feat(编辑能力): 完善保存另存与后台编辑

assets/webui/index.html

@@ -22,6 +22,7 @@
 					<button id="closeButton" class="icon-button" type="button" title="关闭" disabled><span class="close-icon"></span></button>
 					<button id="newButton" class="icon-button" type="button" title="新建"><span class="new-icon"></span></button>
 					<button id="saveButton" class="icon-button" type="button" title="保存" disabled><span class="save-icon"></span></button>
+					<button id="saveAsButton" class="icon-button" type="button" title="另存" disabled><span class="save-as-icon"></span></button>
 					<button id="editButton" class="icon-button" type="button" title="编辑" data-pressed="false" disabled><span class="edit-icon"></span></button>
 					<button id="convertButton" class="icon-button" type="button" title="转换"><span class="convert-icon"></span></button>
 					<button id="togglePagesButton" class="icon-button" type="button" title="页面栏" data-pressed="true"><span class="pages-icon"></span></button>
@@ -206,7 +207,7 @@
 						<div class="form-row"><label for="convertCompression">压缩</label><select id="convertCompression"><option value="0">原始</option><option value="1">无损</option><option value="2">轻压</option><option value="3">均衡</option><option value="4">强压</option></select></div>
 						<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><div class="form-select"><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><span id="convertDPIValue">300</span></div></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="convertDestination">输出</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>

assets/webui/ofdgo.css

@@ -563,6 +563,7 @@ button:not(:disabled):hover {
 .close-icon,
 .new-icon,
 .save-icon,
+.save-as-icon,
 .edit-icon,
 .convert-icon,
 .pages-icon,
@@ -593,6 +594,10 @@ button:not(:disabled):hover {
 	mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='black' stroke-width='1.7' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='m15 4 5 5M3 21l2-7L16 3a2 2 0 0 1 5 5L10 19Z'/%3E%3C/svg%3E") center / contain no-repeat;
 }
 
+.save-as-icon {
+	mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='black' stroke-width='1.7' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M10 21H5a2 2 0 0 1-2-2V5a2 2 0 0 1 2-2h11l5 5v3M7 3v5h8M7 21v-8h4m3 8 7-7m-7 0h7v7'/%3E%3C/svg%3E") center / contain no-repeat;
+}
+
 .convert-icon {
 	mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='black' stroke-width='1.7' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M3 7h18l-4-4M21 17H3l4 4'/%3E%3C/svg%3E") center / contain no-repeat;
 }

assets/webui/ofdgo.js

@@ -52,6 +52,8 @@ const state = {
 	wasmRecovering: false,
 	wasmRecoveries: 0,
 	exporting: false,
+	saving: false,
+	saveRequestID: 0,
 	signing: false,
 	signCanceled: false,
 	exportRequestID: 0,
@@ -61,6 +63,8 @@ const state = {
 	editorInfo: null,
 	editorViews: new Map(),
 	savedRevision: null,
+	saveHandle: null,
+	saveStamp: null,
 	packageDirty: false,
 	encryptionDirty: false,
 	insertObject: null,
@@ -428,6 +432,7 @@ const el = {
 	pageStatus: document.querySelector("#pageStatus"),
 	pageCancel: document.querySelector("#pageCancel"),
 	saveButton: document.querySelector("#saveButton"),
+	saveAsButton: document.querySelector("#saveAsButton"),
 	createPanel: document.querySelector("#createPanel"),
 	createMode: document.querySelector("#createMode"),
 	createImages: document.querySelector("#createImages"),
@@ -607,7 +612,7 @@ const annotationFields = Object.fromEntries(["CreateForm", "CreateCancel", "Cont
 el.editorTools.addEventListener("scroll", () => fontPicker.position());
 
 const canvasEditor = new CanvasEditor(el.viewerPanel, {
-	textControls: [el.textFont, el.textFontToggle, el.textFontAdd, el.textFontList, el.textSize, el.textColor, textBackground, ...textFormatButtons, el.undoButton, el.redoButton, el.saveButton, el.fontInput, document.querySelector("#textReflow")],
+	textControls: [el.textFont, el.textFontToggle, el.textFontAdd, el.textFontList, el.textSize, el.textColor, textBackground, ...textFormatButtons, el.undoButton, el.redoButton, el.saveButton, el.saveAsButton, el.fontInput, document.querySelector("#textReflow")],
 	keepTextFocus: () => fontPicker.open || el.closePanel.open || canvasEditor.input?.fontDialog,
 	textClipboardScope: () => `${state.wasmSeq}:${state.fileName}:${state.doc?.documents?.[state.doc.documentIndex || 0]?.root}:${state.doc?.documentIndex || 0}:${state.doc?.documentVersion || ""}`,
 	busy: () => document.body.hasAttribute("data-busy"),
@@ -1475,7 +1480,8 @@ el.insertCancel.addEventListener("click", () => el.insertPanel.close());
 el.insertPanel.addEventListener("close", () => { state.insertObject = null; });
 el.insertForm.addEventListener("submit", insertObject);
 el.textFontAdd.addEventListener("click", () => openFontFile(el.fontInput));
-el.saveButton.addEventListener("click", () => exportFile(true, null, "ofd"));
+el.saveButton.addEventListener("click", () => exportFile(true, null, "ofd", false));
+el.saveAsButton.addEventListener("click", () => exportFile(true, null, "ofd", true));
 editorClick(el.encryptSaveButton, openEncryptionPanel);
 el.signButton.addEventListener("click", () => {
 	if (!state.doc || document.body.hasAttribute("data-busy")) return;
@@ -1744,10 +1750,10 @@ function handleKeyDown(event) {
 	}
 	const key = event.key;
 	const target = event.target;
-	if ((event.ctrlKey || event.metaKey) && !event.shiftKey && key.toLowerCase() === "s" && state.doc
+	if ((event.ctrlKey || event.metaKey) && key.toLowerCase() === "s" && state.doc
 		&& (state.editorInfo || state.ofdBytes)) {
 		event.preventDefault();
-		if (!document.body.hasAttribute("data-busy") && !formDialogOpen()) exportFile(true, null, "ofd");
+		if (!document.body.hasAttribute("data-busy") && !formDialogOpen()) exportFile(true, null, "ofd", event.shiftKey);
 		return;
 	}
 	if ((event.ctrlKey || event.metaKey) && !event.shiftKey && key.toLowerCase() === "a" && state.doc
@@ -2320,20 +2326,24 @@ function setDirty(dirty) {
 }
 
 function discardChanges() {
+	if (state.saving) return false;
 	return !state.dirty || window.confirm("文档尚未保存，放弃更改？");
 }
 
 async function closeFile() {
+	if (state.saving) return;
 	if (!state.doc || state.exporting || batch.unlocking || document.body.hasAttribute("data-busy")) return;
 	let openSeq = state.openSeq;
 	if (state.dirty || canvasEditor.input || canvasEditor.nudge || canvasEditor.nudgeCommit || canvasEditor.crop) {
+		el.closePanel.querySelector('[value="save"]').textContent = state.saveHandle ? "保存" : "另存";
 		el.closePanel.returnValue = "cancel";
 		const choice = new Promise(resolve => el.closePanel.addEventListener("close", () => resolve(el.closePanel.returnValue), { once: true }));
 		el.closePanel.showModal();
 		const action = await choice;
 		if (openSeq !== state.openSeq || action === "cancel") return;
 		if (action === "save") {
-			if (!await exportFile(true, null, "ofd")) return;
+			if (!await exportFile(true, null, "ofd", false)) return;
+			if (state.dirty) return;
 			openSeq = state.openSeq;
 		}
 	}
@@ -2345,6 +2355,8 @@ async function closeFile() {
 	state.ofdBytes = null;
 	state.doc = null;
 	state.fileName = "ofdgo.ofd";
+	state.saveHandle = null;
+	state.saveStamp = null;
 	state.editing = false;
 	state.editorInfo = null;
 	state.savedRevision = null;
@@ -2497,6 +2509,7 @@ function selectManagedVersion(id, focus = false) {
 }
 
 async function changeVersion(action) {
+	if (state.saving) return;
 	const manager = state.versionManagement;
 	if (!state.ready || state.exporting || !state.editing && action !== "select" || !manager?.entries || manager.loading || manager.failed || document.body.hasAttribute("data-busy")) return;
 	const entry = manager.entries.find(entry => entry.id === manager.id);
@@ -2518,6 +2531,7 @@ async function changeVersion(action) {
 }
 
 async function switchReadingVersion(id) {
+	if (state.saving) return;
 	if (!state.doc || state.editing || !state.ready || state.exporting || document.body.hasAttribute("data-busy")) return;
 	if (id === (state.doc.documentVersion || "")) return true;
 	const dirty = state.dirty;
@@ -2556,7 +2570,7 @@ async function switchReadingVersion(id) {
 
 function updateVersionControls() {
 	const manager = state.versionManagement, busy = document.body.hasAttribute("data-busy");
-	const disabled = !state.doc || !state.ready || state.exporting || busy;
+	const disabled = !state.doc || !state.ready || state.exporting || state.saving || busy;
 	const title = state.editing ? "版本管理" : "版本浏览";
 	el.versionManageButton.hidden = !state.editing && !(state.doc?.versionCount > 0);
 	el.versionTitle.textContent = title;
@@ -2691,6 +2705,7 @@ function selectManagedDocument(index, focus = false) {
 }
 
 async function switchDocument(index) {
+	if (state.saving) return;
 	if (!state.doc || document.body.hasAttribute("data-busy") || state.exporting || formDialogOpen()) return;
 	const previous = state.doc.documentIndex || 0;
 	if (index === previous) return;
@@ -2819,6 +2834,7 @@ function confirmTextReflow(item) {
 }
 
 function openCreatePanel(insert = false, packageDocument = false) {
+	if (state.saving && insert !== true) return;
 	if (document.body.hasAttribute("data-busy")) {
 		return;
 	}
@@ -2912,6 +2928,8 @@ async function createDocument(event) {
 		setPan(false);
 		state.ofdBytes = null;
 		state.fileName = `${title.replace(/[\\/:*?"<>|]+/g, "_").replace(/\.ofd$/i, "")}.ofd`;
+		state.saveHandle = null;
+		state.saveStamp = null;
 		state.conversionWarnings = [];
 		state.savedRevision = null;
 		state.packageDirty = false;
@@ -4112,9 +4130,19 @@ function releasePageResources() {
 }
 
 async function openOFDFile() {
+	if (state.saving) return;
 	if (document.body.hasAttribute("data-busy")) {
 		return;
 	}
+	if (!nativeHost && window.showOpenFilePicker) {
+		try {
+			const [handle] = await window.showOpenFilePicker({types: [{description: "OFD、PDF", accept: {"application/ofd": [".ofd"], "application/pdf": [".pdf"]}}]});
+			const file = await handle.getFile();
+			await requestLocalFontsBeforeOpen();
+			await openOFD(file, null, handle);
+		} catch (error) { if (error.name !== "AbortError") showError(error, !state.doc); }
+		return;
+	}
 	await requestLocalFontsBeforeOpen();
 	el.ofdInput.value = "";
 	el.ofdInput.click();
@@ -4139,11 +4167,12 @@ async function openOFDFromDrop(event) {
 		setStatus("一次拖入一个文件");
 		return;
 	}
+	const handlePromise = event.dataTransfer.items[0]?.getAsFileSystemHandle?.();
 	const file = event.dataTransfer.files[0];
 	if (file && isDocumentFile(file)) {
 		await requestLocalFontsBeforeOpen();
 	}
-	await openOFD(file);
+	await openOFD(file, null, await handlePromise?.catch(() => null));
 }
 
 function openFontFile(input) {
@@ -4249,7 +4278,7 @@ async function boot() {
 					return;
 				}
 				opening = opening.then(async () => {
-					await openOFD(await files[0].getFile());
+					await openOFD(await files[0].getFile(), null, files[0]);
 				}).catch((err) => showError(err, !state.doc));
 			});
 		}
@@ -4557,11 +4586,15 @@ async function loadWASM() {
 					else setProgress("正在生成文档", null);
 				}
 			} else if (data.type === "export") {
+				if (data.id === state.saveRequestID && state.saving && !state.exporting) {
+					if (data.stage === "save") el.cancelExportButton.disabled = true;
+					return;
+				}
 				if (wasmRequests.get(data.id)?.openSeq === state.openSeq && state.exporting) {
 					if (data.stage === "save") {
 						el.cancelExportButton.disabled = true;
 						if (state.signing) el.signCancel.disabled = true;
-						setProgress("正在保存文件", null);
+						setProgress("正在写入文件", null);
 					} else if (!el.cancelExportButton.disabled) {
 						if (data.stage === "prepare") {
 							const label = { snapshot: "正在准备文档", ids: "正在检查标识", commit: "正在整理文档", fonts: "正在处理字体", pages: "正在处理页面", references: "正在检查引用", resources: "正在整理资源", compress: "正在压缩文件", write: "正在写入文件", sign: "正在签署文档", encrypt: "正在加密文档" }[data.phase];
@@ -4600,6 +4633,7 @@ async function loadWASM() {
 				} else {
 					const err = new Error(missingGlyphMessage(data.missingGlyphs) || (data.reasonCode === "layoutRequired" ? "跨段或换行修改需先设置段落排版" : data.error));
 					err.code = data.code;
+					if (data.errorName) err.name = data.errorName;
 					err.missingGlyphs = data.missingGlyphs;
 					if (data.canceled) {
 						err.name = "AbortError";
@@ -4729,7 +4763,8 @@ async function downloadRemoteDocument(options) {
 	}
 }
 
-async function openOFD(file, remote = null) {
+async function openOFD(file, remote = null, handle = file?.handle) {
+	if (state.saving) return;
 	if (!file) {
 		return;
 	}
@@ -4785,6 +4820,8 @@ async function openOFD(file, remote = null) {
 		const doc = convertedDoc || await openWithCredentials(await fontManager.files(fontManager.userFonts), openSeq, bytes);
 		if (openSeq !== state.openSeq) return;
 		state.ofdBytes = bytes;
+		state.saveHandle = format === "ofd" && !remote ? handle || null : null;
+		state.saveStamp = state.saveHandle && !nativeHost ? {size: file.size, modified: file.lastModified} : null;
 		state.conversionWarnings = warnings;
 		state.fileName = (name || "ofdgo.ofd").replace(/\.pdf$/i, ".ofd");
 		if (remote && !/\.ofd$/i.test(state.fileName)) state.fileName += ".ofd";
@@ -6712,11 +6749,11 @@ async function commitInvoice(draft, request) {
 	const key = invoicePanel.key;
 	settings.busy = true;
 	settingsElements.Form.inert = true;
-	settingsElements.Status.textContent = "正在保存修改";
+	settingsElements.Status.textContent = "正在应用修改";
 	try {
 		invoicePanel.result = null;
 		if (!await changeDocument("ofdgoChangeInvoice", null, JSON.stringify({ ...draft.scope, source: draft.entry?.source, index: draft.entry?.index || 0, digest: draft.detail.digest, ...request }))) {
-			if (settingsElements.Status.textContent === "正在保存修改") settingsElements.Status.textContent = el.statusText.textContent;
+			if (settingsElements.Status.textContent === "正在应用修改") settingsElements.Status.textContent = el.statusText.textContent;
 			return;
 		}
 		const result = invoicePanel.result;
@@ -6742,7 +6779,7 @@ async function commitInvoice(draft, request) {
 		await loadDocumentSettings();
 		const warning = invoiceIssues(result?.issues).replaceAll("\n", " · ");
 		if (warning) {
-			const status = "已保存 · " + warning;
+			const status = "已应用 · " + warning;
 			if (invoiceCurrent()) invoiceCurrent().status = status;
 			settingsElements.Status.textContent = status;
 		}
@@ -6861,11 +6898,11 @@ async function commitSettings(name, ...args) {
 	const pending = settings.drafts.get(settings.view), baseline = settings.baseline;
 	settings.busy = true;
 	settingsElements.Form.inert = true;
-	settingsElements.Status.textContent = "正在保存修改";
+	settingsElements.Status.textContent = "正在应用修改";
 	const view = settings.view, focus = document.activeElement?.id, body = document.querySelector("#settingsBody"), scroll = body?.scrollTop || 0;
 	try {
 		if (!await changeDocument(name, null, ...args)) {
-			if (settingsElements.Status.textContent === "正在保存修改") settingsElements.Status.textContent = el.statusText.textContent;
+			if (settingsElements.Status.textContent === "正在应用修改") settingsElements.Status.textContent = el.statusText.textContent;
 			return false;
 		}
 		settings.drafts.delete(view);
@@ -7803,6 +7840,7 @@ function updateEncryptionType() {
 }
 
 async function applyEncryption(event) {
+	if (state.saving) { event.preventDefault(); return; }
 	event.preventDefault();
 	if (!state.doc || document.body.hasAttribute("data-busy") || el.encryptionSubmit.disabled) return;
 	const mode = el.encryptionType.value;
@@ -7884,7 +7922,7 @@ function renderSecurity() {
 	el.securitySchemeRow.hidden = !encryption?.encrypted;
 	el.securityMethod.textContent = scheme ? "SM4-CBC" : "";
 	el.securityMethodRow.hidden = !encryption?.encrypted || !scheme;
-	el.encryptSaveButton.disabled = !state.doc || !state.ready || state.exporting || document.body.hasAttribute("data-busy");
+	el.encryptSaveButton.disabled = !state.doc || !state.ready || state.exporting || state.saving || document.body.hasAttribute("data-busy");
 	el.verifyButton.disabled = el.encryptSaveButton.disabled;
 	el.signButton.disabled = el.encryptSaveButton.disabled;
 }
@@ -8034,6 +8072,7 @@ function updateSignPlacement() {
 }
 
 async function signDocument(event) {
+	if (state.saving) { event.preventDefault(); return; }
 	event.preventDefault();
 	if (!state.doc || document.body.hasAttribute("data-busy")) return;
 	if (!el.signCertificate.files?.length || !el.signKey.files?.length || !el.signRoots.files?.length) {
@@ -8587,8 +8626,8 @@ function compressionOptions(value) {
 	return preset > 2 ? { mode: 2, level: preset - 2 } : { mode: preset };
 }
 
-async function exportFile(whole, indices = null, value = el.exportFormat.value) {
+async function exportFile(whole, indices = null, value = el.exportFormat.value, saveAs = true) {
-	if (!state.doc || document.body.hasAttribute("data-busy")) {
+	if (!state.doc || state.saving || state.exporting || document.body.hasAttribute("data-busy")) {
 		return;
 	}
 	const saving = value === "ofd";
@@ -8608,14 +8647,36 @@ async function exportFile(whole, indices = null, value = el.exportFormat.value)
 	const mime = archive ? "application/zip" : format.mime;
 	let openSeq = state.openSeq;
 	const fileName = saving && indices !== null ? `${baseFileName()}_选页.ofd` : whole ? `${baseFileName()}.${extension}` : pageFileName(extension);
+	const wasmSeq = state.wasmSeq;
 	const pageIndex = state.pageIndex;
 	const dpi = exportFormatUsesDPI(format.value) ? currentImageDPI() : 0;
-	const status = saving ? "正在保存文档" : whole ? STATUS.exporting : STATUS.pageExporting;
+	let action = saving ? saveAs || !state.saveHandle || indices !== null ? "另存" : "保存" : "导出";
+	const status = saving ? `正在${action}文档` : whole ? STATUS.exporting : STATUS.pageExporting;
+	let retrySaveAs = false;
+	let background = false;
+	let savedRevision = null;
+	let snapshotPrepared = false;
 	state.exporting = true;
+	state.saving = saving && indices === null;
 	updateControls();
 	setBusy(true, "正在生成文件", null, status);
 	try {
-		const file = nativeHost || window.showSaveFilePicker ? await saveFilePicker({
+		let file = saving && indices === null && !saveAs ? state.saveHandle : null;
+		if (file && !nativeHost) {
+			try {
+				const permission = await file.queryPermission({mode: "readwrite"});
+				if (permission !== "granted" && await file.requestPermission({mode: "readwrite"}) !== "granted") file = null;
+			} catch (error) {
+				if (!["NotAllowedError", "SecurityError"].includes(error.name)) throw error;
+				file = null;
+			}
+			if (file && state.saveStamp) {
+				const current = await file.getFile();
+				if (current.size !== state.saveStamp.size || current.lastModified !== state.saveStamp.modified) throw new Error("文件已被修改，请另存");
+			}
+		}
+		if (saving && !file) action = "另存";
+		file ||= nativeHost || window.showSaveFilePicker ? await saveFilePicker({
 			suggestedName: fileName,
 			types: [{ description: label, accept: { [mime]: [`.${extension}`] } }],
 		}) : null;
@@ -8631,34 +8692,63 @@ async function exportFile(whole, indices = null, value = el.exportFormat.value)
 			setBusy(true, "正在生成文件", null, status);
 		}
 		const readingSave = saving && !state.editorInfo && indices === null && compression.mode === 0;
+		const destination = !nativeHost && file && file === state.saveHandle && state.saveStamp ? {fileHandle: file, saveStamp: state.saveStamp} : file;
+		if (saving && indices === null && !readingSave) {
+			snapshotPrepared = true;
+			await callWASM("ofdgoPrepareSave");
+			savedRevision = state.editorInfo?.revision;
+			background = true;
+			state.exporting = false;
+			setBusy(false);
+			updateControls();
+		}
 		const result = readingSave
 			? { label: "OFD", size: state.ofdBytes.byteLength, mime, blob: state.ofdBytes }
-			: saving ? await callWASM("ofdgoSaveDocument", indices, ...outputOptions, file) : whole
+			: saving ? await callWASM(background ? "ofdgoSaveSnapshot" : "ofdgoSaveDocument", indices, ...outputOptions, destination) : whole
 			? await callWASM("ofdgoExportDocument", format.value, dpi, indices, state.renderBackend, ...outputOptions, file)
 			: await callWASM("ofdgoExportPage", pageIndex, format.value, dpi, state.renderBackend, ...outputOptions, file);
-		if (openSeq !== state.openSeq) {
+		if ((!background && openSeq !== state.openSeq) || wasmSeq !== state.wasmSeq) {
 			return;
 		}
 		if (readingSave && file) {
 			const writer = await file.createWritable();
-			await writer.write(result.blob);
+			try {
-			await writer.close();
+				await writer.write(result.blob);
+				await writer.close();
+			} catch (error) {
+				await writer.abort().catch(() => {});
+				throw error;
+			}
 			delete result.blob;
 		}
 		if (result.blob) {
 			downloadBytes(result.blob, result.mime, fileName);
 		}
-		if (saving && indices === null && state.editorInfo) {
+		if (saving && indices === null && state.editorInfo && file) {
-			state.savedRevision = state.editorInfo.revision;
+			state.savedRevision = background ? savedRevision : state.editorInfo.revision;
 			state.packageDirty = false;
 			state.encryptionDirty = false;
-			setDirty(false);
+			updatePendingChanges();
 		}
-		setStatus(`${result.label}已${saving ? "保存" : "导出"}（${formatBytes(result.size)}）`);
+		if (saving && indices === null && file) {
+			state.saveHandle = file;
+			state.fileName = file.name;
+			state.saveStamp = null;
+			if (!nativeHost) {
+				try {
+					const current = await file.getFile();
+					state.saveStamp = {size: current.size, modified: current.lastModified};
+				} catch { state.saveHandle = null; }
+			}
+			document.title = `${nativeHost ? "OFDGo" : "OFDGo WebUI"} - ${state.fileName}`;
+			el.metaFile.textContent = state.fileName;
+		}
+		setStatus(`${result.label}已${action}（${formatBytes(result.size)}）`);
 		return true;
 	} catch (err) {
-		if (openSeq === state.openSeq) {
+		retrySaveAs = saving && !saveAs && !nativeHost && !!state.saveHandle && ["NotAllowedError", "SecurityError"].includes(err.name);
-			const canceled = saving ? "保存已取消" : "导出已取消";
+		if ((background || openSeq === state.openSeq) && wasmSeq === state.wasmSeq && !retrySaveAs) {
+			const canceled = `${action}已取消`;
 			if (el.batchPagesPanel.open) el.batchPagesStatus.textContent = err.name === "AbortError" ? canceled : err.message;
 			if (err.name === "AbortError") {
 				setStatus(canceled);
@@ -8667,14 +8757,21 @@ async function exportFile(whole, indices = null, value = el.exportFormat.value)
 			}
 		}
 	} finally {
-		state.exporting = false;
+		if (snapshotPrepared) await callWASM("ofdgoDiscardSave").catch(() => {});
-		state.exportRequestID = 0;
+		state.saving = false;
-		el.cancelExportButton.hidden = true;
+		state.saveRequestID = 0;
-		if (openSeq === state.openSeq) {
+		if (!background) {
-			setBusy(false);
+			state.exporting = false;
+			state.exportRequestID = 0;
+		}
+		el.cancelExportButton.hidden = !state.exportRequestID;
+		if (!document.body.hasAttribute("data-busy")) el.progressPanel.hidden = true;
+		if ((background || openSeq === state.openSeq) && wasmSeq === state.wasmSeq) {
+			if (!background) setBusy(false);
 			updateControls();
 		}
 	}
+	if (retrySaveAs && (background || openSeq === state.openSeq) && wasmSeq === state.wasmSeq) return exportFile(whole, indices, value, true);
 }
 
 function cancelExport() {
@@ -8682,7 +8779,8 @@ function cancelExport() {
 		remoteDownload.abort();
 		return;
 	}
-	if (!state.exportRequestID || el.cancelExportButton.disabled) {
+	const requestID = state.exportRequestID || state.saveRequestID;
+	if (!requestID || el.cancelExportButton.disabled) {
 		return;
 	}
 	el.cancelExportButton.disabled = true;
@@ -8694,7 +8792,7 @@ function cancelExport() {
 		el.importStatus.textContent = "正在取消操作";
 	}
 	setProgress("正在取消操作", null);
-	wasmWorker.postMessage({ type: "cancel", id: state.exportRequestID });
+	wasmWorker.postMessage({ type: "cancel", id: requestID });
 }
 
 function virtualIndex(offsets, top) {
@@ -12023,14 +12121,14 @@ function updateDocumentControls() {
 	const busy = document.body.hasAttribute("data-busy");
 	const disabled = !state.doc || !state.ready || state.exporting || busy;
 	el.documentManageButton.hidden = !state.editing;
-	el.documentManageButton.disabled = disabled;
+	el.documentManageButton.disabled = disabled || state.saving;
 	resourceElements.ManageButton.disabled = disabled;
 	settingsElements.Button.disabled = disabled;
 	updateInvoiceControl(disabled);
 	updateResourceControls();
 	el.documentRow.hidden = !count || !state.editing && count < 2;
-	el.documentSelect.disabled = disabled;
+	el.documentSelect.disabled = disabled || state.saving;
-	const actionsDisabled = disabled || !state.editing || Boolean(manager?.loading || manager?.failed);
+	const actionsDisabled = disabled || state.saving || !state.editing || Boolean(manager?.loading || manager?.failed);
 	el.documentList.inert = busy || Boolean(manager?.loading);
 	el.documentAddButton.disabled = actionsDisabled;
 	el.documentImportButton.disabled = actionsDisabled;
@@ -12045,7 +12143,8 @@ function updateControls() {
 	renderSecurity();
 	updateStructureControls();
 	const hasDoc = Boolean(state.doc);
-	el.closeButton.disabled = !hasDoc || state.exporting || document.body.hasAttribute("data-busy");
+	el.newButton.disabled = state.saving;
+	el.closeButton.disabled = !hasDoc || state.exporting || state.saving || document.body.hasAttribute("data-busy");
 	updateDocumentControls();
 	updateDisplayControls();
 	updateEditorTools();
@@ -12083,7 +12182,8 @@ function updateEditorTools() {
 	el.editorTools.hidden = !state.editing;
 	const pagesDisabled = !state.editing || !state.ready || state.exporting;
 	el.insertTextButton.disabled = el.insertImageButton.disabled = pagesDisabled || !pageCan("insert");
-	el.saveButton.disabled = !state.doc || !state.ready || state.exporting || (!state.editorInfo && !state.ofdBytes);
+	el.saveButton.disabled = !state.doc || !state.ready || state.exporting || state.saving || (!state.editorInfo && !state.ofdBytes);
+	el.saveAsButton.disabled = el.saveButton.disabled;
 	el.addPageButton.disabled = pagesDisabled;
 	const selectedPages = state.editing ? selectedPageIndexes() : [state.pageIndex];
 	const selectionDisabled = pagesDisabled || !selectedPages.length;
@@ -12225,6 +12325,11 @@ async function callWASM(name, ...args) {
 	}
 	return new Promise((resolve, reject) => {
 		const id = ++wasmRequestID;
+		if (name === "ofdgoPrepareSave" || name === "ofdgoSaveSnapshot") {
+			state.saveRequestID = id;
+			el.cancelExportButton.hidden = false;
+			el.cancelExportButton.disabled = false;
+		}
 		if (name === "ofdgoResources" && resourceElements.Panel.open) resourceManager.requestID = id;
 		wasmRequests.set(id, { resolve, reject, openSeq: state.openSeq });
 		if (name === "ofdgoExportMedia") wasmRequests.get(id).mediaID = args[0];
@@ -12264,7 +12369,7 @@ function showError(err, empty = !state.doc) {
 
 function setBusy(busy, text = "", percent = 0, status = "") {
 	document.body.toggleAttribute("data-busy", busy);
-	el.closeButton.disabled = busy || !state.doc || state.exporting;
+	el.closeButton.disabled = busy || !state.doc || state.exporting || state.saving;
 	el.refreshAppButton.disabled = busy;
 	updateStructureControls();
 	updateDocumentControls();
@@ -12296,7 +12401,11 @@ function setBusy(busy, text = "", percent = 0, status = "") {
 	el.fontList.inert = busy;
 	el.docFontList.inert = busy;
 	if (!busy) {
-		el.progressPanel.hidden = true;
+		el.progressPanel.hidden = !state.saving;
+		if (state.saving) {
+			el.cancelExportButton.hidden = false;
+			setProgress("正在保存文档", null);
+		}
 		if (state.fontSyncPending) {
 			window.setTimeout(syncUserFonts, 0);
 		}

assets/webui/ofdgo_host.js

@@ -27,6 +27,7 @@ export function directoryPicker() {
 class NativeFile {
 	constructor(value) {
 		Object.assign(this, value);
+		if (value.handle) this.handle = new NativeHandle(nativeHost, value.handle);
 		this.byteLength = this.size;
 		this.type ||= "application/octet-stream";
 		if (value.temporary) nativeHost?.resources?.register(this, value.nativeFile);
@@ -157,7 +158,7 @@ class NativeHost {
 				if (data.type === "font") return;
 				const controller = new AbortController();
 				requests.set(data.id, controller);
-				pending = pending.then(async () => {
+				const operation = pending.then(async () => {
 					const engine = await ready;
 					if (closed) return;
 					controller.signal.throwIfAborted();
@@ -188,6 +189,7 @@ class NativeHost {
 					if (closed) { await host.release(result); return; }
 					emit({id:data.id, ...decoded});
 				}).catch(error => emit({id:data.id, ok:false, error:error.message, code:error.code, canceled:error.name === "AbortError"})).finally(() => requests.delete(data.id));
+				if (data.name !== "ofdgoSaveSnapshot") pending = operation;
 			},
 			terminate() {
 				if (closed) return;

assets/webui/ofdgo_wasm.js

@@ -35,7 +35,11 @@ self.onmessage = ({ data }) => {
 		operations.get(data.id)?.abort();
 		return;
 	}
-	if (data.name === "ofdgoResources") operations.set(data.id, new AbortController());
+	if (["ofdgoResources", "ofdgoPrepareSave", "ofdgoSaveSnapshot"].includes(data.name)) operations.set(data.id, new AbortController());
+	if (data.name === "ofdgoSaveSnapshot") {
+		pending = pending.then(() => { void handleMessage(data); });
+		return;
+	}
 	if (data.name === "ofdgoImportDocuments" || data.name === "ofdgoImportImages" || data.name === "ofdgoExportImages" || data.name === "ofdgoConvertFile" || data.name === "ofdgoPackFiles" || data.name === "ofdgoConvertPDF" || data.name === "ofdgoExportPage" || data.name === "ofdgoExportDocument" || data.name === "ofdgoExportAttachment" || data.name === "ofdgoExportResource" || data.name === "ofdgoExportMedia" || data.name === "ofdgoExportVersion" || data.name === "ofdgoSaveDocument" || data.name === "ofdgoSaveSigned" || data.name === "ofdgoImportPages") {
 		operations.set(data.id, new AbortController());
 	}
@@ -173,12 +177,14 @@ async function handleBatchMessage({ id, name, args }) {
 }
 async function handleMessage({ id, name, args }) {
 	let output;
+	let saveFile;
+	let saveStamp;
 	let channel;
 	const signal = operations.get(id)?.signal;
 	const importing = name === "ofdgoImportPages" || name === "ofdgoImportImages" || name === "ofdgoImportDocuments";
 	const converting = name === "ofdgoConvertPDF";
-	const saving = name === "ofdgoSaveDocument" || name === "ofdgoSaveSigned";
+	const saving = name === "ofdgoSaveDocument" || name === "ofdgoSaveSnapshot" || name === "ofdgoSaveSigned";
-	const resources = name === "ofdgoResources";
+	const resources = name === "ofdgoResources" || name === "ofdgoPrepareSave";
 	const key = name === "ofdgoOpen" ? args[3]?.key : name === "ofdgoSaveSigned" || name === "ofdgoLoadImport" ? args[1]?.key : null;
 	const keyPassword = name === "ofdgoOpen" ? args[3]?.keyPassword : name === "ofdgoSaveSigned" || name === "ofdgoLoadImport" ? args[1]?.keyPassword : null;
 	const password = converting ? args[2] : name === "ofdgoSetEncryption" ? args[0]?.password : name === "ofdgoOpen" ? args[3]?.password : name === "ofdgoLoadImport" ? args[1]?.password : null;
@@ -230,7 +236,10 @@ async function handleMessage({ id, name, args }) {
 				});
 				if (converting) args.push((name, done) => requestFont(id, signal, name, done));
 			} else {
-				const file = args.pop();
+				const destination = args.pop();
+				const file = destination?.fileHandle || destination;
+				saveFile = file;
+				saveStamp = destination?.saveStamp;
 				const compression = saving && name !== "ofdgoSaveSigned" && args.at(-1)?.mode !== undefined ? args.pop() : null;
 				const indices = saving ? args.shift() : null;
 				if (file) output = await file.createWritable();
@@ -263,7 +272,7 @@ async function handleMessage({ id, name, args }) {
 						self.postMessage({ id, type: "export", stage: "prepare", phase, completed, total });
 						finish(done);
 					});
-					if (compression) args.push(indices, compression, done => finish(done));
+					if (compression || name === "ofdgoSaveSnapshot") args.push(indices, compression || {mode: 0}, done => finish(done));
 					else if (indices != null) args.push(indices);
 				}
 				if (!saving && args.some(value => value?.mode !== undefined)) args.push(done => finish(done));
@@ -277,6 +286,10 @@ async function handleMessage({ id, name, args }) {
 			result.data.size = size;
 			if (name !== "ofdgoExportMedia") self.postMessage({ id, type: "export", stage: "save" });
 			if (output) {
+				if (saveStamp) {
+					const current = await saveFile.getFile();
+					if (current.size !== saveStamp.size || current.lastModified !== saveStamp.modified) throw new Error("文件已被修改，请另存");
+				}
 				await output.close();
 			} else {
 				result.data.blob = new Blob(chunks, { type: result.data.mime });
@@ -289,7 +302,7 @@ async function handleMessage({ id, name, args }) {
 		self.postMessage({ id, ...result }, transfer);
 	} catch (err) {
 		await output?.abort().catch(() => {});
-		const result = { id, ok: false, error: err.message };
+		const result = { id, ok: false, error: err.message, errorName: err.name };
 		if (signal?.aborted) {
 			result.error = resources ? "查询已取消" : importing ? "导入已取消" : converting ? "转换已取消" : "导出已取消";
 			result.canceled = true;

internal/base/file/file.go

@@ -0,0 +1,216 @@
+// 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 file
+
+import (
+	"context"
+	"crypto/rand"
+	"errors"
+	"fmt"
+	"io"
+	"math/big"
+	"os"
+	"path/filepath"
+	"sync"
+)
+
+// ErrChanged 表示目标文件已被其他操作修改
+var ErrChanged = errors.New("file changed since opening")
+
+// ErrBusy 表示目标文件正在写入
+var ErrBusy = errors.New("file save is in progress")
+
+// activeFiles 协调当前进程内的目标写入
+var activeFiles sync.Map
+
+// Target 保存文件路径及最近确认的文件状态，可跨次写入复用
+type Target struct {
+	mu   sync.Mutex
+	name string
+	info os.FileInfo
+}
+
+// Writer 写入同目录临时文件，提交前检查取消及目标冲突
+type Writer struct {
+	mu     sync.Mutex
+	target *Target
+	file   *os.File
+	ctx    context.Context
+	err    error
+	closed bool
+}
+
+// NewTarget 记录目标当前状态，允许目标尚不存在
+// 入参: name 目标路径
+// 返回: *Target 保存目标, error 路径或文件错误
+func NewTarget(name string) (*Target, error) {
+	if name == "" {
+		return nil, os.ErrInvalid
+	}
+	name, err := filepath.Abs(name)
+	if err != nil {
+		return nil, err
+	}
+	info, err := os.Lstat(name)
+	if err != nil && !errors.Is(err, os.ErrNotExist) {
+		return nil, err
+	}
+	if info != nil && !info.Mode().IsRegular() {
+		return nil, fmt.Errorf("save target is not a regular file")
+	}
+	return &Target{name: name, info: info}, nil
+}
+
+// Name 返回目标绝对路径
+// 返回: string 文件路径
+func (t *Target) Name() string {
+	return t.name
+}
+
+// check 检查目标是否保持最近确认的状态
+// 返回: error 文件状态错误
+func (t *Target) check() error {
+	info, err := os.Lstat(t.name)
+	if errors.Is(err, os.ErrNotExist) {
+		if t.info == nil {
+			return nil
+		}
+		return ErrChanged
+	}
+	if err != nil {
+		return err
+	}
+	if t.info == nil || !os.SameFile(t.info, info) || t.info.Size() != info.Size() || !t.info.ModTime().Equal(info.ModTime()) {
+		return ErrChanged
+	}
+	if info.Mode().Perm()&0222 == 0 {
+		return os.ErrPermission
+	}
+	return nil
+}
+
+// Begin 创建独占写入事务，调用方必须提交或终止
+// 入参: ctx 取消上下文
+// 返回: *Writer 事务, error 创建错误
+func (t *Target) Begin(ctx context.Context) (*Writer, error) {
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	if _, loaded := activeFiles.LoadOrStore(t.name, true); loaded {
+		return nil, ErrBusy
+	}
+	if err := t.check(); err != nil {
+		activeFiles.Delete(t.name)
+		return nil, err
+	}
+	for range 100 {
+		n, err := rand.Int(rand.Reader, big.NewInt(10000000))
+		if err != nil {
+			activeFiles.Delete(t.name)
+			return nil, err
+		}
+		name := fmt.Sprintf("%s.%07d.tmp", t.name, n.Int64())
+		f, err := os.OpenFile(name, os.O_RDWR|os.O_CREATE|os.O_EXCL, 0600)
+		if errors.Is(err, os.ErrExist) {
+			continue
+		}
+		if err != nil {
+			activeFiles.Delete(t.name)
+			return nil, err
+		}
+		return &Writer{target: t, file: f, ctx: ctx}, nil
+	}
+	activeFiles.Delete(t.name)
+	return nil, os.ErrExist
+}
+
+// Write 追加数据并记录写入错误
+// 入参: data 数据
+// 返回: int 写入长度, error 写入错误
+func (w *Writer) Write(data []byte) (int, error) {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+	if w.closed {
+		return 0, os.ErrClosed
+	}
+	if w.err == nil {
+		w.err = w.ctx.Err()
+	}
+	if w.err != nil {
+		return 0, w.err
+	}
+	n, err := w.file.Write(data)
+	if err == nil && n != len(data) {
+		err = io.ErrShortWrite
+	}
+	w.err = err
+	return n, err
+}
+
+// Close 完成写入并替换目标，成功后刷新目标状态
+// 返回: error 提交错误
+func (w *Writer) Close() error {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+	if w.closed {
+		return os.ErrClosed
+	}
+	w.closed = true
+	defer activeFiles.Delete(w.target.name)
+	defer os.Remove(w.file.Name())
+	w.target.mu.Lock()
+	defer w.target.mu.Unlock()
+	if err := errors.Join(w.err, w.ctx.Err(), w.target.check()); err != nil {
+		return errors.Join(err, w.file.Close())
+	}
+	if w.target.info != nil {
+		if err := w.file.Chmod(w.target.info.Mode().Perm()); err != nil {
+			return errors.Join(err, w.file.Close())
+		}
+	}
+	if err := w.file.Sync(); err != nil {
+		return errors.Join(err, w.file.Close())
+	}
+	info, err := w.file.Stat()
+	if err = errors.Join(err, w.file.Close(), w.ctx.Err()); err != nil {
+		return err
+	}
+	if err := w.target.check(); err != nil {
+		return err
+	}
+	if err := Replace(w.file.Name(), w.target.name); err != nil {
+		return err
+	}
+	w.target.info = info
+	if current, err := os.Stat(w.target.name); err == nil {
+		w.target.info = current
+	}
+	return nil
+}
+
+// Abort 丢弃临时输出，不改变目标
+// 返回: error 清理错误
+func (w *Writer) Abort() error {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+	if w.closed {
+		return nil
+	}
+	w.closed = true
+	defer activeFiles.Delete(w.target.name)
+	return errors.Join(w.file.Close(), os.Remove(w.file.Name()))
+}

internal/base/file/file_other.go

@@ -0,0 +1,33 @@
+// 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 file
+
+import "os"
+
+// Open 打开文件，路径替换后已有读取句柄仍有效
+// 入参: name 文件路径
+// 返回: *os.File 文件, error 打开错误
+func Open(name string) (*os.File, error) {
+	return os.Open(name)
+}
+
+// Replace 替换目标路径
+// 入参: source 临时路径, target 目标路径
+// 返回: error 替换错误
+func Replace(source, target string) error {
+	return os.Rename(source, target)
+}

internal/base/file/file_windows.go

@@ -0,0 +1,81 @@
+// 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 file
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"syscall"
+	"unsafe"
+)
+
+// replaceFileProc 保留目标文件属性并替换文件内容
+var replaceFileProc = syscall.NewLazyDLL("kernel32.dll").NewProc("ReplaceFileW")
+
+// Open 保留替换共享权限，路径替换后已有读取句柄仍有效
+// 入参: name 文件路径
+// 返回: *os.File 文件, error 打开错误
+func Open(name string) (*os.File, error) {
+	path, err := nativePath(name)
+	if err != nil {
+		return nil, err
+	}
+	handle, err := syscall.CreateFile(path, syscall.GENERIC_READ, syscall.FILE_SHARE_READ|syscall.FILE_SHARE_WRITE|syscall.FILE_SHARE_DELETE, nil, syscall.OPEN_EXISTING, syscall.FILE_ATTRIBUTE_NORMAL, 0)
+	if err != nil {
+		return nil, &os.PathError{Op: "open", Path: name, Err: err}
+	}
+	return os.NewFile(uintptr(handle), name), nil
+}
+
+// Replace 替换目标，目标不存在时重命名
+// 入参: source 临时路径, target 目标路径
+// 返回: error 替换错误
+func Replace(source, target string) error {
+	from, err := nativePath(source)
+	if err != nil {
+		return err
+	}
+	to, err := nativePath(target)
+	if err != nil {
+		return err
+	}
+	result, _, err := replaceFileProc.Call(uintptr(unsafe.Pointer(to)), uintptr(unsafe.Pointer(from)), 0, 0, 0, 0)
+	if result != 0 {
+		return nil
+	}
+	if err == syscall.ERROR_FILE_NOT_FOUND {
+		return os.Rename(source, target)
+	}
+	return &os.LinkError{Op: "replace", Old: source, New: target, Err: err}
+}
+
+// nativePath 转换绝对长路径
+// 入参: name 路径
+// 返回: *uint16 原生路径, error 转换错误
+func nativePath(name string) (*uint16, error) {
+	path, err := filepath.Abs(name)
+	if err != nil {
+		return nil, err
+	}
+	if !strings.HasPrefix(path, `\\?\`) {
+		if strings.HasPrefix(path, `\\`) {
+			path = `\\?\UNC\` + path[2:]
+		} else {
+			path = `\\?\` + path
+		}
+	}
+	return syscall.UTF16PtrFromString(path)
+}

internal/webui/webui.go

@@ -419,6 +419,7 @@ type outputContext struct {
 type businessEngine struct {
 	currentSession *Session
 	currentEditor  *ofdgo.Editor
+	saveSnapshot   *ofdgo.Editor
 	pendingImport  *ofdgo.Reader
 	copiedObjects  *editorClipboard
 	copiedStyle    *ofdgo.GraphicObject
@@ -7162,6 +7163,54 @@ func (e *businessEngine) saveSigned(args []platformValue) (any, error) {
 	return successResult(map[string]any{"mime": "application/ofd", "label": "OFD"}), nil
 }
 
+// prepareSave 创建独立保存快照，后续写出不占用当前编辑文档
+// 入参: args 取消检查回调
+// 返回: any 快照修订, error 准备错误
+func (e *businessEngine) prepareSave(args []platformValue) (any, error) {
+	e.saveSnapshot = nil
+	editor := e.currentEditor
+	if editor == nil {
+		if e.currentSession == nil {
+			return nil, fmt.Errorf("ofd document is not opened")
+		}
+		var err error
+		editor, err = e.currentSession.Reader.Editor()
+		if err != nil {
+			return nil, err
+		}
+	}
+	ctx := e.operationContext()
+	if len(args) > 0 {
+		ctx = e.newOutputContext(args[0])
+	}
+	snapshot, err := editor.Snapshot(ctx)
+	if err != nil {
+		return nil, err
+	}
+	e.saveSnapshot = snapshot
+	return successResult(map[string]any{"revision": editor.Revision()}), nil
+}
+
+// savePrepared 写出并释放已准备的快照，不修改当前编辑状态
+// 入参: args 写出回调、进度回调及输出配置
+// 返回: any 保存结果, error 保存错误
+func (e *businessEngine) savePrepared(args []platformValue) (any, error) {
+	snapshot := e.saveSnapshot
+	e.saveSnapshot = nil
+	if snapshot == nil {
+		return nil, fmt.Errorf("save snapshot is not prepared")
+	}
+	return e.saveEditor(snapshot, args)
+}
+
+// discardSave 释放尚未写出的保存快照
+// 入参: args 空参数
+// 返回: any 操作结果, error 错误信息
+func (e *businessEngine) discardSave(args []platformValue) (any, error) {
+	e.saveSnapshot = nil
+	return successResult(nil), nil
+}
+
 // saveDocument 分块写出当前编辑文档或指定页面
 // 入参: args 数据写出回调、可选准备进度回调和可选页面索引
 // 返回: any 保存结果, error 错误信息
@@ -7403,6 +7452,9 @@ func (e *businessEngine) businessCommands() map[string]func([]platformValue) (an
 		"ofdgoUndo":                   func([]platformValue) (any, error) { return e.restoreEditor(false) },
 		"ofdgoRedo":                   func([]platformValue) (any, error) { return e.restoreEditor(true) },
 		"ofdgoSaveDocument":           e.saveDocument,
+		"ofdgoPrepareSave":            e.prepareSave,
+		"ofdgoSaveSnapshot":           e.savePrepared,
+		"ofdgoDiscardSave":            e.discardSave,
 		"ofdgoSetEncryption":          e.setEncryption,
 		"ofdgoSaveSigned":             e.saveSigned,
 		"ofdgoPreviewSignatureSeal":   e.previewSignatureSeal,

internal/webui/webui_native.go

@@ -82,6 +82,7 @@ type NativeEngine struct {
 	CleanupOutput func(context.Context, NativeOutputTarget) error
 	gate          chan struct{}
 	once          sync.Once
+	saves         sync.WaitGroup
 	closed        bool
 }
 
@@ -149,13 +150,33 @@ func (e *NativeEngine) Call(ctx context.Context, name string, args []any, emit f
 	case <-ctx.Done():
 		return nativeFailure(ctx.Err())
 	}
-	defer func() { <-e.gate }()
+	locked := true
+	defer func() {
+		if locked {
+			<-e.gate
+		}
+	}()
 	if err := ctx.Err(); err != nil {
 		return nativeFailure(err)
 	}
 	if e.closed {
 		return nativeFailure(fmt.Errorf("native engine is closed"))
 	}
+	if name == "ofdgoSaveSnapshot" {
+		snapshot := e.saveSnapshot
+		e.saveSnapshot = nil
+		if snapshot == nil {
+			return nativeFailure(fmt.Errorf("save snapshot is not prepared"))
+		}
+		output := &NativeEngine{OpenWriter: e.OpenWriter}
+		output.currentEditor = snapshot
+		e.saves.Add(1)
+		defer e.saves.Done()
+		<-e.gate
+		locked = false
+		defer output.Close()
+		return output.Call(ctx, "ofdgoSaveDocument", args, emit)
+	}
 	e.ctx = ctx
 	if e.currentSession != nil {
 		e.currentSession.Renderer.OutputContext = ctx
@@ -219,6 +240,8 @@ func (e *NativeEngine) Close() error {
 	e.gate <- struct{}{}
 	defer func() { <-e.gate }()
 	e.closed = true
+	e.saveSnapshot = nil
+	e.saves.Wait()
 	var err error
 	if e.currentSession != nil {
 		err = e.currentSession.Close()
@@ -728,7 +751,7 @@ func (c *nativeCall) prepare(name string, args []any) ([]any, error) {
 		args = append(args, c.fileCallback(files))
 	}
 	switch name {
-	case "ofdgoResources":
+	case "ofdgoResources", "ofdgoPrepareSave":
 		return append(args, checkpoint), nil
 	case "ofdgoImportPages", "ofdgoImportDocuments", "ofdgoImportImages":
 		return append(args, c.progress("import", "", true)), nil

internal/webui/webui_wasm.go

@@ -56,6 +56,8 @@ func RunWASM() {
 		"ofdgoImportPages":      true,
 		"ofdgoImportDocuments":  true,
 		"ofdgoSaveDocument":     true,
+		"ofdgoPrepareSave":      true,
+		"ofdgoSaveSnapshot":     true,
 		"ofdgoSetEncryption":    true,
 		"ofdgoSaveSigned":       true,
 	}

internal/webview/webview.go

@@ -450,7 +450,7 @@ func (h *Host) call(ctx context.Context, name string, value any) (any, error) {
 	case "remove":
 		return nil, h.files.remove(text("handle"), text("name"), flag("recursive"))
 	case "write.begin":
-		writer, err := h.files.begin(text("handle"))
+		writer, err := h.files.begin(guigo.PageContext(ctx), text("handle"))
 		if err != nil {
 			return nil, err
 		}
@@ -660,7 +660,7 @@ func (h *Host) openWriter(ctx context.Context, value any, name string) (io.Write
 			return nil, fmt.Errorf("输出文件已存在")
 		}
 	}
-	return h.files.begin(id)
+	return h.files.begin(ctx, id)
 }
 
 // reserveOutput 为一次转换预留独立输出文件或目录

internal/webview/webview_files.go

@@ -29,18 +29,23 @@ import (
 	"strings"
 	"sync"
 	"time"
+
+	basefile "github.com/xiaoqidun/ofdgo/internal/base/file"
 )
 
 // fileEntry 保存窗口授权的文件或目录
 type fileEntry struct {
-	path      string
+	path       string
-	name      string
+	name       string
-	data      []byte
+	data       []byte
-	file      *os.File
+	file       *os.File
-	stop      func() bool
+	stop       func() bool
-	directory bool
+	directory  bool
-	owned     bool
+	owned      bool
-	temporary bool
+	temporary  bool
+	saveTarget *basefile.Target
+	readers    int
+	retired    bool
 }
 
 // fileStore 管理窗口范围内的文件授权和临时数据
@@ -55,12 +60,8 @@ type fileStore struct {
 // fileWriter 在同目录临时文件中保存输出
 type fileWriter struct {
 	id     string
-	mu     sync.Mutex
 	store  *fileStore
-	file   *os.File
+	output *basefile.Writer
-	target string
-	err    error
-	closed bool
 }
 
 // newFileStore 创建独立文件授权表
@@ -124,7 +125,14 @@ func (s *fileStore) add(name string, directory bool) (map[string]any, error) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
 	id := rand.Text()
-	s.entries[id] = &fileEntry{path: name, name: filepath.Base(name), directory: directory}
+	entry := &fileEntry{path: name, name: filepath.Base(name), directory: directory}
+	if !directory {
+		entry.saveTarget, err = basefile.NewTarget(name)
+		if err != nil {
+			return nil, err
+		}
+	}
+	s.entries[id] = entry
 	return s.descriptor(id), nil
 }
 
@@ -161,9 +169,10 @@ func (s *fileStore) file(id string) (map[string]any, error) {
 	if entry == nil || entry.directory {
 		return nil, fmt.Errorf("文件授权无效")
 	}
+	handle := s.descriptor(id)
 	size := int64(len(entry.data))
 	if entry.data == nil {
-		file, err := openReadFile(entry.path)
+		file, err := basefile.Open(entry.path)
 		if err != nil {
 			return nil, err
 		}
@@ -177,7 +186,7 @@ func (s *fileStore) file(id string) (map[string]any, error) {
 		entry = &fileEntry{path: entry.path, name: entry.name, file: file}
 		s.entries[id] = entry
 	}
-	return map[string]any{"nativeFile": id, "name": entry.name, "size": size, "url": "/__native/data/" + id}, nil
+	return map[string]any{"nativeFile": id, "name": entry.name, "size": size, "url": "/__native/data/" + id, "handle": handle}, nil
 }
 
 // resolve 按授权标识读取文件并保持随机读取句柄
@@ -194,7 +203,7 @@ func (s *fileStore) resolve(id string) (io.ReaderAt, int64, error) {
 		return bytes.NewReader(entry.data), int64(len(entry.data)), nil
 	}
 	if entry.file == nil {
-		file, err := openReadFile(entry.path)
+		file, err := basefile.Open(entry.path)
 		if err != nil {
 			return nil, 0, err
 		}
@@ -237,7 +246,27 @@ func (s *fileStore) resource(id string) (io.ReaderAt, int64, func() error, error
 	if entry.data != nil {
 		return bytes.NewReader(entry.data), int64(len(entry.data)), nil, nil
 	}
-	file, err := openReadFile(entry.path)
+	if entry.file != nil && !entry.temporary {
+		info, err := entry.file.Stat()
+		if err != nil {
+			return nil, 0, nil, err
+		}
+		entry.readers++
+		var once sync.Once
+		var closeErr error
+		return entry.file, info.Size(), func() error {
+			once.Do(func() {
+				s.mu.Lock()
+				defer s.mu.Unlock()
+				entry.readers--
+				if entry.retired && entry.readers == 0 {
+					closeErr = entry.file.Close()
+				}
+			})
+			return closeErr
+		}, nil
+	}
+	file, err := basefile.Open(entry.path)
 	if err != nil {
 		return nil, 0, nil, err
 	}
@@ -374,9 +403,9 @@ func (s *fileStore) reserve(id, base, extension string, directory bool) (string,
 }
 
 // begin 创建文件写入事务
-// 入参: id 输出授权标识
+// 入参: ctx 取消上下文, id 输出授权标识
 // 返回: *fileWriter 事务写入器, error 创建错误
-func (s *fileStore) begin(id string) (*fileWriter, error) {
+func (s *fileStore) begin(ctx context.Context, id string) (*fileWriter, error) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
 	if s.closed {
@@ -386,11 +415,18 @@ func (s *fileStore) begin(id string) (*fileWriter, error) {
 	if entry == nil || entry.directory || entry.path == "" {
 		return nil, fmt.Errorf("输出授权无效")
 	}
-	file, err := temporaryFile(filepath.Dir(entry.path), filepath.Base(entry.path)+".")
+	if entry.saveTarget == nil {
+		var err error
+		entry.saveTarget, err = basefile.NewTarget(entry.path)
+		if err != nil {
+			return nil, err
+		}
+	}
+	output, err := entry.saveTarget.Begin(ctx)
 	if err != nil {
 		return nil, err
 	}
-	writer := &fileWriter{id: rand.Text(), store: s, file: file, target: entry.path}
+	writer := &fileWriter{id: rand.Text(), store: s, output: output}
 	s.writers[writer.id] = writer
 	return writer, nil
 }
@@ -429,7 +465,8 @@ func (s *fileStore) remove(id, name string, recursive bool) error {
 	defer root.Close()
 	for key, entry := range s.entries {
 		if entry.path == target || recursive && strings.HasPrefix(entry.path, target+string(filepath.Separator)) {
-			if entry.file != nil {
+			entry.retired = true
+			if entry.file != nil && entry.readers == 0 {
 				entry.file.Close()
 			}
 			delete(s.entries, key)
@@ -445,62 +482,21 @@ func (s *fileStore) remove(id, name string, recursive bool) error {
 // 入参: data 输出数据
 // 返回: int 写入字节数, error 写入错误
 func (w *fileWriter) Write(data []byte) (int, error) {
-	w.mu.Lock()
+	return w.output.Write(data)
-	defer w.mu.Unlock()
-	if w.closed {
-		return 0, os.ErrClosed
-	}
-	if w.err != nil {
-		return 0, w.err
-	}
-	n, err := w.file.Write(data)
-	if err == nil && n != len(data) {
-		err = io.ErrShortWrite
-	}
-	w.err = err
-	return n, err
 }
 
 // Close 同步并替换目标文件
 // 返回: error 提交错误
 func (w *fileWriter) Close() error {
 	defer w.release()
-	w.mu.Lock()
+	return w.output.Close()
-	defer w.mu.Unlock()
-	if w.closed {
-		return os.ErrClosed
-	}
-	w.closed = true
-	if w.err != nil {
-		return errors.Join(w.err, w.file.Close(), os.Remove(w.file.Name()))
-	}
-	if err := w.file.Sync(); err != nil {
-		w.file.Close()
-		os.Remove(w.file.Name())
-		return err
-	}
-	if err := w.file.Close(); err != nil {
-		os.Remove(w.file.Name())
-		return err
-	}
-	if err := replaceFile(w.file.Name(), w.target); err != nil {
-		os.Remove(w.file.Name())
-		return err
-	}
-	return nil
 }
 
 // Abort 删除未提交的临时输出
 // 返回: error 清理错误
 func (w *fileWriter) Abort() error {
 	defer w.release()
-	w.mu.Lock()
+	return w.output.Abort()
-	defer w.mu.Unlock()
-	if w.closed {
-		return nil
-	}
-	w.closed = true
-	return errors.Join(w.file.Close(), os.Remove(w.file.Name()))
 }
 
 // release 移除已结束的写入事务
@@ -556,9 +552,12 @@ func (s *fileStore) close() error {
 		if entry.stop != nil {
 			entry.stop()
 		}
-		if entry.file != nil {
+		s.mu.Lock()
+		entry.retired = true
+		if entry.file != nil && entry.readers == 0 {
 			err = errors.Join(err, entry.file.Close())
 		}
+		s.mu.Unlock()
 	}
 	return errors.Join(err, os.RemoveAll(s.temporary))
 }

internal/webview/webview_other.go

@@ -16,21 +16,9 @@
 
 package webview
 
-import "os"
-
 // conversionMemory 未提供系统内存探测时仅按并行数调度
 var conversionMemory func() int64
 
-// openReadFile 打开独立读取句柄
-func openReadFile(name string) (*os.File, error) {
-	return os.Open(name)
-}
-
-// replaceFile 替换目标文件并保留已有读取句柄
-func replaceFile(source, target string) error {
-	return os.Rename(source, target)
-}
-
 // fontNameLanguage 未指定系统显示语言时沿用字体名称表顺序
 // 返回: uint16 未指定平台标识, uint16 未指定语言标识
 func fontNameLanguage() (uint16, uint16) {

internal/webview/webview_windows.go

@@ -15,68 +15,13 @@
 package webview
 
 import (
-	"os"
-	"path/filepath"
-	"strings"
 	"syscall"
 	"unsafe"
 )
 
-// replaceFileProc 保留目标文件属性并替换文件内容
-var replaceFileProc = syscall.NewLazyDLL("kernel32.dll").NewProc("ReplaceFileW")
-
 // memoryStatusProc 查询系统物理内存和提交额度
 var memoryStatusProc = syscall.NewLazyDLL("kernel32.dll").NewProc("GlobalMemoryStatusEx")
 
-// openReadFile 允许原子替换路径，同时保持已有读取句柄有效
-func openReadFile(name string) (*os.File, error) {
-	path, err := nativeFilePath(name)
-	if err != nil {
-		return nil, &os.PathError{Op: "open", Path: name, Err: err}
-	}
-	handle, err := syscall.CreateFile(path, syscall.GENERIC_READ, syscall.FILE_SHARE_READ|syscall.FILE_SHARE_WRITE|syscall.FILE_SHARE_DELETE, nil, syscall.OPEN_EXISTING, syscall.FILE_ATTRIBUTE_NORMAL, 0)
-	if err != nil {
-		return nil, &os.PathError{Op: "open", Path: name, Err: err}
-	}
-	return os.NewFile(uintptr(handle), name), nil
-}
-
-// replaceFile 替换已有文件，目标不存在时直接重命名
-func replaceFile(source, target string) error {
-	from, err := nativeFilePath(source)
-	if err != nil {
-		return err
-	}
-	to, err := nativeFilePath(target)
-	if err != nil {
-		return err
-	}
-	result, _, err := replaceFileProc.Call(uintptr(unsafe.Pointer(to)), uintptr(unsafe.Pointer(from)), 0, 0, 0, 0)
-	if result != 0 {
-		return nil
-	}
-	if err == syscall.ERROR_FILE_NOT_FOUND {
-		return os.Rename(source, target)
-	}
-	return &os.LinkError{Op: "replace", Old: source, New: target, Err: err}
-}
-
-// nativeFilePath 转换绝对路径并支持长路径与网络共享
-func nativeFilePath(name string) (*uint16, error) {
-	path, err := filepath.Abs(name)
-	if err != nil {
-		return nil, err
-	}
-	if !strings.HasPrefix(path, `\\?\`) {
-		if strings.HasPrefix(path, `\\`) {
-			path = `\\?\UNC\` + path[2:]
-		} else {
-			path = `\\?\` + path
-		}
-	}
-	return syscall.UTF16PtrFromString(path)
-}
-
 // fontNameLanguage 获取系统显示语言对应的OpenType名称表标识
 // 返回: uint16 名称表平台标识, uint16 系统显示语言标识
 func fontNameLanguage() (uint16, uint16) {

ofdgo.go

@@ -20,6 +20,8 @@ import (
 	"image"
 	"io"
 	"io/fs"
+
+	basefile "github.com/xiaoqidun/ofdgo/internal/base/file"
 )
 
 // Open 打开OFD文件
@@ -27,14 +29,24 @@ import (
 // 入参: path 文件路径, options 阅读选项
 // 返回: *Reader 阅读器实例, error 错误信息
 func Open(path string, options ...ReaderOption) (*Reader, error) {
-	r, err := zip.OpenReader(path)
+	f, err := basefile.Open(path)
 	if err != nil {
 		return nil, err
 	}
+	info, err := f.Stat()
+	if err != nil {
+		f.Close()
+		return nil, err
+	}
+	r, err := zip.NewReader(f, info.Size())
+	if err != nil {
+		f.Close()
+		return nil, err
+	}
 	reader := &Reader{
 		Path:   path,
-		Zip:    &r.Reader,
+		Zip:    r,
-		Closer: r,
+		Closer: f,
 	}
 	if err := reader.open(options); err != nil {
 		reader.Close()

ofdgo_editor.go

@@ -33,6 +33,7 @@ import (
 	"time"
 	"unicode/utf8"
 
+	basefile "github.com/xiaoqidun/ofdgo/internal/base/file"
 	baseimage "github.com/xiaoqidun/ofdgo/internal/base/image"
 )
 
@@ -40,7 +41,7 @@ import (
 const editorPathValidationLimit = 1024
 
 // Editor 编辑OFD文档，长度单位为毫米，页面索引从0开始，实例需串行使用
-// Info可修改文档元数据，通过方法管理页面、对象和资源，WriteTo另存结果，不覆盖输入
+// Info可修改文档元数据，通过方法管理页面、对象和资源，WriteTo输出副本，Save和SaveAs通过绑定路径保存
 // OnWriteProgress可选，按fonts、pages、references、resources、compress、write阶段同步回报进度，返回错误则停止保存
 // completed和total为当前阶段已处理及总工作项，compress累计完成条目数且total为0，write阶段不计数
 // 阶段可重复，准备完成不代表保存成功
@@ -73,6 +74,7 @@ type Editor struct {
 	outlines         []byte
 	encryption       *encryptionState
 	output           *outputOptimization
+	saveTarget       *basefile.Target
 	validatedPaths   *renderCache[string, bool]
 	richIndex        *richTextIndex
 }

ofdgo_editor_documents.go

@@ -451,6 +451,7 @@ func (e *Editor) adoptDocumentReader(ctx context.Context, reader *Reader) error
 		next.revision, next.serial = e.revision, e.serial
 		next.OnWriteProgress, next.output = e.OnWriteProgress, e.output
 		next.encryption = e.encryption
+		next.saveTarget = e.saveTarget
 		next.backends, next.fontDirs, next.fontFS = e.backends, e.fontDirs, e.fontFS
 		next.validatedPaths = e.validatedPaths
 		*e = *next

ofdgo_editor_font_binding.go

@@ -908,6 +908,7 @@ func (e *Editor) restoreResourceSnapshot(state Editor) {
 	}
 	state.backends, state.fontDirs, state.fontFS = e.backends, e.fontDirs, e.fontFS
 	state.encryption, state.output, state.OnWriteProgress = e.encryption, e.output, e.OnWriteProgress
+	state.saveTarget = e.saveTarget
 	state.fontRenderer, state.fontSourcesCache = nil, nil
 	state.fontMetrics = make(map[string]FontMetrics)
 	*e = state

ofdgo_editor_history.go

@@ -171,6 +171,7 @@ func (e *Editor) restoreTransaction(state Editor) {
 	state.fontSourcesCache = e.fontSourcesCache
 	state.validatedPaths = e.validatedPaths
 	state.encryption, state.output, state.OnWriteProgress = e.encryption, e.output, e.OnWriteProgress
+	state.saveTarget = e.saveTarget
 	*e = state
 }
 

ofdgo_writer.go

@@ -20,6 +20,7 @@ import (
 	"context"
 	"encoding/hex"
 	"encoding/xml"
+	"errors"
 	"fmt"
 	"io"
 	"maps"
@@ -29,6 +30,8 @@ import (
 	"strconv"
 	"strings"
 	"time"
+
+	basefile "github.com/xiaoqidun/ofdgo/internal/base/file"
 )
 
 // editorProgress 编辑与保存阶段的进度回调，nil表示不回报进度
@@ -54,6 +57,141 @@ type ofdXML struct {
 // ofdAttrs OFD节点属性
 type ofdAttrs []xml.Attr
 
+// ErrSaveTarget 表示编辑器尚未绑定保存目标
+var ErrSaveTarget = errors.New("save target is not set")
+
+// ErrSaveConflict 表示保存目标在打开或最近保存后被其他操作修改
+var ErrSaveConflict = basefile.ErrChanged
+
+// ErrSaveBusy 表示目标文件正在提交其他写入事务
+var ErrSaveBusy = basefile.ErrBusy
+
+// Snapshot 创建独立编辑快照，完成后可与原编辑器并行使用
+// 创建过程需与原实例串行，保留修订及保存目标，不复制撤销记录和进度回调
+// 原包压缩数据直接复制，快照不依赖原阅读器及文件句柄，内存随快照释放
+// 自定义后端及字体文件系统仍由调用方提供，需支持并行读取
+// 入参: ctx 取消上下文
+// 返回: *Editor 独立快照, error 准备或取消错误
+func (e *Editor) Snapshot(ctx context.Context) (*Editor, error) {
+	reader, err := e.readerContext(ctx, nil)
+	if err != nil {
+		return nil, err
+	}
+	defer reader.Close()
+	next := &Reader{files: make(map[string][]byte, len(reader.files)), encryption: reader.encryption, documentIndex: reader.documentIndex, selectedVersion: cloneEditorData(reader.selectedVersion)}
+	if reader.encryption != nil {
+		next.encryption = &encryptionState{info: cloneEditorData(reader.encryption.info), options: cloneEncryptionOptions(reader.encryption.options)}
+	}
+	if reader.Zip != nil {
+		var data bytes.Buffer
+		var count int64
+		archive := zip.NewWriter(convertWriter{context: ctx, writer: &data, count: &count})
+		for _, file := range reader.Zip.File {
+			if err := ctx.Err(); err != nil {
+				return nil, err
+			}
+			if err := archive.Copy(file); err != nil {
+				return nil, err
+			}
+		}
+		if err := archive.Close(); err != nil {
+			return nil, err
+		}
+		next.Zip, err = zip.NewReader(bytes.NewReader(data.Bytes()), int64(data.Len()))
+		if err != nil {
+			return nil, err
+		}
+	}
+	for name, data := range reader.files {
+		if err := ctx.Err(); err != nil {
+			return nil, err
+		}
+		next.files[name] = bytes.Clone(data)
+	}
+	if err := next.initRootContext(ctx); err != nil {
+		return nil, err
+	}
+	snapshot, err := next.EditorContext(ctx)
+	if err != nil {
+		return nil, err
+	}
+	snapshot.revision, snapshot.serial, snapshot.saveTarget = e.revision, e.serial, e.saveTarget
+	snapshot.backends, snapshot.fontDirs, snapshot.fontFS = e.backends, slices.Clone(e.fontDirs), slices.Clone(e.fontFS)
+	return snapshot, nil
+}
+
+// SetSavePath 绑定保存目标并记录当前文件状态，不读取或修改编辑内容
+// 绑定已有文件时应在打开后立即调用；空路径解除绑定，调用需与编辑操作串行
+// 入参: name 目标路径
+// 返回: error 路径或文件状态错误
+func (e *Editor) SetSavePath(name string) error {
+	if name == "" {
+		e.saveTarget = nil
+		return nil
+	}
+	target, err := basefile.NewTarget(name)
+	if err != nil {
+		return err
+	}
+	e.saveTarget = target
+	return nil
+}
+
+// SavePath 返回当前保存目标，未绑定时返回空字符串
+// 返回: string 绝对文件路径
+func (e *Editor) SavePath() string {
+	if e.saveTarget == nil {
+		return ""
+	}
+	return e.saveTarget.Name()
+}
+
+// Save 将当前完整文档写回已绑定目标，不改变编辑状态及撤销记录
+// 调用需与编辑操作串行，支持取消；失败保留原文件，成功后可继续编辑和保存
+// 入参: ctx 取消上下文, options 输出配置
+// 返回: int64 输出字节数, error 保存错误
+func (e *Editor) Save(ctx context.Context, options WriteOptions) (int64, error) {
+	if e.saveTarget == nil {
+		return 0, ErrSaveTarget
+	}
+	return e.saveFile(ctx, e.saveTarget, options)
+}
+
+// SaveAs 将完整文档另存，成功后切换保存目标，不改变撤销记录
+// 调用需与编辑操作串行，取消或失败时保持原目标
+// 入参: ctx 取消上下文, name 目标路径, options 输出配置
+// 返回: int64 输出字节数, error 保存错误
+func (e *Editor) SaveAs(ctx context.Context, name string, options WriteOptions) (int64, error) {
+	target, err := basefile.NewTarget(name)
+	if err != nil {
+		return 0, err
+	}
+	if e.saveTarget != nil && target.Name() == e.saveTarget.Name() {
+		target = e.saveTarget
+	}
+	n, err := e.saveFile(ctx, target, options)
+	if err == nil {
+		e.saveTarget = target
+	}
+	return n, err
+}
+
+// saveFile 使用共用文件事务提交文档
+// 入参: ctx 取消上下文, target 保存目标, options 输出配置
+// 返回: int64 输出字节数, error 保存错误
+func (e *Editor) saveFile(ctx context.Context, target *basefile.Target, options WriteOptions) (int64, error) {
+	writer, err := target.Begin(ctx)
+	if err != nil {
+		return 0, err
+	}
+	defer writer.Abort()
+	n, err := e.WriteToWithOptions(ctx, writer, options)
+	if err != nil {
+		return n, err
+	}
+	return n, writer.Close()
+}
+
 // WriteTo 逐个条目写出OFD，不关闭调用方输出流，出错时应丢弃本次输出
 // 新增资源仅写入实际引用的部分，静态TrueType轮廓字体按实际文字生成子集
 // 原有字体在全包引用可确定时保留字形编号裁剪；编辑资源、复杂字体及无法确定的引用保持原样