Interface for asyncronous reading and writing of files in an <app-instance>.files folder. The file to be read/written is identified by a ulong64 id, which is converted to a filename with _sprintf(name, "%llu", id).
Note: currently the implementation is blocking, but could be changed to non-blocking without change to the app.
| File | common/interface/files.h |
| Public functions |
CreateFilesProvider CreateTempFilesProvider |
| Classes |
IFilesProvider IFiles IFilesWrite IFilesRead IFilesDel IFilesWrite ITempFilesProvider ITempFiles |
class IFilesProvider * CreateFilesProvider(class IIoMux * iomux);Function to allocate the FilesProvider resource, to be called from the app-main, so that the real FileProvider can be replaced by a unit-test implementation.
class ITempFilesProvider * CreateTempFilesProvider(class IIoMux * iomux);Function to allocate the TempFilesProvider Resource, to be called from the app-main, so that the read Fileprovider could be replaced by a unit-test implementation
class IFilesProvider {
public:
virtual ~IFilesProvider() {}
virtual class IFiles * CreateFiles(class IInstanceLog * const log, const char * serviceId, const char * path) = 0;
};Allocate the FilesProvider for a given instance. serviceId should be AppService->GetAppServiceId(), path should be the same as the dbName, it is used to create the actual path on the system for the files in the form /apps/<serviceId>/<dbName>.files, which is a folder created by the taskmanager for the app. log is used to log dependent of the log flag LOG_FILES.
class IFiles {
public:
virtual ~IFiles() {}
virtual class IFilesWrite * Write(class UTask * user, ulong64 id) = 0;
virtual class IFilesRead * Read(class UTask * user, ulong64 id, unsigned length, unsigned offset = 0, bool progress = false) = 0;
virtual class IFilesDel * Del(class UTask * user, ulong64 id) = 0;
};Interface class to initiate the read and write operations
Initiates a write operation. The allocated IFilesWrite class is derived from ITask, so the ITask/UTask mechanisms are used for progress and completion
Initiates a read operation. The allocated IFilesRead class is derived from ITask, so the ITask/UTask mechanisms are used for progress and completion. length is the length of the initial block, to be read. This block is available at the first TaskProgress callback. offset is the offset inside the file from which reading should start. progress indicates that a TaskProgress call should be used always when the data is available, even if this is the last data. In this case TaskComplete is called after the next read, when the file is closed.
Initiates a delete operation. The allocated IFilesDel class is derived from ITask, so the ITask/UTask mechanisms are used for completion.
class IFilesWrite : public ITask {
public:
virtual void Write(const byte * data, unsigned length, bool last) = 0;
virtual ulong64 GetId() const = 0;
virtual const char * GetAbsoluteFileName() const = 0;
virtual void Close() = 0;
};Write a block of data to the file. This function may be called in the TaskProgress callback or assynchronously after the first TaskProgress call. The passed buffer may be freed on return from the call. last indicates the last block of data, when set the file is closed and the task completes.
Returns the id of the file.
Returns the absolute path file name of the file, if needed for a command execution.
class IFilesRead : public ITask {
public:
virtual void Read(unsigned length, bool last) = 0;
virtual void Get(const byte * & data, unsigned & length) const = 0;
virtual void Close() = 0;
};Initiates reading of the next block. May be called after TaskProgress for the previous block.
Get a pointer to the read block of data. May be called after the TaskProgress for the read operation. The pointer is valid until the next call to Read. A length of 0 indicates the end of file.
Returns the absolute path file name of the file, if needed for a command execution.
class IFilesDel : public ITask {
public:
};
ITask class for a delete operation
class ITempFilesProvider {
public:
virtual ~ITempFilesProvider() {}
virtual class ITempFiles * CreateTempFiles(class IInstanceLog * const log, const char * serviceId, const char * path) = 0;
};Interface for asyncronous reading and writing of files in an <app-instance>.temp folder. The file to be read/written is identified by a ulong64 id, which is converted to a filename with _sprintf(name, "%llu", id).
Note: Currently the implementation is blocking, but could be changed to non-blocking without change to the app.
Allocate the TempFilesProvider for a given instance.
serviceId should be AppService->GetAppServiceId(), path should be the same as the dbName, it is used
to create the actual path on the system for the files in the form /apps/<serviceId>/<dbName>.temp, which
is a folder created by the taskmanager for the app.
log is used to log dependent of the log flag LOG_FILES.
class ITempFiles {
public:
virtual ~ITempFiles() {}
virtual class IFilesWrite * Write(class UTask * user) = 0;
virtual class IFilesRead * Read(class UTask * user, ulong64 id, unsigned length, unsigned offset = 0, bool progress = false) = 0;
virtual class IFilesDel * Del(class UTask * user, ulong64 id) = 0;
};Interface class to initiate the read and write operations. IFilesWrite, IFilesRead and IFilesDel are defined in files.htm
Initiates a write operation. The allocated IFilesWrite class is derived from ITask, so the ITask/UTask mechanisms are used for progress and completion
Initiates a read operation. The allocated IFilesRead class is derived from ITask, so the ITask/UTask mechanisms are used for progress and completion. length is the length of the initial block, to be read. This block is available at the first TaskProgress callback.
Initiates a delete operation. The allocated IFilesDel class is derived from ITask, so the ITask/UTask mechanisms are used for completion.