File size: 15,225 Bytes
2c1d035 46b1742 2e65b18 2c1d035 46b1742 2c1d035 46b1742 2c1d035 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 | export function createReaderPdfTextRuntime(readerContext) {
function pdfOcrSource() {
return VoiceOfMLReader.pdfPageSource(readerContext.ocrManifestUrl, location.href, location.origin, "ocr-manifest.json");
}
function v3ResourceUrl(ref) {
readerContext.validateResource(ref);
return new URL(readerContext.readerDownloadApiUrl(`/api/reader-bucket-resource?path=${encodeURIComponent(ref.path)}`), location.href).href;
}
function createPdfV3Repository(sourceSha, pageCount) {
return readerContext.createV3Repository({ sourceSha, pageCount, signal: readerContext.readerAbortController.signal,
resourceUrl: readerContext.v3ResourceUrl,
readJson: (url, ref) => readerContext.readPdfOcrJson(url,
VoiceOfMLReaderSecurity.LIMITS.chapterBytes, ref.sha256, ref.bytes),
readBytes: async (url, ref, signal) => {
const response = await readerContext.fetchReaderUrl(url, signal ? { signal } : {});
if (!response.ok) throw new Error(`HTTP ${response.status}`);
const packed = await VoiceOfMLReaderSecurity.readBytes(response, VoiceOfMLReaderSecurity.LIMITS.chapterBytes);
const actual = [...new Uint8Array(await crypto.subtle.digest("SHA-256", packed))]
.map(value => value.toString(16).padStart(2, "0")).join("");
if (packed.byteLength !== ref.bytes || actual !== ref.sha256) throw new Error("PDF_V3_HASH_MISMATCH");
return packed;
}
});
}
async function readPdfOcrJson(url, limit = VoiceOfMLReaderSecurity.LIMITS.chapterBytes, digest = "", size = 0, priority = "auto") {
const response = await readerContext.fetchReaderUrl(url, { priority });
if (!response.ok) throw new Error(`HTTP ${response.status}`);
let bytes = await VoiceOfMLReaderSecurity.readBytes(response, limit);
if (size && bytes.byteLength !== size) throw new Error("PDF_OCR_SIZE_MISMATCH");
if (digest) {
const actual = [...new Uint8Array(await crypto.subtle.digest("SHA-256", bytes))]
.map((value) => value.toString(16).padStart(2, "0")).join("");
if (actual !== digest) throw new Error("PDF_OCR_HASH_MISMATCH");
}
const parsed = new URL(url, location.href);
if (/\.gz$/i.test(parsed.searchParams.get("path") || parsed.pathname)) {
if (typeof DecompressionStream !== "function") throw new Error("PDF_OCR_GZIP_UNSUPPORTED");
const stream = new Blob([bytes]).stream().pipeThrough(new DecompressionStream("gzip"));
bytes = await VoiceOfMLReaderSecurity.readBytes(new Response(stream), limit);
}
return JSON.parse(new TextDecoder().decode(bytes));
}
async function loadPdfOcrManifest() {
if (readerContext.pdfOcrManifest) return readerContext.pdfOcrManifest;
if (!readerContext.ocrManifestUrl) return null;
if (!readerContext.pdfOcrManifestPromise) {
if (!readerContext.pdfOcrSource()) throw new Error("PDF_OCR_SOURCE_INVALID");
readerContext.pdfOcrManifestPromise = readerContext.readPdfOcrJson(readerContext.ocrManifestUrl, VoiceOfMLReaderSecurity.LIMITS.manifestBytes, "", 0, "high").then((manifest) => {
readerContext.assertReaderActive();
if (manifest.page_count !== readerContext.documentState.pageCount) throw new Error("PDF_OCR_PAGE_COUNT_MISMATCH");
readerContext.pdfOcrManifest = VoiceOfMLReaderSecurity.validatePdfOcrManifest(manifest);
return readerContext.pdfOcrManifest;
});
}
try { return await readerContext.pdfOcrManifestPromise; }
catch (error) { readerContext.pdfOcrManifestPromise = null; throw error; }
}
function loadPdfOcrPage(page, priority = "high") {
const cached = readerContext.cachedPdfOcrPage(page);
if (cached) return Promise.resolve(cached);
const pending = readerContext.pdfOcrPagePromises.get(page);
if (pending) return pending;
const task = Promise.resolve().then(() => {
// OCR is published as its own manifest. The image page manifest may be
// intentionally lean and contain only page_count.
return readerContext.loadPdfOcrManifest().then((manifest) => {
if (manifest?.text_layer) {
readerContext.pdfTextLayerRepository ||= readerContext.createPdfV3Repository(manifest.source_sha256, manifest.page_count);
return readerContext.pdfTextLayerRepository.textPage(manifest.text_layer, page).then(payload => {
if (readerContext.pdfV3Map) {
const geometry = readerContext.pdfV3Map.pages[page - 1];
if (Math.abs((payload.geometry.width / payload.geometry.height) / (geometry.width / geometry.height) - 1) > .01)
throw new Error("PDF_V3_TEXT_GEOMETRY_MISMATCH");
}
readerContext.assertReaderActive(); readerContext.cachePdfOcrPage(page, payload); return payload;
});
}
const entry = manifest?.pages?.[page - 1];
if (!entry || entry.p !== page) throw new Error("PDF_OCR_PAGE_MISSING");
return readerContext.readPdfOcrJson(readerContext.pdfOcrSource().assetUrl(entry.o),
VoiceOfMLReaderSecurity.LIMITS.chapterBytes, entry.os, entry.ob, priority).then((payload) => {
VoiceOfMLReaderSecurity.validatePdfOcrPage(payload, page);
readerContext.cachePdfOcrPage(page, payload);
return payload;
});
});
}).finally(() => readerContext.pdfOcrPagePromises.delete(page));
readerContext.pdfOcrPagePromises.set(page, task);
return task;
}
function estimatePdfTextContentBytes(content) {
let bytes = 0;
for (const item of content?.items || [])
bytes += String(item.str || "").length * 2 + (item.transform?.length || 0) * 8 + 64;
for (const style of Object.values(content?.styles || {}))
bytes += Object.entries(style || {}).reduce(
(total, [key, value]) => total + key.length + String(value).length * 2 + 16, 0
);
return Math.max(128, bytes);
}
function cachePdfTextContent(page, content) {
const bytes = readerContext.estimatePdfTextContentBytes(content);
if (bytes > readerContext.PDF_TEXT_CONTENT_CACHE_BYTES) return;
const previous = readerContext.pdfTextContentCache.get(page);
if (previous) readerContext.pdfTextContentCacheBytes -= previous.bytes;
readerContext.pdfTextContentCache.delete(page);
readerContext.pdfTextContentCache.set(page, { content, bytes });
readerContext.pdfTextContentCacheBytes += bytes;
while (readerContext.pdfTextContentCacheBytes > readerContext.PDF_TEXT_CONTENT_CACHE_BYTES) {
const oldest = readerContext.pdfTextContentCache.keys().next().value;
const removed = readerContext.pdfTextContentCache.get(oldest);
readerContext.pdfTextContentCacheBytes -= removed.bytes;
readerContext.pdfTextContentCache.delete(oldest);
}
}
function cachedPdfTextContent(page) {
const record = readerContext.pdfTextContentCache.get(page);
if (!record) return null;
readerContext.pdfTextContentCache.delete(page);
readerContext.pdfTextContentCache.set(page, record);
return record.content;
}
function loadPdfTextContent(page, pdfPage, generation = null) {
readerContext.assertReaderActive();
const cached = readerContext.cachedPdfTextContent(page);
if (cached) return Promise.resolve(cached);
const pending = readerContext.pdfTextContentPromises.get(page);
if (pending) {
if (generation === null) pending.request.demanded = true;
else pending.request.generation = generation;
readerContext.drainPdfTextWaiters();
return pending;
}
// Rendering and search share extraction, but retain their own cancellation
// and result ownership. Only active work lives here, not another text cache.
const request = { demanded: generation === null, generation, page };
const task = Promise.resolve().then(async () => {
const background = await readerContext.acquirePdfTextSlot(request.demanded, request);
try {
readerContext.assertReaderActive();
if (!request.demanded && !readerContext.isReaderGenerationCurrent("search", request.generation)) throw readerContext.readerAbortError();
const text = await readerContext.awaitReader(pdfPage.getTextContent());
readerContext.cachePdfTextContent(page, text);
return text;
} finally {
readerContext.releasePdfTextSlot(background);
}
})
.finally(() => {
if (readerContext.pdfTextContentPromises.get(page) === task) readerContext.pdfTextContentPromises.delete(page);
});
task.request = request;
readerContext.pdfTextContentPromises.set(page, task);
return task;
}
function estimatePdfOcrPageBytes(payload) {
if (payload?.kind === "pdf-text-layer") return Math.max(128, JSON.stringify(payload).length * 2);
return Math.max(128, (payload?.blocks || []).reduce(
(total, block) => total + String(block?.t || "").length * 2 + 48, 0
));
}
function cachePdfOcrPage(page, payload) {
const bytes = readerContext.estimatePdfOcrPageBytes(payload);
if (bytes > readerContext.PDF_OCR_PAGE_CACHE_BYTES) return;
const previous = readerContext.pdfOcrPageCache.get(page);
if (previous) readerContext.pdfOcrPageCacheBytes -= previous.bytes;
readerContext.pdfOcrPageCache.delete(page);
readerContext.pdfOcrPageCache.set(page, { payload, bytes });
readerContext.pdfOcrPageCacheBytes += bytes;
while (readerContext.pdfOcrPageCacheBytes > readerContext.PDF_OCR_PAGE_CACHE_BYTES) {
const oldest = readerContext.pdfOcrPageCache.keys().next().value;
const removed = readerContext.pdfOcrPageCache.get(oldest);
readerContext.pdfOcrPageCacheBytes -= removed.bytes;
readerContext.pdfOcrPageCache.delete(oldest);
}
}
function cachedPdfOcrPage(page) {
const record = readerContext.pdfOcrPageCache.get(page);
if (!record) return null;
readerContext.pdfOcrPageCache.delete(page);
readerContext.pdfOcrPageCache.set(page, record);
return record.payload;
}
async function renderPdfOcrText(shell) {
if (shell.dataset.textReady === "1" || !readerContext.ocrManifestUrl) return;
if (shell._ocrPromise) return shell._ocrPromise;
const layer = shell.querySelector(".reader-pdf-text");
if (!layer) return;
const epoch = shell._textEpoch || 0;
const task = (async () => {
try {
const page = Number(shell.dataset.page);
await readerContext.acquirePdfTextSlot(readerContext.isPdfPageVisible(shell));
try {
if (epoch !== (shell._textEpoch || 0)) return;
const payload = await readerContext.loadPdfOcrPage(page, readerContext.isPdfPageVisible(shell) ? "high" : "low");
readerContext.assertReaderActive();
if (epoch !== (shell._textEpoch || 0)) return;
if (payload.kind === "pdf-text-layer") {
readerContext.populateIndependentTextLayer(layer, payload);
shell._bookmarkTextItems = payload.regions.map(region => ({ text: region.text, y: region.box[1] }));
} else {
VoiceOfMLReaderSecurity.validatePdfOcrPage(payload, page);
readerContext.populateOcrTextLayer(layer, payload.blocks, payload.layout);
shell._bookmarkTextItems = payload.blocks.map((block) => ({ text: block.t, y: block.b?.[1] || 0 }));
}
shell.dataset.textReady = "1";
readerContext.highlightPdfText(shell);
} finally {
readerContext.releasePdfTextSlot();
}
} catch (error) {
if (!readerContext.readerAbortController.signal.aborted)
console.warn(`PDF page ${shell.dataset.page} OCR text failed`, error);
}
})().finally(() => { if (shell._ocrPromise === task) delete shell._ocrPromise; });
shell._ocrPromise = task;
return task;
}
async function renderPdfText(page, shell, signal = null) {
if (readerContext.ocrManifestUrl && readerContext.pdfV3Manifest) return readerContext.renderPdfOcrText(shell);
if (shell.dataset.textReady === "1") return;
const layer = shell.querySelector(".reader-pdf-text");
if (!layer || typeof page.getTextContent !== "function") return;
const epoch = shell._textEpoch || 0;
try {
const pageNumber = Number(shell.dataset.page);
const text = await readerContext.loadPdfTextContent(pageNumber, page);
readerContext.assertReaderActive();
if (signal?.aborted) return;
readerContext.cachePdfTextContent(pageNumber, text);
if (epoch !== (shell._textEpoch || 0) || !shell.isConnected) return;
const pdfViewport = page.getViewport({ scale: 1 });
shell._bookmarkTextItems = text.items
.filter((item) => item.str && item.str.trim())
.map((item) => {
const point =
item.transform && pdfViewport.convertToViewportPoint
? pdfViewport.convertToViewportPoint(item.transform[4], item.transform[5])
: null;
return {
text: item.str,
y: point ? Math.max(0, Math.min(1, point[1] / Math.max(1, pdfViewport.height))) : 0
};
});
readerContext.populatePdfTextLayer(layer, text.items, pdfViewport, text.styles);
shell.dataset.textReady = "1";
readerContext.highlightPdfText(shell);
} catch (error) {
if (!readerContext.readerAbortController.signal.aborted && !signal?.aborted)
console.warn(`PDF page ${shell.dataset.page} text extraction failed`, error);
}
}
function highlightPdfText(shell, query = readerContext.searchState.query) {
if (!shell || readerContext.readerAbortController.signal.aborted || !query) return;
const layer = shell.querySelector(".reader-pdf-text");
if (!layer || layer.querySelector("mark")) return;
const walker = document.createTreeWalker(layer, NodeFilter.SHOW_TEXT), runs = [];
let raw = "";
while (walker.nextNode()) {
const node = walker.currentNode, start = raw.length;
raw += node.data;
runs.push({ node, start, end: raw.length });
}
const mapping = readerContext.pdfSearchText(raw);
const hits = [];
for (const hit of mapping.text.matchAll(new RegExp(readerContext.fullSearchEscape(readerContext.normalizePdfSearchText(query)), "giu"))) {
hits.push(hit);
if (hits.length === 100) break;
}
// Bound highlights in the displayed page, without limiting searchable results.
for (const hit of hits.reverse()) {
const start = readerContext.pdfSourceOffset(mapping, hit.index), end = readerContext.pdfSourceOffset(mapping, hit.index + hit[0].length - 1) + 1;
readerContext.highlightTextParts(runs.filter((run) => run.end > start && run.start < end).map((run) => ({
node: run.node, start: Math.max(start, run.start) - run.start, end: Math.min(end, run.end) - run.start
})));
}
}
return {
pdfOcrSource,
v3ResourceUrl,
createPdfV3Repository,
readPdfOcrJson,
loadPdfOcrManifest,
loadPdfOcrPage,
estimatePdfTextContentBytes,
cachePdfTextContent,
cachedPdfTextContent,
loadPdfTextContent,
estimatePdfOcrPageBytes,
cachePdfOcrPage,
cachedPdfOcrPage,
renderPdfOcrText,
renderPdfText,
highlightPdfText
};
}
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