From 7b02207537d35bfa1714bf8beafc921f717d100a Mon Sep 17 00:00:00 2001
From: 单军华
Date: Wed, 11 Jul 2018 10:47:42 +0800
Subject: [PATCH] 首次上传
---
screendisplay/Pods/SDWebImage/SDWebImage/SDWebImagePrefetcher.m | 144 ++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 144 insertions(+), 0 deletions(-)
diff --git a/screendisplay/Pods/SDWebImage/SDWebImage/SDWebImagePrefetcher.m b/screendisplay/Pods/SDWebImage/SDWebImage/SDWebImagePrefetcher.m
new file mode 100644
index 0000000..18c433e
--- /dev/null
+++ b/screendisplay/Pods/SDWebImage/SDWebImage/SDWebImagePrefetcher.m
@@ -0,0 +1,144 @@
+/*
+ * 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, nonnull) SDWebImageManager *manager;
+@property (strong, atomic, nullable) NSArray<NSURL *> *prefetchURLs; // may be accessed from different queue
+@property (assign, nonatomic) NSUInteger requestedCount;
+@property (assign, nonatomic) NSUInteger skippedCount;
+@property (assign, nonatomic) NSUInteger finishedCount;
+@property (assign, nonatomic) NSTimeInterval startedTime;
+@property (copy, nonatomic, nullable) SDWebImagePrefetcherCompletionBlock completionBlock;
+@property (copy, nonatomic, nullable) SDWebImagePrefetcherProgressBlock progressBlock;
+
+@end
+
+@implementation SDWebImagePrefetcher
+
++ (nonnull instancetype)sharedImagePrefetcher {
+ static dispatch_once_t once;
+ static id instance;
+ dispatch_once(&once, ^{
+ instance = [self new];
+ });
+ return instance;
+}
+
+- (nonnull instancetype)init {
+ return [self initWithImageManager:[SDWebImageManager new]];
+}
+
+- (nonnull instancetype)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 {
+ NSURL *currentURL;
+ @synchronized(self) {
+ if (index >= self.prefetchURLs.count) return;
+ currentURL = self.prefetchURLs[index];
+ self.requestedCount++;
+ }
+ [self.manager loadImageWithURL:currentURL options:self.options progress:nil completed:^(UIImage *image, NSData *data, NSError *error, SDImageCacheType cacheType, BOOL finished, NSURL *imageURL) {
+ if (!finished) return;
+ self.finishedCount++;
+
+ if (self.progressBlock) {
+ self.progressBlock(self.finishedCount,(self.prefetchURLs).count);
+ }
+ if (!image) {
+ // Add last failed
+ self.skippedCount++;
+ }
+ if ([self.delegate respondsToSelector:@selector(imagePrefetcher:didPrefetchURL:finishedCount:totalCount:)]) {
+ [self.delegate imagePrefetcher:self
+ didPrefetchURL:currentURL
+ finishedCount:self.finishedCount
+ totalCount:self.prefetchURLs.count
+ ];
+ }
+ if (self.prefetchURLs.count > self.requestedCount) {
+ dispatch_async(self.prefetcherQueue, ^{
+ // we need dispatch to avoid function recursion call. This can prevent stack overflow even for huge urls list
+ [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:(nullable NSArray<NSURL *> *)urls {
+ [self prefetchURLs:urls progress:nil completed:nil];
+}
+
+- (void)prefetchURLs:(nullable NSArray<NSURL *> *)urls
+ progress:(nullable SDWebImagePrefetcherProgressBlock)progressBlock
+ completed:(nullable 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 {
+ @synchronized(self) {
+ self.prefetchURLs = nil;
+ self.skippedCount = 0;
+ self.requestedCount = 0;
+ self.finishedCount = 0;
+ }
+ [self.manager cancelAll];
+}
+
+@end
--
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