Discard rendered pages while the reader is in a hidden tab#229
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pistachionet wants to merge 1 commit into
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Discard rendered pages while the reader is in a hidden tab#229pistachionet wants to merge 1 commit into
pistachionet wants to merge 1 commit into
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Adds Reader.setSuspended(), which for PDF views destroys all page views to release page canvases, snapshot canvases, extracted page data, and worker-side page resources, and pauses the rendering queue so nothing re-renders while hidden. On resume, rendering is unpaused and visible pages re-render through the normal path. Each loaded reader view otherwise retains 10+ rendered page canvases (roughly 30-60 MB each on HiDPI displays) plus a same-size snapshot copy of each, indefinitely. Also explicitly zero snapshot canvas backing stores when a page is destroyed, instead of waiting for GC. Requires the PDFRenderingQueue paused flag from the zotero/pdf.js companion PR.
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Each loaded PDF view retains at least 10 fully rendered page canvases (
PDFPageViewBuffer,DEFAULT_CACHE_SIZE = 10— the buffer never shrinks below that). On a 2x HiDPI display at page-width zoom a page canvas is ~2400×3100 device pixels ≈ 30 MB RGBA, up to themaxCanvasPixels = 2^25cap. On top of that, the annotation overlay renderer (src/pdf/page.js) keeps a full-size_snapshotCanvascopy of every rendered page canvas (captured unconditionally in_maybeRefreshSnapshot(), even for pages with no annotations), plus extracted per-page data in_pdfPages. That's roughly 600 MB per loaded PDF tab, retained indefinitely while the tab is hidden, since nothing is released on tab deselection.This pr adds Reader.setSuspended(), which for PDF views destroys all page views to release page canvases, snapshot canvases, extracted page data, and worker-side page resources, and pauses the rendering queue so nothing re-renders while hidden. On resume, rendering is unpaused and visible pages re-render through the normal path.
Each loaded reader view otherwise retains 10+ rendered page canvases (roughly 30-60 MB each on HiDPI displays) plus a same-size snapshot copy of each, indefinitely.
Also explicitly zero snapshot canvas backing stores when a page is destroyed, instead of waiting for GC.
Requires the PDFRenderingQueue paused flag from the zotero/pdf.js companion PR.