[PR] Reduce the per-run work done when opening a Word document [poi]

["pjfanning (via GitHub)" <gi...@apache.org>]

pjfanning opened a new pull request, #1243:
URL: https://github.com/apache/poi/pull/1243

   Opening a .docx eagerly constructs an `XWPFParagraph` for every paragraph and an `XWPFRun` for every run, so anything done per run in those constructors is paid by every document. Three things were.
   
   ### `XWPFRun` ran an XPath query on every run
   
   The constructor built a ~200-character query string by concatenation and called `r.selectPath(...)` looking for `./mc:AlternateContent/mc:Choice/w:drawing`, on every run — while almost every real run is plain text with no picture content at all.
   
   The two query strings are now `static final` constants (they were built from compile-time constants, so they are byte-identical), and the whole picture/drawing block is skipped unless the run can actually hold such content: `sizeOfPictArray() > 0 || sizeOfDrawingArray() > 0`, or a direct `mc:AlternateContent` child found by a plain DOM sibling scan.
   
   The guard is a strict superset of the three sources that feed `pictTextObjs`. The XPath is anchored at `./mc:AlternateContent`, i.e. direct children only, and the DOM scan checks exactly those children by namespace and local name — so the case where `selectPath` matches while both `sizeOf` counts are zero still passes the guard. When the guard is false all three sources are provably empty, so `pictureText` would have been `""` and both loops no-ops.
   
   ### `XWPFParagraph` walked every run's children with a cursor
   
   After building the runs it opened an `XmlCursor` and ran `selectPath("child::*")` over the children of every run to find `CTFtnEdnRef` footnote references, which are rare. Checked against the generated schema: `CTFtnEdnRef` occurs in `CTR` only as `w:footnoteReference` and `w:endnoteReference`, so the walk is now skipped when the run has neither.
   
   The cursor walk itself is deliberately unchanged rather than replaced with the typed accessors, because `getFootnoteReferenceArray()` + `getEndnoteReferenceArray()` would group all footnote refs before all endnote refs and change the append order for a run that mixes both.
   
   ### `XWPFTable` parsed every cell twice
   
   `processCTRow` constructed a full `XWPFParagraph` — and therefore all its `XWPFRun`s — for every paragraph of every cell, purely to precompute the `text` field, then discarded the objects. But the line above it already did `new XWPFTableRow(row, this)`, which builds an `XWPFTableCell` per cell, each of which already builds an `XWPFParagraph` per paragraph. Every table cell was being parsed twice on open. It now reads the paragraphs from the row it just built.
   
   Same set and order (`XWPFTableRow` uses `ctRow.getTcArray()`; a cell's paragraphs are its direct `w:p` children in document order), and both paragraph sets resolve to the same `XWPFDocument`, so `getText()` is unchanged. The drawing-id reservations that the discarded objects performed were duplicates of ones the cell paragraphs had already made.
   
   I did not make `getText()` lazy: `text` is captured at construction today and never updated by `addRow`/`createRow`/`setText`, so a lazy version would start reflecting later mutations, and `text` is a `protected` field an out-of-tree subclass could read.
   
   All 313 `org.apache.poi.xwpf.*` tests pass.
   
   🤖 Generated with [Claude Code](https://claude.com/claude-code)


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Re: [PR] Reduce the per-run work done when opening a Word document [poi]

["pjfanning (via GitHub)" <gi...@apache.org>]

pjfanning merged PR #1243:
URL: https://github.com/apache/poi/pull/1243


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