[core] Modularize FileSource codebase (#15768)

* [core] Introduce FileSourceManager and use it for default platform impl

  - Add `FileSourceManager` interface that provides access to `FileSource`
    instances and means of registering / unregistering `FileSource` factories
  - Split `DefaultFileSource` into smaller parts
  - Add `DatabaseFileSource` interface and it's default implementation
  - Remove inter-dependencies between concrete `FileSource` classes

* [build] Add files to next build system

* [core] Add generic property setters / getters

* [core] Remove setOnlineStatus from OnlineFileSource interface

* [core] Hide threading implementation details from DatabaseFileSource interface

* [core] Make DB file source methods virtual

* [core] Add documentation for DatabaseFileSource and rename one method

* [core] Use simple callback instead of ActorRef

* [core] Remove ActorRef from OnlineFileSource public header

* [core] Add callback to FileSource::forward async API

* [core] Pass OfflineRegionDefinition by value

* [core] Update tests to use modular file sources

* [core] Update unit tests

* [core] Update unit tests after rebase

* [core] Backport low prio fix for cached requests

* [core] Backport pack database

* [core] Return removed factory from unRegisterFileSourceFactory

* [core] Rename shadowed args in onlinefilesource

* [core] Remove simple std::function callback aliases

* [core] Expose online file source property keys in public header file

* [test-runner] Add proxy file source test runner

* [cache] Update mbgl-cache utility to use new file source

* [metrics] Rebaseline binary size metrics

* [offline] Update offline utility

* [core] Update changelog

1 files changed, 17 insertions, 7 deletions

diff --git a/platform/default/src/mbgl/storage/local_file_source.cpp b/platform/default/src/mbgl/storage/local_file_source.cpp
index ca2eedc7ba..54f12baf79 100644
--- a/platform/default/src/mbgl/storage/local_file_source.cpp
+++ b/platform/default/src/mbgl/storage/local_file_source.cpp
@@ -1,15 +1,17 @@
-#include <mbgl/storage/local_file_source.hpp>
 #include <mbgl/storage/file_source_request.hpp>
 #include <mbgl/storage/local_file_request.hpp>
+#include <mbgl/storage/local_file_source.hpp>
+#include <mbgl/storage/resource.hpp>
 #include <mbgl/storage/response.hpp>
+#include <mbgl/util/constants.hpp>
 #include <mbgl/util/string.hpp>
 #include <mbgl/util/thread.hpp>
 #include <mbgl/util/url.hpp>
 
 namespace {
-
-const std::string fileProtocol = "file://";
-
+bool acceptsURL(const std::string& url) {
+    return 0 == url.rfind(mbgl::util::FILE_PROTOCOL, 0);
+}
 } // namespace
 
 namespace mbgl {
@@ -28,7 +30,7 @@ public:
         }
 
         // Cut off the protocol and prefix with path.
-        const auto path = mbgl::util::percentDecode(url.substr(fileProtocol.size()));
+        const auto path = mbgl::util::percentDecode(url.substr(std::char_traits<char>::length(util::FILE_PROTOCOL)));
         requestLocalFile(path, std::move(req));
     }
 };
@@ -47,8 +49,16 @@ std::unique_ptr<AsyncRequest> LocalFileSource::request(const Resource& resource,
     return std::move(req);
 }
 
-bool LocalFileSource::acceptsURL(const std::string& url) {
-    return 0 == url.rfind(fileProtocol, 0);
+bool LocalFileSource::canRequest(const Resource& resource) const {
+    return acceptsURL(resource.url);
+}
+
+void LocalFileSource::pause() {
+    impl->pause();
+}
+
+void LocalFileSource::resume() {
+    impl->resume();
 }
 
 } // namespace mbgl