- Created by Mike McGreevy, last modified by Barbara Jones on Jan 10, 2020
H5LT_OPEN_FILE_IMAGE
Opens an HDF5 file image in memory.
Procedure:
H5LT_OPEN_FILE_IMAGE (buf_ptr, buf_size, flags)
Signature:
hid_t H5LTopen_file_image( void *buf_ptr, size_t buf_size, unsigned flags )
Parameters:
void *buf_ptr | IN: A pointer to the supplied initial image A value of |
size_t buf_size | IN: Size of the supplied buffer A value of 0 is invalid and will cause the function to fail. |
unsigned flags | IN: Flags specifying whether to open the image read-only or read/write, whether HDF5 is to take control of the buffer, and instruction regarding releasing the buffer Valid values are: H5LT_FILE_IMAGE_OPEN_RWSpecifies opening the file image in read/write mode.Default without this flag: File image will be opened read-only.H5LT_FILE_IMAGE_DONT_COPYSpecifies to not copy the provided file image buffer; the buffer will be used directly. HDF5 will release the file image when finished.Default without this flag: Copy the file image buffer and open the copied file image.H5LT_FILE_IMAGE_DONT_RELEASESpecifies that HDF5 is not to release the buffer when the file opened withH5LTopen_file_image is closed; releasing the buffer will be left to the application.Default without this flag: HDF5 will automatically release the file image buffer after the file image is closed.This flag is valid only when used with H5LT_FILE_IMAGE_DONT_COPY. |
Description:
Motivation:
H5LT_OPEN_FILE_IMAGE and other elements of HDF5 are used to load an image of an HDF5 file into system memory and open that image as a regular HDF5 file. An application can then use the file without the overhead of disk I/O.
H5LT_OPEN_FILE_IMAGE opens the HDF5 file image that is located in system memory at the address indicated by buf_ptr of size buf_size. H5LT_OPEN_FILE_IMAGE opens a file image with the Core driver, H5FD_CORE.
The flags passed in flags specify whether to open the image read-only or read/write, whether HDF5 is to take control of the buffer, and instruction regarding releasing the buffer.
Recommended Reading:
This function is part of the file image operations feature set. It is highly recommended to study the guide “HDF5 File Image Operations” before using this feature set.
See the “See Also” section below for links to other elements of HDF5 file image operations.
Returns:
Returns a file identifier if successful; otherwise returns a negative value.
Failure Modes:
H5LT_OPEN_FILE_IMAGE will fail if either buf_ptr is NULL or buf_size equals 0 (zero).
Example:
/* attempt to set file image in the core driver */
file_id[i] = H5LTopen_file_image(buf_ptr[i], (size_t)buf_size[i], input_flags[i]);
History:
| Release | Change |
|---|---|
| 1.8.9 | C function introduced in this release. |
--- Last Modified: January 10, 2020 | 11:30 AM