Close() cancels any IO that may be pending, and closes the FileIO object.

Any pending callbacks will still run, reporting PP_ERROR_ABORTED if pending IO was interrupted. It is not valid to call Open() again after a call to this method. Note: If the FileIO object is destroyed, and it is still open, then it will be implicitly closed, so you are not required to call Close().

Parameters:

[in]

file_io

A PP_Resource corresponding to a file FileIO.

Create() creates a new FileIO object.

Parameters:

[in]

instance

A PP_Instance identifying the instance with the file.

Returns:

A PP_Resource corresponding to a FileIO if successful or 0 if the module is invalid.

Flush() flushes changes to disk.

This call can be very expensive! The FileIO object must have been opened with write access and there must be no other operations pending.

Parameters:

[in]	file_io	A PP_Resource corresponding to a file FileIO.
[in]	callback	A PP_CompletionCallback to be called upon completion of Flush().

Returns:

An int32_t containing an error code from pp_errors.h. PP_ERROR_FAILED will be returned if the file isn't opened, and PP_ERROR_INPROGRESS will be returned if there is another operation pending.

IsFileIO() determines if the provided resource is a FileIO.

Parameters:

[in]

resource

A PP_Resource corresponding to a FileIO.

Returns:

PP_TRUE if the resource is a PPB_FileIO, PP_FALSE if the resource is invalid or some type other than PPB_FileIO.

Open() opens the specified regular file for I/O according to the given open flags, which is a bit-mask of the PP_FileOpenFlags values.

Upon success, the corresponding file is classified as "in use" by this FileIO object until such time as the FileIO object is closed or destroyed.

Parameters:

[in]	file_io	A PP_Resource corresponding to a FileIO.
[in]	file_ref	A PP_Resource corresponding to a file reference.
[in]	open_flags	A bit-mask of the PP_FileOpenFlags values.
[in]	callback	A PP_CompletionCallback to be called upon completion of Open().

Returns:

An int32_t containing an error code from pp_errors.h.

Query() queries info about the file opened by this FileIO object.

The FileIO object must be opened, and there must be no other operations pending.

Parameters:

[in]	file_io	A PP_Resource corresponding to a FileIO.
[out]	info	The PP_FileInfo structure representing all information about the file.
[in]	callback	A PP_CompletionCallback to be called upon completion of Query(). info must remain valid until after the callback runs. If you pass a blocking callback, info must remain valid until after Query() returns.

Returns:

An int32_t containing an error code from pp_errors.h. PP_ERROR_FAILED will be returned if the file isn't opened, and PP_ERROR_INPROGRESS will be returned if there is another operation pending.

Read() reads from an offset in the file.

The size of the buffer must be large enough to hold the specified number of bytes to read. This function might perform a partial read, meaning all the requested bytes might not be returned, even if the end of the file has not been reached. The FileIO object must have been opened with read access.

ReadToArray() is preferred to Read() when doing asynchronous operations.

Parameters:

[in]	file_io	A PP_Resource corresponding to a file FileIO.
[in]	offset	The offset into the file.
[in]	buffer	The buffer to hold the specified number of bytes read.
[in]	bytes_to_read	The number of bytes to read from offset.
[in]	callback	A PP_CompletionCallback to be called upon completion of Read(). buffer must remain valid until after the callback runs. If you pass a blocking callback, buffer must remain valid until after Read() returns.

Returns:

The number of bytes read or an error code from pp_errors.h. If the return value is 0, then end-of-file was reached. It is valid to call Read() multiple times with a completion callback to queue up parallel reads from the file, but pending reads cannot be interleaved with other operations.

ReadToArray() reads from an offset in the file.

A PP_ArrayOutput must be provided so that output will be stored in its allocated buffer. This function might perform a partial read. The FileIO object must have been opened with read access.

Parameters:

[in]	file_io	A PP_Resource corresponding to a file FileIO.
[in]	offset	The offset into the file.
[in]	max_read_length	The maximum number of bytes to read from offset.
[in]	output	A PP_ArrayOutput to hold the output data.
[in]	callback	A PP_CompletionCallback to be called upon completion of ReadToArray().

Returns:

The number of bytes read or an error code from pp_errors.h. If the return value is 0, then end-of-file was reached. It is valid to call ReadToArray() multiple times with a completion callback to queue up parallel reads from the file, but pending reads cannot be interleaved with other operations.

SetLength() sets the length of the file.

If the file size is extended, then the extended area of the file is zero-filled. The FileIO object must have been opened with write access and there must be no other operations pending.

Parameters:

[in]	file_io	A PP_Resource corresponding to a file FileIO.
[in]	length	The length of the file to be set.
[in]	callback	A PP_CompletionCallback to be called upon completion of SetLength().

Returns:

An int32_t containing an error code from pp_errors.h. PP_ERROR_FAILED will be returned if the file isn't opened, and PP_ERROR_INPROGRESS will be returned if there is another operation pending.

Touch() Updates time stamps for the file opened by this FileIO object.

This function will fail if the FileIO object has not been opened. The FileIO object must be opened, and there must be no other operations pending.

Parameters:

[in]	file_io	A PP_Resource corresponding to a file FileIO.
[in]	last_access_time	The last time the FileIO was accessed.
[in]	last_modified_time	The last time the FileIO was modified.
[in]	callback	A PP_CompletionCallback to be called upon completion of Touch().

Returns:

An int32_t containing an error code from pp_errors.h. PP_ERROR_FAILED will be returned if the file isn't opened, and PP_ERROR_INPROGRESS will be returned if there is another operation pending.

Write() writes to an offset in the file.

This function might perform a partial write. The FileIO object must have been opened with write access.

Parameters:

[in]	file_io	A PP_Resource corresponding to a file FileIO.
[in]	offset	The offset into the file.
[in]	buffer	The buffer to hold the specified number of bytes read.
[in]	bytes_to_write	The number of bytes to write to offset.
[in]	callback	A PP_CompletionCallback to be called upon completion of Write().

Returns:

The number of bytes written or an error code from pp_errors.h. If the return value is 0, then end-of-file was reached. It is valid to call Write() multiple times with a completion callback to queue up parallel writes to the file, but pending writes cannot be interleaved with other operations.