FS_HasEnoughSpaceToCreateFile

Returns TRUE if the file with the specified path and size can be created with certainty, and FALSE otherwise.

Description

Calculates a theoretical value to determine whether a file of the specified pathname and size can be created in the space available.
This function calculates the theoretically required size, taking into account the number of clusters consumed in media that contain FAT structures, such as NAND archives and SD Card archives. In making the calculation, this function always assumes that the directory levels in the specified path consume one cluster each, regardless of whether directories at the levels actually exist.

The purpose of this function is to quickly determine whether a file can definitely be created, without taking the time to check the actual internal status of the drive. Therefore, there will be times when it would be possible to create the file, but the function returns FALSE because the calculation did not yield 100% certainty. If you require an exact determination and time is not a factor, use this function in combination with the FS_GetPathInfo function and omit the process of determining the size of existing directories.

To determine the Save Data size of a NAND application, also see the information about the Save Data Size List.

The archive information that is passed to this function as an argument must have been obtained in advance by calling the FS_GetArchiveResource function. If this function returns TRUE, the disk capacity that is expected based on the path and file size is reflected in the archive information, and the availableSize and availableClusters members are reduced. By reusing this archive information and repeatedly calling this function, you can determine whether an entire batch of multiple files can be created. An example of this usage is shown below.


 // First, get the current archive information. 
 FSArchiveResource   resource[1];
 if (FS_GetArchiveResource("sdmc:/", resource))
 {
 // Individually determine pathname and size of files you want to create.
BOOL    enough = TRUE;
 enough &= FS_HasEnoughSpaceToCreateFile(resource, "sdmc:/foo/file1.txt", 1000);
 enough &= FS_HasEnoughSpaceToCreateFile(resource, "sdmc:/bar/file2.txt", 10000);
 if (enough)
 {
 // If completely successful, there is enough space to create all of the specified files.
}
 }
 return retval;

This function immediately calculates the size that would logically be sufficient, without actually accessing the archive. As a result, if a path that actually indicates the same directory is specified several times, the size required to create that directory is counted multiple times. Directories consume a single cluster of capacity for each level, so the duplicated size will be extremely large if a deep path is specified. To avoid this kind of error, the common path component should be collectively called only once. An example of this usage is shown below.


 // Specifying "sdmc:/foo/bar", as follows, causes the size required to create it to be counted several times.
 //      enough &= FS_HasEnoughSpaceToCreateFile(resource, "sdmc:/foo/bar/file1.txt", 1000);
 //      enough &= FS_HasEnoughSpaceToCreateFile(resource, "sdmc:/foo/bar/file2.txt", 10000);
 //      enough &= FS_HasEnoughSpaceToCreateFile(resource, "sdmc:/foo/bar/file3.txt", 10);
 
 // To avoid duplicate size calculations, first test the common directory once.
enough &= FS_HasEnoughSpaceToCreateFile(resource, "sdmc:/foo/bar/", 0);
 // The rest can be omitted, assuming sdmc:/foo/bar/ exists.
 enough &= FS_HasEnoughSpaceToCreateFile(resource, "file1.txt", 1000);
 enough &= FS_HasEnoughSpaceToCreateFile(resource, "file2.txt", 10000);
 enough &= FS_HasEnoughSpaceToCreateFile(resource, "file3.txt", 10);

`resource`	Archive information that was obtained beforehand using the `FS_GetArchiveResource` function.
`path`	Pathname of the file you want to create. If a directory is to be created, you must append a forward slash (/) to the end of the entry. If you specify an empty string, it is taken to mean that the file already exists, and the pathname will be omitted.
`size`	Size of the file to create. Specify 0 when creating a directory.

FS_HasEnoughSpaceToCreateFile

Syntax

Arguments

Return Values

Description

See Also

Revision History