Originally, I intended to add Storage API, StorageFile and StorageInfo
stubs. When I tried to implement a simple info() call, I ended up fixing
Request to contain some pointer field and all callbacks to have Request*
parameter. And, now I have to place callback pointer into Request. which
calls another callback.
And, eventually, these "simple" callbacks would again require another
pointer (to some caller class).
With ConnectionManager singleton one can start their Requests without
creating Storage instance. Moreover, Storage instance should contain
cloud API, not Requests-related handling and timer starting methods.
Thus, these methods were moved into ConnectionManager itself.
This commit adds:
* ConfMan's new "cloud" domain;
* CloudManager's init() method, where it loads keys from "cloud" configs
domain;
* CurlJsonRequest's addHeader() and addPostField() methods;
* temporary Storage's printInfo() method;
* DropboxStorage's implementation of printInfo(), which is using access
token and user id;
* DropboxStorage's loadFromConfig() static method to load access token
and user id from configs and create a Storage instance with those;
* temporary DropboxStorage's authThroughConsole() static method, which
guides user through auth process from the console.
So, in CloudManager's init() implementation ScummVM checks that there is
"current_storage_type" key in "cloud" domain of configs, and loads
corresponding storage if there is such key.
If there is no such key, ScummVM offers user to auth with Dropbox.
That's done through console, and thus it's temporary (it also requires
restarting ScummVM twice and manually editing config.ini file).
Now we can do REST API request by creating CurlJsonRequest and waiting
for it to call our callback. Passed pointer is Common::JSONValue.
This commit also does some minor variable renaming fixes.
Now it is based on MemoryReadWriteStream, which is introduced by this
commit. This stream is using ring buffer and is dynamically increasing
its size when necessary.
NetworkReadStream actually saves whole response in the memory now.
There is a pause mechanism in libcurl, but if libcurl is requesting
something compressed, it would have to uncompress data as it goes even
if we paused the request. Even though our own stream won't be notified
about this data when when "pause" the request, libcurl's own buffer
wound be expanding.
CurlRequest uses own multi_handle, in which it creates an easy_handle to
make a request.
Every time `handle()` is called it checks whether request is complete
and, if it is, stops.
This commit introduces Common::CloudManager, which can be accessed from
OSystem.
The backend for this manager is Cloud::Manager (defined in
backends/cloud/manager.h). It should load all users storages from
configs and provide access to current Storage instance. For now it just
creates a new one.
Cloud::Storage (backends/cloud/storage.h) provides an API to interact
with cloud storage, for example, create new directory or sync files.
Right now it's not ready and has only two dummy methods: listDirectory()
and syncSaves().
There is Cloud::Dropbox::DropboxStorage backend
(backends/cloud/dropbox/dropboxstorage.h) for Cloud::Storage. Right now
it implements both listDirectory() and syncSaves() with starting timer
task and handling it by printing out some JSON examples.
This commit also adds CloudThread class, which work() method is called
every second by TimerManager.
Right now it prints JSON examples on the console, so that's why it's
introduced with SimpleJSON library.
