2017-12-31
2017-12-31 本文已影响0人
张霸天
// Software License Agreement (BSD License)
//
// Copyright (c) 2010-2016, Deusty, LLC
// All rights reserved.
//
// Redistribution and use of this software in source and binary forms,
// with or without modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
//
// * Neither the name of Deusty nor the names of its contributors may be used
// to endorse or promote products derived from this software without specific
// prior written permission of Deusty, LLC.
// Disable legacy macros
#ifndef DD_LEGACY_MACROS
#define DD_LEGACY_MACROS 0
#endif
#import "DDLog.h"
/**
* This class provides an abstract implementation of a database logger.
*
* That is, it provides the base implementation for a database logger to build atop of.
* All that is needed for a concrete database logger is to extend this class
* and override the methods in the implementation file that are prefixed with "db_".
**/
@interface DDAbstractDatabaseLogger : DDAbstractLogger {
@protected
NSUInteger _saveThreshold;
NSTimeInterval _saveInterval;
NSTimeInterval _maxAge;
NSTimeInterval _deleteInterval;
BOOL _deleteOnEverySave;
BOOL _saveTimerSuspended;
NSUInteger _unsavedCount;
dispatch_time_t _unsavedTime;
// 时间控制的
dispatch_source_t _saveTimer;
dispatch_time_t _lastDeleteTime;
dispatch_source_t _deleteTimer;
}
// 漂亮，每多久记录一次的好方法
/**
* Specifies how often to save the data to disk.
* Since saving is an expensive operation (disk io) it is not done after every log statement.
* These properties allow you to configure how/when the logger saves to disk.
*
* A save is done when either (whichever happens first):
*
* - The number of unsaved log entries reaches saveThreshold
* - The amount of time since the oldest unsaved log entry was created reaches saveInterval
*
* You can optionally disable the saveThreshold by setting it to zero.
* If you disable the saveThreshold you are entirely dependent on the saveInterval.
*
* You can optionally disable the saveInterval by setting it to zero (or a negative value).
* If you disable the saveInterval you are entirely dependent on the saveThreshold.
*
* It's not wise to disable both saveThreshold and saveInterval.
*
* The default saveThreshold is 500.
* The default saveInterval is 60 seconds.
**/
// threshold 是临界值的意思，用来批量设置，棒棒的
@property (assign, readwrite) NSUInteger saveThreshold;
/**
* See the description for the `saveThreshold` property
*/
@property (assign, readwrite) NSTimeInterval saveInterval;
/**
* It is likely you don't want the log entries to persist forever.
* Doing so would allow the database to grow infinitely large over time.
*
* The maxAge property provides a way to specify how old a log statement can get
* before it should get deleted from the database.
*
* The deleteInterval specifies how often to sweep for old log entries.
* Since deleting is an expensive operation (disk io) is is done on a fixed interval.
*
* An alternative to the deleteInterval is the deleteOnEverySave option.
* This specifies that old log entries should be deleted during every save operation.
*
* You can optionally disable the maxAge by setting it to zero (or a negative value).
* If you disable the maxAge then old log statements are not deleted.
*
* You can optionally disable the deleteInterval by setting it to zero (or a negative value).
*
* If you disable both deleteInterval and deleteOnEverySave then old log statements are not deleted.
*
* It's not wise to enable both deleteInterval and deleteOnEverySave.
*
* The default maxAge is 7 days.
* The default deleteInterval is 5 minutes.
* The default deleteOnEverySave is NO.
**/
@property (assign, readwrite) NSTimeInterval maxAge;
/**
* See the description for the `maxAge` property
*/
@property (assign, readwrite) NSTimeInterval deleteInterval;
/**
* See the description for the `maxAge` property
*/
@property (assign, readwrite) BOOL deleteOnEverySave;
/**
* Forces a save of any pending log entries (flushes log entries to disk).
**/
- (void)savePendingLogEntries;
/**
* Removes any log entries that are older than maxAge.
**/
- (void)deleteOldLogEntries;
@end
// Software License Agreement (BSD License)
//
// Copyright (c) 2010-2016, Deusty, LLC
// All rights reserved.
//
// Redistribution and use of this software in source and binary forms,
// with or without modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
//
// * Neither the name of Deusty nor the names of its contributors may be used
// to endorse or promote products derived from this software without specific
// prior written permission of Deusty, LLC.
#import "DDAbstractDatabaseLogger.h"
#import <math.h>
#if !__has_feature(objc_arc)
#error This file must be compiled with ARC. Use -fobjc-arc flag (or convert project to ARC).
#endif
@interface DDAbstractDatabaseLogger ()
- (void)destroySaveTimer;
- (void)destroyDeleteTimer;
@end
#pragma mark -
@implementation DDAbstractDatabaseLogger
- (instancetype)init {
if ((self = [super init])) {
_saveThreshold = 500;
_saveInterval = 60; // 60 seconds
_maxAge = (60 * 60 * 24 * 7); // 7 days
_deleteInterval = (60 * 5); // 5 minutes
}
return self;
}
- (void)dealloc {
[self destroySaveTimer];
[self destroyDeleteTimer];
}
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
#pragma mark Override Me
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
- (BOOL)db_log:(DDLogMessage *)logMessage {
// Override me and add your implementation.
//
// Return YES if an item was added to the buffer.
// Return NO if the logMessage was ignored.
return NO;
}
- (void)db_save {
// Override me and add your implementation.
}
- (void)db_delete {
// Override me and add your implementation.
}
- (void)db_saveAndDelete {
// Override me and add your implementation.
}
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
#pragma mark Private API
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// 用来执行保存操作
- (void)performSaveAndSuspendSaveTimer {
//保存了
if (_unsavedCount > 0) {
if (_deleteOnEverySave) {
[self db_saveAndDelete];
} else {
[self db_save];
}
}
// 将没保存设置为0
// 将没保存的数量设置为0
_unsavedCount = 0;
_unsavedTime = 0;
// 如果_有savetime这个线程，并且线程没有被挂起
// 就把这个线程挂起
if (_saveTimer && !_saveTimerSuspended) {
dispatch_suspend(_saveTimer);
_saveTimerSuspended = YES;
}
}
// 删除数据
- (void)performDelete {
if (_maxAge > 0.0) {
[self db_delete];
_lastDeleteTime = dispatch_time(DISPATCH_TIME_NOW, 0);
}
}
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
#pragma mark Timers
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
- (void)destroySaveTimer {
if (_saveTimer) {
// 用来cancel 线程
dispatch_source_cancel(_saveTimer);
// 将_save 重置
if (_saveTimerSuspended) {
// Must resume a timer before releasing it (or it will crash)
dispatch_resume(_saveTimer);
_saveTimerSuspended = NO;
}
#if !OS_OBJECT_USE_OBJC
dispatch_release(_saveTimer);
#endif
_saveTimer = NULL;
}
}
// 更新timer 的正确方法
- (void)updateAndResumeSaveTimer {
if ((_saveTimer != NULL) && (_saveInterval > 0.0) && (_unsavedTime > 0.0)) {
// 使用timeinterval 的正确方法
uint64_t interval = (uint64_t)(_saveInterval * (NSTimeInterval) NSEC_PER_SEC);
// 设置每一次的savetime 为从unsavedtime 开始每隔interval save 一次
dispatch_time_t startTime = dispatch_time(_unsavedTime, interval);
// 使用dispatch_source 开始了
dispatch_source_set_timer(_saveTimer, startTime, interval, 1ull * NSEC_PER_SEC);
// 开始save timer 这个source
if (_saveTimerSuspended) {
dispatch_resume(_saveTimer);
_saveTimerSuspended = NO;
}
}
}
- (void)createSuspendedSaveTimer {
// 初始化sourcetimer
if ((_saveTimer == NULL) && (_saveInterval > 0.0)) {
_saveTimer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0, self.loggerQueue);
// 漂亮， 什么都不用多写
dispatch_source_set_event_handler(_saveTimer, ^{ @autoreleasepool {
[self performSaveAndSuspendSaveTimer];
} });
// 使用savetimer suspend 来 做标志位
_saveTimerSuspended = YES;
}
}
- (void)destroyDeleteTimer {
if (_deleteTimer) {
dispatch_source_cancel(_deleteTimer);
#if !OS_OBJECT_USE_OBJC
dispatch_release(_deleteTimer);
#endif
_deleteTimer = NULL;
}
}
- (void)updateDeleteTimer {
if ((_deleteTimer != NULL) && (_deleteInterval > 0.0) && (_maxAge > 0.0)) {
uint64_t interval = (uint64_t)(_deleteInterval * (NSTimeInterval) NSEC_PER_SEC);
dispatch_time_t startTime;
// 我去标准化流程 😂
if (_lastDeleteTime > 0) {
startTime = dispatch_time(_lastDeleteTime, interval);
} else {
startTime = dispatch_time(DISPATCH_TIME_NOW, interval);
}
dispatch_source_set_timer(_deleteTimer, startTime, interval, 1ull * NSEC_PER_SEC);
}
}
- (void)createAndStartDeleteTimer {
if ((_deleteTimer == NULL) && (_deleteInterval > 0.0) && (_maxAge > 0.0)) {
_deleteTimer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0, self.loggerQueue);
if (_deleteTimer != NULL) {
dispatch_source_set_event_handler(_deleteTimer, ^{ @autoreleasepool {
[self performDelete];
} });
[self updateDeleteTimer];
if (_deleteTimer != NULL) {
dispatch_resume(_deleteTimer);
}
}
}
}
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
#pragma mark Configuration
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
- (NSUInteger)saveThreshold {
// The design of this method is taken from the DDAbstractLogger implementation.
// For extensive documentation please refer to the DDAbstractLogger implementation.
// Note: The internal implementation MUST access the colorsEnabled variable directly,
// This method is designed explicitly for external access.
//
// Using "self." syntax to go through this method will cause immediate deadlock.
// This is the intended result. Fix it by accessing the ivar directly.
// Great strides have been take to ensure this is safe to do. Plus it's MUCH faster.
NSAssert(![self isOnGlobalLoggingQueue], @"Core architecture requirement failure");
NSAssert(![self isOnInternalLoggerQueue], @"MUST access ivar directly, NOT via self.* syntax.");
// 来吧 耦合吧
dispatch_queue_t globalLoggingQueue = [DDLog loggingQueue];
__block NSUInteger result;
// 设置都是async， sync是用来读取的，
// 然后再使用当前的logger queue
dispatch_sync(globalLoggingQueue, ^{
dispatch_sync(self.loggerQueue, ^{
result = _saveThreshold;
});
});
return result;
}
- (void)setSaveThreshold:(NSUInteger)threshold {
dispatch_block_t block = ^{
@autoreleasepool {
// 这里有个细节
// 先更改save的数值，在使用保存函数
if (_saveThreshold != threshold) {
_saveThreshold = threshold;
// Since the saveThreshold has changed,
// we check to see if the current unsavedCount has surpassed the new threshold.
//
// If it has, we immediately save the log.
if ((_unsavedCount >= _saveThreshold) && (_saveThreshold > 0)) {
[self performSaveAndSuspendSaveTimer];
}
}
}
};
// The design of the setter logic below is taken from the DDAbstractLogger implementation.
// For documentation please refer to the DDAbstractLogger implementation.
if ([self isOnInternalLoggerQueue]) {
block();
} else {
// 漂亮，强制使用 queue 检查
dispatch_queue_t globalLoggingQueue = [DDLog loggingQueue];
NSAssert(![self isOnGlobalLoggingQueue], @"Core architecture requirement failure");
// 这里所有的操作都在大的loggerqueue中，而且，小的async， 大的也是async
dispatch_async(globalLoggingQueue, ^{
dispatch_async(self.loggerQueue, block);
});
}
}
- (NSTimeInterval)saveInterval {
// The design of this method is taken from the DDAbstractLogger implementation.
// For extensive documentation please refer to the DDAbstractLogger implementation.
// Note: The internal implementation MUST access the colorsEnabled variable directly,
// This method is designed explicitly for external access.
//
// Using "self." syntax to go through this method will cause immediate deadlock.
// This is the intended result. Fix it by accessing the ivar directly.
// Great strides have been take to ensure this is safe to do. Plus it's MUCH faster.
NSAssert(![self isOnGlobalLoggingQueue], @"Core architecture requirement failure");
NSAssert(![self isOnInternalLoggerQueue], @"MUST access ivar directly, NOT via self.* syntax.");
dispatch_queue_t globalLoggingQueue = [DDLog loggingQueue];
__block NSTimeInterval result;
// 只要是设置，就使用sync
dispatch_sync(globalLoggingQueue, ^{
dispatch_sync(self.loggerQueue, ^{
result = _saveInterval;
});
});
return result;
}
- (void)setSaveInterval:(NSTimeInterval)interval {
dispatch_block_t block = ^{
@autoreleasepool {
// C99 recommended floating point comparison macro
// Read: isLessThanOrGreaterThan(floatA, floatB)
// 最佳实践
if (/* saveInterval != interval */ isle99issgreater(_saveInterval, interval)) {
_saveInterval = interval;
// There are several cases we need to handle here.
//
// 1. If the saveInterval was previously enabled and it just got disabled,
// then we need to stop the saveTimer. (And we might as well release it.)
//
// 2. If the saveInterval was previously disabled and it just got enabled,
// then we need to setup the saveTimer. (Plus we might need to do an immediate save.)
//
// 3. If the saveInterval increased, then we need to reset the timer so that it fires at the later date.
//
// 4. If the saveInterval decreased, then we need to reset the timer so that it fires at an earlier date.
// (Plus we might need to do an immediate save.)
if (_saveInterval > 0.0) {
if (_saveTimer == NULL) {
// Handles #2
//
// Since the saveTimer uses the unsavedTime to calculate it's first fireDate,
// if a save is needed the timer will fire immediately.
[self createSuspendedSaveTimer];
[self updateAndResumeSaveTimer];
} else {
// Handles #3
// Handles #4
//
// Since the saveTimer uses the unsavedTime to calculate it's first fireDate,
// if a save is needed the timer will fire immediately.
[self updateAndResumeSaveTimer];
}
} else if (_saveTimer) {
// Handles #1
[self destroySaveTimer];
}
}
}
};
// The design of the setter logic below is taken from the DDAbstractLogger implementation.
// For documentation please refer to the DDAbstractLogger implementation.
if ([self isOnInternalLoggerQueue]) {
block();
} else {
dispatch_queue_t globalLoggingQueue = [DDLog loggingQueue];
NSAssert(![self isOnGlobalLoggingQueue], @"Core architecture requirement failure");
dispatch_async(globalLoggingQueue, ^{
dispatch_async(self.loggerQueue, block);
});
}
}
- (NSTimeInterval)maxAge {
// The design of this method is taken from the DDAbstractLogger implementation.
// For extensive documentation please refer to the DDAbstractLogger implementation.
// Note: The internal implementation MUST access the colorsEnabled variable directly,
// This method is designed explicitly for external access.
//
// Using "self." syntax to go through this method will cause immediate deadlock.
// This is the intended result. Fix it by accessing the ivar directly.
// Great strides have been take to ensure this is safe to do. Plus it's MUCH faster.
NSAssert(![self isOnGlobalLoggingQueue], @"Core architecture requirement failure");
NSAssert(![self isOnInternalLoggerQueue], @"MUST access ivar directly, NOT via self.* syntax.");
dispatch_queue_t globalLoggingQueue = [DDLog loggingQueue];
__block NSTimeInterval result;
dispatch_sync(globalLoggingQueue, ^{
dispatch_sync(self.loggerQueue, ^{
result = _maxAge;
});
});
return result;
}
- (void)setMaxAge:(NSTimeInterval)interval {
dispatch_block_t block = ^{
@autoreleasepool {
// C99 recommended floating point comparison macro
// Read: isLessThanOrGreaterThan(floatA, floatB)
if (/* maxAge != interval */ islessgreater(_maxAge, interval)) {
NSTimeInterval oldMaxAge = _maxAge;
NSTimeInterval newMaxAge = interval;
_maxAge = interval;
// There are several cases we need to handle here.
//
// 1. If the maxAge was previously enabled and it just got disabled,
// then we need to stop the deleteTimer. (And we might as well release it.)
//
// 2. If the maxAge was previously disabled and it just got enabled,
// then we need to setup the deleteTimer. (Plus we might need to do an immediate delete.)
//
// 3. If the maxAge was increased,
// then we don't need to do anything.
//
// 4. If the maxAge was decreased,
// then we should do an immediate delete.
BOOL shouldDeleteNow = NO;
if (oldMaxAge > 0.0) {
if (newMaxAge <= 0.0) {
// Handles #1
[self destroyDeleteTimer];
} else if (oldMaxAge > newMaxAge) {
// Handles #4
shouldDeleteNow = YES;
}
} else if (newMaxAge > 0.0) {
// Handles #2
shouldDeleteNow = YES;
}
if (shouldDeleteNow) {
[self performDelete];
if (_deleteTimer) {
[self updateDeleteTimer];
} else {
[self createAndStartDeleteTimer];
}
}
}
}
};
// The design of the setter logic below is taken from the DDAbstractLogger implementation.
// For documentation please refer to the DDAbstractLogger implementation.
if ([self isOnInternalLoggerQueue]) {
block();
} else {
dispatch_queue_t globalLoggingQueue = [DDLog loggingQueue];
NSAssert(![self isOnGlobalLoggingQueue], @"Core architecture requirement failure");
dispatch_async(globalLoggingQueue, ^{
dispatch_async(self.loggerQueue, block);
});
}
}
- (NSTimeInterval)deleteInterval {
// The design of this method is taken from the DDAbstractLogger implementation.
// For extensive documentation please refer to the DDAbstractLogger implementation.
// Note: The internal implementation MUST access the colorsEnabled variable directly,
// This method is designed explicitly for external access.
//
// Using "self." syntax to go through this method will cause immediate deadlock.
// This is the intended result. Fix it by accessing the ivar directly.
// Great strides have been take to ensure this is safe to do. Plus it's MUCH faster.
NSAssert(![self isOnGlobalLoggingQueue], @"Core architecture requirement failure");
NSAssert(![self isOnInternalLoggerQueue], @"MUST access ivar directly, NOT via self.* syntax.");
dispatch_queue_t globalLoggingQueue = [DDLog loggingQueue];
__block NSTimeInterval result;
dispatch_sync(globalLoggingQueue, ^{
dispatch_sync(self.loggerQueue, ^{
result = _deleteInterval;
});
});
return result;
}
- (void)setDeleteInterval:(NSTimeInterval)interval {
dispatch_block_t block = ^{
@autoreleasepool {
// C99 recommended floating point comparison macro
// Read: isLessThanOrGreaterThan(floatA, floatB)
if (/* deleteInterval != interval */ islessgreater(_deleteInterval, interval)) {
_deleteInterval = interval;
// There are several cases we need to handle here.
//
// 1. If the deleteInterval was previously enabled and it just got disabled,
// then we need to stop the deleteTimer. (And we might as well release it.)
//
// 2. If the deleteInterval was previously disabled and it just got enabled,
// then we need to setup the deleteTimer. (Plus we might need to do an immediate delete.)
//
// 3. If the deleteInterval increased, then we need to reset the timer so that it fires at the later date.
//
// 4. If the deleteInterval decreased, then we need to reset the timer so that it fires at an earlier date.
// (Plus we might need to do an immediate delete.)
if (_deleteInterval > 0.0) {
if (_deleteTimer == NULL) {
// Handles #2
//
// Since the deleteTimer uses the lastDeleteTime to calculate it's first fireDate,
// if a delete is needed the timer will fire immediately.
[self createAndStartDeleteTimer];
} else {
// Handles #3
// Handles #4
//
// Since the deleteTimer uses the lastDeleteTime to calculate it's first fireDate,
// if a save is needed the timer will fire immediately.
[self updateDeleteTimer];
}
} else if (_deleteTimer) {
// Handles #1
[self destroyDeleteTimer];
}
}
}
};
// The design of the setter logic below is taken from the DDAbstractLogger implementation.
// For documentation please refer to the DDAbstractLogger implementation.
if ([self isOnInternalLoggerQueue]) {
block();
} else {
dispatch_queue_t globalLoggingQueue = [DDLog loggingQueue];
NSAssert(![self isOnGlobalLoggingQueue], @"Core architecture requirement failure");
dispatch_async(globalLoggingQueue, ^{
dispatch_async(self.loggerQueue, block);
});
}
}
- (BOOL)deleteOnEverySave {
// The design of this method is taken from the DDAbstractLogger implementation.
// For extensive documentation please refer to the DDAbstractLogger implementation.
// Note: The internal implementation MUST access the colorsEnabled variable directly,
// This method is designed explicitly for external access.
//
// Using "self." syntax to go through this method will cause immediate deadlock.
// This is the intended result. Fix it by accessing the ivar directly.
// Great strides have been take to ensure this is safe to do. Plus it's MUCH faster.
NSAssert(![self isOnGlobalLoggingQueue], @"Core architecture requirement failure");
NSAssert(![self isOnInternalLoggerQueue], @"MUST access ivar directly, NOT via self.* syntax.");
dispatch_queue_t globalLoggingQueue = [DDLog loggingQueue];
__block BOOL result;
dispatch_sync(globalLoggingQueue, ^{
dispatch_sync(self.loggerQueue, ^{
result = _deleteOnEverySave;
});
});
return result;
}
- (void)setDeleteOnEverySave:(BOOL)flag {
dispatch_block_t block = ^{
_deleteOnEverySave = flag;
};
// The design of the setter logic below is taken from the DDAbstractLogger implementation.
// For documentation please refer to the DDAbstractLogger implementation.
if ([self isOnInternalLoggerQueue]) {
block();
} else {
dispatch_queue_t globalLoggingQueue = [DDLog loggingQueue];
NSAssert(![self isOnGlobalLoggingQueue], @"Core architecture requirement failure");
dispatch_async(globalLoggingQueue, ^{
dispatch_async(self.loggerQueue, block);
});
}
}
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
#pragma mark Public API
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
- (void)savePendingLogEntries {
dispatch_block_t block = ^{
@autoreleasepool {
[self performSaveAndSuspendSaveTimer];
}
};
if ([self isOnInternalLoggerQueue]) {
block();
} else {
dispatch_async(self.loggerQueue, block);
}
}
- (void)deleteOldLogEntries {
dispatch_block_t block = ^{
@autoreleasepool {
[self performDelete];
}
};
if ([self isOnInternalLoggerQueue]) {
block();
} else {
dispatch_async(self.loggerQueue, block);
}
}
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
#pragma mark DDLogger
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
- (void)didAddLogger {
// If you override me be sure to invoke [super didAddLogger];
[self createSuspendedSaveTimer];
[self createAndStartDeleteTimer];
}
- (void)willRemoveLogger {
// If you override me be sure to invoke [super willRemoveLogger];
[self performSaveAndSuspendSaveTimer];
[self destroySaveTimer];
[self destroyDeleteTimer];
}
- (void)logMessage:(DDLogMessage *)logMessage {
if ([self db_log:logMessage]) {
BOOL firstUnsavedEntry = (++_unsavedCount == 1);
if ((_unsavedCount >= _saveThreshold) && (_saveThreshold > 0)) {
[self performSaveAndSuspendSaveTimer];
} else if (firstUnsavedEntry) {
_unsavedTime = dispatch_time(DISPATCH_TIME_NOW, 0);
[self updateAndResumeSaveTimer];
}
}
}
- (void)flush {
// This method is invoked by DDLog's flushLog method.
//
// It is called automatically when the application quits,
// or if the developer invokes DDLog's flushLog method prior to crashing or something.
[self performSaveAndSuspendSaveTimer];
}
@end
