iOS client for Grain
grain.social
ios
photography
atproto
build: signpost every on-disk image cache write
Adds a minimal ImagePipelineDelegate whose willCache hook emits a
DiskCacheWrite os_signpost event with the image's last path component
and byte count. Verifies the fullsize-never-cached discipline holds:
after the refactor every event should fall in the thumb/avatar byte
range (tens to a few hundred KB), never the fullsize range (1-5 MB).
authored by
Hima Aramona
and committed by
Chad Miller
f77545d0
e9d2b428
+26
-1
+1
-1
Grain/GrainApp.swift
+1
-1
Grain/GrainApp.swift
···
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if let dataCache = try? DataCache(name: "social.grain.images") {
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config.dataCache = dataCache
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}
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await MainActor.run { ImagePipeline.shared = ImagePipeline(configuration: config) }
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await MainActor.run { ImagePipeline.shared = ImagePipeline(configuration: config, delegate: GrainImagePipelineDelegate()) }
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appSignposter.endInterval("NukePipelineSetup", state)
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appLogger.debug("[NukePipelineSetup] end")
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}
+25
Grain/Utilities/ImagePipelineSignposting.swift
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Grain/Utilities/ImagePipelineSignposting.swift
···
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import Foundation
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import Nuke
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import os
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private let diskCacheSignposter = OSSignposter(subsystem: "social.grain.grain", category: "DiskCache")
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/// Emits an os_signpost event every time Nuke is about to write an image to
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/// the on-disk `DataCache`. After the "fullsize never disk-cached" refactor,
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/// only thumb + avatar URLs should appear in `DiskCacheWrite` events — a
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/// fullsize URL showing up means the `.disableDiskCacheWrites` option leaked.
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/// `data.count` in the event payload makes thumb (~50–300 KB) vs fullsize
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/// (~1–5 MB) vs avatar (~5–50 KB) obvious at a glance.
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final class GrainImagePipelineDelegate: ImagePipelineDelegate {
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func willCache(
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data: Data,
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image _: ImageContainer?,
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for request: ImageRequest,
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pipeline _: ImagePipeline,
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completion: @escaping (Data?) -> Void
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) {
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let name = request.url?.lastPathComponent ?? "nil"
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diskCacheSignposter.emitEvent("DiskCacheWrite", "\(name) bytes=\(data.count)")
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completion(data)
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}
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}