Files
POCloud-iOS/Pods/FirebaseDatabase/Firebase/Database/Core/FRepo.m
Patrick McDonagh 95467f9161 Adds firebase live data
Also no longer crashes when touching something while loading
2018-05-31 19:55:47 -05:00

1120 lines
51 KiB
Objective-C

/*
* Copyright 2017 Google
*
* 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.
*/
#import <Foundation/Foundation.h>
#import <FirebaseCore/FIRLogger.h>
#import <dlfcn.h>
#import "FRepo.h"
#import "FSnapshotUtilities.h"
#import "FConstants.h"
#import "FIRDatabaseQuery_Private.h"
#import "FQuerySpec.h"
#import "FTupleNodePath.h"
#import "FRepo_Private.h"
#import "FRepoManager.h"
#import "FServerValues.h"
#import "FTupleSetIdPath.h"
#import "FSyncTree.h"
#import "FEventRegistration.h"
#import "FAtomicNumber.h"
#import "FSyncTree.h"
#import "FListenProvider.h"
#import "FEventRaiser.h"
#import "FSnapshotHolder.h"
#import "FIRDatabaseConfig_Private.h"
#import "FLevelDBStorageEngine.h"
#import "FPersistenceManager.h"
#import "FWriteRecord.h"
#import "FCachePolicy.h"
#import "FClock.h"
#import "FIRDatabase_Private.h"
#import "FTree.h"
#import "FTupleTransaction.h"
#import "FIRTransactionResult.h"
#import "FIRTransactionResult_Private.h"
#import "FIRMutableData.h"
#import "FIRMutableData_Private.h"
#import "FIRDataSnapshot.h"
#import "FIRDataSnapshot_Private.h"
#import "FValueEventRegistration.h"
#import "FEmptyNode.h"
#if TARGET_OS_IOS || TARGET_OS_TV
#import <UIKit/UIKit.h>
#endif
@interface FRepo()
@property (nonatomic, strong) FOffsetClock *serverClock;
@property (nonatomic, strong) FPersistenceManager* persistenceManager;
@property (nonatomic, strong) FIRDatabase *database;
@property (nonatomic, strong, readwrite) FAuthenticationManager *auth;
@property (nonatomic, strong) FSyncTree *infoSyncTree;
@property (nonatomic) NSInteger writeIdCounter;
@property (nonatomic) BOOL hijackHash;
@property (nonatomic, strong) FTree *transactionQueueTree;
@property (nonatomic) BOOL loggedTransactionPersistenceWarning;
/**
* Test only. For load testing the server.
*/
@property (nonatomic, strong) id (^interceptServerDataCallback)(NSString *pathString, id data);
@end
@implementation FRepo
- (id)initWithRepoInfo:(FRepoInfo*)info config:(FIRDatabaseConfig *)config database:(FIRDatabase *)database {
self = [super init];
if (self) {
self.repoInfo = info;
self.config = config;
self.database = database;
// Access can occur outside of shared queue, so the clock needs to be initialized here
self.serverClock = [[FOffsetClock alloc] initWithClock:[FSystemClock clock] offset:0];
self.connection = [[FPersistentConnection alloc] initWithRepoInfo:self.repoInfo dispatchQueue:[FIRDatabaseQuery sharedQueue] config:self.config];
// Needs to be called before authentication manager is instantiated
self.eventRaiser = [[FEventRaiser alloc] initWithQueue:self.config.callbackQueue];
dispatch_async([FIRDatabaseQuery sharedQueue], ^{
[self deferredInit];
});
}
return self;
}
- (void)deferredInit {
// TODO: cleanup on dealloc
__weak FRepo *weakSelf = self;
[self.config.authTokenProvider listenForTokenChanges:^(NSString *token) {
[weakSelf.connection refreshAuthToken:token];
}];
// Open connection now so that by the time we are connected the deferred init has run
// This relies on the fact that all callbacks run on repos queue
self.connection.delegate = self;
[self.connection open];
self.dataUpdateCount = 0;
self.rangeMergeUpdateCount = 0;
self.interceptServerDataCallback = nil;
if (self.config.persistenceEnabled) {
NSString* repoHashString = [NSString stringWithFormat:@"%@_%@", self.repoInfo.host, self.repoInfo.namespace];
NSString* persistencePrefix = [NSString stringWithFormat:@"%@/%@", self.config.sessionIdentifier, repoHashString];
id<FCachePolicy> cachePolicy = [[FLRUCachePolicy alloc] initWithMaxSize:self.config.persistenceCacheSizeBytes];
id<FStorageEngine> engine;
if (self.config.forceStorageEngine != nil) {
engine = self.config.forceStorageEngine;
} else {
FLevelDBStorageEngine *levelDBEngine = [[FLevelDBStorageEngine alloc] initWithPath:persistencePrefix];
// We need the repo info to run the legacy migration. Future migrations will be managed by the database itself
// Remove this once we are confident that no-one is using legacy migration anymore...
[levelDBEngine runLegacyMigration:self.repoInfo];
engine = levelDBEngine;
}
self.persistenceManager = [[FPersistenceManager alloc] initWithStorageEngine:engine cachePolicy:cachePolicy];
} else {
self.persistenceManager = nil;
}
[self initTransactions];
// A list of data pieces and paths to be set when this client disconnects
self.onDisconnect = [[FSparseSnapshotTree alloc] init];
self.infoData = [[FSnapshotHolder alloc] init];
FListenProvider *infoListenProvider = [[FListenProvider alloc] init];
infoListenProvider.startListening = ^(FQuerySpec *query,
NSNumber *tagId,
id<FSyncTreeHash> hash,
fbt_nsarray_nsstring onComplete) {
NSArray *infoEvents = @[];
FRepo *strongSelf = weakSelf;
id<FNode> node = [strongSelf.infoData getNode:query.path];
// This is possibly a hack, but we have different semantics for .info endpoints. We don't raise null events
// on initial data...
if (![node isEmpty]) {
infoEvents = [strongSelf.infoSyncTree applyServerOverwriteAtPath:query.path newData:node];
[strongSelf.eventRaiser raiseCallback:^{
onComplete(kFWPResponseForActionStatusOk);
}];
}
return infoEvents;
};
infoListenProvider.stopListening = ^(FQuerySpec *query, NSNumber *tagId) {};
self.infoSyncTree = [[FSyncTree alloc] initWithListenProvider:infoListenProvider];
FListenProvider *serverListenProvider = [[FListenProvider alloc] init];
serverListenProvider.startListening = ^(FQuerySpec *query,
NSNumber *tagId,
id<FSyncTreeHash> hash,
fbt_nsarray_nsstring onComplete) {
[weakSelf.connection listen:query tagId:tagId hash:hash onComplete:^(NSString *status) {
NSArray *events = onComplete(status);
[weakSelf.eventRaiser raiseEvents:events];
}];
// No synchronous events for network-backed sync trees
return @[];
};
serverListenProvider.stopListening = ^(FQuerySpec *query, NSNumber *tag) {
[weakSelf.connection unlisten:query tagId:tag];
};
self.serverSyncTree = [[FSyncTree alloc] initWithPersistenceManager:self.persistenceManager
listenProvider:serverListenProvider];
[self restoreWrites];
[self updateInfo:kDotInfoConnected withValue:@NO];
[self setupNotifications];
}
- (void) restoreWrites {
NSArray *writes = self.persistenceManager.userWrites;
NSDictionary *serverValues = [FServerValues generateServerValues:self.serverClock];
__block NSInteger lastWriteId = NSIntegerMin;
[writes enumerateObjectsUsingBlock:^(FWriteRecord *write, NSUInteger idx, BOOL *stop) {
NSInteger writeId = write.writeId;
fbt_void_nsstring_nsstring callback = ^(NSString *status, NSString *errorReason) {
[self warnIfWriteFailedAtPath:write.path status:status message:@"Persisted write"];
[self ackWrite:writeId rerunTransactionsAtPath:write.path status:status];
};
if (lastWriteId >= writeId) {
[NSException raise:NSInternalInconsistencyException format:@"Restored writes were not in order!"];
}
lastWriteId = writeId;
self.writeIdCounter = writeId + 1;
if ([write isOverwrite]) {
FFLog(@"I-RDB038001", @"Restoring overwrite with id %ld", (long)write.writeId);
[self.connection putData:[write.overwrite valForExport:YES]
forPath:[write.path toString]
withHash:nil
withCallback:callback];
id<FNode> resolved = [FServerValues resolveDeferredValueSnapshot:write.overwrite withServerValues:serverValues];
[self.serverSyncTree applyUserOverwriteAtPath:write.path newData:resolved writeId:writeId isVisible:YES];
} else {
FFLog(@"I-RDB038002", @"Restoring merge with id %ld", (long)write.writeId);
[self.connection mergeData:[write.merge valForExport:YES]
forPath:[write.path toString]
withCallback:callback];
FCompoundWrite *resolved = [FServerValues resolveDeferredValueCompoundWrite:write.merge withServerValues:serverValues];
[self.serverSyncTree applyUserMergeAtPath:write.path changedChildren:resolved writeId:writeId];
}
}];
}
- (NSString*)name {
return self.repoInfo.namespace;
}
- (NSString *) description {
return [self.repoInfo description];
}
- (void) interrupt {
[self.connection interruptForReason:kFInterruptReasonRepoInterrupt];
}
- (void) resume {
[self.connection resumeForReason:kFInterruptReasonRepoInterrupt];
}
// NOTE: Typically if you're calling this, you should be in an @autoreleasepool block to make sure that ARC kicks
// in and cleans up things no longer referenced (i.e. pendingPutsDB).
- (void) dispose {
[self.connection interruptForReason:kFInterruptReasonRepoInterrupt];
// We need to nil out any references to LevelDB, to make sure the
// LevelDB exclusive locks are released.
[self.persistenceManager close];
}
- (NSInteger) nextWriteId {
return self->_writeIdCounter++;
}
- (NSTimeInterval) serverTime {
return [self.serverClock currentTime];
}
- (void) set:(FPath *)path withNode:(id<FNode>)node withCallback:(fbt_void_nserror_ref)onComplete {
id value = [node valForExport:YES];
FFLog(@"I-RDB038003", @"Setting: %@ with %@ pri: %@", [path toString], [value description], [[node getPriority] val]);
// TODO: Optimize this behavior to either (a) store flag to skip resolving where possible and / or
// (b) store unresolved paths on JSON parse
NSDictionary* serverValues = [FServerValues generateServerValues:self.serverClock];
id<FNode> newNode = [FServerValues resolveDeferredValueSnapshot:node withServerValues:serverValues];
NSInteger writeId = [self nextWriteId];
[self.persistenceManager saveUserOverwrite:node atPath:path writeId:writeId];
NSArray *events = [self.serverSyncTree applyUserOverwriteAtPath:path newData:newNode writeId:writeId isVisible:YES];
[self.eventRaiser raiseEvents:events];
[self.connection putData:value forPath:[path toString] withHash:nil withCallback:^(NSString *status, NSString *errorReason) {
[self warnIfWriteFailedAtPath:path status:status message:@"setValue: or removeValue:"];
[self ackWrite:writeId rerunTransactionsAtPath:path status:status];
[self callOnComplete:onComplete withStatus:status errorReason:errorReason andPath:path];
}];
FPath* affectedPath = [self abortTransactionsAtPath:path error:kFTransactionSet];
[self rerunTransactionsForPath:affectedPath];
}
- (void) update:(FPath *)path withNodes:(FCompoundWrite *)nodes withCallback:(fbt_void_nserror_ref)callback {
NSDictionary *values = [nodes valForExport:YES];
FFLog(@"I-RDB038004", @"Updating: %@ with %@", [path toString], [values description]);
NSDictionary* serverValues = [FServerValues generateServerValues:self.serverClock];
FCompoundWrite *resolved = [FServerValues resolveDeferredValueCompoundWrite:nodes withServerValues:serverValues];
if (!resolved.isEmpty) {
NSInteger writeId = [self nextWriteId];
[self.persistenceManager saveUserMerge:nodes atPath:path writeId:writeId];
NSArray *events = [self.serverSyncTree applyUserMergeAtPath:path changedChildren:resolved writeId:writeId];
[self.eventRaiser raiseEvents:events];
[self.connection mergeData:values forPath:[path description] withCallback:^(NSString *status, NSString *errorReason) {
[self warnIfWriteFailedAtPath:path status:status message:@"updateChildValues:"];
[self ackWrite:writeId rerunTransactionsAtPath:path status:status];
[self callOnComplete:callback withStatus:status errorReason:errorReason andPath:path];
}];
[nodes enumerateWrites:^(FPath *childPath, id<FNode> node, BOOL *stop) {
FPath* pathFromRoot = [path child:childPath];
FFLog(@"I-RDB038005", @"Cancelling transactions at path: %@", pathFromRoot);
FPath *affectedPath = [self abortTransactionsAtPath:pathFromRoot error:kFTransactionSet];
[self rerunTransactionsForPath:affectedPath];
}];
} else {
FFLog(@"I-RDB038006", @"update called with empty data. Doing nothing");
// Do nothing, just call the callback
[self callOnComplete:callback withStatus:@"ok" errorReason:nil andPath:path];
}
}
- (void) onDisconnectCancel:(FPath *)path withCallback:(fbt_void_nserror_ref)callback {
[self.connection onDisconnectCancelPath:path withCallback:^(NSString *status, NSString *errorReason) {
BOOL success = [status isEqualToString:kFWPResponseForActionStatusOk];
if (success) {
[self.onDisconnect forgetPath:path];
} else {
FFLog(@"I-RDB038007", @"cancelDisconnectOperations: at %@ failed: %@", path, status);
}
[self callOnComplete:callback withStatus:status errorReason:errorReason andPath:path];
}];
}
- (void) onDisconnectSet:(FPath *)path withNode:(id<FNode>)node withCallback:(fbt_void_nserror_ref)callback {
[self.connection onDisconnectPutData:[node valForExport:YES] forPath:path withCallback:^(NSString *status, NSString *errorReason) {
BOOL success = [status isEqualToString:kFWPResponseForActionStatusOk];
if (success) {
[self.onDisconnect rememberData:node onPath:path];
} else {
FFWarn(@"I-RDB038008", @"onDisconnectSetValue: or onDisconnectRemoveValue: at %@ failed: %@", path, status);
}
[self callOnComplete:callback withStatus:status errorReason:errorReason andPath:path];
}];
}
- (void) onDisconnectUpdate:(FPath *)path withNodes:(FCompoundWrite *)nodes withCallback:(fbt_void_nserror_ref)callback {
if (!nodes.isEmpty) {
NSDictionary *values = [nodes valForExport:YES];
[self.connection onDisconnectMergeData:values forPath:path withCallback:^(NSString *status, NSString *errorReason) {
BOOL success = [status isEqualToString:kFWPResponseForActionStatusOk];
if (success) {
[nodes enumerateWrites:^(FPath *relativePath, id<FNode> nodeUnresolved, BOOL *stop) {
FPath* childPath = [path child:relativePath];
[self.onDisconnect rememberData:nodeUnresolved onPath:childPath];
}];
} else {
FFWarn(@"I-RDB038009", @"onDisconnectUpdateChildValues: at %@ failed %@", path, status);
}
[self callOnComplete:callback withStatus:status errorReason:errorReason andPath:path];
}];
} else {
// Do nothing, just call the callback
[self callOnComplete:callback withStatus:@"ok" errorReason:nil andPath:path];
}
}
- (void) purgeOutstandingWrites {
FFLog(@"I-RDB038010", @"Purging outstanding writes");
NSArray *events = [self.serverSyncTree removeAllWrites];
[self.eventRaiser raiseEvents:events];
// Abort any transactions
[self abortTransactionsAtPath:[FPath empty] error:kFErrorWriteCanceled];
// Remove outstanding writes from connection
[self.connection purgeOutstandingWrites];
}
- (void) addEventRegistration:(id <FEventRegistration>)eventRegistration forQuery:(FQuerySpec *)query {
NSArray *events = nil;
if ([[query.path getFront] isEqualToString:kDotInfoPrefix]) {
events = [self.infoSyncTree addEventRegistration:eventRegistration forQuery:query];
} else {
events = [self.serverSyncTree addEventRegistration:eventRegistration forQuery:query];
}
[self.eventRaiser raiseEvents:events];
}
- (void) removeEventRegistration:(id<FEventRegistration>)eventRegistration forQuery:(FQuerySpec *)query {
// These are guaranteed not to raise events, since we're not passing in a cancelError. However we can future-proof
// a little bit by handling the return values anyways.
FFLog(@"I-RDB038011", @"Removing event registration with hande: %lu", (unsigned long)eventRegistration.handle);
NSArray *events = nil;
if ([[query.path getFront] isEqualToString:kDotInfoPrefix]) {
events = [self.infoSyncTree removeEventRegistration:eventRegistration forQuery:query cancelError:nil];
} else {
events = [self.serverSyncTree removeEventRegistration:eventRegistration forQuery:query cancelError:nil];
}
[self.eventRaiser raiseEvents:events];
}
- (void) keepQuery:(FQuerySpec *)query synced:(BOOL)synced {
NSAssert(![[query.path getFront] isEqualToString:kDotInfoPrefix], @"Can't keep .info tree synced!");
[self.serverSyncTree keepQuery:query synced:synced];
}
- (void) updateInfo:(NSString *) pathString withValue:(id)value {
// hack to make serverTimeOffset available in a threadsafe way. Property is marked as atomic
if ([pathString isEqualToString:kDotInfoServerTimeOffset]) {
NSTimeInterval offset = [(NSNumber *)value doubleValue]/1000.0;
self.serverClock = [[FOffsetClock alloc] initWithClock:[FSystemClock clock] offset:offset];
}
FPath* path = [[FPath alloc] initWith:[NSString stringWithFormat:@"%@/%@", kDotInfoPrefix, pathString]];
id<FNode> newNode = [FSnapshotUtilities nodeFrom:value];
[self.infoData updateSnapshot:path withNewSnapshot:newNode];
NSArray *events = [self.infoSyncTree applyServerOverwriteAtPath:path newData:newNode];
[self.eventRaiser raiseEvents:events];
}
- (void) callOnComplete:(fbt_void_nserror_ref)onComplete withStatus:(NSString *)status errorReason:(NSString *)errorReason andPath:(FPath *)path {
if (onComplete) {
FIRDatabaseReference * ref = [[FIRDatabaseReference alloc] initWithRepo:self path:path];
BOOL statusOk = [status isEqualToString:kFWPResponseForActionStatusOk];
NSError* err = nil;
if (!statusOk) {
err = [FUtilities errorForStatus:status andReason:errorReason];
}
[self.eventRaiser raiseCallback:^{
onComplete(err, ref);
}];
}
}
- (void)ackWrite:(NSInteger)writeId rerunTransactionsAtPath:(FPath *)path status:(NSString *)status {
if ([status isEqualToString:kFErrorWriteCanceled]) {
// This write was already removed, we just need to ignore it...
} else {
BOOL success = [status isEqualToString:kFWPResponseForActionStatusOk];
NSArray *clearEvents = [self.serverSyncTree ackUserWriteWithWriteId:writeId revert:!success persist:YES clock:self.serverClock];
if ([clearEvents count] > 0) {
[self rerunTransactionsForPath:path];
}
[self.eventRaiser raiseEvents:clearEvents];
}
}
- (void) warnIfWriteFailedAtPath:(FPath *)path status:(NSString *)status message:(NSString *)message {
if (!([status isEqualToString:kFWPResponseForActionStatusOk] || [status isEqualToString:kFErrorWriteCanceled])) {
FFWarn(@"I-RDB038012", @"%@ at %@ failed: %@", message, path, status);
}
}
#pragma mark -
#pragma mark FPersistentConnectionDelegate methods
- (void) onDataUpdate:(FPersistentConnection *)fpconnection forPath:(NSString *)pathString message:(id)data isMerge:(BOOL)isMerge tagId:(NSNumber *)tagId {
FFLog(@"I-RDB038013", @"onDataUpdateForPath: %@ withMessage: %@", pathString, data);
// For testing.
self.dataUpdateCount++;
FPath* path = [[FPath alloc] initWith:pathString];
data = self.interceptServerDataCallback ? self.interceptServerDataCallback(pathString, data) : data;
NSArray *events = nil;
if (tagId != nil) {
if (isMerge) {
NSDictionary *message = data;
FCompoundWrite *taggedChildren = [FCompoundWrite compoundWriteWithValueDictionary:message];
events = [self.serverSyncTree applyTaggedQueryMergeAtPath:path changedChildren:taggedChildren tagId:tagId];
} else {
id<FNode> taggedSnap = [FSnapshotUtilities nodeFrom:data];
events = [self.serverSyncTree applyTaggedQueryOverwriteAtPath:path newData:taggedSnap tagId:tagId];
}
} else if (isMerge) {
NSDictionary *message = data;
FCompoundWrite *changedChildren = [FCompoundWrite compoundWriteWithValueDictionary:message];
events = [self.serverSyncTree applyServerMergeAtPath:path changedChildren:changedChildren];
} else {
id<FNode> snap = [FSnapshotUtilities nodeFrom:data];
events = [self.serverSyncTree applyServerOverwriteAtPath:path newData:snap];
}
if ([events count] > 0) {
// Since we have a listener outstanding for each transaction, receiving any events
// is a proxy for some change having occurred.
[self rerunTransactionsForPath:path];
}
[self.eventRaiser raiseEvents:events];
}
- (void)onRangeMerge:(NSArray *)ranges forPath:(NSString *)pathString tagId:(NSNumber *)tag {
FFLog(@"I-RDB038014", @"onRangeMerge: %@ => %@", pathString, ranges);
// For testing
self.rangeMergeUpdateCount++;
FPath* path = [[FPath alloc] initWith:pathString];
NSArray *events;
if (tag != nil) {
events = [self.serverSyncTree applyTaggedServerRangeMergeAtPath:path updates:ranges tagId:tag];
} else {
events = [self.serverSyncTree applyServerRangeMergeAtPath:path updates:ranges];
}
if (events.count > 0) {
// Since we have a listener outstanding for each transaction, receiving any events
// is a proxy for some change having occurred.
[self rerunTransactionsForPath:path];
}
[self.eventRaiser raiseEvents:events];
}
- (void)onConnect:(FPersistentConnection *)fpconnection {
[self updateInfo:kDotInfoConnected withValue:@YES];
}
- (void)onDisconnect:(FPersistentConnection *)fpconnection {
[self updateInfo:kDotInfoConnected withValue:@NO];
[self runOnDisconnectEvents];
}
- (void)onServerInfoUpdate:(FPersistentConnection *)fpconnection updates:(NSDictionary *)updates {
for (NSString* key in updates) {
id val = [updates objectForKey:key];
[self updateInfo:key withValue:val];
}
}
- (void) setupNotifications {
NSString * const *backgroundConstant = (NSString * const *) dlsym(RTLD_DEFAULT, "UIApplicationDidEnterBackgroundNotification");
if (backgroundConstant) {
FFLog(@"I-RDB038015", @"Registering for background notification.");
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(didEnterBackground)
name:*backgroundConstant
object:nil];
} else {
FFLog(@"I-RDB038016", @"Skipped registering for background notification.");
}
}
- (void) didEnterBackground {
if (!self.config.persistenceEnabled)
return;
// Targetted compilation is ONLY for testing. UIKit is weak-linked in actual release build.
#if TARGET_OS_IOS || TARGET_OS_TV
// The idea is to wait until any outstanding sets get written to disk. Since the sets might still be in our
// dispatch queue, we wait for the dispatch queue to catch up and for persistence to catch up.
// This may be undesirable though. The dispatch queue might just be processing a bunch of incoming data or
// something. We might want to keep track of whether there are any unpersisted sets or something.
FFLog(@"I-RDB038017", @"Entering background. Starting background task to finish work.");
Class uiApplicationClass = NSClassFromString(@"UIApplication");
assert(uiApplicationClass); // If we are here, we should be on iOS and UIApplication should be available.
UIApplication *application = [uiApplicationClass sharedApplication];
__block UIBackgroundTaskIdentifier bgTask = [application beginBackgroundTaskWithExpirationHandler:^{
[application endBackgroundTask:bgTask];
}];
NSDate *start = [NSDate date];
dispatch_async([FIRDatabaseQuery sharedQueue], ^{
NSTimeInterval finishTime = [start timeIntervalSinceNow]*-1;
FFLog(@"I-RDB038018", @"Background task completed. Queue time: %f", finishTime);
[application endBackgroundTask:bgTask];
});
#endif
}
#pragma mark -
#pragma mark Internal methods
/**
* Applies all the changes stored up in the onDisconnect tree
*/
- (void) runOnDisconnectEvents {
FFLog(@"I-RDB038019", @"Running onDisconnectEvents");
NSDictionary* serverValues = [FServerValues generateServerValues:self.serverClock];
FSparseSnapshotTree* resolvedTree = [FServerValues resolveDeferredValueTree:self.onDisconnect withServerValues:serverValues];
NSMutableArray *events = [[NSMutableArray alloc] init];
[resolvedTree forEachTreeAtPath:[FPath empty] do:^(FPath *path, id<FNode> node) {
[events addObjectsFromArray:[self.serverSyncTree applyServerOverwriteAtPath:path newData:node]];
FPath* affectedPath = [self abortTransactionsAtPath:path error:kFTransactionSet];
[self rerunTransactionsForPath:affectedPath];
}];
self.onDisconnect = [[FSparseSnapshotTree alloc] init];
[self.eventRaiser raiseEvents:events];
}
- (NSDictionary *) dumpListens {
return [self.connection dumpListens];
}
#pragma mark -
#pragma mark Transactions
/**
* Setup the transaction data structures
*/
- (void) initTransactions {
self.transactionQueueTree = [[FTree alloc] init];
self.hijackHash = NO;
self.loggedTransactionPersistenceWarning = NO;
}
/**
* Creates a new transaction, add its to the transactions we're tracking, and sends it to the server if possible
*/
- (void) startTransactionOnPath:(FPath *)path update:(fbt_transactionresult_mutabledata)update onComplete:(fbt_void_nserror_bool_datasnapshot)onComplete withLocalEvents:(BOOL)applyLocally {
if (self.config.persistenceEnabled && !self.loggedTransactionPersistenceWarning) {
self.loggedTransactionPersistenceWarning = YES;
FFInfo(@"I-RDB038020", @"runTransactionBlock: usage detected while persistence is enabled. Please be aware that transactions "
@"*will not* be persisted across app restarts. "
@"See https://www.firebase.com/docs/ios/guide/offline-capabilities.html#section-handling-transactions-offline for more details.");
}
FIRDatabaseReference * watchRef = [[FIRDatabaseReference alloc] initWithRepo:self path:path];
// make sure we're listening on this node
// Note: we can't do this asynchronously. To preserve event ordering, it has to be done in this block.
// This is ok, this block is guaranteed to be our own event loop
NSUInteger handle = [[FUtilities LUIDGenerator] integerValue];
fbt_void_datasnapshot cb = ^(FIRDataSnapshot *snapshot) {};
FValueEventRegistration *registration = [[FValueEventRegistration alloc] initWithRepo:self
handle:handle
callback:cb
cancelCallback:nil];
[watchRef.repo addEventRegistration:registration forQuery:watchRef.querySpec];
fbt_void_void unwatcher = ^{ [watchRef removeObserverWithHandle:handle]; };
// Save all the data that represents this transaction
FTupleTransaction* transaction = [[FTupleTransaction alloc] init];
transaction.path = path;
transaction.update = update;
transaction.onComplete = onComplete;
transaction.status = FTransactionInitializing;
transaction.order = [FUtilities LUIDGenerator];
transaction.applyLocally = applyLocally;
transaction.retryCount = 0;
transaction.unwatcher = unwatcher;
transaction.currentWriteId = nil;
transaction.currentInputSnapshot = nil;
transaction.currentOutputSnapshotRaw = nil;
transaction.currentOutputSnapshotResolved = nil;
// Run transaction initially
id<FNode> currentState = [self latestStateAtPath:path excludeWriteIds:nil];
transaction.currentInputSnapshot = currentState;
FIRMutableData * mutableCurrent = [[FIRMutableData alloc] initWithNode:currentState];
FIRTransactionResult * result = transaction.update(mutableCurrent);
if (!result.isSuccess) {
// Abort the transaction
transaction.unwatcher();
transaction.currentOutputSnapshotRaw = nil;
transaction.currentOutputSnapshotResolved = nil;
if (transaction.onComplete) {
FIRDatabaseReference *ref = [[FIRDatabaseReference alloc] initWithRepo:self path:transaction.path];
FIndexedNode *indexedNode = [FIndexedNode indexedNodeWithNode:transaction.currentInputSnapshot];
FIRDataSnapshot *snap = [[FIRDataSnapshot alloc] initWithRef:ref indexedNode:indexedNode];
[self.eventRaiser raiseCallback:^{
transaction.onComplete(nil, NO, snap);
}];
}
} else {
// Note: different from js. We don't need to validate, FIRMutableData does validation.
// We also don't have to worry about priorities. Just mark as run and add to queue.
transaction.status = FTransactionRun;
FTree* queueNode = [self.transactionQueueTree subTree:transaction.path];
NSMutableArray* nodeQueue = [queueNode getValue];
if (nodeQueue == nil) {
nodeQueue = [[NSMutableArray alloc] init];
}
[nodeQueue addObject:transaction];
[queueNode setValue:nodeQueue];
// Update visibleData and raise events
// Note: We intentionally raise events after updating all of our transaction state, since the user could
// start new transactions from the event callbacks
NSDictionary* serverValues = [FServerValues generateServerValues:self.serverClock];
id<FNode> newValUnresolved = [result.update nodeValue];
id<FNode> newVal = [FServerValues resolveDeferredValueSnapshot:newValUnresolved withServerValues:serverValues];
transaction.currentOutputSnapshotRaw = newValUnresolved;
transaction.currentOutputSnapshotResolved = newVal;
transaction.currentWriteId = [NSNumber numberWithInteger:[self nextWriteId]];
NSArray *events = [self.serverSyncTree applyUserOverwriteAtPath:path newData:newVal
writeId:[transaction.currentWriteId integerValue]
isVisible:transaction.applyLocally];
[self.eventRaiser raiseEvents:events];
[self sendAllReadyTransactions];
}
}
/**
* @param writeIdsToExclude A specific set to exclude
*/
- (id<FNode>) latestStateAtPath:(FPath *)path excludeWriteIds:(NSArray *)writeIdsToExclude {
id<FNode> latestState = [self.serverSyncTree calcCompleteEventCacheAtPath:path excludeWriteIds:writeIdsToExclude];
return latestState ? latestState : [FEmptyNode emptyNode];
}
/**
* Sends any already-run transactions that aren't waiting for outstanding transactions to complete.
*
* Externally, call the version with no arguments.
* Internally, calls itself recursively with a particular transactionQueueTree node to recurse through the tree
*/
- (void) sendAllReadyTransactions {
FTree* node = self.transactionQueueTree;
[self pruneCompletedTransactionsBelowNode:node];
[self sendReadyTransactionsForTree:node];
}
- (void) sendReadyTransactionsForTree:(FTree *)node {
NSMutableArray* queue = [node getValue];
if (queue != nil) {
queue = [self buildTransactionQueueAtNode:node];
NSAssert([queue count] > 0, @"Sending zero length transaction queue");
NSUInteger notRunIndex = [queue indexOfObjectPassingTest:^BOOL(id obj, NSUInteger idx, BOOL *stop) {
return ((FTupleTransaction*)obj).status != FTransactionRun;
}];
// If they're all run (and not sent), we can send them. Else, we must wait.
if (notRunIndex == NSNotFound) {
[self sendTransactionQueue:queue atPath:node.path];
}
} else if ([node hasChildren]) {
[node forEachChild:^(FTree *child) {
[self sendReadyTransactionsForTree:child];
}];
}
}
/**
* Given a list of run transactions, send them to the server and then handle the result (success or failure).
*/
- (void) sendTransactionQueue:(NSMutableArray *)queue atPath:(FPath *)path {
// Mark transactions as sent and bump the retry count
NSMutableArray *writeIdsToExclude = [[NSMutableArray alloc] init];
for (FTupleTransaction *transaction in queue) {
[writeIdsToExclude addObject:transaction.currentWriteId];
}
id<FNode> latestState = [self latestStateAtPath:path excludeWriteIds:writeIdsToExclude];
id<FNode> snapToSend = latestState;
NSString *latestHash = [latestState dataHash];
for (FTupleTransaction* transaction in queue) {
NSAssert(transaction.status == FTransactionRun, @"[FRepo sendTransactionQueue:] items in queue should all be run.");
FFLog(@"I-RDB038021", @"Transaction at %@ set to SENT", transaction.path);
transaction.status = FTransactionSent;
transaction.retryCount++;
FPath *relativePath = [FPath relativePathFrom:path to:transaction.path];
// If we've gotten to this point, the output snapshot must be defined.
snapToSend = [snapToSend updateChild:relativePath withNewChild:transaction.currentOutputSnapshotRaw];
}
id dataToSend = [snapToSend valForExport:YES];
NSString *pathToSend = [path description];
latestHash = self.hijackHash ? @"badhash" : latestHash;
// Send the put
[self.connection putData:dataToSend forPath:pathToSend withHash:latestHash withCallback:^(NSString *status, NSString *errorReason) {
FFLog(@"I-RDB038022", @"Transaction put response: %@ : %@", pathToSend, status);
NSMutableArray *events = [[NSMutableArray alloc] init];
if ([status isEqualToString:kFWPResponseForActionStatusOk]) {
// Queue up the callbacks and fire them after cleaning up all of our transaction state, since
// the callback could trigger more transactions or sets.
NSMutableArray *callbacks = [[NSMutableArray alloc] init];
for (FTupleTransaction *transaction in queue) {
transaction.status = FTransactionCompleted;
[events addObjectsFromArray:[self.serverSyncTree ackUserWriteWithWriteId:[transaction.currentWriteId integerValue]
revert:NO
persist:NO
clock:self.serverClock]];
if (transaction.onComplete) {
// We never unset the output snapshot, and given that this transaction is complete, it should be set
id <FNode> node = transaction.currentOutputSnapshotResolved;
FIndexedNode *indexedNode = [FIndexedNode indexedNodeWithNode:node];
FIRDatabaseReference *ref = [[FIRDatabaseReference alloc] initWithRepo:self path:transaction.path];
FIRDataSnapshot *snapshot = [[FIRDataSnapshot alloc] initWithRef:ref indexedNode:indexedNode];
fbt_void_void cb = ^{
transaction.onComplete(nil, YES, snapshot);
};
[callbacks addObject:[cb copy]];
}
transaction.unwatcher();
}
// Now remove the completed transactions.
[self pruneCompletedTransactionsBelowNode:[self.transactionQueueTree subTree:path]];
// There may be pending transactions that we can now send.
[self sendAllReadyTransactions];
// Finally, trigger onComplete callbacks
[self.eventRaiser raiseCallbacks:callbacks];
} else {
// transactions are no longer sent. Update their status appropriately.
if ([status isEqualToString:kFWPResponseForActionStatusDataStale]) {
for (FTupleTransaction *transaction in queue) {
if (transaction.status == FTransactionSentNeedsAbort) {
transaction.status = FTransactionNeedsAbort;
} else {
transaction.status = FTransactionRun;
}
}
} else {
FFWarn(@"I-RDB038023", @"runTransactionBlock: at %@ failed: %@", path, status);
for (FTupleTransaction *transaction in queue) {
transaction.status = FTransactionNeedsAbort;
[transaction setAbortStatus:status reason:errorReason];
}
}
}
[self rerunTransactionsForPath:path];
[self.eventRaiser raiseEvents:events];
}];
}
/**
* Finds all transactions dependent on the data at changed Path and reruns them.
*
* Should be called any time cached data changes.
*
* Return the highest path that was affected by rerunning transactions. This is the path at which events need to
* be raised for.
*/
- (FPath *) rerunTransactionsForPath:(FPath *)changedPath {
// For the common case that there are no transactions going on, skip all this!
if ([self.transactionQueueTree isEmpty]) {
return changedPath;
} else {
FTree* rootMostTransactionNode = [self getAncestorTransactionNodeForPath:changedPath];
FPath* path = rootMostTransactionNode.path;
NSArray* queue = [self buildTransactionQueueAtNode:rootMostTransactionNode];
[self rerunTransactionQueue:queue atPath:path];
return path;
}
}
/**
* Does all the work of rerunning transactions (as well as cleans up aborted transactions and whatnot).
*/
- (void) rerunTransactionQueue:(NSArray *)queue atPath:(FPath *)path {
if (queue.count == 0) {
return; // nothing to do
}
// Queue up the callbacks and fire them after cleaning up all of our transaction state, since
// the callback could trigger more transactions or sets.
NSMutableArray *events = [[NSMutableArray alloc] init];
NSMutableArray *callbacks = [[NSMutableArray alloc] init];
// Ignore, by default, all of the sets in this queue, since we're re-running all of them. However, we want to include
// the results of new sets triggered as part of this re-run, so we don't want to ignore a range, just these specific
// sets.
NSMutableArray *writeIdsToExclude = [[NSMutableArray alloc] init];
for (FTupleTransaction *transaction in queue) {
[writeIdsToExclude addObject:transaction.currentWriteId];
}
for (FTupleTransaction* transaction in queue) {
FPath* relativePath __unused = [FPath relativePathFrom:path to:transaction.path];
BOOL abortTransaction = NO;
NSAssert(relativePath != nil, @"[FRepo rerunTransactionsQueue:] relativePath should not be null.");
if (transaction.status == FTransactionNeedsAbort) {
abortTransaction = YES;
if (![transaction.abortStatus isEqualToString:kFErrorWriteCanceled]) {
NSArray *ackEvents = [self.serverSyncTree ackUserWriteWithWriteId:[transaction.currentWriteId integerValue]
revert:YES
persist:NO
clock:self.serverClock];
[events addObjectsFromArray:ackEvents];
}
} else if (transaction.status == FTransactionRun) {
if (transaction.retryCount >= kFTransactionMaxRetries) {
abortTransaction = YES;
[transaction setAbortStatus:kFTransactionTooManyRetries reason:nil];
[events addObjectsFromArray:[self.serverSyncTree ackUserWriteWithWriteId:[transaction.currentWriteId integerValue]
revert:YES
persist:NO
clock:self.serverClock]];
} else {
// This code reruns a transaction
id<FNode> currentNode = [self latestStateAtPath:transaction.path excludeWriteIds:writeIdsToExclude];
transaction.currentInputSnapshot = currentNode;
FIRMutableData * mutableCurrent = [[FIRMutableData alloc] initWithNode:currentNode];
FIRTransactionResult * result = transaction.update(mutableCurrent);
if (result.isSuccess) {
NSNumber *oldWriteId = transaction.currentWriteId;
NSDictionary* serverValues = [FServerValues generateServerValues:self.serverClock];
id<FNode> newVal = [result.update nodeValue];
id<FNode> newValResolved = [FServerValues resolveDeferredValueSnapshot:newVal withServerValues:serverValues];
transaction.currentOutputSnapshotRaw = newVal;
transaction.currentOutputSnapshotResolved = newValResolved;
transaction.currentWriteId = [NSNumber numberWithInteger:[self nextWriteId]];
// Mutates writeIdsToExclude in place
[writeIdsToExclude removeObject:oldWriteId];
[events addObjectsFromArray:[self.serverSyncTree applyUserOverwriteAtPath:transaction.path
newData:transaction.currentOutputSnapshotResolved
writeId:[transaction.currentWriteId integerValue]
isVisible:transaction.applyLocally]];
[events addObjectsFromArray:[self.serverSyncTree ackUserWriteWithWriteId:[oldWriteId integerValue]
revert:YES
persist:NO
clock:self.serverClock]];
} else {
abortTransaction = YES;
// The user aborted the transaction. JS treats ths as a "nodata" abort, but it's not an error, so we don't send them an error.
[transaction setAbortStatus:nil reason:nil];
[events addObjectsFromArray:[self.serverSyncTree ackUserWriteWithWriteId:[transaction.currentWriteId integerValue]
revert:YES
persist:NO
clock:self.serverClock]];
}
}
}
[self.eventRaiser raiseEvents:events];
events = nil;
if (abortTransaction) {
// Abort
transaction.status = FTransactionCompleted;
transaction.unwatcher();
if (transaction.onComplete) {
FIRDatabaseReference * ref = [[FIRDatabaseReference alloc] initWithRepo:self path:transaction.path];
FIndexedNode *lastInput = [FIndexedNode indexedNodeWithNode:transaction.currentInputSnapshot];
FIRDataSnapshot * snap = [[FIRDataSnapshot alloc] initWithRef:ref indexedNode:lastInput];
fbt_void_void cb = ^{
// Unlike JS, no need to check for "nodata" because ObjC has abortError = nil
transaction.onComplete(transaction.abortError, NO, snap);
};
[callbacks addObject:[cb copy]];
}
}
}
// Note: unlike current js client, we don't need to preserve priority. Users can set priority via FIRMutableData
// Clean up completed transactions.
[self pruneCompletedTransactionsBelowNode:self.transactionQueueTree];
// Now fire callbacks, now that we're in a good, known state.
[self.eventRaiser raiseCallbacks:callbacks];
// Try to send the transaction result to the server
[self sendAllReadyTransactions];
}
- (FTree *) getAncestorTransactionNodeForPath:(FPath *)path {
FTree* transactionNode = self.transactionQueueTree;
while (![path isEmpty] && [transactionNode getValue] == nil) {
NSString* front = [path getFront];
transactionNode = [transactionNode subTree:[[FPath alloc] initWith:front]];
path = [path popFront];
}
return transactionNode;
}
- (NSMutableArray *) buildTransactionQueueAtNode:(FTree *)node {
NSMutableArray* queue = [[NSMutableArray alloc] init];
[self aggregateTransactionQueuesForNode:node andQueue:queue];
[queue sortUsingComparator:^NSComparisonResult(FTupleTransaction* obj1, FTupleTransaction* obj2) {
return [obj1.order compare:obj2.order];
}];
return queue;
}
- (void) aggregateTransactionQueuesForNode:(FTree *)node andQueue:(NSMutableArray *)queue {
NSArray* nodeQueue = [node getValue];
[queue addObjectsFromArray:nodeQueue];
[node forEachChild:^(FTree *child) {
[self aggregateTransactionQueuesForNode:child andQueue:queue];
}];
}
/**
* Remove COMPLETED transactions at or below this node in the transactionQueueTree
*/
- (void) pruneCompletedTransactionsBelowNode:(FTree *)node {
NSMutableArray* queue = [node getValue];
if (queue != nil) {
int i = 0;
// remove all of the completed transactions from the queue
while (i < queue.count) {
FTupleTransaction* transaction = [queue objectAtIndex:i];
if (transaction.status == FTransactionCompleted) {
[queue removeObjectAtIndex:i];
} else {
i++;
}
}
if (queue.count > 0) {
[node setValue:queue];
} else {
[node setValue:nil];
}
}
[node forEachChildMutationSafe:^(FTree *child) {
[self pruneCompletedTransactionsBelowNode:child];
}];
}
/**
* Aborts all transactions on ancestors or descendants of the specified path. Called when doing a setValue: or
* updateChildValues: since we consider them incompatible with transactions
*
* @param path path for which we want to abort related transactions.
*/
- (FPath *) abortTransactionsAtPath:(FPath *)path error:(NSString *)error {
// For the common case that there are no transactions going on, skip all this!
if ([self.transactionQueueTree isEmpty]) {
return path;
} else {
FPath* affectedPath = [self getAncestorTransactionNodeForPath:path].path;
FTree* transactionNode = [self.transactionQueueTree subTree:path];
[transactionNode forEachAncestor:^BOOL(FTree *ancestor) {
[self abortTransactionsAtNode:ancestor error:error];
return NO;
}];
[self abortTransactionsAtNode:transactionNode error:error];
[transactionNode forEachDescendant:^(FTree *child) {
[self abortTransactionsAtNode:child error:error];
}];
return affectedPath;
}
}
/**
* Abort transactions stored in this transactions queue node.
*
* @param node Node to abort transactions for.
*/
- (void) abortTransactionsAtNode:(FTree *)node error:(NSString *)error {
NSMutableArray* queue = [node getValue];
if (queue != nil) {
// Queue up the callbacks and fire them after cleaning up all of our transaction state, since
// can be immediately aborted and removed.
NSMutableArray* callbacks = [[NSMutableArray alloc] init];
// Go through queue. Any already-sent transactions must be marked for abort, while the unsent ones
// can be immediately aborted and removed
NSMutableArray *events = [[NSMutableArray alloc] init];
int lastSent = -1;
// Note: all of the sent transactions will be at the front of the queue, so safe to increment lastSent
for (FTupleTransaction* transaction in queue) {
if (transaction.status == FTransactionSentNeedsAbort) {
// No-op. already marked.
} else if (transaction.status == FTransactionSent) {
// Mark this transaction for abort when it returns
lastSent++;
transaction.status = FTransactionSentNeedsAbort;
[transaction setAbortStatus:error reason:nil];
} else {
// we can abort this immediately
transaction.unwatcher();
if ([error isEqualToString:kFTransactionSet]) {
[events addObjectsFromArray:[self.serverSyncTree ackUserWriteWithWriteId:[transaction.currentWriteId integerValue]
revert:YES
persist:NO
clock:self.serverClock]];
} else {
// If it was cancelled it was already removed from the sync tree, no need to ack
NSAssert([error isEqualToString:kFErrorWriteCanceled], nil);
}
if (transaction.onComplete) {
NSError* abortReason = [FUtilities errorForStatus:error andReason:nil];
FIRDataSnapshot * snapshot = nil;
fbt_void_void cb = ^{
transaction.onComplete(abortReason, NO, snapshot);
};
[callbacks addObject:[cb copy]];
}
}
}
if (lastSent == -1) {
// We're not waiting for any sent transactions. We can clear the queue.
[node setValue:nil];
} else {
// Remove the transactions we aborted
NSRange theRange;
theRange.location = lastSent + 1;
theRange.length = queue.count - theRange.location;
[queue removeObjectsInRange:theRange];
}
// Now fire the callbacks
[self.eventRaiser raiseEvents:events];
[self.eventRaiser raiseCallbacks:callbacks];
}
}
@end