blob: c97da92b2a07225a5d49fa120755192989deb3a6 [file] [log] [blame]
// Copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#pragma once
#include <algorithm>
#include <bitset>
#include <iosfwd>
#include <limits>
#include <set>
#include <string>
#include <vector>
#include "base/atomicops.h"
#include "base/basictypes.h"
#include "base/file_path.h"
#include "base/gtest_prod_util.h"
#include "base/synchronization/lock.h"
#include "base/time.h"
#include "chrome/browser/sync/protocol/sync.pb.h"
#include "chrome/browser/sync/syncable/autofill_migration.h"
#include "chrome/browser/sync/syncable/blob.h"
#include "chrome/browser/sync/syncable/dir_open_result.h"
#include "chrome/browser/sync/syncable/directory_event.h"
#include "chrome/browser/sync/syncable/syncable_id.h"
#include "chrome/browser/sync/syncable/model_type.h"
#include "chrome/browser/sync/util/dbgq.h"
#include "chrome/common/deprecated/event_sys.h"
class DictionaryValue;
struct PurgeInfo;
namespace sync_api {
class ReadTransaction;
class WriteNode;
class ReadNode;
namespace syncable {
class DirectoryChangeListener;
class Entry;
std::ostream& operator<<(std::ostream& s, const Entry& e);
class DirectoryBackingStore;
static const int64 kInvalidMetaHandle = 0;
// Update syncable_enum_conversions{.h,.cc,} if you change
// any fields in this file.
enum {
enum MetahandleField {
// Primary key into the table. Keep this as a handle to the meta entry
// across transactions.
enum BaseVersion {
// After initial upload, the version is controlled by the server, and is
// increased whenever the data or metadata changes on the server.
enum Int64Field {
// A numeric position value that indicates the relative ordering of
// this object among its siblings.
LOCAL_EXTERNAL_ID, // ID of an item in the external local storage that this
// entry is associated with. (such as bookmarks.js)
enum {
enum IdField {
// Code in InitializeTables relies on ID being the first IdField value.
enum {
enum IndexedBitField {
enum IsDelField {
enum BitField {
IS_DIR = IS_DEL + 1,
enum {
enum StringField {
// Name, will be truncated by server. Can be duplicated in a folder.
// The server version of |NON_UNIQUE_NAME|.
// A tag string which identifies this node as a particular top-level
// permanent object. The tag can be thought of as a unique key that
// identifies a singleton instance.
UNIQUE_SERVER_TAG, // Tagged by the server
UNIQUE_CLIENT_TAG, // Tagged by the client
enum {
// From looking at the sqlite3 docs, it's not directly stated, but it
// seems the overhead for storing a NULL blob is very small.
enum ProtoField {
enum {
enum {
// Past this point we have temporaries, stored in memory only.
enum BitTemp {
enum {
class BaseTransaction;
class WriteTransaction;
class ReadTransaction;
class Directory;
class ScopedDirLookup;
// Instead of:
// Entry e = transaction.GetById(id);
// use:
// Entry e(transaction, GET_BY_ID, id);
// Why? The former would require a copy constructor, and it would be difficult
// to enforce that an entry never outlived its transaction if there were a copy
// constructor.
enum GetById {
enum GetByClientTag {
enum GetByServerTag {
enum GetByHandle {
enum Create {
enum CreateNewUpdateItem {
typedef std::set<int64> MetahandleSet;
// Why the singular enums? So the code compile-time dispatches instead of
// runtime dispatches as it would with a single enum and an if() statement.
// The EntryKernel class contains the actual data for an entry.
struct EntryKernel {
std::string string_fields[STRING_FIELDS_COUNT];
sync_pb::EntitySpecifics specifics_fields[PROTO_FIELDS_COUNT];
int64 int64_fields[INT64_FIELDS_COUNT];
Id id_fields[ID_FIELDS_COUNT];
std::bitset<BIT_FIELDS_COUNT> bit_fields;
std::bitset<BIT_TEMPS_COUNT> bit_temps;
// Set the dirty bit, and optionally add this entry's metahandle to
// a provided index on dirty bits in |dirty_index|. Parameter may be null,
// and will result only in setting the dirty bit of this entry.
inline void mark_dirty(syncable::MetahandleSet* dirty_index) {
if (!dirty_ && dirty_index) {
dirty_ = true;
// Clear the dirty bit, and optionally remove this entry's metahandle from
// a provided index on dirty bits in |dirty_index|. Parameter may be null,
// and will result only in clearing dirty bit of this entry.
inline void clear_dirty(syncable::MetahandleSet* dirty_index) {
if (dirty_ && dirty_index) {
dirty_ = false;
inline bool is_dirty() const {
return dirty_;
// Setters.
inline void put(MetahandleField field, int64 value) {
int64_fields[field - INT64_FIELDS_BEGIN] = value;
inline void put(Int64Field field, int64 value) {
int64_fields[field - INT64_FIELDS_BEGIN] = value;
inline void put(IdField field, const Id& value) {
id_fields[field - ID_FIELDS_BEGIN] = value;
inline void put(BaseVersion field, int64 value) {
int64_fields[field - INT64_FIELDS_BEGIN] = value;
inline void put(IndexedBitField field, bool value) {
bit_fields[field - BIT_FIELDS_BEGIN] = value;
inline void put(IsDelField field, bool value) {
bit_fields[field - BIT_FIELDS_BEGIN] = value;
inline void put(BitField field, bool value) {
bit_fields[field - BIT_FIELDS_BEGIN] = value;
inline void put(StringField field, const std::string& value) {
string_fields[field - STRING_FIELDS_BEGIN] = value;
inline void put(ProtoField field, const sync_pb::EntitySpecifics& value) {
specifics_fields[field - PROTO_FIELDS_BEGIN].CopyFrom(value);
inline void put(BitTemp field, bool value) {
bit_temps[field - BIT_TEMPS_BEGIN] = value;
// Const ref getters.
inline int64 ref(MetahandleField field) const {
return int64_fields[field - INT64_FIELDS_BEGIN];
inline int64 ref(Int64Field field) const {
return int64_fields[field - INT64_FIELDS_BEGIN];
inline const Id& ref(IdField field) const {
return id_fields[field - ID_FIELDS_BEGIN];
inline int64 ref(BaseVersion field) const {
return int64_fields[field - INT64_FIELDS_BEGIN];
inline bool ref(IndexedBitField field) const {
return bit_fields[field - BIT_FIELDS_BEGIN];
inline bool ref(IsDelField field) const {
return bit_fields[field - BIT_FIELDS_BEGIN];
inline bool ref(BitField field) const {
return bit_fields[field - BIT_FIELDS_BEGIN];
inline const std::string& ref(StringField field) const {
return string_fields[field - STRING_FIELDS_BEGIN];
inline const sync_pb::EntitySpecifics& ref(ProtoField field) const {
return specifics_fields[field - PROTO_FIELDS_BEGIN];
inline bool ref(BitTemp field) const {
return bit_temps[field - BIT_TEMPS_BEGIN];
// Non-const, mutable ref getters for object types only.
inline std::string& mutable_ref(StringField field) {
return string_fields[field - STRING_FIELDS_BEGIN];
inline sync_pb::EntitySpecifics& mutable_ref(ProtoField field) {
return specifics_fields[field - PROTO_FIELDS_BEGIN];
inline Id& mutable_ref(IdField field) {
return id_fields[field - ID_FIELDS_BEGIN];
// Dumps all kernel info into a DictionaryValue and returns it.
// Transfers ownership of the DictionaryValue to the caller.
DictionaryValue* ToValue() const;
// Tracks whether this entry needs to be saved to the database.
bool dirty_;
// A read-only meta entry.
class Entry {
friend class Directory;
friend std::ostream& operator << (std::ostream& s, const Entry& e);
// After constructing, you must check good() to test whether the Get
// succeeded.
Entry(BaseTransaction* trans, GetByHandle, int64 handle);
Entry(BaseTransaction* trans, GetById, const Id& id);
Entry(BaseTransaction* trans, GetByServerTag, const std::string& tag);
Entry(BaseTransaction* trans, GetByClientTag, const std::string& tag);
bool good() const { return 0 != kernel_; }
BaseTransaction* trans() const { return basetrans_; }
// Field accessors.
inline int64 Get(MetahandleField field) const {
return kernel_->ref(field);
inline Id Get(IdField field) const {
return kernel_->ref(field);
inline int64 Get(Int64Field field) const {
return kernel_->ref(field);
inline int64 Get(BaseVersion field) const {
return kernel_->ref(field);
inline bool Get(IndexedBitField field) const {
return kernel_->ref(field);
inline bool Get(IsDelField field) const {
return kernel_->ref(field);
inline bool Get(BitField field) const {
return kernel_->ref(field);
const std::string& Get(StringField field) const;
inline const sync_pb::EntitySpecifics& Get(ProtoField field) const {
return kernel_->ref(field);
inline bool Get(BitTemp field) const {
return kernel_->ref(field);
ModelType GetServerModelType() const;
ModelType GetModelType() const;
// If this returns false, we shouldn't bother maintaining
// a position value (sibling ordering) for this item.
bool ShouldMaintainPosition() const {
return GetModelType() == BOOKMARKS;
inline bool ExistsOnClientBecauseNameIsNonEmpty() const {
return !kernel_->ref(NON_UNIQUE_NAME).empty();
inline bool IsRoot() const {
return kernel_->ref(ID).IsRoot();
Directory* dir() const;
const EntryKernel GetKernelCopy() const {
return *kernel_;
// Compute a local predecessor position for |update_item|, based on its
// absolute server position. The returned ID will be a valid predecessor
// under SERVER_PARENT_ID that is consistent with the
Id ComputePrevIdFromServerPosition(const Id& parent_id) const;
// Dumps all entry info into a DictionaryValue and returns it.
// Transfers ownership of the DictionaryValue to the caller.
DictionaryValue* ToValue() const;
protected: // Don't allow creation on heap, except by sync API wrappers.
friend class sync_api::ReadNode;
void* operator new(size_t size) { return (::operator new)(size); }
inline Entry(BaseTransaction* trans)
: basetrans_(trans),
kernel_(NULL) { }
BaseTransaction* const basetrans_;
EntryKernel* kernel_;
// Like GetServerModelType() but without the DCHECKs.
ModelType GetServerModelTypeHelper() const;
// A mutable meta entry. Changes get committed to the database when the
// WriteTransaction is destroyed.
class MutableEntry : public Entry {
friend class WriteTransaction;
friend class Directory;
void Init(WriteTransaction* trans, const Id& parent_id,
const std::string& name);
MutableEntry(WriteTransaction* trans, Create, const Id& parent_id,
const std::string& name);
MutableEntry(WriteTransaction* trans, CreateNewUpdateItem, const Id& id);
MutableEntry(WriteTransaction* trans, GetByHandle, int64);
MutableEntry(WriteTransaction* trans, GetById, const Id&);
MutableEntry(WriteTransaction* trans, GetByClientTag, const std::string& tag);
MutableEntry(WriteTransaction* trans, GetByServerTag, const std::string& tag);
inline WriteTransaction* write_transaction() const {
return write_transaction_;
// Field Accessors. Some of them trigger the re-indexing of the entry.
// Return true on success, return false on failure, which means
// that putting the value would have caused a duplicate in the index.
// TODO(chron): Remove some of these unecessary return values.
bool Put(Int64Field field, const int64& value);
bool Put(IdField field, const Id& value);
// Do a simple property-only update if the PARENT_ID field. Use with caution.
// The normal Put(IS_PARENT) call will move the item to the front of the
// sibling order to maintain the linked list invariants when the parent
// changes. That's usually what you want to do, but it's inappropriate
// when the caller is trying to change the parent ID of a the whole set
// of children (e.g. because the ID changed during a commit). For those
// cases, there's this function. It will corrupt the sibling ordering
// if you're not careful.
void PutParentIdPropertyOnly(const Id& parent_id);
bool Put(StringField field, const std::string& value);
bool Put(BaseVersion field, int64 value);
bool Put(ProtoField field, const sync_pb::EntitySpecifics& value);
bool Put(BitField field, bool value);
inline bool Put(IsDelField field, bool value) {
return PutIsDel(value);
bool Put(IndexedBitField field, bool value);
// Sets the position of this item, and updates the entry kernels of the
// adjacent siblings so that list invariants are maintained. Returns false
// and fails if |predecessor_id| does not identify a sibling. Pass the root
// ID to put the node in first position.
bool PutPredecessor(const Id& predecessor_id);
bool Put(BitTemp field, bool value);
syncable::MetahandleSet* GetDirtyIndexHelper();
bool PutIsDel(bool value);
private: // Don't allow creation on heap, except by sync API wrappers.
friend class sync_api::WriteNode;
void* operator new(size_t size) { return (::operator new)(size); }
bool PutImpl(StringField field, const std::string& value);
bool PutUniqueClientTag(const std::string& value);
// Adjusts the successor and predecessor entries so that they no longer
// refer to this entry.
void UnlinkFromOrder();
// Kind of redundant. We should reduce the number of pointers
// floating around if at all possible. Could we store this in Directory?
// Scope: Set on construction, never changed after that.
WriteTransaction* const write_transaction_;
class LessParentIdAndHandle;
template <typename FieldType, FieldType field_index>
class LessField;
class LessEntryMetaHandles {
inline bool operator()(const syncable::EntryKernel& a,
const syncable::EntryKernel& b) const {
return a.ref(META_HANDLE) < b.ref(META_HANDLE);
typedef std::set<EntryKernel, LessEntryMetaHandles> OriginalEntries;
// How syncable indices & Indexers work.
// The syncable Directory maintains several indices on the Entries it tracks.
// The indices follow a common pattern:
// (a) The index allows efficient lookup of an Entry* with particular
// field values. This is done by use of a std::set<> and a custom
// comparator.
// (b) There may be conditions for inclusion in the index -- for example,
// deleted items might not be indexed.
// (c) Because the index set contains only Entry*, one must be careful
// to remove Entries from the set before updating the value of
// an indexed field.
// The traits of an index are a Comparator (to define the set ordering) and a
// ShouldInclude function (to define the conditions for inclusion). For each
// index, the traits are grouped into a class called an Indexer which
// can be used as a template type parameter.
// Traits type for metahandle index.
struct MetahandleIndexer {
// This index is of the metahandle field values.
typedef LessField<MetahandleField, META_HANDLE> Comparator;
// This index includes all entries.
inline static bool ShouldInclude(const EntryKernel* a) {
return true;
// Traits type for ID field index.
struct IdIndexer {
// This index is of the ID field values.
typedef LessField<IdField, ID> Comparator;
// This index includes all entries.
inline static bool ShouldInclude(const EntryKernel* a) {
return true;
// Traits type for unique client tag index.
struct ClientTagIndexer {
// This index is of the client-tag values.
typedef LessField<StringField, UNIQUE_CLIENT_TAG> Comparator;
// Items are only in this index if they have a non-empty client tag value.
static bool ShouldInclude(const EntryKernel* a);
// This index contains EntryKernels ordered by parent ID and metahandle.
// It allows efficient lookup of the children of a given parent.
struct ParentIdAndHandleIndexer {
// This index is of the parent ID and metahandle. We use a custom
// comparator.
class Comparator {
bool operator() (const syncable::EntryKernel* a,
const syncable::EntryKernel* b) const;
// This index does not include deleted items.
static bool ShouldInclude(const EntryKernel* a);
// Given an Indexer providing the semantics of an index, defines the
// set type used to actually contain the index.
template <typename Indexer>
struct Index {
typedef std::set<EntryKernel*, typename Indexer::Comparator> Set;
// a WriteTransaction has a writer tag describing which body of code is doing
// the write. This is defined up here since DirectoryChangeEvent also contains
// one.
enum WriterTag {
// The name Directory in this case means the entire directory
// structure within a single user account.
// Sqlite is a little goofy, in that each thread must access a database
// via its own handle. So, a Directory object should only be accessed
// from a single thread. Use DirectoryManager's Open() method to
// always get a directory that has been properly initialized on the
// current thread.
// The db is protected against concurrent modification by a reader/
// writer lock, negotiated by the ReadTransaction and WriteTransaction
// friend classes. The in-memory indices are protected against
// concurrent modification by the kernel lock.
// All methods which require the reader/writer lock to be held either
// are protected and only called from friends in a transaction
// or are public and take a Transaction* argument.
// All methods which require the kernel lock to be already held take a
// ScopeKernelLock* argument.
// To prevent deadlock, the reader writer transaction lock must always
// be held before acquiring the kernel lock.
class ScopedKernelLock;
class IdFilter;
class DirectoryManager;
class Directory {
friend class BaseTransaction;
friend class Entry;
friend class MutableEntry;
friend class ReadTransaction;
friend class ReadTransactionWithoutDB;
friend class ScopedKernelLock;
friend class ScopedKernelUnlock;
friend class WriteTransaction;
friend class SyncableDirectoryTest;
FRIEND_TEST_ALL_PREFIXES(SyncableDirectoryTest, TestPurgeEntriesWithTypeIn);
class EventListenerHookup;
// Various data that the Directory::Kernel we are backing (persisting data
// for) needs saved across runs of the application.
struct PersistedKernelInfo {
AutofillMigrationDebugInfo autofill_migration_debug_info;
// Set the |download_progress| entry for the given model to a
// "first sync" start point. When such a value is sent to the server,
// a full download of all objects of the model will be initiated.
void reset_download_progress(ModelType model_type);
// Last sync timestamp fetched from the server.
sync_pb::DataTypeProgressMarker download_progress[MODEL_TYPE_COUNT];
// true iff we ever reached the end of the changelog.
ModelTypeBitSet initial_sync_ended;
// The store birthday we were given by the server. Contents are opaque to
// the client.
std::string store_birthday;
// The next local ID that has not been used with this cache-GUID.
int64 next_id;
// The persisted notification state.
std::string notification_state;
AutofillMigrationState autofill_migration_state;
// What the Directory needs on initialization to create itself and its Kernel.
// Filled by DirectoryBackingStore::Load.
struct KernelLoadInfo {
PersistedKernelInfo kernel_info;
std::string cache_guid; // Created on first initialization, never changes.
int64 max_metahandle; // Computed (using sql MAX aggregate) on init.
KernelLoadInfo() : max_metahandle(0) {
// The dirty/clean state of kernel fields backed by the share_info table.
// This is public so it can be used in SaveChangesSnapshot for persistence.
enum KernelShareInfoStatus {
// When the Directory is told to SaveChanges, a SaveChangesSnapshot is
// constructed and forms a consistent snapshot of what needs to be sent to
// the backing store.
struct SaveChangesSnapshot {
KernelShareInfoStatus kernel_info_status;
PersistedKernelInfo kernel_info;
OriginalEntries dirty_metas;
MetahandleSet metahandles_to_purge;
virtual ~Directory();
DirOpenResult Open(const FilePath& file_path, const std::string& name);
void Close();
int64 NextMetahandle();
// Always returns a negative id. Positive client ids are generated
// by the server only.
Id NextId();
const FilePath& file_path() const { return kernel_->db_path; }
bool good() const { return NULL != store_; }
// The download progress is an opaque token provided by the sync server
// to indicate the continuation state of the next GetUpdates operation.
void GetDownloadProgress(
ModelType type,
sync_pb::DataTypeProgressMarker* value_out) const;
void GetDownloadProgressAsString(
ModelType type,
std::string* value_out) const;
void SetDownloadProgress(
ModelType type,
const sync_pb::DataTypeProgressMarker& value);
bool initial_sync_ended_for_type(ModelType type) const;
void set_initial_sync_ended_for_type(ModelType type, bool value);
AutofillMigrationState get_autofill_migration_state() const;
AutofillMigrationDebugInfo get_autofill_migration_debug_info() const;
void set_autofill_migration_state(AutofillMigrationState state);
void set_autofill_migration_state_debug_info(
syncable::AutofillMigrationDebugInfo::PropertyToSet property_to_set,
const syncable::AutofillMigrationDebugInfo& info);
const std::string& name() const { return kernel_->name; }
// (Account) Store birthday is opaque to the client, so we keep it in the
// format it is in the proto buffer in case we switch to a binary birthday
// later.
std::string store_birthday() const;
void set_store_birthday(const std::string& store_birthday);
std::string GetAndClearNotificationState();
void SetNotificationState(const std::string& notification_state);
// Unique to each account / client pair.
std::string cache_guid() const;
void SetChangeListener(DirectoryChangeListener* listener);
protected: // for friends, mainly used by Entry constructors
virtual EntryKernel* GetEntryByHandle(int64 handle);
virtual EntryKernel* GetEntryByHandle(int64 metahandle,
ScopedKernelLock* lock);
virtual EntryKernel* GetEntryById(const Id& id);
EntryKernel* GetEntryByServerTag(const std::string& tag);
virtual EntryKernel* GetEntryByClientTag(const std::string& tag);
EntryKernel* GetRootEntry();
bool ReindexId(EntryKernel* const entry, const Id& new_id);
void ReindexParentId(EntryKernel* const entry, const Id& new_parent_id);
void ClearDirtyMetahandles();
// These don't do semantic checking.
// The semantic checking is implemented higher up.
void UnlinkEntryFromOrder(EntryKernel* entry,
WriteTransaction* trans,
ScopedKernelLock* lock);
// Overridden by tests.
virtual DirectoryBackingStore* CreateBackingStore(
const std::string& dir_name,
const FilePath& backing_filepath);
// These private versions expect the kernel lock to already be held
// before calling.
EntryKernel* GetEntryById(const Id& id, ScopedKernelLock* const lock);
DirOpenResult OpenImpl(const FilePath& file_path, const std::string& name);
template <class T> void TestAndSet(T* kernel_data, const T* data_to_set);
struct DirectoryEventTraits {
typedef DirectoryEvent EventType;
static inline bool IsChannelShutdownEvent(const DirectoryEvent& event) {
return DIRECTORY_DESTROYED == event;
typedef EventChannel<DirectoryEventTraits, base::Lock> Channel;
typedef std::vector<int64> ChildHandles;
// Returns the child meta handles for given parent id.
void GetChildHandles(BaseTransaction*, const Id& parent_id,
ChildHandles* result);
// Find the first or last child in the positional ordering under a parent,
// and return its id. Returns a root Id if parent has no children.
virtual Id GetFirstChildId(BaseTransaction* trans, const Id& parent_id);
Id GetLastChildId(BaseTransaction* trans, const Id& parent_id);
// Compute a local predecessor position for |update_item|. The position
// is determined by the SERVER_POSITION_IN_PARENT value of |update_item|,
// as well as the SERVER_POSITION_IN_PARENT values of any up-to-date
// children of |parent_id|.
Id ComputePrevIdFromServerPosition(
const EntryKernel* update_item,
const syncable::Id& parent_id);
// SaveChanges works by taking a consistent snapshot of the current Directory
// state and indices (by deep copy) under a ReadTransaction, passing this
// snapshot to the backing store under no transaction, and finally cleaning
// up by either purging entries no longer needed (this part done under a
// WriteTransaction) or rolling back the dirty bits. It also uses
// internal locking to enforce SaveChanges operations are mutually exclusive.
bool SaveChanges();
// Returns the number of entities with the unsynced bit set.
int64 unsynced_entity_count() const;
// Get GetUnsyncedMetaHandles should only be called after SaveChanges and
// before any new entries have been created. The intention is that the
// syncer should call it from its PerformSyncQueries member.
typedef std::vector<int64> UnsyncedMetaHandles;
void GetUnsyncedMetaHandles(BaseTransaction* trans,
UnsyncedMetaHandles* result);
// Get all the metahandles for unapplied updates
typedef std::vector<int64> UnappliedUpdateMetaHandles;
void GetUnappliedUpdateMetaHandles(BaseTransaction* trans,
UnappliedUpdateMetaHandles* result);
// Get the channel for post save notification, used by the syncer.
inline Channel* channel() const {
return kernel_->channel;
// Checks tree metadata consistency.
// If full_scan is false, the function will avoid pulling any entries from the
// db and scan entries currently in ram.
// If full_scan is true, all entries will be pulled from the database.
// No return value, CHECKs will be triggered if we're given bad
// information.
void CheckTreeInvariants(syncable::BaseTransaction* trans,
bool full_scan);
void CheckTreeInvariants(syncable::BaseTransaction* trans,
const OriginalEntries* originals);
void CheckTreeInvariants(syncable::BaseTransaction* trans,
const MetahandleSet& handles,
const IdFilter& idfilter);
// Purges all data associated with any entries whose ModelType or
// ServerModelType is found in |types|, from _both_ memory and disk.
// Only valid, "real" model types are allowed in |types| (see model_type.h
// for definitions). "Purge" is just meant to distinguish from "deleting"
// entries, which means something different in the syncable namespace.
// WARNING! This can be real slow, as it iterates over all entries.
// WARNING! Performs synchronous I/O.
virtual void PurgeEntriesWithTypeIn(const std::set<ModelType>& types);
// Helper to prime ids_index, parent_id_and_names_index, unsynced_metahandles
// and unapplied_metahandles from metahandles_index.
void InitializeIndices();
// Constructs a consistent snapshot of the current Directory state and
// indices (by deep copy) under a ReadTransaction for use in |snapshot|.
// See SaveChanges() for more information.
void TakeSnapshotForSaveChanges(SaveChangesSnapshot* snapshot);
// Purges from memory any unused, safe to remove entries that were
// successfully deleted on disk as a result of the SaveChanges that processed
// |snapshot|. See SaveChanges() for more information.
void VacuumAfterSaveChanges(const SaveChangesSnapshot& snapshot);
// Rolls back dirty bits in the event that the SaveChanges that
// processed |snapshot| failed, for example, due to no disk space.
void HandleSaveChangesFailure(const SaveChangesSnapshot& snapshot);
// For new entry creation only
void InsertEntry(EntryKernel* entry, ScopedKernelLock* lock);
void InsertEntry(EntryKernel* entry);
// Used by CheckTreeInvariants
void GetAllMetaHandles(BaseTransaction* trans, MetahandleSet* result);
bool SafeToPurgeFromMemory(const EntryKernel* const entry) const;
// Internal setters that do not acquire a lock internally. These are unsafe
// on their own; caller must guarantee exclusive access manually by holding
// a ScopedKernelLock.
void set_initial_sync_ended_for_type_unsafe(ModelType type, bool x);
void SetNotificationStateUnsafe(const std::string& notification_state);
Directory& operator = (const Directory&);
typedef Index<MetahandleIndexer>::Set MetahandlesIndex;
typedef Index<IdIndexer>::Set IdsIndex;
// All entries in memory must be in both the MetahandlesIndex and
// the IdsIndex, but only non-deleted entries will be the
// ParentIdChildIndex.
typedef Index<ParentIdAndHandleIndexer>::Set ParentIdChildIndex;
// Contains both deleted and existing entries with tags.
// We can't store only existing tags because the client would create
// items that had a duplicated ID in the end, resulting in a DB key
// violation. ID reassociation would fail after an attempted commit.
typedef Index<ClientTagIndexer>::Set ClientTagIndex;
// Used by tests.
void init_kernel(const std::string& name);
struct Kernel {
Kernel(const FilePath& db_path, const std::string& name,
const KernelLoadInfo& info);
void AddRef(); // For convenience.
void Release();
FilePath const db_path;
// TODO(timsteele): audit use of the member and remove if possible
volatile base::subtle::AtomicWord refcount;
// Implements ReadTransaction / WriteTransaction using a simple lock.
base::Lock transaction_mutex;
// The name of this directory.
std::string const name;
// Protects all members below.
// The mutex effectively protects all the indices, but not the
// entries themselves. So once a pointer to an entry is pulled
// from the index, the mutex can be unlocked and entry read or written.
// Never hold the mutex and do anything with the database or any
// other buffered IO. Violating this rule will result in deadlock.
base::Lock mutex;
// Entries indexed by metahandle
MetahandlesIndex* metahandles_index;
// Entries indexed by id
IdsIndex* ids_index;
ParentIdChildIndex* parent_id_child_index;
ClientTagIndex* client_tag_index;
// So we don't have to create an EntryKernel every time we want to
// look something up in an index. Needle in haystack metaphor.
EntryKernel needle;
// 3 in-memory indices on bits used extremely frequently by the syncer.
MetahandleSet* const unapplied_update_metahandles;
MetahandleSet* const unsynced_metahandles;
// Contains metahandles that are most likely dirty (though not
// necessarily). Dirtyness is confirmed in TakeSnapshotForSaveChanges().
MetahandleSet* const dirty_metahandles;
// When a purge takes place, we remove items from all our indices and stash
// them in here so that SaveChanges can persist their permanent deletion.
MetahandleSet* const metahandles_to_purge;
// TODO(ncarter): Figure out what the hell this is, and comment it.
Channel* const channel;
// The listener for directory change events, triggered when the transaction
// is ending.
DirectoryChangeListener* change_listener_;
KernelShareInfoStatus info_status;
// These 3 members are backed in the share_info table, and
// their state is marked by the flag above.
// A structure containing the Directory state that is written back into the
// database on SaveChanges.
PersistedKernelInfo persisted_info;
// A unique identifier for this account's cache db, used to generate
// unique server IDs. No need to lock, only written at init time.
std::string cache_guid;
// It doesn't make sense for two threads to run SaveChanges at the same
// time; this mutex protects that activity.
base::Lock save_changes_mutex;
// The next metahandle is protected by kernel mutex.
int64 next_metahandle;
// Keep a history of recently flushed metahandles for debugging
// purposes. Protected by the save_changes_mutex.
DebugQueue<int64, 1000> flushed_metahandles;
// Helper method used to do searches on |parent_id_child_index|.
ParentIdChildIndex::iterator LocateInParentChildIndex(
const ScopedKernelLock& lock,
const Id& parent_id,
int64 position_in_parent,
const Id& item_id_for_tiebreaking);
// Return an iterator to the beginning of the range of the children of
// |parent_id| in the kernel's parent_id_child_index.
ParentIdChildIndex::iterator GetParentChildIndexLowerBound(
const ScopedKernelLock& lock,
const Id& parent_id);
// Return an iterator to just past the end of the range of the
// children of |parent_id| in the kernel's parent_id_child_index.
ParentIdChildIndex::iterator GetParentChildIndexUpperBound(
const ScopedKernelLock& lock,
const Id& parent_id);
Kernel* kernel_;
DirectoryBackingStore* store_;
class ScopedKernelLock {
explicit ScopedKernelLock(const Directory*);
~ScopedKernelLock() {}
base::AutoLock scoped_lock_;
Directory* const dir_;
// Transactions are now processed FIFO with a straight lock
class BaseTransaction {
friend class Entry;
inline Directory* directory() const { return directory_; }
inline Id root_id() const { return Id(); }
virtual ~BaseTransaction();
BaseTransaction(Directory* directory, const char* name,
const char* source_file, int line, WriterTag writer);
// For unit testing. Everything will be mocked out no point initializing.
explicit BaseTransaction(Directory* directory);
void UnlockAndLog(OriginalEntries* entries);
virtual bool NotifyTransactionChangingAndEnding(
OriginalEntries* entries,
ModelTypeBitSet* models_with_changes);
virtual void NotifyTransactionComplete(ModelTypeBitSet models_with_changes);
Directory* const directory_;
Directory::Kernel* const dirkernel_; // for brevity
const char* const name_;
base::TimeTicks time_acquired_;
const char* const source_file_;
const int line_;
WriterTag writer_;
void Lock();
// Locks db in constructor, unlocks in destructor.
class ReadTransaction : public BaseTransaction {
ReadTransaction(Directory* directory, const char* source_file,
int line);
ReadTransaction(const ScopedDirLookup& scoped_dir,
const char* source_file, int line);
virtual ~ReadTransaction();
protected: // Don't allow creation on heap, except by sync API wrapper.
friend class sync_api::ReadTransaction;
void* operator new(size_t size) { return (::operator new)(size); }
// Locks db in constructor, unlocks in destructor.
class WriteTransaction : public BaseTransaction {
friend class MutableEntry;
explicit WriteTransaction(Directory* directory, WriterTag writer,
const char* source_file, int line);
explicit WriteTransaction(const ScopedDirLookup& directory,
WriterTag writer, const char* source_file,
int line);
virtual ~WriteTransaction();
void SaveOriginal(EntryKernel* entry);
// Before an entry gets modified, we copy the original into a list
// so that we can issue change notifications when the transaction
// is done.
OriginalEntries* const originals_;
explicit WriteTransaction(Directory *directory);
bool IsLegalNewParent(BaseTransaction* trans, const Id& id, const Id& parentid);
int64 Now();
// This function sets only the flags needed to get this entry to sync.
void MarkForSyncing(syncable::MutableEntry* e);
// This is not a reset. It just sets the numeric fields which are not
// initialized by the constructor to zero.
void ZeroFields(EntryKernel* entry, int first_field);
} // namespace syncable
std::ostream& operator <<(std::ostream&, const syncable::Blob&);