[flexbuffers] Add "AlignedBlob", a version of "Blob" with explicit alignment.#8993
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@dbaileychess very sorry, a small editor malfunction :-( |
…ignment. A blob is an array of bytes and has no intrinsic alignment (i.e. the alignment is 1). The alignment of the existing flexbuffers blob is solely affected by the width of the integer needed to store the blob's size: that integer's width becomes the alignment of the blob. The proposed AlignedBlob function here piggybacks on this effect and simply uses a user-defined alignment for the width of the integer that stores the blob's size; this automatically imparts that same alignment on the blob itself. (The width is bounded below by the actual width needed to store the blob's size.) The ability to control the alignment of a blob is important for use cases in which the blob itself stores structured data that we want to access without further copies (e.g. other flatbuffer messages).
dbaileychess
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Mar 23, 2026
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A blob is an array of bytes and has no intrinsic alignment (i.e. the alignment is 1). The alignment of the existing flexbuffers blob is solely affected by the width of the integer needed to store the blob's size: that integer's width becomes the alignment of the blob.
The proposed AlignedBlob function here piggybacks on this effect and simply uses a user-defined alignment for the width of the integer that stores the blob's size; this automatically imparts that same alignment on the blob itself. (The width is bounded below by the actual width needed to store the blob's size.)
The ability to control the alignment of a blob is important for use cases in which the blob itself stores structured data that we want to access without further copies (e.g. other flatbuffer messages).