Initial commit

2017-08-15 16:59:01 +08:00
commit bdc83e07ef
5766 changed files with 423223 additions and 0 deletions
@@ -0,0 +1,140 @@
+/*
+ * This file is part of the SDWebImage package.
+ * (c) Olivier Poitrey <rs@dailymotion.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+#import "SDWebImagePrefetcher.h"
+
+@interface SDWebImagePrefetcher ()
+
+@property (strong, nonatomic) SDWebImageManager *manager;
+@property (strong, nonatomic) NSArray *prefetchURLs;
+@property (assign, nonatomic) NSUInteger requestedCount;
+@property (assign, nonatomic) NSUInteger skippedCount;
+@property (assign, nonatomic) NSUInteger finishedCount;
+@property (assign, nonatomic) NSTimeInterval startedTime;
+@property (copy, nonatomic) SDWebImagePrefetcherCompletionBlock completionBlock;
+@property (copy, nonatomic) SDWebImagePrefetcherProgressBlock progressBlock;
+
+@end
+
+@implementation SDWebImagePrefetcher
+
+ (SDWebImagePrefetcher *)sharedImagePrefetcher {
+    static dispatch_once_t once;
+    static id instance;
+    dispatch_once(&once, ^{
+        instance = [self new];
+    });
+    return instance;
+}
+
+- (id)init {
+    return [self initWithImageManager:[SDWebImageManager new]];
+}
+
+- (id)initWithImageManager:(SDWebImageManager *)manager {
+    if ((self = [super init])) {
+        _manager = manager;
+        _options = SDWebImageLowPriority;
+        _prefetcherQueue = dispatch_get_main_queue();
+        self.maxConcurrentDownloads = 3;
+    }
+    return self;
+}
+
+- (void)setMaxConcurrentDownloads:(NSUInteger)maxConcurrentDownloads {
+    self.manager.imageDownloader.maxConcurrentDownloads = maxConcurrentDownloads;
+}
+
+- (NSUInteger)maxConcurrentDownloads {
+    return self.manager.imageDownloader.maxConcurrentDownloads;
+}
+
+- (void)startPrefetchingAtIndex:(NSUInteger)index {
+    if (index >= self.prefetchURLs.count) return;
+    self.requestedCount++;
+    [self.manager downloadImageWithURL:self.prefetchURLs[index] options:self.options progress:nil completed:^(UIImage *image, NSError *error, SDImageCacheType cacheType, BOOL finished, NSURL *imageURL) {
+        if (!finished) return;
+        self.finishedCount++;
+
+        if (image) {
+            if (self.progressBlock) {
+                self.progressBlock(self.finishedCount,[self.prefetchURLs count]);
+            }
+        }
+        else {
+            if (self.progressBlock) {
+                self.progressBlock(self.finishedCount,[self.prefetchURLs count]);
+            }
+            // Add last failed
+            self.skippedCount++;
+        }
+        if ([self.delegate respondsToSelector:@selector(imagePrefetcher:didPrefetchURL:finishedCount:totalCount:)]) {
+            [self.delegate imagePrefetcher:self
+                            didPrefetchURL:self.prefetchURLs[index]
+                             finishedCount:self.finishedCount
+                                totalCount:self.prefetchURLs.count
+             ];
+        }
+        if (self.prefetchURLs.count > self.requestedCount) {
+            dispatch_async(self.prefetcherQueue, ^{
+                [self startPrefetchingAtIndex:self.requestedCount];
+            });
+        } else if (self.finishedCount == self.requestedCount) {
+            [self reportStatus];
+            if (self.completionBlock) {
+                self.completionBlock(self.finishedCount, self.skippedCount);
+                self.completionBlock = nil;
+            }
+            self.progressBlock = nil;
+        }
+    }];
+}
+
+- (void)reportStatus {
+    NSUInteger total = [self.prefetchURLs count];
+    if ([self.delegate respondsToSelector:@selector(imagePrefetcher:didFinishWithTotalCount:skippedCount:)]) {
+        [self.delegate imagePrefetcher:self
+               didFinishWithTotalCount:(total - self.skippedCount)
+                          skippedCount:self.skippedCount
+         ];
+    }
+}
+
+- (void)prefetchURLs:(NSArray *)urls {
+    [self prefetchURLs:urls progress:nil completed:nil];
+}
+
+- (void)prefetchURLs:(NSArray *)urls progress:(SDWebImagePrefetcherProgressBlock)progressBlock completed:(SDWebImagePrefetcherCompletionBlock)completionBlock {
+    [self cancelPrefetching]; // Prevent duplicate prefetch request
+    self.startedTime = CFAbsoluteTimeGetCurrent();
+    self.prefetchURLs = urls;
+    self.completionBlock = completionBlock;
+    self.progressBlock = progressBlock;
+
+    if (urls.count == 0) {
+        if (completionBlock) {
+            completionBlock(0,0);
+        }
+    } else {
+        // Starts prefetching from the very first image on the list with the max allowed concurrency
+        NSUInteger listCount = self.prefetchURLs.count;
+        for (NSUInteger i = 0; i < self.maxConcurrentDownloads && self.requestedCount < listCount; i++) {
+            [self startPrefetchingAtIndex:i];
+        }
+    }
+}
+
+- (void)cancelPrefetching {
+    self.prefetchURLs = nil;
+    self.skippedCount = 0;
+    self.requestedCount = 0;
+    self.finishedCount = 0;
+    [self.manager cancelAll];
+}
+
+@end