo.newBuilder().setWritable(true).setReadable(true).build()
* becomes
* {@link #READABLE READABLE} | {@link #MODIFIABLE MODIFIABLE} | {@link #INSERTABLE
* INSERTABLE}
*/
@Deprecated
public final class Builder {
private int infoBits;
private Builder() {
infoBits = 1;
}
/**
* Set readability flag.
*
* @since 0.26
*/
public Builder setReadable(boolean readable) {
setBit(1, readable);
return this;
}
/**
* Set writability flag.
*
* @since 0.26
*/
public Builder setWritable(boolean readable) {
setBit(2, readable);
return this;
}
/**
* Set invocability flag.
*
* @since 0.26
*/
public Builder setInvocable(boolean readable) {
setBit(3, readable);
return this;
}
/**
* Set internal attribute flag.
*
* @since 0.26
*/
public Builder setInternal(boolean readable) {
setBit(4, readable);
return this;
}
/**
* Set removability flag.
*
* @since 0.32
*/
public Builder setRemovable(boolean removable) {
setBit(5, removable);
return this;
}
/**
* Get the current bit flags of this builder in an integer value.
*
* @since 0.26
*/
public int build() {
return infoBits;
}
private void setBit(int b, boolean value) {
int v = value ? 1 : 0;
infoBits = infoBits & ~(1 << b) | (v << b);
}
}
}