[ios, macos] Offline storage size API

Added a property to MGLOfflineStorage that indicates the disk space occupied by all cached and offline resources.

Fixes #5580.

3 files changed, 25 insertions, 0 deletions

diff --git a/platform/darwin/src/MGLOfflineStorage.h b/platform/darwin/src/MGLOfflineStorage.h
index 20cc521f2e..211135f84f 100644
--- a/platform/darwin/src/MGLOfflineStorage.h
+++ b/platform/darwin/src/MGLOfflineStorage.h
@@ -217,6 +217,14 @@ typedef void (^MGLOfflinePackRemovalCompletionHandler)(NSError * _Nullable error
  */
 - (void)setMaximumAllowedMapboxTiles:(uint64_t)maximumCount;
 
+/**
+ The cumulative size, measured in bytes, of all downloaded resources on disk.
+ 
+ The returned value includes all resources, including tiles, whether downloaded
+ as part of an offline pack or due to caching during normal use of `MGLMapView`.
+ */
+@property (nonatomic, readonly) unsigned long long countOfBytesCompleted;
+
 @end
 
 NS_ASSUME_NONNULL_END
diff --git a/platform/darwin/src/MGLOfflineStorage.mm b/platform/darwin/src/MGLOfflineStorage.mm
index dd15920eab..dab870ea3b 100644
--- a/platform/darwin/src/MGLOfflineStorage.mm
+++ b/platform/darwin/src/MGLOfflineStorage.mm
@@ -275,6 +275,19 @@ NSString * const MGLOfflinePackMaximumCountUserInfoKey = @"MaximumCount";
     _mbglFileSource->setOfflineMapboxTileCountLimit(maximumCount);
 }
 
+#pragma mark -
+
+- (unsigned long long)countOfBytesCompleted {
+    NSURL *cacheURL = [[self class] cacheURLIncludingSubdirectory:YES];
+    NSString *cachePath = cacheURL.path;
+    if (!cachePath) {
+        return 0;
+    }
+    
+    NSDictionary *attributes = [[NSFileManager defaultManager] attributesOfItemAtPath:cachePath error:NULL];
+    return attributes.fileSize;
+}
+
 #pragma mark MGLOfflinePackDelegate methods
 
 - (void)offlinePack:(MGLOfflinePack *)pack progressDidChange:(__unused MGLOfflinePackProgress)progress {
diff --git a/platform/darwin/test/MGLOfflineStorageTests.m b/platform/darwin/test/MGLOfflineStorageTests.m
index e2346c5f61..e44bd06e3d 100644
--- a/platform/darwin/test/MGLOfflineStorageTests.m
+++ b/platform/darwin/test/MGLOfflineStorageTests.m
@@ -144,4 +144,8 @@
     XCTAssertEqual([MGLOfflineStorage sharedOfflineStorage].packs.count, countOfPacks - 1, @"Removed pack should have been removed from the canonical collection of packs owned by the shared offline storage object. This assertion can fail if this test is run before -testAAALoadPacks or -testAddPack.");
 }
 
+- (void)testCountOfBytesCompleted {
+    XCTAssertGreaterThan([MGLOfflineStorage sharedOfflineStorage].countOfBytesCompleted, 0);
+}
+
 @end