Load an array from a file. More...

Functions

AFAPI array readArray (const char *filename, const unsigned index)
 
AFAPI array readArray (const char *filename, const char *key)
 
AFAPI int readArrayCheck (const char *filename, const char *key)
 When reading by key, it may be a good idea to run this function first to check for the key and then call the readArray using the index. More...
 
AFAPI af_err af_read_array_index (af_array *out, const char *filename, const unsigned index)
 
AFAPI af_err af_read_array_key (af_array *out, const char *filename, const char *key)
 
AFAPI af_err af_read_array_key_check (int *index, const char *filename, const char *key)
 When reading by key, it may be a good idea to run this function first to check for the key and then call the readArray using the index. More...
 

Detailed Description

Load an array from a file.

The readArray function lets users read arrays saved in files. Arrays can either be read using the index in the file (0-indexed), or using the key that was used along with the Array.

Note that if there are multiple arrays with the same key, only the first one will be read.

The format of the file (version 1) is as follows:

Header:

Description Data Type Size (Bytes) Detailed Desc
Version Char 1 ArrayFire File Format Version for future use. Currently set to 1
Array Count Int 4 No. of Arrays stored in file

Per Array:

Description Data Type Size (Bytes) Detailed Desc
Length of Key String Int 4 No. of characters (excluding null ending) in the key string
Key Char [] length Key of the Array. Used when reading from file
Offset Int64 8 No of bytes between offset and start of next array
Array Type Char 1 Type corresponding to af_dtype enum
Dims (4 values) Int64 4 * 8 = 32 Dimensions of the Array
Data Type sizeof(Type) * dims.elements() Actual data of the array

The offset is equal to 1 byte (type) + 32 bytes (dims) + size of data.

An file with 2 arrays would look like (representative)

1
2
Array 1 Key Length
Array 1 Key
Array 1 Offset
Array 1 Type
Array 1 Dims
Array 1 Data
Array 2 Key Length
Array 2 Key
Array 2 Offset
Array 2 Type
Array 2 Dims
Array 2 Data


Function Documentation

◆ af_read_array_index()

AFAPI af_err af_read_array_index ( af_array out,
const char *  filename,
const unsigned  index 
)
Parameters
[out]outis the array read from index
[in]filenameis the path to the location on disk
[in]indexis the 0-based sequential location of the array to be read
Note
This function will throw an exception if the key is not found.

◆ af_read_array_key()

AFAPI af_err af_read_array_key ( af_array out,
const char *  filename,
const char *  key 
)
Parameters
[out]outis the array read from key
[in]filenameis the path to the location on disk
[in]keyis the tag/name of the array to be read. The key needs to have an exact match.
Note
This function will throw an exception if the key is not found.

◆ af_read_array_key_check()

AFAPI af_err af_read_array_key_check ( int *  index,
const char *  filename,
const char *  key 
)

When reading by key, it may be a good idea to run this function first to check for the key and then call the readArray using the index.

This will avoid exceptions in case of key not found.

Parameters
[out]indexof the array in the file if the key is found. -1 if key is not found.
[in]filenameis the path to the location on disk
[in]keyis the tag/name of the array to be read. The key needs to have an exact match.

◆ readArray() [1/2]

AFAPI array af::readArray ( const char *  filename,
const char *  key 
)
Parameters
[in]filenameis the path to the location on disk
[in]keyis the tag/name of the array to be read. The key needs to have an exact match.
Returns
array read by key
Note
This function will throw an exception if the key is not found.

◆ readArray() [2/2]

AFAPI array af::readArray ( const char *  filename,
const unsigned  index 
)
Parameters
[in]filenameis the path to the location on disk
[in]indexis the 0-based sequential location of the array to be read
Returns
array read from the index location
Note
This function will throw an exception if the index is out of bounds

◆ readArrayCheck()

AFAPI int af::readArrayCheck ( const char *  filename,
const char *  key 
)

When reading by key, it may be a good idea to run this function first to check for the key and then call the readArray using the index.

This will avoid exceptions in case of key not found.

Parameters
[in]filenameis the path to the location on disk
[in]keyis the tag/name of the array to be read. The key needs to have an exact match.
Returns
index of the array in the file if the key is found. -1 if key is not found.