lxw_workbook_options Struct Reference

Workbook options. More...

Detailed Description

Optional parameters when creating a new Workbook object via workbook_new_opt().

The following properties are supported:

• constant_memory: This option reduces the amount of data stored in memory so that large files can be written efficiently. This option is off by default. See the notes below for limitations when this mode is on.
• tmpdir: libxlsxwriter stores workbook data in temporary files prior to assembling the final XLSX file. The temporary files are created in the system's temp directory. If the default temporary directory isn't accessible to your application, or doesn't contain enough space, you can specify an alternative location using the tmpdir option.
• use_zip64: Make the zip library use ZIP64 extensions when writing very large xlsx files to allow the zip container, or individual XML files within it, to be greater than 4 GB. See ZIP64 on Wikipedia for more information. This option is off by default.
• output_buffer: Output to a buffer instead of a file. The buffer must be freed manually by calling free(). This option can only be used if filename is NULL.
• output_buffer_size: Used with output_buffer to get the size of the created buffer. This option can only be used if filename is NULL.

Note

In constant_memory mode each row of in-memory data is written to disk and then freed when a new row is started via one of the worksheet_write_*() functions. Therefore, once this option is active data should be written in sequential row by row order. For this reason worksheet_merge_range() and some other row based functionality doesn't work in this mode. See Constant Memory Mode for more details.

Also, in constant_memory mode the library uses temp file storage for worksheet data. This can lead to an issue on OSes that map the /tmp directory into memory since it is possible to consume the "system" memory even though the "process" memory remains constant. In these cases you should use an alternative temp file location by using the tmpdir option shown above. See Constant memory mode and the /tmp directory for more details.

Examples

constant_memory.c, and output_buffer.c.

Data Fields
uint8_t	constant_memory
const char *	tmpdir
uint8_t	use_zip64
const char **	output_buffer
size_t *	output_buffer_size

Field Documentation

constant_memory

uint8_t lxw_workbook_options::constant_memory

Optimize the workbook to use constant memory for worksheets.

Examples

constant_memory.c.

tmpdir

const char* lxw_workbook_options::tmpdir

Directory to use for the temporary files created by libxlsxwriter.

use_zip64

uint8_t lxw_workbook_options::use_zip64

Allow ZIP64 extensions when creating the xlsx file zip container.

output_buffer

const char** lxw_workbook_options::output_buffer

Output buffer to use instead of writing to a file

Examples

output_buffer.c.

output_buffer_size

size_t* lxw_workbook_options::output_buffer_size

Used with output_buffer to get the size of the created buffer