feat: open FSSHTTP OneNote sections

2026-07-22 19:26:08 +02:00
parent a7b1cd7d16
commit eb15fecb3f
12 changed files with 877 additions and 21 deletions
--- a/src/onenote/fsshttpb/data-elements.ts
+++ b/src/onenote/fsshttpb/data-elements.ts
@@ -553,11 +553,14 @@ function parseObjectGroupData(
      context.limits.maxVectorBytes,
      'Object binary item size'
    );
+    const offset = body.offset;
+    const data = body.read(size);
    result = {
      kind: 'object',
      objectReferences,
      cellReferences,
-      data: body.read(size),
+      data,
+      dataReference: { source: body.bytes, offset, size },
    };
  } else if (header.type === FSSHTTP_OBJECT.objectGroupBlobReference) {
    result = {
--- a/src/onenote/fsshttpb/types.ts
+++ b/src/onenote/fsshttpb/types.ts
@@ -120,6 +120,7 @@ export type FssHttpObjectGroupData =
      objectReferences: ExGuid[];
      cellReferences: FssHttpCellId[];
      data: Uint8Array;
+      dataReference: FileDataBlobReference;
    }
  | {
      kind: 'excluded';
--- a/src/onenote/one/property-access.ts
+++ b/src/onenote/one/property-access.ts
@@ -21,6 +21,7 @@ import type {
  ObjectSpace,
  PropertyEntry,
  StoreObject,
+  StoreObjectSpaceReference,
 } from '../onestore/types.js';
 import { exGuidKey } from '../onestore/types.js';

@@ -40,13 +41,16 @@ export function objectReferences(
    propertyId,
    countObjectReferences
  );
+  if (object.resolvedObjectIds) {
+    return resolvedReferenceSlice(object.resolvedObjectIds, offset, count);
+  }
  return resolveReferenceSlice(object, object.props.objectIds, offset, count);
 }

 export function objectSpaceReferences(
  object: StoreObject,
  propertyId: number
-): ExGuid[] {
+): StoreObjectSpaceReference[] {
  const property = findProperty(object.props, propertyId);
  if (!property) return [];
  let count: number;
@@ -60,12 +64,15 @@ export function objectSpaceReferences(
    propertyId,
    countObjectSpaceReferences
  );
+  if (object.resolvedObjectSpaceIds) {
+    return resolvedReferenceSlice(object.resolvedObjectSpaceIds, offset, count);
+  }
  return resolveReferenceSlice(
    object,
    object.props.objectSpaceIds,
    offset,
    count
-  );
+  ).map((id) => ({ id, key: exGuidKey(id) }));
 }

 export function rootObject(
@@ -257,6 +264,19 @@ function resolveReferenceSlice(
  });
 }

+function resolvedReferenceSlice<T>(
+  ids: readonly T[],
+  offset: number,
+  count: number
+): T[] {
+  if (offset + count > ids.length) {
+    throw new Error(
+      `Reference range ${offset}+${count} exceeds resolved stream length ${ids.length}`
+    );
+  }
+  return ids.slice(offset, offset + count);
+}
+
 function propertyTypeError(propertyId: number, expected: string): Error {
  return new Error(`Property 0x${propertyId.toString(16)} is not ${expected}`);
 }
--- a/src/onenote/one/section-content.ts
+++ b/src/onenote/one/section-content.ts
@@ -83,14 +83,14 @@ export function buildSectionContentModel(
      series,
      PROPERTY.ChildGraphSpaceElementNodes
    );
-    for (const pageSpaceId of pageSpaceIds) {
+    for (const pageSpaceReference of pageSpaceIds) {
      context.currentPage = undefined;
-      const pageSpace = store.objectSpaces.get(exGuidKey(pageSpaceId));
+      const pageSpace = store.objectSpaces.get(pageSpaceReference.key);
      if (!pageSpace) {
        addDiagnostic(
          context,
          'MISSING_PAGE_SPACE',
-          `Page object space ${exGuidKey(pageSpaceId)} is missing`,
+          `Page object space ${pageSpaceReference.key} is missing`,
          'PageSeriesNode'
        );
        continue;
@@ -111,7 +111,7 @@ export function buildSectionContentModel(
        addDiagnostic(
          context,
          'PAGE_PARSE_FAILED',
-          `Could not parse page ${exGuidKey(pageSpaceId)}: ${error instanceof Error ? error.message : String(error)}`,
+          `Could not parse page ${pageSpaceReference.key}: ${error instanceof Error ? error.message : String(error)}`,
          'Page',
          'error'
        );
--- a/src/onenote/one/section.ts
+++ b/src/onenote/one/section.ts
@@ -26,6 +26,7 @@ import type {
  ObjectSpace,
  PropertyEntry,
  StoreObject,
+  StoreObjectSpaceReference,
 } from '../onestore/types.js';
 import { exGuidKey } from '../onestore/types.js';
 import { JCID, PROPERTY } from './constants.js';
@@ -55,7 +56,9 @@ export function buildSectionDto(
  const root = store.rootObjectSpace;
  const metadata = rootObject(root, 2, 'section metadata root');
  assertJcid(metadata, JCID.SectionMetadata, 'SectionMetadata');
-  const displayName = optionalString(metadata, PROPERTY.SectionDisplayName);
+  const displayName = cleanMetadataString(
+    optionalString(metadata, PROPERTY.SectionDisplayName)
+  );

  const section = rootObject(root, 1, 'section content root');
  assertJcid(section, JCID.SectionNode, 'SectionNode');
@@ -69,14 +72,14 @@ export function buildSectionDto(
      series,
      PROPERTY.ChildGraphSpaceElementNodes
    );
-    for (const pageSpaceId of pageSpaceIds) {
+    for (const pageSpaceReference of pageSpaceIds) {
      context.currentPage = undefined;
-      const pageSpace = store.objectSpaces.get(exGuidKey(pageSpaceId));
+      const pageSpace = store.objectSpaces.get(pageSpaceReference.key);
      if (!pageSpace) {
        addDiagnostic(
          context,
          'MISSING_PAGE_SPACE',
-          `Page object space ${exGuidKey(pageSpaceId)} is missing`,
+          `Page object space ${pageSpaceReference.key} is missing`,
          'PageSeriesNode'
        );
        continue;
@@ -99,7 +102,7 @@ export function buildSectionDto(
        addDiagnostic(
          context,
          'PAGE_PARSE_FAILED',
-          `Could not parse page ${exGuidKey(pageSpaceId)}: ${message}`,
+          `Could not parse page ${pageSpaceReference.key}: ${message}`,
          'Page',
          'error'
        );
@@ -116,7 +119,7 @@ export function buildSectionDto(
    diagnostics,
    parserInfo: {
      implementation: 'typescript',
-      supportedVariant: 'desktop-revision-store',
+      supportedVariant: store.variant,
      referenceRevision: 'onenote.rs@5138a39a3f4e72b840932f9872fecde52fa9da60',
    },
  };
@@ -398,13 +401,16 @@ function objectReferences(object: StoreObject, propertyId: number): ExGuid[] {
    propertyId,
    countObjectReferences
  );
+  if (object.resolvedObjectIds) {
+    return resolvedReferenceSlice(object.resolvedObjectIds, offset, count);
+  }
  return resolveReferenceSlice(object, object.props.objectIds, offset, count);
 }

 function objectSpaceReferences(
  object: StoreObject,
  propertyId: number
-): ExGuid[] {
+): StoreObjectSpaceReference[] {
  const property = findProperty(object.props, propertyId);
  if (!property) return [];
  let count: number;
@@ -421,12 +427,15 @@ function objectSpaceReferences(
    propertyId,
    countObjectSpaceReferences
  );
+  if (object.resolvedObjectSpaceIds) {
+    return resolvedReferenceSlice(object.resolvedObjectSpaceIds, offset, count);
+  }
  return resolveReferenceSlice(
    object,
    object.props.objectSpaceIds,
    offset,
    count
-  );
+  ).map((id) => ({ id, key: exGuidKey(id) }));
 }

 function resolveReferenceSlice(
@@ -447,6 +456,19 @@ function resolveReferenceSlice(
  });
 }

+function resolvedReferenceSlice<T>(
+  ids: readonly T[],
+  offset: number,
+  count: number
+): T[] {
+  if (offset + count > ids.length) {
+    throw new Error(
+      `Reference range ${offset}+${count} exceeds resolved stream length ${ids.length}`
+    );
+  }
+  return ids.slice(offset, offset + count);
+}
+
 function rootObject(
  space: ObjectSpace,
  role: number,
@@ -659,3 +681,8 @@ function addDiagnostic(
 function stripOneExtension(filename: string): string {
  return (filename.split(/[\\/]/).at(-1) ?? filename).replace(/\.one$/i, '');
 }
+
+function cleanMetadataString(value: string | undefined): string | undefined {
+  const result = value?.split('\0').join('').trim();
+  return result || undefined;
+}
--- a/src/onenote/onestore/desktop-store.ts
+++ b/src/onenote/onestore/desktop-store.ts
@@ -45,6 +45,7 @@ import { exGuidKey } from './types.js';

 export interface DesktopOneStore {
  kind: 'section' | 'table-of-contents';
+  variant: 'desktop-revision-store' | 'fsshttpb-package-store';
  fileIdentity: string;
  rootObjectSpace: ObjectSpace;
  objectSpaces: Map<string, ObjectSpace>;
@@ -185,6 +186,7 @@ function parseDesktopRevisionStore(

  return {
    kind: expectedKind === 'desktop-one' ? 'section' : 'table-of-contents',
+    variant: 'desktop-revision-store',
    fileIdentity,
    rootObjectSpace,
    objectSpaces,
--- a/src/onenote/onestore/fsshttp-store.test.ts
+++ b/src/onenote/onestore/fsshttp-store.test.ts
@@ -0,0 +1,48 @@
+import { readFileSync } from 'node:fs';
+import { resolve } from 'node:path';
+
+import { describe, expect, it } from 'vitest';
+
+import {
+  parseOneNoteSection,
+  parseOneNoteSectionContent,
+} from '../parser/parse-section.js';
+
+function fixtureBytes(): Uint8Array {
+  const encoded = readFileSync(
+    resolve(process.cwd(), 'tests/fixtures/joplin-quick-notes-fsshttp.one.b64'),
+    'utf8'
+  );
+  return Uint8Array.from(Buffer.from(encoded.replaceAll(/\s/gu, ''), 'base64'));
+}
+
+describe('FSSHTTPB OneStore adapter', () => {
+  it('opens the pinned Joplin section through the public parser', () => {
+    const parsed = parseOneNoteSection(fixtureBytes(), {
+      sourceName: 'Quick Notes.one',
+    });
+
+    expect(parsed).toMatchObject({
+      format: 'one',
+      sourceName: 'Quick Notes.one',
+      sectionName: 'Section title.one',
+      parserInfo: { supportedVariant: 'fsshttpb-package-store' },
+    });
+    expect(parsed.pages).toHaveLength(1);
+    expect(parsed.pages[0]).toMatchObject({
+      title: 'Page title',
+      text: expect.stringContaining('Page content'),
+    });
+  });
+
+  it('feeds FSSHTTPB objects into the rich-content model', () => {
+    const parsed = parseOneNoteSectionContent(fixtureBytes(), {
+      sourceName: 'Quick Notes.one',
+    });
+
+    expect(parsed.sectionName).toBe('Section title.one');
+    expect(parsed.pages).toHaveLength(1);
+    expect(parsed.pages[0]).toMatchObject({ title: 'Page title' });
+    expect(parsed.pages[0]?.text).toContain('Page content');
+  });
+});
--- a/src/onenote/onestore/fsshttp-store.ts
+++ b/src/onenote/onestore/fsshttp-store.ts
@@ -0,0 +1,694 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at https://mozilla.org/MPL/2.0/.
+// SPDX-License-Identifier: MPL-2.0
+//
+// Portions adapted from onenote.rs (MPL-2.0), revision
+// 5138a39a3f4e72b840932f9872fecde52fa9da60: `onestore/fsshttpb/*`.
+// Deviations: immutable browser-native records, explicit cycle/count bounds,
+// newest-revision precedence, and store-specific resolved reference arrays.
+
+import { BinaryReader } from '../binary/BinaryReader.js';
+import { NIL_GUID, readGuid } from '../binary/guid.js';
+import {
+  fssHttpCellKey,
+  type FssHttpCellId,
+  type FssHttpObjectDeclaration,
+  type FssHttpObjectGroup,
+  type FssHttpObjectGroupData,
+  type FssHttpOneStorePackage,
+  type FssHttpRevisionManifest,
+  type FssHttpSerialNumber,
+  type FssHttpStorageIndex,
+  type FssHttpStorageIndexCellMapping,
+  type FssHttpStorageManifest,
+} from '../fsshttpb/types.js';
+import type { ParserDiagnostic } from '../model/diagnostics.js';
+import { ONE_SECTION_FILE_TYPE } from '../parser/detect-format.js';
+import { OneNoteParserError } from '../parser/error.js';
+import type { OneNoteParserLimits } from '../parser/limits.js';
+import { parseFssHttpOneStorePackage } from '../fsshttpb/package.js';
+import type { DesktopOneStore } from './desktop-store.js';
+import { findProperty, parseObjectPropSetRange } from './property-set.js';
+import type {
+  ExGuid,
+  ObjectSpace,
+  PropertyEntry,
+  StoreFileData,
+  StoreObject,
+} from './types.js';
+import { exGuidKey } from './types.js';
+
+const HEADER_ROOT = exGuidKey({
+  guid: '{1A5A319C-C26B-41AA-B9C5-9BD8C44E07D4}',
+  value: 1,
+});
+const DATA_ROOT = exGuidKey({
+  guid: '{84DEFAB9-AAA3-4A0D-A3A8-520C77AC7073}',
+  value: 2,
+});
+const REVISION_ROLE_GUID = '{4A3717F8-1C14-49E7-9526-81D942DE1741}';
+const PROPERTY_FILE_IDENTITY_GUID = 0x1c001d94;
+const PROPERTY_FILE_ANCESTOR_IDENTITY_GUID = 0x1c001d95;
+const PROPERTY_FILE_NAME_CRC = 0x14001d93;
+
+interface StoreContext {
+  package: FssHttpOneStorePackage;
+  index: FssHttpStorageIndex;
+  limits: OneNoteParserLimits;
+  diagnostics: ParserDiagnostic[];
+  objectCount: number;
+}
+
+interface GroupEntry {
+  declaration: FssHttpObjectDeclaration;
+  data: FssHttpObjectGroupData;
+}
+
+/** Parse an unfragmented FSSHTTPB package into the shared OneStore model. */
+export function parseFssHttpOneStore(
+  bytes: Uint8Array,
+  limits: OneNoteParserLimits,
+  diagnostics: ParserDiagnostic[]
+): DesktopOneStore {
+  const packageStore = parseFssHttpOneStorePackage(bytes, limits);
+  if (packageStore.dataElements.fragments.size > 0) {
+    throw new OneNoteParserError(
+      'UNSUPPORTED_FORMAT',
+      'FSSHTTPB Data Element Fragment reconstruction is not supported',
+      { structure: 'Data Element Fragment' }
+    );
+  }
+
+  const index = selectStorageIndex(packageStore, limits, diagnostics);
+  const context: StoreContext = {
+    package: packageStore,
+    index,
+    limits,
+    diagnostics,
+    objectCount: 0,
+  };
+  const manifest = selectStorageManifest(context);
+  if (manifest.schema !== packageStore.cellSchema) {
+    throw new OneNoteParserError(
+      'INVALID_STRUCTURE',
+      `Storage Manifest schema ${manifest.schema} does not match package schema ${packageStore.cellSchema}`,
+      { structure: 'Storage Manifest' }
+    );
+  }
+
+  const headerCell = requiredManifestRoot(manifest, HEADER_ROOT, 'header');
+  const dataRootCell = requiredManifestRoot(manifest, DATA_ROOT, 'data');
+  validateHeaderCell(context, headerCell);
+
+  const rootObjectSpace = parseObjectSpace(context, dataRootCell);
+  const objectSpaces = new Map<string, ObjectSpace>();
+  objectSpaces.set(fssHttpCellKey(dataRootCell), rootObjectSpace);
+
+  const skippedCells = new Set([
+    fssHttpCellKey(headerCell),
+    fssHttpCellKey(dataRootCell),
+  ]);
+  for (const mapping of index.cellMappings.values()) {
+    const key = fssHttpCellKey(mapping.cellId);
+    if (skippedCells.has(key) || isNilExGuid(mapping.id)) continue;
+    objectSpaces.set(key, parseObjectSpace(context, mapping.cellId));
+  }
+
+  return {
+    kind:
+      packageStore.fileType === ONE_SECTION_FILE_TYPE
+        ? 'section'
+        : 'table-of-contents',
+    variant: 'fsshttpb-package-store',
+    fileIdentity: packageStore.fileIdentity,
+    rootObjectSpace,
+    objectSpaces,
+  };
+}
+
+function selectStorageIndex(
+  packageStore: FssHttpOneStorePackage,
+  limits: OneNoteParserLimits,
+  diagnostics: ParserDiagnostic[]
+): FssHttpStorageIndex {
+  const indexes = packageStore.dataElements.storageIndexes;
+  const requested = indexes.get(exGuidKey(packageStore.storageIndexId));
+  if (requested) return requested;
+  if (indexes.size !== 1) {
+    throw new OneNoteParserError(
+      'MISSING_REFERENCE',
+      `Storage Index ${exGuidKey(packageStore.storageIndexId)} is absent`,
+      { structure: 'Storage Index' }
+    );
+  }
+  addDiagnostic(
+    diagnostics,
+    limits,
+    'FSSHTTP_STORAGE_INDEX_FALLBACK',
+    `Storage Index ${exGuidKey(packageStore.storageIndexId)} was absent; used the package's only Storage Index`,
+    'Storage Index'
+  );
+  return indexes.values().next().value!;
+}
+
+function selectStorageManifest(context: StoreContext): FssHttpStorageManifest {
+  const manifests = context.package.dataElements.storageManifests;
+  for (const mapping of context.index.manifestMappings) {
+    const manifest = manifests.get(exGuidKey(mapping.id));
+    if (manifest) return manifest;
+  }
+  if (manifests.size !== 1) {
+    throw new OneNoteParserError(
+      'MISSING_REFERENCE',
+      context.index.manifestMappings.length === 0
+        ? 'Storage Index has no resolvable Storage Manifest mapping'
+        : 'Storage Index manifest mappings do not resolve uniquely',
+      { structure: 'Storage Manifest' }
+    );
+  }
+  addDiagnostic(
+    context.diagnostics,
+    context.limits,
+    'FSSHTTP_STORAGE_MANIFEST_FALLBACK',
+    "Storage Index manifest mappings did not resolve; used the package's only Storage Manifest",
+    'Storage Manifest'
+  );
+  return manifests.values().next().value!;
+}
+
+function requiredManifestRoot(
+  manifest: FssHttpStorageManifest,
+  key: string,
+  name: string
+): FssHttpCellId {
+  const cell = manifest.roots.get(key);
+  if (!cell) {
+    throw new OneNoteParserError(
+      'MISSING_REFERENCE',
+      `Storage Manifest has no ${name} cell root`,
+      { structure: 'Storage Manifest root' }
+    );
+  }
+  return cell;
+}
+
+function validateHeaderCell(context: StoreContext, cell: FssHttpCellId): void {
+  const mapping = requiredCellMapping(context, cell);
+  const revisionId = resolveCurrentRevisionId(context, mapping);
+  if (!revisionId) {
+    throw new OneNoteParserError(
+      'MISSING_REFERENCE',
+      'Header cell has no current revision',
+      { structure: 'OneStore package header cell' }
+    );
+  }
+  const revision = requiredRevisionManifest(context, revisionId);
+  const entries = revision.objectGroupIds.flatMap((groupId) =>
+    pairedGroupEntries(context, groupId)
+  );
+  const headerEntry = entries.find(
+    ({ declaration }) => declaration.partitionId === 1
+  );
+  if (!headerEntry || headerEntry.data.kind !== 'object') {
+    throw new OneNoteParserError(
+      'INVALID_STRUCTURE',
+      'Header cell has no object-data property set',
+      { structure: 'OneStore package header cell' }
+    );
+  }
+  const props = parseObjectPropSetRange(
+    headerEntry.data.dataReference.source,
+    headerEntry.data.dataReference.offset,
+    headerEntry.data.dataReference.size,
+    context.limits
+  );
+  requiredBytesProperty(
+    props.properties.entries,
+    PROPERTY_FILE_IDENTITY_GUID,
+    16
+  );
+  requiredBytesProperty(
+    props.properties.entries,
+    PROPERTY_FILE_ANCESTOR_IDENTITY_GUID,
+    16
+  );
+  const crc = findProperty(props, PROPERTY_FILE_NAME_CRC);
+  if (!crc || crc.value.kind !== 'u32') {
+    throw new OneNoteParserError(
+      'INVALID_STRUCTURE',
+      'Header cell FileNameCrc property is absent or malformed',
+      { structure: 'OneStore package header cell' }
+    );
+  }
+}
+
+function requiredBytesProperty(
+  entries: PropertyEntry[],
+  propertyId: number,
+  length: number
+): Uint8Array {
+  const entry = entries.find(
+    (candidate) => candidate.id === (propertyId & 0x03ffffff)
+  );
+  if (
+    !entry ||
+    entry.value.kind !== 'bytes' ||
+    entry.value.value.length !== length
+  ) {
+    throw new OneNoteParserError(
+      'INVALID_STRUCTURE',
+      `Header property 0x${propertyId.toString(16)} is absent or malformed`,
+      { structure: 'OneStore package header cell' }
+    );
+  }
+  // Exercise the exact mixed-endian GUID range while preserving bounded reads.
+  readGuid(new BinaryReader(entry.value.value, 0, length, 'Header GUID'));
+  return entry.value.value;
+}
+
+function parseObjectSpace(
+  context: StoreContext,
+  cell: FssHttpCellId
+): ObjectSpace {
+  const mapping = requiredCellMapping(context, cell);
+  const revisionId = resolveCurrentRevisionId(context, mapping);
+  if (!revisionId) {
+    return {
+      id: cell.objectSpace,
+      roots: new Map(),
+      objects: new Map(),
+    };
+  }
+
+  const roots = new Map<number, ExGuid>();
+  const objects = new Map<string, StoreObject>();
+  for (const revision of revisionChain(context, revisionId)) {
+    for (const root of revision.roots) {
+      const role = parseRevisionRole(root.role);
+      if (!roots.has(role)) roots.set(role, root.objectId);
+    }
+    for (const groupId of revision.objectGroupIds) {
+      parseObjectGroup(context, cell, groupId, objects);
+    }
+  }
+  return { id: cell.objectSpace, roots, objects };
+}
+
+function revisionChain(
+  context: StoreContext,
+  firstRevisionId: ExGuid
+): FssHttpRevisionManifest[] {
+  const result: FssHttpRevisionManifest[] = [];
+  const seen = new Set<string>();
+  let revisionId: ExGuid | undefined = firstRevisionId;
+  while (revisionId) {
+    if (result.length >= context.limits.maxTransactionFragments) {
+      throw new OneNoteParserError(
+        'LIMIT_EXCEEDED',
+        `Revision chain exceeds ${context.limits.maxTransactionFragments} entries`,
+        { structure: 'FSSHTTPB revision chain' }
+      );
+    }
+    const key = exGuidKey(revisionId);
+    if (seen.has(key)) {
+      throw new OneNoteParserError(
+        'INVALID_STRUCTURE',
+        `Revision chain contains a cycle at ${key}`,
+        { structure: 'FSSHTTPB revision chain' }
+      );
+    }
+    seen.add(key);
+    const revision = requiredRevisionManifest(context, revisionId);
+    result.push(revision);
+    if (isNilExGuid(revision.baseRevisionId)) break;
+    revisionId = resolveRevisionId(context, revision.baseRevisionId);
+    if (!revisionId) {
+      throw new OneNoteParserError(
+        'MISSING_REFERENCE',
+        `Base revision ${exGuidKey(revision.baseRevisionId)} is unresolved`,
+        { structure: 'Revision Manifest' }
+      );
+    }
+  }
+  return result;
+}
+
+function parseObjectGroup(
+  context: StoreContext,
+  cell: FssHttpCellId,
+  groupId: ExGuid,
+  objects: Map<string, StoreObject>
+): void {
+  const entries = pairedGroupEntries(context, groupId);
+  const partitions = new Map<string, Map<number, GroupEntry>>();
+  for (const entry of entries) {
+    const objectKey = exGuidKey(entry.declaration.objectId);
+    let objectPartitions = partitions.get(objectKey);
+    if (!objectPartitions) {
+      objectPartitions = new Map();
+      partitions.set(objectKey, objectPartitions);
+    }
+    if (objectPartitions.has(entry.declaration.partitionId)) {
+      throw new OneNoteParserError(
+        'INVALID_STRUCTURE',
+        `Object ${objectKey} repeats partition ${entry.declaration.partitionId}`,
+        { structure: 'Object Group' }
+      );
+    }
+    objectPartitions.set(entry.declaration.partitionId, entry);
+  }
+
+  for (const [objectKey, objectPartitions] of partitions) {
+    if (objects.has(objectKey)) continue;
+    context.objectCount += 1;
+    if (context.objectCount > context.limits.maxObjects) {
+      throw new OneNoteParserError(
+        'LIMIT_EXCEEDED',
+        `Resolved object count exceeds ${context.limits.maxObjects}`,
+        { structure: 'FSSHTTPB Object Group' }
+      );
+    }
+    objects.set(
+      objectKey,
+      parseStoreObject(context, cell, objectPartitions, objectKey)
+    );
+  }
+}
+
+function pairedGroupEntries(
+  context: StoreContext,
+  groupId: ExGuid
+): GroupEntry[] {
+  const group = context.package.dataElements.objectGroups.get(
+    exGuidKey(groupId)
+  );
+  if (!group) {
+    throw new OneNoteParserError(
+      'MISSING_REFERENCE',
+      `Object Group ${exGuidKey(groupId)} is absent`,
+      { structure: 'Object Group' }
+    );
+  }
+  validateGroupCounts(group, groupId);
+  return group.declarations.map((declaration, index) => {
+    const data = group.data[index]!;
+    validateDeclarationData(declaration, data);
+    return { declaration, data };
+  });
+}
+
+function validateGroupCounts(group: FssHttpObjectGroup, groupId: ExGuid): void {
+  if (group.declarations.length !== group.data.length) {
+    throw new OneNoteParserError(
+      'INVALID_STRUCTURE',
+      `Object Group ${exGuidKey(groupId)} has ${group.declarations.length} declarations and ${group.data.length} data entries`,
+      { structure: 'Object Group' }
+    );
+  }
+  if (
+    group.changeFrequencies.length !== 0 &&
+    group.changeFrequencies.length !== group.declarations.length
+  ) {
+    throw new OneNoteParserError(
+      'INVALID_STRUCTURE',
+      `Object Group ${exGuidKey(groupId)} metadata count does not match its declarations`,
+      { structure: 'Object Group Metadata Block' }
+    );
+  }
+}
+
+function validateDeclarationData(
+  declaration: FssHttpObjectDeclaration,
+  data: FssHttpObjectGroupData
+): void {
+  if (
+    declaration.objectReferenceCount !== data.objectReferences.length ||
+    declaration.cellReferenceCount !== data.cellReferences.length
+  ) {
+    throw new OneNoteParserError(
+      'INVALID_STRUCTURE',
+      `Object ${exGuidKey(declaration.objectId)} declaration/reference counts do not match its data`,
+      { structure: 'Object Group' }
+    );
+  }
+  if (declaration.kind === 'object') {
+    const actualSize =
+      data.kind === 'object'
+        ? data.data.byteLength
+        : data.kind === 'excluded'
+          ? data.dataSize
+          : undefined;
+    if (actualSize === undefined || declaration.dataSize !== actualSize) {
+      throw new OneNoteParserError(
+        'INVALID_STRUCTURE',
+        `Object ${exGuidKey(declaration.objectId)} declaration/data sizes do not match`,
+        { structure: 'Object Group' }
+      );
+    }
+  }
+}
+
+function parseStoreObject(
+  context: StoreContext,
+  cell: FssHttpCellId,
+  partitions: ReadonlyMap<number, GroupEntry>,
+  objectKey: string
+): StoreObject {
+  const metadata = requiredObjectPartition(
+    partitions,
+    4,
+    objectKey,
+    'metadata'
+  );
+  const objectData = requiredObjectPartition(partitions, 1, objectKey, 'data');
+  const metadataReader = new BinaryReader(
+    metadata.dataReference.source,
+    metadata.dataReference.offset,
+    metadata.dataReference.size,
+    'FSSHTTPB object metadata'
+  );
+  const jcid = metadataReader.u32();
+  const props = parseObjectPropSetRange(
+    objectData.dataReference.source,
+    objectData.dataReference.offset,
+    objectData.dataReference.size,
+    context.limits
+  );
+
+  const contextCells = objectData.cellReferences.filter(
+    (reference) =>
+      exGuidKey(reference.objectSpace) === exGuidKey(cell.objectSpace)
+  );
+  const objectSpaceCells = objectData.cellReferences.filter(
+    (reference) =>
+      exGuidKey(reference.objectSpace) !== exGuidKey(cell.objectSpace)
+  );
+  if (props.objectIds.length < objectData.objectReferences.length) {
+    throw new OneNoteParserError(
+      'INVALID_STRUCTURE',
+      `Object ${objectKey} has fewer property-set object IDs than resolved references`,
+      { structure: 'ObjectPropSet mapping table' }
+    );
+  }
+  if (
+    props.contextIds.length !== contextCells.length ||
+    props.objectSpaceIds.length !== objectSpaceCells.length
+  ) {
+    throw new OneNoteParserError(
+      'INVALID_STRUCTURE',
+      `Object ${objectKey} property-set cell reference counts do not match`,
+      { structure: 'ObjectPropSet mapping table' }
+    );
+  }
+
+  const objectId = partitions.values().next().value!.declaration.objectId;
+  return {
+    id: objectId,
+    jcid,
+    props,
+    mapping: new Map(),
+    contextId: cell.context,
+    resolvedObjectIds: objectData.objectReferences,
+    resolvedObjectSpaceIds: objectSpaceCells.map((reference) => ({
+      id: reference.objectSpace,
+      key: fssHttpCellKey(reference),
+    })),
+    resolvedContextIds: contextCells.map((reference) => reference.context),
+    fileData: parseFileData(context, partitions, objectKey),
+  };
+}
+
+function requiredObjectPartition(
+  partitions: ReadonlyMap<number, GroupEntry>,
+  partitionId: number,
+  objectKey: string,
+  name: string
+): Extract<FssHttpObjectGroupData, { kind: 'object' }> {
+  const entry = partitions.get(partitionId);
+  if (!entry) {
+    throw new OneNoteParserError(
+      'MISSING_REFERENCE',
+      `Object ${objectKey} ${name} partition is absent`,
+      { structure: 'Object Group' }
+    );
+  }
+  if (entry.data.kind === 'excluded') {
+    throw new OneNoteParserError(
+      'UNSUPPORTED_FORMAT',
+      `Object ${objectKey} ${name} partition is excluded from this package`,
+      { structure: 'Object Group Data Excluded' }
+    );
+  }
+  if (entry.data.kind !== 'object') {
+    throw new OneNoteParserError(
+      'INVALID_STRUCTURE',
+      `Object ${objectKey} ${name} partition is not object data`,
+      { structure: 'Object Group' }
+    );
+  }
+  return entry.data;
+}
+
+function parseFileData(
+  context: StoreContext,
+  partitions: ReadonlyMap<number, GroupEntry>,
+  objectKey: string
+): StoreFileData | undefined {
+  const entry = partitions.get(2);
+  if (!entry) return undefined;
+  if (entry.data.kind !== 'blob-reference') {
+    throw new OneNoteParserError(
+      entry.data.kind === 'excluded'
+        ? 'UNSUPPORTED_FORMAT'
+        : 'INVALID_STRUCTURE',
+      `Object ${objectKey} file-data partition is not an available BLOB reference`,
+      { structure: 'Object Group BLOB reference' }
+    );
+  }
+  const blob = context.package.dataElements.blobs.get(
+    exGuidKey(entry.data.blobId)
+  );
+  if (!blob) {
+    throw new OneNoteParserError(
+      'MISSING_REFERENCE',
+      `Object Data BLOB ${exGuidKey(entry.data.blobId)} is absent`,
+      { structure: 'Object Data BLOB' }
+    );
+  }
+  return {
+    referenceKind: 'embedded',
+    dataReference: `<fsshttpb>${exGuidKey(entry.data.blobId)}`,
+    extension: '',
+    storageGuid: entry.data.blobId.guid,
+    blob,
+  };
+}
+
+function requiredCellMapping(
+  context: StoreContext,
+  cell: FssHttpCellId
+): FssHttpStorageIndexCellMapping {
+  const mapping = context.index.cellMappings.get(fssHttpCellKey(cell));
+  if (!mapping) {
+    throw new OneNoteParserError(
+      'MISSING_REFERENCE',
+      `Cell mapping ${fssHttpCellKey(cell)} is absent`,
+      { structure: 'Storage Index Cell Mapping' }
+    );
+  }
+  return mapping;
+}
+
+function resolveCurrentRevisionId(
+  context: StoreContext,
+  mapping: FssHttpStorageIndexCellMapping
+): ExGuid | undefined {
+  const cellRevision = context.package.dataElements.cellManifests.get(
+    exGuidKey(mapping.id)
+  );
+  if (cellRevision && isNilExGuid(cellRevision)) return undefined;
+  const resolved = cellRevision
+    ? resolveRevisionId(context, cellRevision)
+    : resolveRevisionId(context, mapping.id);
+  if (resolved) return resolved;
+
+  const serialMatches = [...context.index.revisionMappings.values()].filter(
+    (candidate) => sameSerial(candidate.serial, mapping.serial)
+  );
+  if (serialMatches.length > 1) {
+    throw new OneNoteParserError(
+      'INVALID_STRUCTURE',
+      'Cell mapping serial number resolves to multiple revision mappings',
+      { structure: 'Storage Index Revision Mapping' }
+    );
+  }
+  return serialMatches[0]?.revision;
+}
+
+function resolveRevisionId(
+  context: StoreContext,
+  id: ExGuid
+): ExGuid | undefined {
+  const mapped = context.index.revisionMappings.get(exGuidKey(id));
+  if (mapped) return mapped.revision;
+  return context.package.dataElements.revisionManifests.has(exGuidKey(id))
+    ? id
+    : undefined;
+}
+
+function requiredRevisionManifest(
+  context: StoreContext,
+  id: ExGuid
+): FssHttpRevisionManifest {
+  const revision = context.package.dataElements.revisionManifests.get(
+    exGuidKey(id)
+  );
+  if (!revision) {
+    throw new OneNoteParserError(
+      'MISSING_REFERENCE',
+      `Revision Manifest ${exGuidKey(id)} is absent`,
+      { structure: 'Revision Manifest' }
+    );
+  }
+  return revision;
+}
+
+function parseRevisionRole(role: ExGuid): number {
+  if (role.guid !== REVISION_ROLE_GUID || role.value < 1 || role.value > 4) {
+    throw new OneNoteParserError(
+      'INVALID_STRUCTURE',
+      `Invalid revision root role ${exGuidKey(role)}`,
+      { structure: 'Revision Manifest root declaration' }
+    );
+  }
+  return role.value;
+}
+
+function isNilExGuid(id: ExGuid): boolean {
+  return id.guid === NIL_GUID && id.value === 0;
+}
+
+function sameSerial(
+  left: FssHttpSerialNumber,
+  right: FssHttpSerialNumber
+): boolean {
+  return left.guid === right.guid && left.value === right.value;
+}
+
+function addDiagnostic(
+  diagnostics: ParserDiagnostic[],
+  limits: OneNoteParserLimits,
+  code: string,
+  message: string,
+  structure: string
+): void {
+  if (diagnostics.length >= limits.maxDiagnostics) return;
+  diagnostics.push({
+    severity: 'warning',
+    code,
+    message,
+    structure,
+    recoverable: true,
+  });
+}
--- a/src/onenote/onestore/property-set.ts
+++ b/src/onenote/onestore/property-set.ts
@@ -39,13 +39,30 @@ export function parseObjectPropSet(
      { offset: reference.offset, structure: 'ObjectPropSet' }
    );
  }
-  const reader = new BinaryReader(
+  return parseObjectPropSetRange(
    bytes,
    reference.offset,
    reference.size,
-    'ObjectPropSet'
+    limits
  );
+}

+/** Parse a property set from an exact bounded range in the source file. */
+export function parseObjectPropSetRange(
+  bytes: Uint8Array,
+  offset: number,
+  size: number,
+  limits: OneNoteParserLimits
+): ObjectPropSet {
+  const reader = new BinaryReader(bytes, offset, size, 'ObjectPropSet');
+
+  return parseObjectPropSetReader(reader, limits);
+}
+
+function parseObjectPropSetReader(
+  reader: BinaryReader,
+  limits: OneNoteParserLimits
+): ObjectPropSet {
  const oidHeader = readStreamHeader(reader, limits);
  const objectIds = readCompactIds(reader, oidHeader.count);
  let objectSpaceIds: CompactId[] = [];
--- a/src/onenote/onestore/types.ts
+++ b/src/onenote/onestore/types.ts
@@ -92,12 +92,24 @@ export interface StoreFileData {
  blob?: FileDataBlobReference;
 }

+/** A resolved object-space reference plus the store-specific lookup key. */
+export interface StoreObjectSpaceReference {
+  id: ExGuid;
+  key: string;
+}
+
 export interface StoreObject {
  id: ExGuid;
  jcid: number;
  props: ObjectPropSet;
  mapping: ReadonlyMap<number, string>;
  contextId: ExGuid;
+  /** Pre-resolved FSSHTTPB object stream, indexed like `props.objectIds`. */
+  resolvedObjectIds?: readonly ExGuid[];
+  /** Pre-resolved FSSHTTPB object-space stream, indexed like `props.objectSpaceIds`. */
+  resolvedObjectSpaceIds?: readonly StoreObjectSpaceReference[];
+  /** Pre-resolved FSSHTTPB context stream, indexed like `props.contextIds`. */
+  resolvedContextIds?: readonly ExGuid[];
  fileData?: StoreFileData;
 }

--- a/src/onenote/parser/parse-section.ts
+++ b/src/onenote/parser/parse-section.ts
@@ -7,7 +7,10 @@ import type { OneNoteSectionContentModel } from '../one/content-model.js';
 import { buildSectionDto } from '../one/section.js';
 import { buildSectionContentModel } from '../one/section-content.js';
 import { parseDesktopOneStore } from '../onestore/desktop-store.js';
-import { toBytes } from './detect-format.js';
+import type { DesktopOneStore } from '../onestore/desktop-store.js';
+import { parseFssHttpOneStore } from '../onestore/fsshttp-store.js';
+import { detectOneNoteFormat, toBytes } from './detect-format.js';
+import { OneNoteParserError } from './error.js';
 import type { OneNoteParserLimits } from './limits.js';
 import { resolveParserLimits } from './limits.js';

@@ -16,7 +19,7 @@ export interface ParseOneNoteSectionOptions {
  limits?: Partial<OneNoteParserLimits>;
 }

-/** Parse a desktop revision-store `.one` section without network access. */
+/** Parse a supported desktop or FSSHTTPB `.one` section without network access. */
 export function parseOneNoteSection(
  input: ArrayBuffer | Uint8Array,
  options: ParseOneNoteSectionOptions = {}
@@ -24,7 +27,7 @@ export function parseOneNoteSection(
  const bytes = toBytes(input);
  const limits = resolveParserLimits(options.limits);
  const diagnostics: OneNoteSectionDto['diagnostics'] = [];
-  const store = parseDesktopOneStore(bytes, limits, diagnostics);
+  const store = parseSectionStore(bytes, limits, diagnostics);
  return buildSectionDto(
    store,
    options.sourceName ?? 'Untitled.one',
@@ -41,7 +44,7 @@ export function parseOneNoteSectionContent(
  const bytes = toBytes(input);
  const limits = resolveParserLimits(options.limits);
  const diagnostics: OneNoteSectionContentModel['diagnostics'] = [];
-  const store = parseDesktopOneStore(bytes, limits, diagnostics);
+  const store = parseSectionStore(bytes, limits, diagnostics);
  return buildSectionContentModel(
    store,
    options.sourceName ?? 'Untitled.one',
@@ -49,3 +52,22 @@ export function parseOneNoteSectionContent(
    diagnostics
  );
 }
+
+function parseSectionStore(
+  bytes: Uint8Array,
+  limits: OneNoteParserLimits,
+  diagnostics: OneNoteSectionDto['diagnostics']
+): DesktopOneStore {
+  if (detectOneNoteFormat(bytes).kind !== 'fsshttp-one') {
+    return parseDesktopOneStore(bytes, limits, diagnostics);
+  }
+  const store = parseFssHttpOneStore(bytes, limits, diagnostics);
+  if (store.kind !== 'section') {
+    throw new OneNoteParserError(
+      'INVALID_FORMAT',
+      'Expected an FSSHTTPB OneNote section, found a table of contents',
+      { structure: 'OneStore Packaging Structure' }
+    );
+  }
+  return store;
+}
--- a/src/onenote/parser/parse-toc.ts
+++ b/src/onenote/parser/parse-toc.ts
@@ -187,6 +187,16 @@ function objectReferences(object: StoreObject, propertyId: number): ExGuid[] {
    propertyId,
    countObjectReferences
  );
+  if (object.resolvedObjectIds) {
+    if (offset + count > object.resolvedObjectIds.length) {
+      throw new OneNoteParserError(
+        'MISSING_REFERENCE',
+        'TOC object-reference range exceeds its resolved OID stream',
+        { structure: 'TOCEntryIndex_OidIndex' }
+      );
+    }
+    return object.resolvedObjectIds.slice(offset, offset + count);
+  }
  if (offset + count > object.props.objectIds.length) {
    throw new OneNoteParserError(
      'MISSING_REFERENCE',