RFR: 8349503: Consolidate multi-byte access into ByteArray

[Raffaello Giulietti]

On Wed, 5 Feb 2025 23:41:19 GMT, Chen Liang <liach at openjdk.org> wrote:

> `MethodHandles.byteArrayViewVarHandle` exposes checked multi-byte access to byte arrays via VarHandle. This larger access speeds up many operations, yet it cannot be used in early bootstrap, and as a result, people tend to use `Unsafe` which can threaten memory safety of the Java Platform.
> 
> To promote the safe use of multi-byte access, I propose to move the checked implementations from VarHandle to ByteArray to allow earlier use and reduce maintenance costs. In addition, ByteArrayLittleEndian is consolidated, and now the access methods are distinguished by BO (byte order) / BE (big endian) / LE (little endian) suffixes to indicate their access features.

What about dropping "BE" from all big-endian method names?
This would reduces the number of files to review in `java.io` to 0 (admittedly, it's a rather mechanical review).
I know this would be less symmetrical, but...

src/java.base/share/classes/jdk/internal/util/ByteArray.java line 53:

> 51: 
> 52:     public static char getCharBO(byte[] array, int index, boolean big) {
> 53:         Preconditions.checkIndex(index, array.length - Character.BYTES + 1, Preconditions.AIOOBE_FORMATTER);

Suggestion:

        Preconditions.checkIndex(index, array.length - (Character.BYTES - 1), Preconditions.AIOOBE_FORMATTER);


Similarly for all cases below.

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PR Comment: https://git.openjdk.org/jdk/pull/23478#issuecomment-2639657316
PR Review Comment: https://git.openjdk.org/jdk/pull/23478#discussion_r1944571743