Upstream Chrome on iOS source code [1/11].

ios/chrome/app/spotlight/spotlight_util.mm

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#import "ios/chrome/app/spotlight/spotlight_util.h"
+
+#import <CoreSpotlight/CoreSpotlight.h>
+
+#include "base/metrics/histogram.h"
+#include "base/strings/sys_string_conversions.h"
+#include "ios/public/provider/chrome/browser/chrome_browser_provider.h"
+#include "ios/public/provider/chrome/browser/spotlight/spotlight_provider.h"
+#include "url/gurl.h"
+
+namespace {
+// This enum is used for Histogram. Items should not be removed or reordered and
+// this enum should be kept synced with histograms.xml.
+// The three states correspond to:
+// - SPOTLIGHT_UNSUPPORTED: Framework CoreSpotlight is not found and
+// [CSSearchableIndex class] returns nil.
+// - SPOTLIGHT_UNAVAILABLE: Framework is loaded but [CSSearchableIndex
+// isIndexingAvailable] return NO. Note: It is unclear if this state is
+// reachable (I could not find configuration where CoreSpotlight was loaded but
+// [CSSearchableIndex isIndexingAvailable] returned NO.
+// - SPOTLIGHT_AVAILABLE: Framework is loaded and [CSSearchableIndex
+// isIndexingAvailable] returns YES. Note: This does not mean the actual
+// indexing will happen. If the user disables Spotlight in the system settings,
+// [CSSearchableIndex isIndexingAvailable] still returns YES.
+enum Availability {
+  SPOTLIGHT_UNSUPPORTED = 0,
+  SPOTLIGHT_UNAVAILABLE,
+  SPOTLIGHT_AVAILABLE,
+  SPOTLIGHT_AVAILABILITY_COUNT
+};
+
+// Documentation says that failed deletion should be retried. Set a maximum
+// value to avoid infinite loop.
+const int kMaxDeletionAttempts = 5;
+
+// Execute blockName block with up to retryCount retries on error. Execute
+// callback when done.
+void DoWithRetry(BlockWithError callback,
+                 NSUInteger retryCount,
+                 void (^blockName)(BlockWithError error)) {
+  BlockWithError retryCallback = ^(NSError* error) {
+    if (error && retryCount > 0) {
+      DoWithRetry(callback, retryCount - 1, blockName);
+    } else {
+      if (callback) {
+        callback(error);
+      }
+    }
+  };
+  blockName(retryCallback);
+}
+
+// Execute blockName block with up to kMaxDeletionAttempts retries on error.
+// Execute callback when done.
+void DoWithRetry(BlockWithError completion,
+                 void (^blockName)(BlockWithError error)) {
+  DoWithRetry(completion, kMaxDeletionAttempts, blockName);
+}
+
+}  // namespace
+
+namespace spotlight {
+
+// NSUserDefaults key of entry containing date of the latest bookmarks indexing.
+const char kSpotlightLastIndexingDateKey[] = "SpotlightLastIndexingDate";
+
+// NSUserDefault key of entry containing Chrome version of the latest bookmarks
+// indexing.
+const char kSpotlightLastIndexingVersionKey[] = "SpotlightLastIndexingVersion";
+
+// The current version of the Spotlight index format.
+// Change this value if there are change int the information indexed in
+// Spotlight. This will force reindexation on next startup.
+// Value is stored in |kSpotlightLastIndexingVersionKey|.
+const int kCurrentSpotlightIndexVersion = 2;
+
+Domain SpotlightDomainFromString(NSString* domain) {
+  SpotlightProvider* provider =
+      ios::GetChromeBrowserProvider()->GetSpotlightProvider();
+  if ([domain hasPrefix:[provider->GetBookmarkDomain()
+                            stringByAppendingString:@"."]]) {
+    return DOMAIN_BOOKMARKS;
+  } else if ([domain hasPrefix:[provider->GetTopSitesDomain()
+                                   stringByAppendingString:@"."]]) {
+    return DOMAIN_TOPSITES;
+  } else if ([domain hasPrefix:[provider->GetActionsDomain()
+                                   stringByAppendingString:@"."]]) {
+    return DOMAIN_ACTIONS;
+  }
+  // On normal flow, it is not possible to reach this point. When testing the
+  // app, it may be possible though if the app is downgraded.
+  NOTREACHED();
+  return DOMAIN_UNKNOWN;
+}
+
+NSString* StringFromSpotlightDomain(Domain domain) {
+  SpotlightProvider* provider =
+      ios::GetChromeBrowserProvider()->GetSpotlightProvider();
+  switch (domain) {
+    case DOMAIN_BOOKMARKS:
+      return provider->GetBookmarkDomain();
+    case DOMAIN_TOPSITES:
+      return provider->GetTopSitesDomain();
+    case DOMAIN_ACTIONS:
+      return provider->GetActionsDomain();
+    default:
+      // On normal flow, it is not possible to reach this point. When testing
+      // the app, it may be possible though if the app is downgraded.
+      NOTREACHED();
+      return nil;
+  }
+}
+
+void DeleteItemsWithIdentifiers(NSArray* items, BlockWithError callback) {
+  void (^deleteItems)(BlockWithError) = ^(BlockWithError errorBlock) {
+    [[CSSearchableIndex defaultSearchableIndex]
+        deleteSearchableItemsWithIdentifiers:items
+                           completionHandler:errorBlock];
+  };
+
+  DoWithRetry(callback, deleteItems);
+}
+
+void DeleteSearchableDomainItems(Domain domain, BlockWithError callback) {
+  void (^deleteItems)(BlockWithError) = ^(BlockWithError errorBlock) {
+    [[CSSearchableIndex defaultSearchableIndex]
+        deleteSearchableItemsWithDomainIdentifiers:@[ StringFromSpotlightDomain(
+                                                       domain) ]
+                                 completionHandler:errorBlock];
+  };
+
+  DoWithRetry(callback, deleteItems);
+}
+
+void ClearAllSpotlightEntries(BlockWithError callback) {
+  BlockWithError augmentedCallback = ^(NSError* error) {
+    [[NSUserDefaults standardUserDefaults]
+        removeObjectForKey:@(kSpotlightLastIndexingDateKey)];
+    if (callback) {
+      callback(error);
+    }
+  };
+
+  void (^deleteItems)(BlockWithError) = ^(BlockWithError errorBlock) {
+    [[CSSearchableIndex defaultSearchableIndex]
+        deleteAllSearchableItemsWithCompletionHandler:errorBlock];
+  };
+
+  DoWithRetry(augmentedCallback, deleteItems);
+}
+
+bool IsSpotlightAvailable() {
+  bool provided = ios::GetChromeBrowserProvider()
+                      ->GetSpotlightProvider()
+                      ->IsSpotlightEnabled();
+  if (!provided) {
+    // The product does not support Spotlight, do not go further.
+    return false;
+  }
+  bool loaded = !![CSSearchableIndex class];
+  bool available = loaded && [CSSearchableIndex isIndexingAvailable];
+  static dispatch_once_t once;
+  dispatch_once(&once, ^{
+    Availability availability = SPOTLIGHT_UNSUPPORTED;
+    if (loaded) {
+      availability = SPOTLIGHT_UNAVAILABLE;
+    }
+    if (available) {
+      availability = SPOTLIGHT_AVAILABLE;
+    }
+    UMA_HISTOGRAM_ENUMERATION("IOS.Spotlight.Availability", availability,
+                              SPOTLIGHT_AVAILABILITY_COUNT);
+  });
+  return loaded && available;
+}
+
+void ClearSpotlightIndexWithCompletion(BlockWithError completion) {
+  DCHECK(IsSpotlightAvailable());
+  ClearAllSpotlightEntries(completion);
+}
+
+NSString* GetSpotlightCustomAttributeItemID() {
+  return ios::GetChromeBrowserProvider()
+      ->GetSpotlightProvider()
+      ->GetCustomAttributeItemID();
+}
+
+void GetURLForSpotlightItemID(NSString* itemID, BlockWithNSURL completion) {
+  NSString* queryString =
+      [NSString stringWithFormat:@"%@ == \"%@\"",
+                                 GetSpotlightCustomAttributeItemID(), itemID];
+
+  CSSearchQuery* query =
+      [[CSSearchQuery alloc] initWithQueryString:queryString
+                                      attributes:@[ @"contentURL" ]];
+
+  [query setFoundItemsHandler:^(NSArray<CSSearchableItem*>* items) {
+    if ([items count] == 1) {
+      CSSearchableItem* searchableItem = [items objectAtIndex:0];
+      if (searchableItem) {
+        completion([[searchableItem attributeSet] contentURL]);
+        return;
+      }
+    }
+    completion(nil);
+
+  }];
+
+  [query start];
+}
+
+}  // namespace spotlight