Media Galleries: Initial media scanner implementation.

chrome/browser/media_galleries/fileapi/media_path_filter.cc

Index: chrome/browser/media_galleries/fileapi/media_path_filter.cc
===================================================================
--- chrome/browser/media_galleries/fileapi/media_path_filter.cc	(revision 247534)
+++ chrome/browser/media_galleries/fileapi/media_path_filter.cc	(working copy)
@@ -12,7 +12,7 @@
 
 namespace {
 
-const base::FilePath::CharType* const kExtraSupportedExtensions[] = {
+const base::FilePath::CharType* const kExtraSupportedImageExtensions[] = {
   // RAW picture file types.
   // Some of which are just image/tiff.
   FILE_PATH_LITERAL("3fr"),  // (Hasselblad)
@@ -45,8 +45,9 @@
   // - Leica / Panasonic RAW files - image/x-panasonic-raw
   // - Phase One RAW files - image/x-phaseone-raw
   FILE_PATH_LITERAL("raw"),
+};
 
-  // Video files types.
+const base::FilePath::CharType* const kExtraSupportedVideoExtensions[] = {
   FILE_PATH_LITERAL("3gp"),
   FILE_PATH_LITERAL("3gpp"),
   FILE_PATH_LITERAL("avi"),
@@ -58,9 +59,11 @@
   FILE_PATH_LITERAL("mpegps"),
   FILE_PATH_LITERAL("mpg"),
   FILE_PATH_LITERAL("wmv"),
+};
 
-  // Audio file types. Many of these file types are audio files in the same
-  // containers that the MIME sniffer already detects as video/subtype.
+const base::FilePath::CharType* const kExtraSupportedAudioExtensions[] = {
+  // Many of these file types are audio files in the same containers that the
+  // MIME sniffer already detects as video/subtype.
   FILE_PATH_LITERAL("aac"),   // audio/mpeg
   FILE_PATH_LITERAL("alac"),  // video/mp4
   FILE_PATH_LITERAL("flac"),  // audio/x-flac
@@ -86,10 +89,15 @@
 }
 
 bool MediaPathFilter::Match(const base::FilePath& path) {
+  return GetType(path) != MEDIA_GALLERY_SCAN_FILE_TYPE_UNKNOWN;
+}
+
+MediaGalleryScanFileType MediaPathFilter::GetType(const base::FilePath& path) {
   EnsureInitialized();
-  return std::binary_search(media_file_extensions_.begin(),
-                            media_file_extensions_.end(),
-                            StringToLowerASCII(path.Extension()));
+  MediaFileExtensionMap::const_iterator it =
+      media_file_extensions_map_.find(StringToLowerASCII(path.Extension()));
+  return (it == media_file_extensions_map_.end()) ?
+      MEDIA_GALLERY_SCAN_FILE_TYPE_UNKNOWN : it->second;
 }
 
 void MediaPathFilter::EnsureInitialized() {
@@ -97,26 +105,54 @@
   if (initialized_)
     return;
 
-  // This may require I/O, so doing this in the ctor and removing
-  // |initialized_| would result in a ThreadRestrictions failure.
-  net::GetExtensionsForMimeType("image/*", &media_file_extensions_);
-  net::GetExtensionsForMimeType("audio/*", &media_file_extensions_);
-  net::GetExtensionsForMimeType("video/*", &media_file_extensions_);
+  MediaFileExtensionList extensions_list;
 
-  MediaFileExtensionList::iterator new_end =
-      std::remove_if(media_file_extensions_.begin(),
-                     media_file_extensions_.end(),
-                     &IsUnsupportedExtension);
-  media_file_extensions_.erase(new_end, media_file_extensions_.end());
+  // This may require I/O when it calls net::GetExtensionsForMimeType(), so
+  // doing this in the ctor and removing |initialized_| would result in a
+  // ThreadRestrictions failure.
+  GetMediaExtensionList("image/*", &extensions_list);
+  for (size_t i = 0; i < arraysize(kExtraSupportedImageExtensions); ++i)

[vandebo (ex-Chrome), 2014/01/29 18:41:45]

nit: seems silly to add it to the list, just to iterate the list later.  Maybe
have both vector and array versions of AddExtensionosToMediaFileExtensionMap ?
or use vector_as_array from stl_util...

[Lei Zhang, 2014/01/30 00:10:49]

Done.

+    extensions_list.push_back(kExtraSupportedImageExtensions[i]);
+  AddExtensionsToMediaFileExtensionMap(extensions_list,
+                                       MEDIA_GALLERY_SCAN_FILE_TYPE_IMAGE);
+  extensions_list.clear();
+  GetMediaExtensionList("audio/*", &extensions_list);
+  for (size_t i = 0; i < arraysize(kExtraSupportedAudioExtensions); ++i)
+    extensions_list.push_back(kExtraSupportedAudioExtensions[i]);
+  AddExtensionsToMediaFileExtensionMap(extensions_list,
+                                       MEDIA_GALLERY_SCAN_FILE_TYPE_AUDIO);
+  extensions_list.clear();
+  GetMediaExtensionList("video/*", &extensions_list);
+  for (size_t i = 0; i < arraysize(kExtraSupportedVideoExtensions); ++i)
+    extensions_list.push_back(kExtraSupportedVideoExtensions[i]);
+  AddExtensionsToMediaFileExtensionMap(extensions_list,
+                                       MEDIA_GALLERY_SCAN_FILE_TYPE_VIDEO);
 
-  // Add other common extensions.
-  for (size_t i = 0; i < arraysize(kExtraSupportedExtensions); ++i)
-    media_file_extensions_.push_back(kExtraSupportedExtensions[i]);
+  initialized_ = true;
+}
 
-  for (MediaFileExtensionList::iterator itr = media_file_extensions_.begin();
-       itr != media_file_extensions_.end(); ++itr)
-    *itr = base::FilePath::kExtensionSeparator + *itr;
-  std::sort(media_file_extensions_.begin(), media_file_extensions_.end());
+// static
+void MediaPathFilter::GetMediaExtensionList(
+    const std::string& mime_type,
+    MediaFileExtensionList* extensions) {
+  DCHECK(extensions);
 
-  initialized_ = true;
+  net::GetExtensionsForMimeType(mime_type, extensions);
+  MediaFileExtensionList::iterator new_end =
+      std::remove_if(extensions->begin(),
+                     extensions->end(),
+                     &IsUnsupportedExtension);
+  extensions->erase(new_end, extensions->end());
 }
+
+void MediaPathFilter::AddExtensionsToMediaFileExtensionMap(
+    const MediaFileExtensionList& extensions,
+    MediaGalleryScanFileType type) {
+  for (size_t i = 0; i < extensions.size(); ++i) {
+    base::FilePath::StringType extension_with_sep =
+        base::FilePath::kExtensionSeparator + extensions[i];
+    // Overwriting is fine. It means the most recent caller gets priority for
+    // an ambiguous file extension.
+    media_file_extensions_map_[extension_with_sep] = type;
+  }
+}