webhistory.mm

linux下开源浏览器WebKit的源码,市面上的很多商用浏览器都是移植自WebKit

/*
 * Copyright (C) 2005, 2008 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1.  Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer. 
 * 2.  Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution. 
 * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
 *     its contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission. 
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#import "WebHistoryInternal.h"

#import "WebHistoryItemInternal.h"
#import "WebKitLogging.h"
#import "WebNSURLExtras.h"
#import "WebTypesInternal.h"
#import <WebCore/HistoryItem.h>
#import <WebCore/PageGroup.h>

using namespace WebCore;

typedef int64_t WebHistoryDateKey;
typedef HashMap<WebHistoryDateKey, RetainPtr<NSMutableArray> > DateToEntriesMap;

NSString *WebHistoryItemsAddedNotification = @"WebHistoryItemsAddedNotification";
NSString *WebHistoryItemsRemovedNotification = @"WebHistoryItemsRemovedNotification";
NSString *WebHistoryAllItemsRemovedNotification = @"WebHistoryAllItemsRemovedNotification";
NSString *WebHistoryLoadedNotification = @"WebHistoryLoadedNotification";
NSString *WebHistoryItemsDiscardedWhileLoadingNotification = @"WebHistoryItemsDiscardedWhileLoadingNotification";
NSString *WebHistorySavedNotification = @"WebHistorySavedNotification";
NSString *WebHistoryItemsKey = @"WebHistoryItems";

static WebHistory *_sharedHistory = nil;

NSString *FileVersionKey = @"WebHistoryFileVersion";
NSString *DatesArrayKey = @"WebHistoryDates";

#define currentFileVersion 1

@interface WebHistoryPrivate : NSObject {
@private
    NSMutableDictionary *_entriesByURL;
    DateToEntriesMap* _entriesByDate;
    NSMutableArray *_orderedLastVisitedDays;
    BOOL itemLimitSet;
    int itemLimit;
    BOOL ageInDaysLimitSet;
    int ageInDaysLimit;
}

- (WebHistoryItem *)visitedURL:(NSURL *)url withTitle:(NSString *)title;

- (BOOL)addItem:(WebHistoryItem *)entry discardDuplicate:(BOOL)discardDuplicate;
- (void)addItems:(NSArray *)newEntries;
- (BOOL)removeItem:(WebHistoryItem *)entry;
- (BOOL)removeItems:(NSArray *)entries;
- (BOOL)removeAllItems;

- (NSArray *)orderedLastVisitedDays;
- (NSArray *)orderedItemsLastVisitedOnDay:(NSCalendarDate *)calendarDate;
- (BOOL)containsURL:(NSURL *)URL;
- (WebHistoryItem *)itemForURL:(NSURL *)URL;
- (WebHistoryItem *)itemForURLString:(NSString *)URLString;
- (NSArray *)allItems;

- (BOOL)loadFromURL:(NSURL *)URL collectDiscardedItemsInto:(NSMutableArray *)discardedItems error:(NSError **)error;
- (BOOL)saveToURL:(NSURL *)URL error:(NSError **)error;

- (NSCalendarDate *)ageLimitDate;

- (void)setHistoryItemLimit:(int)limit;
- (int)historyItemLimit;
- (void)setHistoryAgeInDaysLimit:(int)limit;
- (int)historyAgeInDaysLimit;

- (void)addVisitedLinksToPageGroup:(PageGroup&)group;

@end

@implementation WebHistoryPrivate

#pragma mark OBJECT FRAMEWORK

+ (void)initialize
{
    [[NSUserDefaults standardUserDefaults] registerDefaults:
        [NSDictionary dictionaryWithObjectsAndKeys:
            @"1000", @"WebKitHistoryItemLimit",
            @"7", @"WebKitHistoryAgeInDaysLimit",
            nil]];    
}

- (id)init
{
    if (![super init])
        return nil;
    
    _entriesByURL = [[NSMutableDictionary alloc] init];
    _entriesByDate = new DateToEntriesMap;

    return self;
}

- (void)dealloc
{
    [_entriesByURL release];
    [_orderedLastVisitedDays release];
    delete _entriesByDate;
    [super dealloc];
}

- (void)finalize
{
    delete _entriesByDate;
    [super finalize];
}

#pragma mark MODIFYING CONTENTS

static WebHistoryDateKey timeIntervalForBeginningOfDay(NSTimeInterval interval)
{
    CFTimeZoneRef timeZone = CFTimeZoneCopyDefault();
    CFGregorianDate date = CFAbsoluteTimeGetGregorianDate(interval, timeZone);
    date.hour = 0;
    date.minute = 0;
    date.second = 0;
    NSTimeInterval result = CFGregorianDateGetAbsoluteTime(date, timeZone);
    CFRelease(timeZone);

    // Converting from double to int64_t is safe here as NSDate's useful range
    // is -2**48 .. 2**47 which will safely fit in an int64_t.
    return (WebHistoryDateKey)result;
}

// Returns whether the day is already in the list of days,
// and fills in *key with the key used to access its location
- (BOOL)findKey:(WebHistoryDateKey*)key forDay:(NSTimeInterval)date
{
    ASSERT_ARG(key, key != nil);
    *key = timeIntervalForBeginningOfDay(date);
    return _entriesByDate->contains(*key);
}

- (void)insertItem:(WebHistoryItem *)entry forDateKey:(WebHistoryDateKey)dateKey
{
    ASSERT_ARG(entry, entry != nil);
    ASSERT(_entriesByDate->contains(dateKey));

    NSMutableArray *entriesForDate = _entriesByDate->get(dateKey).get();
    NSTimeInterval entryDate = [entry lastVisitedTimeInterval];

    unsigned count = [entriesForDate count];

    // The entries for each day are stored in a sorted array with the most recent entry first
    // Check for the common cases of the entry being newer than all existing entries or the first entry of the day
    if (!count || [[entriesForDate objectAtIndex:0] lastVisitedTimeInterval] < entryDate) {
        [entriesForDate insertObject:entry atIndex:0];
        return;
    }
    // .. or older than all existing entries
    if (count > 0 && [[entriesForDate objectAtIndex:count - 1] lastVisitedTimeInterval] >= entryDate) {
        [entriesForDate insertObject:entry atIndex:count];
        return;
    }

    unsigned low = 0;
    unsigned high = count;
    while (low < high) {
        unsigned mid = low + (high - low) / 2;
        if ([[entriesForDate objectAtIndex:mid] lastVisitedTimeInterval] >= entryDate)
            low = mid + 1;
        else
            high = mid;
    }

    // low is now the index of the first entry that is older than entryDate
    [entriesForDate insertObject:entry atIndex:low];
}

- (BOOL)removeItemFromDateCaches:(WebHistoryItem *)entry
{
    WebHistoryDateKey dateKey;
    BOOL foundDate = [self findKey:&dateKey forDay:[entry lastVisitedTimeInterval]];
 
    if (!foundDate)
        return NO;

    DateToEntriesMap::iterator it = _entriesByDate->find(dateKey);
    NSMutableArray *entriesForDate = it->second.get();
    [entriesForDate removeObjectIdenticalTo:entry];
    
    // remove this date entirely if there are no other entries on it
    if ([entriesForDate count] == 0) {
        _entriesByDate->remove(it);
        // Clear _orderedLastVisitedDays so it will be regenerated when next requested.
        [_orderedLastVisitedDays release];
        _orderedLastVisitedDays = nil;
    }
    
    return YES;
}

- (BOOL)removeItemForURLString:(NSString *)URLString
{
    WebHistoryItem *entry = [_entriesByURL objectForKey:URLString];
    if (!entry)
        return NO;

    [_entriesByURL removeObjectForKey:URLString];
    
#if ASSERT_DISABLED
    [self removeItemFromDateCaches:entry];
#else
    BOOL itemWasInDateCaches = [self removeItemFromDateCaches:entry];
    ASSERT(itemWasInDateCaches);
#endif

    if (![_entriesByURL count])
        PageGroup::removeAllVisitedLinks();

    return YES;
}

- (void)addItemToDateCaches:(WebHistoryItem *)entry
{
    WebHistoryDateKey dateKey;
    if ([self findKey:&dateKey forDay:[entry lastVisitedTimeInterval]])
        // other entries already exist for this date
        [self insertItem:entry forDateKey:dateKey];
    else {
        // no other entries exist for this date
        NSMutableArray *entries = [[NSMutableArray alloc] initWithObjects:&entry count:1];
        _entriesByDate->set(dateKey, entries);
        [entries release];
        // Clear _orderedLastVisitedDays so it will be regenerated when next requested.
        [_orderedLastVisitedDays release];
        _orderedLastVisitedDays = nil;
    }
}

- (WebHistoryItem *)visitedURL:(NSURL *)url withTitle:(NSString *)title
{
    ASSERT(url);
    ASSERT(title);
    
    NSString *URLString = [url _web_originalDataAsString];
    WebHistoryItem *entry = [_entriesByURL objectForKey:URLString];

    if (entry) {
        LOG(History, "Updating global history entry %@", entry);
        // Remove the item from date caches before changing its last visited date.  Otherwise we might get duplicate entries
        // as seen in <rdar://problem/6570573>.
        BOOL itemWasInDateCaches = [self removeItemFromDateCaches:entry];
        ASSERT_UNUSED(itemWasInDateCaches, itemWasInDateCaches);

        [entry _visitedWithTitle:title];
    } else {
        LOG(History, "Adding new global history entry for %@", url);
        entry = [[WebHistoryItem alloc] initWithURLString:URLString title:title lastVisitedTimeInterval:[NSDate timeIntervalSinceReferenceDate]];
        [entry _recordInitialVisit];
        [_entriesByURL setObject:entry forKey:URLString];
        [entry release];
    }
    
    [self addItemToDateCaches:entry];

    return entry;
}

- (BOOL)addItem:(WebHistoryItem *)entry discardDuplicate:(BOOL)discardDuplicate
{
    ASSERT_ARG(entry, entry);
    ASSERT_ARG(entry, [entry lastVisitedTimeInterval] != 0);

    NSString *URLString = [entry URLString];

    WebHistoryItem *oldEntry = [_entriesByURL objectForKey:URLString];
    if (oldEntry) {
        if (discardDuplicate)
            return NO;

        // The last reference to oldEntry might be this dictionary, so we hold onto a reference
        // until we're done with oldEntry.
        [oldEntry retain];
        [self removeItemForURLString:URLString];

        // If we already have an item with this URL, we need to merge info that drives the
        // URL autocomplete heuristics from that item into the new one.
        [entry _mergeAutoCompleteHints:oldEntry];
        [oldEntry release];
    }

    [self addItemToDateCaches:entry];
    [_entriesByURL setObject:entry forKey:URLString];
    
    return YES;
}

- (BOOL)removeItem:(WebHistoryItem *)entry
{
    NSString *URLString = [entry URLString];

    // If this exact object isn't stored, then make no change.
    // FIXME: Is this the right behavior if this entry isn't present, but another entry for the same URL is?
    // Maybe need to change the API to make something like removeEntryForURLString public instead.
    WebHistoryItem *matchingEntry = [_entriesByURL objectForKey:URLString];
    if (matchingEntry != entry)
        return NO;

    [self removeItemForURLString:URLString];

    return YES;
}

- (BOOL)removeItems:(NSArray *)entries
{
    NSUInteger count = [entries count];
    if (!count)
        return NO;

    for (NSUInteger index = 0; index < count; ++index)
        [self removeItem:[entries objectAtIndex:index]];
    
    return YES;
}

- (BOOL)removeAllItems
{
    if (_entriesByDate->isEmpty())
        return NO;

    _entriesByDate->clear();
    [_entriesByURL removeAllObjects];

    // Clear _orderedLastVisitedDays so it will be regenerated when next requested.
    [_orderedLastVisitedDays release];
    _orderedLastVisitedDays = nil;

    PageGroup::removeAllVisitedLinks();

    return YES;
}

- (void)addItems:(NSArray *)newEntries
{
    // There is no guarantee that the incoming entries are in any particular
    // order, but if this is called with a set of entries that were created by
    // iterating through the results of orderedLastVisitedDays and orderedItemsLastVisitedOnDayy
    // then they will be ordered chronologically from newest to oldest. We can make adding them
    // faster (fewer compares) by inserting them from oldest to newest.
    NSEnumerator *enumerator = [newEntries reverseObjectEnumerator];
    while (WebHistoryItem *entry = [enumerator nextObject])
        [self addItem:entry discardDuplicate:NO];
}

#pragma mark DATE-BASED RETRIEVAL

- (NSArray *)orderedLastVisitedDays
{
    if (!_orderedLastVisitedDays) {
        Vector<int> daysAsTimeIntervals;
        daysAsTimeIntervals.reserveCapacity(_entriesByDate->size());
        DateToEntriesMap::const_iterator end = _entriesByDate->end();
        for (DateToEntriesMap::const_iterator it = _entriesByDate->begin(); it != end; ++it)
            daysAsTimeIntervals.append(it->first);

        std::sort(daysAsTimeIntervals.begin(), daysAsTimeIntervals.end());
        size_t count = daysAsTimeIntervals.size();
        _orderedLastVisitedDays = [[NSMutableArray alloc] initWithCapacity:count];
        for (int i = count - 1; i >= 0; i--) {
            NSTimeInterval interval = daysAsTimeIntervals[i];
            NSCalendarDate *date = [[NSCalendarDate alloc] initWithTimeIntervalSinceReferenceDate:interval];
            [_orderedLastVisitedDays addObject:date];
            [date release];
        }
    }
    return _orderedLastVisitedDays;
}

- (NSArray *)orderedItemsLastVisitedOnDay:(NSCalendarDate *)date
{
    WebHistoryDateKey dateKey;
    if (![self findKey:&dateKey forDay:[date timeIntervalSinceReferenceDate]])
        return nil;
    return _entriesByDate->get(dateKey).get();
}

#pragma mark URL MATCHING

- (WebHistoryItem *)itemForURLString:(NSString *)URLString
{
    return [_entriesByURL objectForKey:URLString];
}

- (BOOL)containsURL:(NSURL *)URL
{
    return [self itemForURLString:[URL _web_originalDataAsString]] != nil;