feat(转换能力): 支持原生与网页批量并行

assets/webui/index.html

@@ -199,6 +199,7 @@
 						<div id="convertFontRow" class="form-row" hidden><label for="convertFontMode">字体</label><select id="convertFontMode"><option value="0">保持</option><option value="1">内嵌</option><option value="2">外部</option></select></div>
 						<div id="convertDPIRow" class="form-row" hidden><label for="convertDPI">精度</label><select id="convertDPI"><option value="96">96 dpi</option><option value="150">150 dpi</option><option value="300" selected>300 dpi</option><option value="600">600 dpi</option></select></div>
 						<div class="form-row"><label for="convertDestination">保存</label><select id="convertDestination"><option value="directory">目录</option><option value="archive">打包</option></select></div>
+						<div class="form-row"><label for="convertParallel">并行</label><input id="convertParallel" type="number" min="1" step="1" placeholder="自动"></div>
 					</div>
 					<button id="convertClose" class="button" type="button">关闭</button><button id="convertCancel" class="button" type="button" hidden>取消</button><button id="convertStart" class="button" type="submit" disabled>转换</button>
 				</div>

assets/webui/ofdgo.css

@@ -803,7 +803,7 @@ button:not(:disabled):hover {
 .convert-options {
 	flex: none;
 	display: grid;
-	grid-template-columns: repeat(4, minmax(0, 1fr));
+	grid-template-columns: repeat(5, minmax(0, 1fr));
 	grid-column: 1 / -1;
 	grid-row: 1;
 	width: 100%;
@@ -812,11 +812,11 @@ button:not(:disabled):hover {
 }
 
 .convert-options:has(#convertDPIRow[hidden]):has(#convertFontRow[hidden]) {
-	grid-template-columns: repeat(3, minmax(0, 1fr));
+	grid-template-columns: repeat(4, minmax(0, 1fr));
 }
 
 .convert-options:has(#convertDPIRow:not([hidden])):has(#convertFontRow:not([hidden])) {
-	grid-template-columns: repeat(5, minmax(0, 1fr));
+	grid-template-columns: repeat(6, minmax(0, 1fr));
 }
 
 .convert-options .form-row {
@@ -1059,12 +1059,13 @@ button:not(:disabled):hover {
 		margin: 0;
 	}
 	.convert-options:has(#convertDPIRow[hidden]):has(#convertFontRow[hidden]) {
-		grid-template-columns: repeat(3, minmax(0, 1fr));
+		grid-template-columns: repeat(2, minmax(0, 1fr));
 	}
 	.convert-options:has(#convertDPIRow:not([hidden])):has(#convertFontRow:not([hidden])) {
 		grid-template-columns: repeat(2, minmax(0, 1fr));
 	}
-	.convert-options:has(#convertDPIRow:not([hidden])):has(#convertFontRow:not([hidden])) .form-row:last-child {
+	.convert-options:has(#convertDPIRow[hidden]):has(#convertFontRow:not([hidden])) .form-row:last-child,
+	.convert-options:has(#convertDPIRow:not([hidden])):has(#convertFontRow[hidden]) .form-row:last-child {
 		grid-column: 1 / -1;
 	}
 	.convert-options .form-row {

assets/webui/ofdgo.js

@@ -20,8 +20,8 @@ const STATUS = {
 };
 const wasmRequests = new Map();
 const metaContents = new WeakMap();
-const batch = { items: [], formats: [], running: false, canceled: false, worker: null, requests: new Map(), sequence: 0, activeID: 0, progressTime: 0, progress: null };
-const batchElements = Object.fromEntries(["Button", "Panel", "Form", "Input", "Add", "Clear", "Count", "Format", "Compression", "FontRow", "FontMode", "Destination", "DPIRow", "DPI", "List", "Empty", "Progress", "Status", "Close", "Cancel", "Start"].map(name => [name, document.querySelector(`#convert${name}`)]));
+const batch = { items: [], formats: [], running: false, canceled: false, workers: new Set(), requests: new Map(), sequence: 0, progress: null, jobs: [], credentials: Promise.resolve() };
+const batchElements = Object.fromEntries(["Button", "Panel", "Form", "Input", "Add", "Clear", "Count", "Format", "Compression", "FontRow", "FontMode", "Destination", "DPIRow", "DPI", "Parallel", "List", "Empty", "Progress", "Status", "Close", "Cancel", "Start"].map(name => [name, document.querySelector(`#convert${name}`)]));
 const fontBinding = { font: null, choices: [], sequence: 0 };
 const fontBindingElements = Object.fromEntries(["Panel", "Form", "Title", "Name", "SourceRow", "Source", "File", "Hint", "Status", "Cancel", "Submit"].map(name => [name, document.querySelector(`#fontBinding${name}`)]));
 const resourceElements = Object.fromEntries(["ManageButton", "Panel", "Form", "Kind", "List", "Empty", "Reference", "ReferenceGroup", "Actions", "Add", "Preview", "Export", "Rename", "Replace", "Delete", "Locate", "Close", "Binding", "BindingActions", "Page", "Object", "Pick", "Bind", "Unbind", "Viewer", "Status", "File"].map(name => [name, document.querySelector(`#resource${name}`)]));
@@ -8128,7 +8128,7 @@ function renderBatchList() {
 }
 
 function updateBatchControls() {
-	for (const name of ["Add", "Clear", "Format", "Compression", "FontMode", "Destination", "DPI"]) batchElements[name].disabled = batch.running;
+	for (const name of ["Add", "Clear", "Format", "Compression", "FontMode", "Destination", "DPI", "Parallel"]) batchElements[name].disabled = batch.running;
 	batchElements.FontRow.hidden = !(batch.items.length ? batch.items : [null]).some(item => (item?.format || batchElements.Format.value) === "ofd");
 	batchElements.Compression.disabled ||= (batch.items.length ? batch.items : [null]).every(item => (item?.format || batchElements.Format.value) === "txt");
 	batchElements.Clear.disabled ||= !batch.items.length;
@@ -8159,16 +8159,31 @@ function batchStatus(item, status, text) {
 function batchProgress(item, position, count, progress) {
 	if (batch.canceled) return;
 	const now = performance.now();
-	const previous = batch.progress;
+	const previous = item ? item.progress : batch.progress;
 	const sameStage = previous?.item === item && previous?.progress.phase === progress.phase;
-	if (sameStage && now - batch.progressTime < 80 && progress.completed !== progress.total) return;
-	batch.progressTime = now;
-	batch.progress = { item, position, count, progress, started: sameStage ? previous.started : now };
+	if (sameStage && now - previous.updated < 80 && progress.completed !== progress.total) return;
+	const current = { item, position, count, progress, started: sameStage ? previous.started : now, updated: now };
+	if (item) item.progress = current;
+	else batch.progress = current;
 	updateBatchProgress();
 }
 
 function updateBatchProgress() {
-	if (!batch.progress) return;
+	if (batch.canceled) return;
+	for (const item of batch.jobs) {
+		if (item.status !== "running" || !item.progress) continue;
+		const progress = item.progress.progress;
+		const stage = progress.phase?.includes("compress") ? "压缩" : progress.phase?.startsWith("write") ? "写入" : { open: "读取", pages: "解析", convert: "转换", prepare: "准备", fonts: "字体", export: "导出" }[progress.phase] || "处理";
+		batchStatus(item, "running", `${stage}${progress.total > 0 ? ` ${progress.completed}/${progress.total}` : ""}`);
+	}
+	if (!batch.progress) {
+		const completed = batch.jobs.filter(item => ["done", "ready", "unchanged", "failed", "canceled"].includes(item.status)).length;
+		const running = batch.jobs.filter(item => item.status === "running").length;
+		batchElements.Status.textContent = `完成 ${completed}/${batch.jobs.length} · 运行 ${running}`;
+		batchElements.Progress.max = batch.jobs.length || 1;
+		batchElements.Progress.value = completed;
+		return;
+	}
 	const { item, position, count, progress, started } = batch.progress;
 	const compressing = progress.phase === "compress" || progress.phase === "write.compress";
 	const fontMode = (item?.format || batchElements.Format.value) === "ofd" ? batchElements.FontMode.value : "0";
@@ -8182,29 +8197,29 @@ function updateBatchProgress() {
 	else batchElements.Progress.removeAttribute("value");
 }
 
-function batchCall(name, args, onProgress) {
+function batchCall(slot, name, args, onProgress) {
 	return new Promise((resolve, reject) => {
-		if (batch.workerError) { reject(batch.workerError); return; }
+		if (slot.error) { reject(slot.error); return; }
+		if (batch.canceled) { reject(new DOMException("已取消转换", "AbortError")); return; }
 		const id = ++batch.sequence;
-		batch.activeID = id;
-		batch.requests.set(id, { resolve, reject, onProgress, destination: name === "ofdgoConvertFile" ? args[3] : null });
-		try { batch.worker.postMessage({ id, name, args }); }
-		catch (err) { batch.requests.delete(id); batch.activeID = 0; reject(err); }
+		batch.requests.set(id, { slot, resolve, reject, onProgress, destination: name === "ofdgoConvertFile" ? args[3] : null });
+		try { slot.worker.postMessage({ id, name, args }); }
+		catch (err) { batch.requests.delete(id); reject(err); }
 	});
 }
 
 function startBatchWorker() {
-	batch.workerError = null;
 	return new Promise((resolve, reject) => {
 		const worker = createEngineWorker();
-		batch.worker = worker;
+		const slot = { worker, error: null };
+		batch.workers.add(slot);
 		const fail = async error => {
-			batch.workerError = error;
+			slot.error = error;
 			worker.terminate();
 			reject(error);
-			const requests = [...batch.requests.values()];
-			batch.requests.clear();
-			for (const request of requests) {
+			for (const [id, request] of batch.requests) {
+				if (request.slot !== slot) continue;
+				batch.requests.delete(id);
 				if (request.destination && request.outputName) {
 					try { await request.destination.removeEntry(request.outputName, { recursive: true }); }
 					catch (err) { error = new Error(`${error.message}；清理失败：${err.message}`); }
@@ -8215,7 +8230,7 @@ function startBatchWorker() {
 		worker.onerror = event => fail(new Error(event.message || "转换引擎异常"));
 		worker.onmessageerror = () => fail(new Error("转换数据传递失败"));
 		worker.onmessage = async ({ data }) => {
-			if (data.type === "ready") { resolve(); return; }
+			if (data.type === "ready") { resolve(slot); return; }
 			if (data.type === "exit") { fail(new Error(data.error)); return; }
 			if (data.type === "progress") {
 				if (!batch.canceled) batchElements.Status.textContent = { download: "正在下载", compile: "正在编译", start: "正在启动" }[data.phase] || "正在准备";
@@ -8237,8 +8252,8 @@ function startBatchWorker() {
 			}
 			if (data.type === "output") { request.outputName = data.name; return; }
 			if (data.type === "conversion") { request.onProgress?.(data); return; }
+			if (data.memory) slot.memory = data.memory;
 			batch.requests.delete(data.id);
-			if (batch.activeID === data.id) batch.activeID = 0;
 			if (data.ok) request.resolve(data.data);
 			else request.reject(Object.assign(new Error(data.error), { code: data.code, name: data.canceled ? "AbortError" : "Error" }));
 		};
@@ -8250,7 +8265,8 @@ function cancelBatch() {
 	batchElements.Cancel.disabled = true;
 	batch.progress = null;
 	batchElements.Status.textContent = "正在取消";
-	if (batch.activeID) batch.worker.postMessage({ type: "cancel", id: batch.activeID });
+	if (batch.unlocking) finishCredentials(null);
+	for (const [id, request] of batch.requests) request.slot.worker.postMessage({ type: "cancel", id });
 }
 
 function warnBatch(event) {
@@ -8286,6 +8302,8 @@ async function runBatch() {
 	batch.running = true;
 	batch.canceled = false;
 	batch.progress = null;
+	batch.jobs = jobs;
+	batch.credentials = Promise.resolve();
 	const progressTimer = window.setInterval(updateBatchProgress, 1000);
 	renderBatchList();
 	window.addEventListener("beforeunload", warnBatch);
@@ -8294,7 +8312,7 @@ async function runBatch() {
 	let storage = null;
 	let stagingName = "";
 	let packed = false;
-	const entries = [];
+	const results = new Array(jobs.length);
 	try {
 		if (archive) {
 			zipFile = await saveFilePicker({ suggestedName: "转换结果.zip", types: [{ description: "ZIP", accept: { "application/zip": [".zip"] } }] });
@@ -8313,59 +8331,93 @@ async function runBatch() {
 		batch.localFonts = fontManager.localEntries();
 		batch.fontData = new Map();
 		batchElements.Status.textContent = "正在准备";
-		await startBatchWorker();
+		const first = await startBatchWorker();
 		const fonts = await fontManager.files(fontManager.records());
 		const names = new Set();
-		for (const [position, item] of jobs.entries()) {
-			if (batch.canceled) break;
+		const plans = jobs.map(item => {
 			item.details = [];
 			const format = batch.formats.find(format => format.value === (item.format || defaultFormat.value));
 			const base = item.file.name.replace(/\.[^.]+$/, "").replace(/[<>:"/\\|?*\x00-\x1f]/g, "_").replace(/[. ]+$/g, "") || "document";
 			let unique = base;
 			const outputName = () => (format.paged ? unique : `${unique}.${format.extension}`).toLowerCase();
-			for (let suffix = 2; archive && names.has(outputName()); suffix++) unique = `${base} (${suffix})`;
+			for (let suffix = 2; names.has(outputName()); suffix++) unique = `${base} (${suffix})`;
 			names.add(outputName());
 			const options = { format: format.value, pages: pageRange(item), dpi, backend, archive, compression, base: unique, credentials: null,
 				fontNames: [...batch.localFonts.keys()], fontMode: format.value === "ofd" ? Number(batchElements.FontMode.value) : 0 };
-			try {
-				for (;;) {
-					try {
-						const result = await batchCall("ofdgoConvertFile", [item.file, options, fonts, destination], progress => batchProgress(item, position, jobs.length, progress));
-						for (const file of result.files) entries.push(file);
-						item.details = (result.pdf?.Warnings || []).map(warning => `${warning.Page ? `第${warning.Page}页：` : ""}${warning.Message}`);
-						for (const font of result.fonts || []) item.details.push(`${font.name}：${font.changed ? options.fontMode === 1 ? "已嵌入" : "已外置" : `未处理 · ${fontBindingError(font.reason)}`}`);
-						if (result.unchanged && !result.bytes) {
-							batchStatus(item, "unchanged", "原样");
-							item.details = ["无需转换，源文件未改动"];
-						} else batchStatus(item, archive ? "ready" : "done", archive ? "待存" : "完成");
-						break;
-					} catch (err) {
-						if (batch.canceled || !["credentialsRequired", "invalidCredentials", "pdfPassword"].includes(err.code)) throw err;
-						const code = err.code === "pdfPassword" ? options.credentials ? "invalidCredentials" : "credentialsRequired" : err.code;
-						options.credentials?.password?.fill(0);
-						options.credentials?.key?.fill(0);
-						options.credentials?.keyPassword?.fill(0);
-						options.credentials = await requestCredentials(code, state.openSeq, err.code === "pdfPassword");
-						if (!options.credentials) throw new DOMException("已取消解锁", "AbortError");
-						const preservesEncryption = err.code === "pdfPassword" && format.value === "pdf" && compression.mode !== 0 && !options.pages;
-						if (!preservesEncryption && !window.confirm("转换结果将不保留原加密，是否继续？")) throw new DOMException("已取消转换", "AbortError");
+			return { item, format, options };
+		});
+		const capacity = nativeHost ? (await nativeHost.call("batch", {})).parallelism : Math.max(1, (navigator.hardwareConcurrency || 2) - 1);
+		const automatic = nativeHost ? capacity : Math.min(capacity, Math.max(1, Math.floor((navigator.deviceMemory || 4) / 2)));
+		const parallel = Math.min(jobs.length, nativeHost ? capacity : jobs.length, Number(batchElements.Parallel.value) || automatic);
+		const workerMemory = (navigator.deviceMemory || 4) * 1024 ** 3 / 4 / parallel;
+		let next = 0;
+		const run = async initial => {
+			let slot = initial;
+			while (!batch.canceled && next < plans.length) {
+				const position = next++;
+				const { item, format, options } = plans[position];
+				batchStatus(item, "running", "准备");
+				updateBatchProgress();
+				try {
+					if (!slot || slot.error) slot = await startBatchWorker();
+					for (;;) {
+						try {
+							const result = await batchCall(slot, "ofdgoConvertFile", [item.file, options, fonts, destination], progress => batchProgress(item, position, jobs.length, progress));
+							results[position] = result.files;
+							item.details = (result.pdf?.Warnings || []).map(warning => `${warning.Page ? `第${warning.Page}页：` : ""}${warning.Message}`);
+							for (const font of result.fonts || []) item.details.push(`${font.name}：${font.changed ? options.fontMode === 1 ? "已嵌入" : "已外置" : `未处理 · ${fontBindingError(font.reason)}`}`);
+							if (result.unchanged && !result.bytes) {
+								batchStatus(item, "unchanged", "原样");
+								item.details = ["无需转换，源文件未改动"];
+							} else batchStatus(item, archive ? "ready" : "done", archive ? "待存" : "完成");
+							break;
+						} catch (err) {
+							if (batch.canceled || !["credentialsRequired", "invalidCredentials", "pdfPassword"].includes(err.code)) throw err;
+							const code = err.code === "pdfPassword" ? options.credentials ? "invalidCredentials" : "credentialsRequired" : err.code;
+							options.credentials?.password?.fill(0);
+							options.credentials?.key?.fill(0);
+							options.credentials?.keyPassword?.fill(0);
+							const unlock = batch.credentials.then(async () => {
+								if (batch.canceled) throw new DOMException("已取消转换", "AbortError");
+								batch.unlocking = true;
+								try { return await requestCredentials(code, state.openSeq, err.code === "pdfPassword"); }
+								finally { batch.unlocking = false; }
+							});
+							batch.credentials = unlock.then(() => {}, () => {});
+							options.credentials = await unlock;
+							if (!options.credentials) throw new DOMException("已取消解锁", "AbortError");
+							const preservesEncryption = err.code === "pdfPassword" && format.value === "pdf" && compression.mode !== 0 && !options.pages;
+							if (!preservesEncryption && !window.confirm("转换结果将不保留原加密，是否继续？")) throw new DOMException("已取消转换", "AbortError");
+						}
+					}
+				} catch (err) {
+					batchStatus(item, err.name === "AbortError" ? "canceled" : "failed", err.name === "AbortError" ? "取消" : "失败");
+					item.details = [err.message];
+				} finally {
+					item.progress = null;
+					options.credentials?.password?.fill(0);
+					options.credentials?.key?.fill(0);
+					options.credentials?.keyPassword?.fill(0);
+					if (!nativeHost && slot && (next >= plans.length || slot.memory >= workerMemory)) {
+						slot.worker.terminate();
+						batch.workers.delete(slot);
+						slot = null;
 					}
 				}
-			} catch (err) {
-				batchStatus(item, err.name === "AbortError" ? "canceled" : "failed", err.name === "AbortError" ? "取消" : "失败");
-				item.details = [err.message];
-				if (batch.workerError) throw err;
-			} finally {
-				batch.progress = null;
-				options.credentials?.password?.fill(0);
-				options.credentials?.key?.fill(0);
-				options.credentials?.keyPassword?.fill(0);
+				updateBatchProgress();
 			}
-			batchElements.Progress.max = jobs.length;
-			batchElements.Progress.value = position + 1;
-		}
+		};
+		const running = Array.from({ length: parallel }, (_, index) => (async () => {
+			if (index) await new Promise(resolve => window.setTimeout(resolve, index * 200));
+			await run(index === 0 ? first : null);
+		})());
+		const settled = await Promise.allSettled(running);
+		const failure = settled.find(result => result.status === "rejected");
+		if (failure) throw failure.reason;
+		const entries = results.flat().filter(Boolean);
 		if (archive && entries.length && !batch.canceled) {
-			const result = await batchCall("ofdgoPackFiles", [entries, zipFile, compression], progress => batchProgress(null, 0, 1, progress));
+			const slot = [...batch.workers].find(slot => !slot.error) || await startBatchWorker();
+			const result = await batchCall(slot, "ofdgoPackFiles", [entries, zipFile, compression], progress => batchProgress(null, 0, 1, progress));
 			if (result.blob) downloadBytes(result.blob, "application/zip", "转换结果.zip");
 			packed = true;
 			for (const item of jobs) if (item.status === "ready") batchStatus(item, "done", "完成");
@@ -8381,10 +8433,10 @@ async function runBatch() {
 		batch.progress = null;
 		if (!batchElements.Progress.hasAttribute("value")) batchElements.Progress.value = 0;
 		if (archive && !packed) for (const item of jobs) if (item.status === "ready") { item.status = "pending"; item.text = "待转"; }
-		batch.worker?.terminate();
-		batch.worker = null;
+		for (const slot of batch.workers) slot.worker.terminate();
+		batch.workers.clear();
 		batch.requests.clear();
-		batch.activeID = 0;
+		if (nativeHost) await nativeHost.release(results);
 		batch.fontData?.clear();
 		batch.localFonts?.clear();
 		if (storage && stagingName) {

assets/webui/ofdgo_host.js

@@ -1,5 +1,15 @@
+let engineModule = null;
+
 export function createEngineWorker() {
-	return nativeHost ? nativeHost.worker() : new Worker("./ofdgo_wasm.js");
+	if (nativeHost) return nativeHost.worker();
+	const worker = new Worker("./ofdgo_wasm.js");
+	worker.addEventListener("message", event => {
+		if (event.data.type !== "module") return;
+		event.stopImmediatePropagation();
+		engineModule ||= WebAssembly.compileStreaming(fetch("./ofdgo.wasm")).catch(error => { engineModule = null; throw error; });
+		engineModule.then(module => worker.postMessage({ type: "module", module }), error => worker.postMessage({ type: "module", error: error.message }));
+	});
+	return worker;
 }
 
 export async function documentBytes(file) {
@@ -124,7 +134,11 @@ class NativeHost {
 		let unsubscribe;
 		let pending = Promise.resolve();
 		const requests = new Map();
-		const emit = data => { if (!closed) worker.onmessage?.({data}); };
+		const completions = new Map();
+		const emit = data => {
+			if (data.type === "result") { completions.get(data.id)?.(data.result); return; }
+			if (!closed) worker.onmessage?.({data});
+		};
 		const ready = host.call("engine.open", {}).then(({engine}) => {
 			if (closed) return engine;
 			unsubscribe = host.bridge.on(`ofdgo.engine.${engine}`, emit);
@@ -147,7 +161,21 @@ class NativeHost {
 					const engine = await ready;
 					if (closed) return;
 					controller.signal.throwIfAborted();
-					const result = await host.call("engine.call", {engine, id:data.id, name:data.name, args:data.args}, controller.signal);
+					const args = {engine, id:data.id, name:data.name, args:data.args};
+					let result;
+					if (data.name === "ofdgoConvertFile" || data.name === "ofdgoPackFiles") {
+						const completed = new Promise(resolve => completions.set(data.id, resolve));
+						const cancel = () => host.call("engine.cancel", {engine, id:data.id}).catch(() => {});
+						controller.signal.addEventListener("abort", cancel, {once:true});
+						try {
+							await host.call("engine.start", args, controller.signal);
+							result = await completed;
+							await host.call("engine.finish", {engine, id:data.id});
+						} finally {
+							controller.signal.removeEventListener("abort", cancel);
+							completions.delete(data.id);
+						}
+					} else result = await host.call("engine.call", args, controller.signal);
 					if (closed) { await host.release(result); return; }
 					let decoded;
 					try {
@@ -163,9 +191,12 @@ class NativeHost {
 			terminate() {
 				if (closed) return;
 				closed = true;
-				unsubscribe?.();
 				for (const controller of requests.values()) controller.abort();
-				ready.then(engine => host.call("engine.close", {engine})).catch(() => {});
+				ready.then(engine => host.call("engine.close", {engine})).catch(() => {}).finally(() => {
+					unsubscribe?.();
+					for (const resolve of completions.values()) resolve({ok:false, canceled:true, error:"会话已关闭"});
+					completions.clear();
+				});
 			},
 		};
 		ready.catch(() => {});

assets/webui/ofdgo_wasm.js

@@ -4,6 +4,7 @@ let pending = Promise.resolve();
 const operations = new Map();
 const fontRequests = new Map();
 let fontSequence = 0;
+let engineMemory = null;
 
 function requestFont(id, signal, name, done) {
 	if (signal.aborted) { done(null, "", true); return; }
@@ -20,6 +21,11 @@ function requestFont(id, signal, name, done) {
 	self.postMessage({ id, type: "font", request, name });
 }
 self.onmessage = ({ data }) => {
+	if (data.type === "module") {
+		if (data.error) exitWASM(new Error(data.error));
+		else loadWASM(data.module).catch(exitWASM);
+		return;
+	}
 	if (data.type === "font") {
 		fontRequests.get(data.request)?.(data);
 		fontRequests.delete(data.request);
@@ -84,12 +90,15 @@ async function handleBatchMessage({ id, name, args }) {
 			if (!format) throw new Error("不支持此格式");
 			root = destination;
 			const base = options.base.replace(/[<>:"/\\|?*\x00-\x1f]/g, "_").replace(/[. ]+$/g, "") || "document";
-			const target = root ? await availableOutput(root, base, format) : { stem: base, name: format.paged ? base : `${base}.${format.extension}` };
-			if (root && format.paged) {
-				directory = await root.getDirectoryHandle(target.name, { create: true });
+			const target = root ? await navigator.locks.request("ofdgo-convert-output", { signal }, async () => {
+				signal.throwIfAborted();
+				const target = await availableOutput(root, base, format);
+				if (format.paged) directory = await root.getDirectoryHandle(target.name, { create: true });
+				else { await root.getFileHandle(target.name, { create: true }); directory = root; }
 				created = target.name;
 				self.postMessage({ id, type: "output", name: created });
-			} else directory = root;
+				return target;
+			}) : { stem: base, name: format.paged ? base : `${base}.${format.extension}` };
 			const boundary = async (action, pageName) => {
 				signal.throwIfAborted();
 				if (action === "open") {
@@ -144,7 +153,7 @@ async function handleBatchMessage({ id, name, args }) {
 		}
 		result.data.size = size;
 		operations.delete(id);
-		self.postMessage({ id, ...result });
+		self.postMessage({ id, ...result, memory: engineMemory.buffer.byteLength });
 	} catch (err) {
 		await output?.abort().catch(() => {});
 		let message = signal.aborted ? "转换已取消" : err.message;
@@ -152,7 +161,7 @@ async function handleBatchMessage({ id, name, args }) {
 			try { await root.removeEntry(created, { recursive: true }); }
 			catch (cleanupError) { message += `；清理失败：${cleanupError.message}`; }
 		}
-		self.postMessage({ id, ok: false, error: message, code: err.code, canceled: signal.aborted });
+		self.postMessage({ id, ok: false, error: message, code: err.code, canceled: signal.aborted, memory: engineMemory.buffer.byteLength });
 	} finally {
 		credentials?.password?.fill(0);
 		credentials?.key?.fill(0);
@@ -301,12 +310,10 @@ function exitWASM(err) {
 	self.close();
 }
 
-async function loadWASM() {
+async function loadWASM(module) {
 	const go = new Go();
-	self.postMessage({ type: "progress", phase: "download", text: "正在下载引擎", percent: 16 });
-	const response = await fetch("./ofdgo.wasm");
-	self.postMessage({ type: "progress", phase: "compile", text: "正在编译引擎", percent: 35 });
-	const { instance } = await WebAssembly.instantiateStreaming(response, go.importObject);
+	const instance = await WebAssembly.instantiate(module, go.importObject);
+	engineMemory = instance.exports.mem;
 	self.postMessage({ type: "progress", phase: "start", text: "正在启动引擎", percent: 58 });
 	go.run(instance).then(exitWASM, exitWASM);
 	if (!go.exited) {
@@ -316,4 +323,4 @@ async function loadWASM() {
 	}
 }
 
-loadWASM().catch(exitWASM);
+self.postMessage({ type: "module" });

internal/webui/webui.go

@@ -424,6 +424,7 @@ type businessEngine struct {
 	copiedStyle    *ofdgo.GraphicObject
 	ctx            context.Context
 	resolveSource  func(context.Context, any) (io.ReaderAt, int64, error)
+	conversionPool *ofdgo.ConversionPool
 }
 
 // Open 打开浏览器内存中的OFD文档
@@ -1391,6 +1392,7 @@ func (e *businessEngine) convertFile(args []platformValue) (any, error) {
 	}
 	options := ofdgo.ConvertOptions{
 		Format: settings.Get("format").String(), PageRange: settings.Get("pages").String(),
+		Pool:            e.conversionPool,
 		SkipUnchanged:   true,
 		Backends:        &backends,
 		RendererOptions: []ofdgo.RendererOption{ofdgo.WithDPI(settings.Get("dpi").Float())},

internal/webui/webui_native.go

@@ -67,6 +67,8 @@ type NativeOutputTarget struct {
 // hooks应在首次Call前配置，Resolve返回的资源需保持有效直到相应会话关闭
 type NativeEngine struct {
 	businessEngine
+	// ConversionPool 协调不同会话的批量转换资源
+	ConversionPool *ofdgo.ConversionPool
 	// Resolve 按授权标识提供资源读取源
 	Resolve NativeResolver
 	// LoadFont 按名称读取系统字体数据
@@ -134,7 +136,11 @@ func NewNativeEngine(resolve NativeResolver) *NativeEngine { return &NativeEngin
 // 批量输出到非nil目标时必须同时提供ReserveOutput和CleanupOutput，避免误清理既有文件
 // 取消为协作式检查，不能抢占宿主阻塞的ReadAt、字体读取或加密库内部计算
 func (e *NativeEngine) Call(ctx context.Context, name string, args []any, emit func(any)) (result map[string]any) {
-	e.once.Do(func() { e.gate = make(chan struct{}, 1); e.resolveSource = e.source })
+	e.once.Do(func() {
+		e.gate = make(chan struct{}, 1)
+		e.resolveSource = e.source
+		e.conversionPool = e.ConversionPool
+	})
 	if ctx == nil {
 		ctx = context.Background()
 	}

internal/webview/webview.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-//go:build windows && amd64
+//go:build !js || !wasm
 
 package webview
 
@@ -44,17 +44,19 @@ const applicationID = "me.aite.ofdgo"
 
 // Host 连接桌面系统能力和共用文档业务
 type Host struct {
-	mu           sync.Mutex
-	window       *guigo.Window
-	files        *fileStore
-	engines      map[string]*webui.NativeEngine
-	engineStops  map[string]func() bool
-	cancels      map[string]context.CancelFunc
-	fontOnce     sync.Once
-	fonts        []map[string]any
-	fontFiles    map[string]string
-	fontError    error
-	pendingPaths []string
+	mu             sync.Mutex
+	window         *guigo.Window
+	files          *fileStore
+	engines        map[string]*webui.NativeEngine
+	engineStops    map[string]func() bool
+	conversionPool *ofdgo.ConversionPool
+	cancels        map[string]context.CancelFunc
+	batchResults   map[string]any
+	fontOnce       sync.Once
+	fonts          []map[string]any
+	fontFiles      map[string]string
+	fontError      error
+	pendingPaths   []string
 }
 
 // resourceReader 保存资源读取位置及关闭操作
@@ -76,9 +78,14 @@ func Run(ctx context.Context, paths []string, dataDir string) error {
 		return err
 	}
 	h := &Host{files: files, engines: make(map[string]*webui.NativeEngine), cancels: make(map[string]context.CancelFunc), fontFiles: make(map[string]string), pendingPaths: append([]string(nil), paths...)}
+	h.conversionPool, err = ofdgo.NewConversionPool(ofdgo.ConversionPoolOptions{AvailableMemory: conversionMemory})
+	if err != nil {
+		files.close()
+		return err
+	}
 	defer h.close()
 	bindings := make(map[string]guigo.HandlerFunc)
-	for _, name := range []string{"engine.open", "engine.close", "engine.call", "open", "save", "directory", "file", "release", "child", "remove", "write.begin", "write.data", "write.commit", "write.abort", "fonts", "ready", "title"} {
+	for _, name := range []string{"engine.open", "engine.close", "engine.call", "engine.start", "engine.cancel", "engine.finish", "batch", "open", "save", "directory", "file", "release", "child", "remove", "write.begin", "write.data", "write.commit", "write.abort", "fonts", "ready", "title"} {
 		bindings["ofdgo.host."+name] = func(ctx context.Context, args any) (any, error) { return h.call(ctx, name, args) }
 	}
 	static := http.FileServerFS(webuiassets.NativeFS)
@@ -260,6 +267,7 @@ func (h *Host) call(ctx context.Context, name string, value any) (any, error) {
 	switch name {
 	case "engine.open":
 		engine := webui.NewNativeEngine(h.files.resolve)
+		engine.ConversionPool = h.conversionPool
 		engine.OpenWriter = h.openWriter
 		engine.ReserveOutput = h.reserveOutput
 		engine.CleanupOutput = h.cleanupOutput
@@ -273,8 +281,69 @@ func (h *Host) call(ctx context.Context, name string, value any) (any, error) {
 		h.engineStops[id] = context.AfterFunc(guigo.PageContext(ctx), func() { _ = h.closeEngine(id) })
 		h.mu.Unlock()
 		return guigo.Result{Value: map[string]any{"engine": id}, Discard: func() { _ = h.closeEngine(id) }}, nil
+	case "batch":
+		return map[string]any{"parallelism": h.conversionPool.Parallelism()}, nil
 	case "engine.close":
 		return nil, h.closeEngine(text("engine"))
+	case "engine.finish":
+		key := text("engine") + "/" + fmt.Sprint(args["id"])
+		h.mu.Lock()
+		delete(h.batchResults, key)
+		h.mu.Unlock()
+		return nil, nil
+	case "engine.cancel":
+		key := text("engine") + "/" + fmt.Sprint(args["id"])
+		h.mu.Lock()
+		cancel := h.cancels[key]
+		h.mu.Unlock()
+		if cancel != nil {
+			cancel()
+		}
+		return nil, nil
+	case "engine.start":
+		operationName := text("name")
+		if operationName != "ofdgoConvertFile" && operationName != "ofdgoPackFiles" {
+			return nil, fmt.Errorf("unsupported batch operation")
+		}
+		id := text("engine")
+		key := id + "/" + fmt.Sprint(args["id"])
+		page := guigo.PageContext(ctx)
+		operation, cancel := context.WithCancel(page)
+		h.mu.Lock()
+		engine := h.engines[id]
+		_, duplicate := h.cancels[key]
+		if engine == nil || duplicate {
+			h.mu.Unlock()
+			cancel()
+			return nil, fmt.Errorf("invalid batch operation")
+		}
+		h.cancels[key] = cancel
+		h.mu.Unlock()
+		values, _ := args["args"].([]any)
+		go func() {
+			defer cancel()
+			defer func() { h.mu.Lock(); delete(h.cancels, key); h.mu.Unlock() }()
+			result := engine.Call(operation, operationName, values, func(event any) {
+				if value, ok := event.(map[string]any); ok {
+					value["id"] = args["id"]
+					h.emit("ofdgo.engine."+id, value)
+				}
+			})
+			encoded := h.encode(page, result)
+			h.mu.Lock()
+			if page.Err() != nil || h.engines[id] != engine {
+				h.mu.Unlock()
+				h.discard(encoded)
+				return
+			}
+			if h.batchResults == nil {
+				h.batchResults = make(map[string]any)
+			}
+			h.batchResults[key] = encoded
+			h.mu.Unlock()
+			h.emit("ofdgo.engine."+id, map[string]any{"id": args["id"], "type": "result", "result": encoded})
+		}()
+		return guigo.Result{Value: true, Discard: cancel}, nil
 	case "engine.call":
 		id := text("engine")
 		key := id + "/" + fmt.Sprint(args["id"])
@@ -670,6 +739,7 @@ func (h *Host) loadFont(ctx context.Context, name string) ([]byte, error) {
 // 入参: id 会话标识
 // 返回: error 关闭错误
 func (h *Host) closeEngine(id string) error {
+	var results []any
 	h.mu.Lock()
 	engine := h.engines[id]
 	delete(h.engines, id)
@@ -682,7 +752,16 @@ func (h *Host) closeEngine(id string) error {
 			cancel()
 		}
 	}
+	for key, result := range h.batchResults {
+		if strings.HasPrefix(key, id+"/") {
+			results = append(results, result)
+			delete(h.batchResults, key)
+		}
+	}
 	h.mu.Unlock()
+	for _, result := range results {
+		h.discard(result)
+	}
 	if engine != nil {
 		return engine.Close()
 	}

internal/webview/webview_memory_other.go

@@ -0,0 +1,20 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build !windows
+
+package webview
+
+// conversionMemory 未提供系统内存探测时仅按并行数调度
+var conversionMemory func() int64

internal/webview/webview_memory_windows.go

@@ -0,0 +1,45 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package webview
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+// memoryStatusProc 查询系统物理内存和提交额度
+var memoryStatusProc = syscall.NewLazyDLL("kernel32.dll").NewProc("GlobalMemoryStatusEx")
+
+// conversionMemory 预留系统内存后返回可用于新增转换的额度
+// 返回: int64 可用字节数，查询失败时暂停扩容
+func conversionMemory() int64 {
+	status := struct {
+		length           uint32
+		load             uint32
+		total            uint64
+		available        uint64
+		totalPage        uint64
+		availablePage    uint64
+		totalVirtual     uint64
+		availableVirtual uint64
+		extended         uint64
+	}{}
+	status.length = uint32(unsafe.Sizeof(status))
+	ok, _, _ := memoryStatusProc.Call(uintptr(unsafe.Pointer(&status)))
+	if ok == 0 {
+		return 0
+	}
+	return max(0, int64(min(status.available, status.availablePage))-int64(status.total/8))
+}

ofdgo_compression_parallel.go

@@ -20,7 +20,6 @@ import (
 	"crypto/sha256"
 	"image"
 	"io"
-	"runtime"
 	"strconv"
 	"sync"
 
@@ -83,11 +82,17 @@ func (e *Editor) outputImageOptions(key string) (CompressionOptions, image.Point
 // 入参: keys 资源路径, load 串行读取方法，空值表示跳过, results 候选缓存, sources 原始资源摘要，可为空
 // 返回: error 读取、进度或取消错误
 func (e *Editor) prepareOutputImages(keys []string, load func(string) ([]byte, error), results map[outputImageKey][]byte, sources map[string]outputImageSource) error {
-	workers := min(4, runtime.GOMAXPROCS(0))
+	workers := conversionWorkers(e.output.ctx, 4)
 	if workers < 2 || len(keys) < 2 {
 		return nil
 	}
-	limit := outputImageWorkingSetLimit
+	limit, encodedLimit := outputImageWorkingSetLimit, outputImageBatchLimit
+	if pool, _ := e.output.ctx.Value(conversionPoolKey{}).(*ConversionPool); pool != nil {
+		if available := pool.memoryLimit(); available > 0 {
+			limit = int(min(available, int64(int(^uint(0)>>1))))
+			encodedLimit = limit
+		}
+	}
 	if strconv.IntSize == 32 {
 		limit = 64 << 20
 	}
@@ -149,14 +154,14 @@ func (e *Editor) prepareOutputImages(keys []string, load func(string) ([]byte, e
 		if pending[cacheKey] {
 			continue
 		}
-		cost := outputImageWorkingSet(e.output.ctx, data)
-		for running != 0 && (len(data) > outputImageBatchLimit-size || cost > limit-workingSet) {
+		cost := imageWorkingSet(e.output.ctx, data, limit)
+		for running != 0 && (len(data) > encodedLimit-size || cost > limit-workingSet) {
 			if err := finish(); err != nil {
 				return err
 			}
 		}
 		job := outputImageJob{key: cacheKey, data: data, workingSet: cost}
-		if len(data) >= outputImageBatchLimit || cost >= limit {
+		if len(data) >= encodedLimit || cost >= limit {
 			if err := e.runOutputImages([]outputImageJob{job}, results); err != nil {
 				return err
 			}
@@ -167,7 +172,7 @@ func (e *Editor) prepareOutputImages(keys []string, load func(string) ([]byte, e
 		size += len(data)
 		workingSet += cost
 		group.Go(func() {
-			job.candidate, job.err = optimizeImageResource(ctx, job.data, job.key.options, job.key.size)
+			job.candidate, job.err = optimizeOutputImage(ctx, job)
 			completed <- job
 		})
 	}
@@ -184,24 +189,31 @@ func (e *Editor) prepareOutputImages(keys []string, load func(string) ([]byte, e
 // 入参: ctx 取消上下文, data 原始图像编码
 // 返回: int 编码及像素缓冲的估算字节数，上限为outputImageWorkingSetLimit
 func outputImageWorkingSet(ctx context.Context, data []byte) int {
-	if len(data) >= outputImageWorkingSetLimit {
-		return outputImageWorkingSetLimit
+	return imageWorkingSet(ctx, data, outputImageWorkingSetLimit)
+}
+
+// imageWorkingSet 按当前预算估算图像解码工作量
+// 入参: ctx 取消上下文, data 图像编码, limit 估算上限
+// 返回: int 工作量字节数
+func imageWorkingSet(ctx context.Context, data []byte, limit int) int {
+	if len(data) >= limit {
+		return limit
 	}
 	input := bytes.NewReader(data)
-	available := outputImageWorkingSetLimit - len(data)
+	available := limit - len(data)
 	if baseimage.IsTIFF(data) {
 		layout, err := baseimage.ReadTIFFLayoutContext(ctx, input)
 		if err != nil {
-			return outputImageWorkingSetLimit
+			return limit
 		}
 		return len(data) + tiffImageWorkingSet(layout, available)
 	}
 	config, _, err := baseimage.DecodeConfig(imageInput{ReadCloser: io.NopCloser(input), context: ctx})
 	if err != nil || config.Width <= 0 || config.Height <= 0 {
-		return outputImageWorkingSetLimit
+		return limit
 	}
 	if config.Width > available/16/config.Height {
-		return outputImageWorkingSetLimit
+		return limit
 	}
 	return len(data) + config.Width*config.Height*16
 }
@@ -239,7 +251,7 @@ func tiffImageWorkingSet(layout baseimage.TIFFLayout, limit int) int {
 func (e *Editor) runOutputImages(jobs []outputImageJob, results map[outputImageKey][]byte) error {
 	ctx := e.output.ctx
 	optimize := func(job *outputImageJob) {
-		job.candidate, job.err = optimizeImageResource(ctx, job.data, job.key.options, job.key.size)
+		job.candidate, job.err = optimizeOutputImage(ctx, *job)
 	}
 	if len(jobs) == 1 {
 		optimize(&jobs[0])
@@ -261,3 +273,23 @@ func (e *Editor) runOutputImages(jobs []outputImageJob, results map[outputImageK
 	}
 	return nil
 }
+
+// optimizeOutputImage 在共享预算内优化独立图像
+// 入参: ctx 转换上下文, job 图像任务
+// 返回: []byte 候选编码, error 转换错误
+func optimizeOutputImage(ctx context.Context, job outputImageJob) ([]byte, error) {
+	if pool, _ := ctx.Value(conversionPoolKey{}).(*ConversionPool); pool != nil {
+		if job.workingSet == 0 {
+			limit := outputImageWorkingSetLimit
+			if available := pool.memoryLimit(); available > 0 {
+				limit = int(min(available, int64(int(^uint(0)>>1))))
+			}
+			job.workingSet = imageWorkingSet(ctx, job.data, limit)
+		}
+		if err := pool.acquire(ctx, true, int64(job.workingSet)); err != nil {
+			return nil, err
+		}
+		defer pool.release(true, int64(job.workingSet))
+	}
+	return optimizeImageResource(ctx, job.data, job.key.options, job.key.size)
+}

ofdgo_compression_resources.go

@@ -294,7 +294,7 @@ func (e *Editor) compressResourceReferences(parts map[string][]byte, reader *Rea
 				candidate, cached := imageResults[cacheKey]
 				var err error
 				if !cached {
-					candidate, err = optimizeImageResource(e.output.ctx, data, options, demand)
+					candidate, err = optimizeOutputImage(e.output.ctx, outputImageJob{data: data, key: outputImageKey{options: options, size: demand}})
 					if err := e.output.ctx.Err(); err != nil {
 						return err
 					}

ofdgo_convert.go

@@ -45,6 +45,7 @@ type ConvertProgress struct {
 // Input为空时识别源格式，Format为输出格式，Pages使用零基索引，nil表示全部页面
 // PageRange使用一基页码表达式，与Pages互斥，空字符串表示全部页面
 // SkipUnchanged仅在未压缩、源格式与目标相同且未选页时不写出数据
+// Pool可由多个独立转换共享，nil时不限制文件间并发
 // 整份PDF同格式压缩直接重写PDF对象，其余PDF先转换为OFD对象再输出
 // RendererOptions同时用于PDF局部合成和输出，在PDF.RendererOptions之后应用
 // Backends统一配置转换与输出，优先于PDF和RendererOptions中的后端设置
@@ -58,6 +59,7 @@ type ConvertOptions struct {
 	Pages           []int
 	PageRange       string
 	SkipUnchanged   bool
+	Pool            *ConversionPool
 	Compression     CompressionOptions
 	Fonts           FontMode
 	Backends        *RenderBackends
@@ -114,6 +116,13 @@ func OutputFormats() []OutputFormat {
 // 入参: ctx 取消上下文, source 源数据, size 源字节数, output 输出流, options 转换选项
 // 返回: ConvertReport 转换报告, error 错误信息
 func Convert(ctx context.Context, source io.ReaderAt, size int64, output io.Writer, options ConvertOptions) (report ConvertReport, err error) {
+	if options.Pool != nil {
+		if err = options.Pool.acquire(ctx, false, 0); err != nil {
+			return report, err
+		}
+		defer options.Pool.release(false, 0)
+		ctx = context.WithValue(ctx, conversionPoolKey{}, options.Pool)
+	}
 	if err = options.Compression.Validate(); err != nil {
 		return report, err
 	}

ofdgo_convert_pool.go

@@ -0,0 +1,146 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ofdgo
+
+import (
+	"context"
+	"fmt"
+	"runtime"
+	"sync"
+	"time"
+)
+
+// ConversionPoolOptions 设置共享转换并行度及图像工作集预算
+// Parallelism为0时使用GOMAXPROCS，MemoryLimit为0时不指定固定预算
+// AvailableMemory返回可用于新增任务的字节数，nil表示不探测，回调须支持并发调用
+// 内存预算用于调度，不限制解析器及运行时的实际分配
+type ConversionPoolOptions struct {
+	Parallelism     int
+	MemoryLimit     int64
+	AvailableMemory func() int64
+}
+
+// ConversionPool 协调独立转换和图像任务，配置在创建后不变，可跨会话复用
+type ConversionPool struct {
+	options ConversionPoolOptions
+	mu      sync.Mutex
+	changed chan struct{}
+	active  int
+	images  int
+	memory  int64
+}
+
+// conversionPoolKey 标识单次转换使用的共享预算
+type conversionPoolKey struct{}
+
+// NewConversionPool 创建共享转换调度器，不启动后台任务
+// 入参: options 并行及内存选项
+// 返回: *ConversionPool 调度器, error 配置错误
+func NewConversionPool(options ConversionPoolOptions) (*ConversionPool, error) {
+	if options.Parallelism < 0 || options.MemoryLimit < 0 {
+		return nil, fmt.Errorf("invalid conversion pool options")
+	}
+	if options.Parallelism == 0 {
+		options.Parallelism = runtime.GOMAXPROCS(0)
+	}
+	return &ConversionPool{options: options, changed: make(chan struct{})}, nil
+}
+
+// Parallelism 返回同时运行的转换数量上限
+// 返回: int 并行上限
+func (p *ConversionPool) Parallelism() int { return p.options.Parallelism }
+
+// memoryLimit 读取当前可分配的图像工作量预算
+// 返回: int64 可用字节数，负值表示未设置预算
+func (p *ConversionPool) memoryLimit() int64 {
+	limit := int64(-1)
+	if p.options.MemoryLimit > 0 {
+		limit = p.options.MemoryLimit
+	}
+	if p.options.AvailableMemory != nil {
+		available := max(0, p.options.AvailableMemory())
+		if limit < 0 || available < limit {
+			limit = available
+		}
+	}
+	return limit
+}
+
+// acquire 等待转换或图像预算，超预算图像可独占运行
+// 入参: ctx 取消上下文, image 是否为图像任务, size 图像工作量
+// 返回: error 取消错误
+func (p *ConversionPool) acquire(ctx context.Context, image bool, size int64) error {
+	for {
+		if err := ctx.Err(); err != nil {
+			return err
+		}
+		limit := p.memoryLimit()
+		p.mu.Lock()
+		allowed := p.active < p.options.Parallelism && (p.active == 0 || limit != 0)
+		if image {
+			allowed = p.images < runtime.GOMAXPROCS(0) && (p.images == 0 || limit < 0 || size <= limit-p.memory)
+		}
+		if allowed {
+			if image {
+				p.images++
+				p.memory += size
+			} else {
+				p.active++
+			}
+			p.mu.Unlock()
+			return nil
+		}
+		changed := p.changed
+		p.mu.Unlock()
+		timer := time.NewTimer(250 * time.Millisecond)
+		select {
+		case <-ctx.Done():
+			timer.Stop()
+			return ctx.Err()
+		case <-changed:
+		case <-timer.C:
+		}
+		timer.Stop()
+	}
+}
+
+// release 归还任务预算并唤醒等待者
+// 入参: image 是否为图像任务, size 图像工作量
+func (p *ConversionPool) release(image bool, size int64) {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	if image {
+		p.images--
+		p.memory -= size
+	} else {
+		p.active--
+	}
+	close(p.changed)
+	p.changed = make(chan struct{})
+}
+
+// conversionWorkers 按当前文件数量分配内部计算任务
+// 入参: ctx 转换上下文, fallback 非共享模式并行上限
+// 返回: int 内部并行数
+func conversionWorkers(ctx context.Context, fallback int) int {
+	p, _ := ctx.Value(conversionPoolKey{}).(*ConversionPool)
+	if p == nil {
+		return min(fallback, runtime.GOMAXPROCS(0))
+	}
+	p.mu.Lock()
+	active := p.active
+	p.mu.Unlock()
+	return max(1, runtime.GOMAXPROCS(0)/max(1, active))
+}

ofdgo_pdf_mesh.go

@@ -17,7 +17,6 @@ package ofdgo
 import (
 	"fmt"
 	"math"
-	"runtime"
 	"slices"
 	"sync"
 
@@ -438,7 +437,7 @@ func (c *pdfCompositor) mesh(mesh *pdfgo.MeshGradient, space *pdfgo.ColorSpace,
 		}
 		return c.importer.ctx.Err()
 	}
-	workers := min(runtime.GOMAXPROCS(0), 4, max(1, c.height/32))
+	workers := min(conversionWorkers(c.importer.ctx, 4), max(1, c.height/32))
 	if workers == 1 {
 		if err := sampleRows(0, c.height); err != nil {
 			return nil, err