Files
MapLibreParticleLab/include/mbgl/storage/file_source.hpp
2023-02-12 14:45:06 +01:00

120 lines
4.1 KiB
C++

#pragma once
#include <mbgl/storage/resource_transform.hpp>
#include <mbgl/storage/response.hpp>
#include <mbgl/storage/resource_options.hpp>
#include <mbgl/util/client_options.hpp>
#include <mapbox/compatibility/value.hpp>
#include <functional>
#include <memory>
namespace mbgl {
class AsyncRequest;
class Resource;
// TODO: Rename to ResourceProviderType
enum FileSourceType : uint8_t {
Asset,
// TODO: split to separate types
// - Cache for fast KV store (FASTER, LevelDB, RocksDB)
// - Database for read-only offline use-cases
Database,
FileSystem,
Network,
Mbtiles,
ResourceLoader ///< %Resource loader acts as a proxy and has logic
/// for request delegation to Asset, Cache, and other
/// file sources.
};
// TODO: Rename to ResourceProvider to avoid confusion with
// GeoJSONSource, RasterSource, VectorSource, CustomGeometrySource and other *Sources.
class FileSource {
public:
FileSource& operator=(const FileSource&) = delete;
virtual ~FileSource() = default;
using Callback = std::function<void (Response)>;
/// Request a resource. The callback will be called asynchronously, in the same
/// thread as the request was made. This thread must have an active RunLoop. The
/// request may be cancelled before completion by releasing the returned AsyncRequest.
/// If the request is cancelled before the callback is executed, the callback will
/// not be executed.
virtual std::unique_ptr<AsyncRequest> request(const Resource&, Callback) = 0;
/// Allows to forward response from one source to another.
/// Optionally, callback can be provided to receive notification for forward
/// operation.
//
// NOLINTNEXTLINE(performance-unnecessary-value-param)
virtual void forward(const Resource&, const Response&, std::function<void()>) {}
/// When a file source supports consulting a local cache only, it must return true.
/// Cache-only requests are requests that aren't as urgent, but could be useful, e.g.
/// to cover part of the map while loading. The FileSource should only do cheap actions to
/// retrieve the data, e.g. load it from a cache, but not from the internet.
virtual bool supportsCacheOnlyRequests() const { return false; }
/// Checks whether a resource could be requested from this file source.
virtual bool canRequest(const Resource&) const = 0;
/**
* Pause file request activity.
*
* If pause is called then no revalidation or network request activity
* will occur.
*/
virtual void pause() {}
/**
* Resume file request activity.
*
* Calling resume will unpause the file source and process any tasks that
* expired while the file source was paused.
*/
virtual void resume() {}
/// Generic setter method
virtual void setProperty(const std::string&, const mapbox::base::Value&){};
/// Generic getter method
virtual mapbox::base::Value getProperty(const std::string&) const { return {}; };
/// When supported, sets the modifier of the requested resources.
virtual void setResourceTransform(ResourceTransform) {} // NOLINT(performance-unnecessary-value-param)
virtual void setResourceOptions(ResourceOptions) = 0;
virtual ResourceOptions getResourceOptions() = 0;
virtual void setClientOptions(ClientOptions) = 0;
virtual ClientOptions getClientOptions() = 0;
protected:
FileSource() = default;
};
// Properties that may be supported by online file sources:
/// Property name to set / get an access token.
/// type: std::string
constexpr const char* API_KEY_KEY = "api-tkey";
/// Property name to set / get base url.
/// type: std::string
constexpr const char* API_BASE_URL_KEY = "api-base-url";
/// Property name to set / get maximum number of concurrent requests.
/// type: unsigned
constexpr const char* MAX_CONCURRENT_REQUESTS_KEY = "max-concurrent-requests";
// Properties that may be supported by database file sources:
/// Property to set database mode. When set, database opens in read-only mode; database opens in read-write-create mode
/// otherwise. type: bool
constexpr const char* READ_ONLY_MODE_KEY = "read-only-mode";
} // namespace mbgl