ReadViewSDK/.planning/phases/08-pagination-quality-cache-performance/08-03-PLAN.md

phase	plan	type	wave	depends_on	files_modified	autonomous	requirements	must_haves
08-pagination-quality-cache-performance	03	execute	1		Sources/RDReaderView/EPUBTextRendering/RDEPUBTextRendererSupport.swift	true	QUAL-04	truths artifacts key_links Pagination timing is logged with chapter ID, page count, and elapsed milliseconds Diagnostic summary includes per-chapter pagination stats path provides contains Sources/RDReaderView/EPUBTextRendering/RDEPUBTextRendererSupport.swift Pagination timing instrumentation in existing rendering path [EPUB][Perf] from to via pattern RDEPUBTextRendererSupport os.signpost / print timing instrumentation [EPUB][Perf]

Add performance sampling and diagnostic output to the pagination pipeline: log chapter ID, page count, and elapsed time for each pagination pass. This provides the baseline data needed to detect regressions and validate that quality improvements don't degrade performance.

Purpose: QUAL-04 requires that pagination improvements don't significantly degrade first-screen time, re-pagination time, or interaction smoothness. Without measurement, this can't be verified.

Output: Timing instrumentation in the existing rendering path with [EPUB][Perf] log prefix.

<execution_context> @$HOME/.claude/get-shit-done/workflows/execute-plan.md @$HOME/.claude/get-shit-done/templates/summary.md </execution_context>

@.planning/PROJECT.md @.planning/ROADMAP.md @.planning/STATE.md @.planning/phases/08-pagination-quality-cache-performance/08-CONTEXT.md @.planning/phases/08-pagination-quality-cache-performance/08-RESEARCH.md

From RDEPUBTextRendererSupport.swift:

• The main pagination entry point processes a chapter HTML string and produces an array of pages
• Existing logging pattern: print("[EPUB][Attachment] footnote classes=...")
• Use the same print("[EPUB]...") convention for consistency

From RDEPUBDTCoreTextRenderer.swift:

• RDEPUBTextChapterRenderRequest contains chapter identification
• Rendering produces NSAttributedString per page

Task 1: Add pagination timing instrumentation Sources/RDReaderView/EPUBTextRendering/RDEPUBTextRendererSupport.swift - Sources/RDReaderView/EPUBTextRendering/RDEPUBTextRendererSupport.swift (full file — find the main pagination entry point) - Sources/RDReaderView/EPUBTextRendering/RDEPUBDTCoreTextRenderer.swift (understand render request flow and chapter identification) Add timing instrumentation to the pagination pipeline in `RDEPUBTextRendererSupport.swift`.

What to instrument: The function that takes chapter HTML and produces paginated output (the main entry point called by the renderer). Wrap the core pagination logic with CFAbsoluteTimeGetCurrent() before and after.

What to log: After pagination completes, print a single diagnostic line:

[EPUB][Perf] chapter={chapterIdentifier} pages={pageCount} elapsed={milliseconds}ms

Where:

• chapterIdentifier = the chapter href or file name passed into the rendering request
• pageCount = number of pages produced
• milliseconds = elapsed time as a rounded integer

Implementation approach:

1. At the top of the pagination function, capture let startTime = CFAbsoluteTimeGetCurrent()
2. At the end (after pages are produced), compute let elapsed = Int(round((CFAbsoluteTimeGetCurrent() - startTime) * 1000))
3. Print: print("[EPUB][Perf] chapter=\(chapterID) pages=\(pages.count) elapsed=\(elapsed)ms")

Use the same logging convention as the existing [EPUB][Attachment] logs. If the function already has a chapter identifier parameter, use it directly. If not, extract it from the request context.

Do NOT add os.signpost or OSLog — keep it simple with print to match existing project conventions. A more sophisticated logging system can be added in Phase 9. xcodebuild build -project ReadViewDemo/ReadViewDemo.xcodeproj -scheme ReadViewDemo -destination 'platform=iOS Simulator,name=iPhone 16' 2>&1 | tail -5 <acceptance_criteria> - RDEPUBTextRendererSupport.swift contains CFAbsoluteTimeGetCurrent() for timing capture - RDEPUBTextRendererSupport.swift contains print("[EPUB][Perf] diagnostic output - Diagnostic line includes chapter identifier, page count, and elapsed milliseconds - xcodebuild build exits 0 </acceptance_criteria> Pagination timing instrumentation is in place, build compiles, diagnostic log line fires after each chapter pagination

- Build succeeds - Running the demo app produces `[EPUB][Perf]` log lines in the console after navigating between chapters

<success_criteria>

• Each pagination pass logs chapter ID, page count, and elapsed time
• Log format is consistent with existing [EPUB] convention
• No performance overhead beyond a single CFAbsoluteTimeGetCurrent() call (negligible) </success_criteria>

Create `.planning/phases/08-pagination-quality-cache-performance/08-03-SUMMARY.md` when done