Library: assetsys.h
#define ASSETSYS_IMPLEMENTATION
#include "libs/assetsys.h"
#include <stdio.h> // for printf
void list_assets( assetsys_t* assetsys, char const* path, int indent )
{
// Print folder names and recursively list assets
for( int i = 0; i < assetsys_subdir_count( assetsys, path ); ++i )
{
char const* subdir_name = assetsys_subdir_name( assetsys, path, i );
for( int j = 0; j < indent; ++j ) printf( " " );
printf( "%s/\n", subdir_name );
char const* subdir_path = assetsys_subdir_path( assetsys, path, i );
list_assets( assetsys, subdir_path, indent + 1 );
}
// Print file names
for( int i = 0; i < assetsys_file_count( assetsys, path ); ++i )
{
char const* file_name = assetsys_file_name( assetsys, path, i );
for( int j = 0; j < indent; ++j ) printf( " " );
printf( "%s\n", file_name );
}
}
int main( int, char** )
{
assetsys_t* assetsys = assetsys_create( 0 );
// Mount current working folder as a virtual "/data" path
assetsys_mount( assetsys, ".", "/data" );
// Print all files and subfolders
list_assets( assetsys, "/", 0 ); // Start at root
// Load a file
assetsys_file_t file;
assetsys_file( assetsys, "/data/readme.txt", &file );
int size = assetsys_file_size( assetsys, file );
char* content = (char*) malloc( size + 1 ); // extra space for '\0'
assetsys_file_load( assetsys, file, content );
content[ size ] = '\0'; // zero terminate the text file
printf( "%s\n", content );
free( content );
assetsys_destroy( assetsys );
}assetsys.h is a system for loading binary assets into your game. It allows you to mount directories and archive files
(bundles of files; assetsys.h supports using standard zip files for this) assign them a virtual path. You then load
assets through assetsys using the virtual path (which can stay the same even if the mounts change). assetsys.h is
case-insensitive regardless of platform, and only accepts forward slash "/" as path separator, to ensure consistent
behavior. It allows you to mount several paths or archive files to the same virtual path, even if they contain files of
the same name, and a later mount will take precedence over a previous one. This allows you to, for example, have a
data archive file and an update archive file, where update contains new versions of only some of the files.
assetsys.h is a single-header library, and does not need any .lib files or other binaries, or any build scripts. To use
it, you just include assetsys.h to get the API declarations. To get the definitions, you must include assetsys.h from
one single C or C++ file, and #define the symbol ASSETSYS_IMPLEMENTATION before you do.
assetsys.h has a dependency om another single-header library, strpool.h, which is used for efficient storage and comparison of the filename and path strings. assetsys.h automatically includes strpool.h, so it must reside in the same path. It does not specify the STRPOOL_IMPLEMENTATION define, on the assumption that you might be including strpool.h in some other part of your program. If you are not, you can make assetsys.h include the strpool implemention by doing:
#define ASSETSYS_IMPLEMENTATION
#define STRPOOL_IMPLEMENTATION
#include "assetsys.h"
There are a few different things in assetsys.h which are configurable by #defines. Most of the API use the int data
type, for integer values where the exact size is not important. However, for some functions, it specifically makes use
of an unsigned 64 bit data types. It default to using unsigned long long, but can be redefined by #defining
ASSETSYS_U64, before including assetsys.h. This is useful if you, for example, use the types from <stdint.h> in the
rest of your program, and you want assetsys.h to use compatible types. In this case, you would include assetsys.h using
the following code:
#define ASSETSYS_U64 uint64_t
#include "assetsys.h"
Note that when customizing the data type, you need to use the same definition in every place where you include assetsys.h, as they affect the declarations as well as the definitions.
The rest of the customizations only affect the implementation, so will only need to be defined in the file where you have the #define ASSETSYS_IMPLEMENTATION.
To store the internal data structures, ini.h needs to do dynamic allocation by calling malloc. Programs might want to
keep track of allocations done, or use custom defined pools to allocate memory from. assetsys.h allows for specifying
custom memory allocation functions for malloc and free. This is done with the following code:
#define ASSETSYS_IMPLEMENTATION
#define ASSETSYS_MALLOC( ctx, size ) ( my_custom_malloc( ctx, size ) )
#define ASSETSYS_FREE( ctx, ptr ) ( my_custom_free( ctx, ptr ) )
#include "assetsys.h"
where my_custom_malloc and my_custom_free are your own memory allocation/deallocation functions. The ctx parameter
is an optional parameter of type void*. When assetsys_init is called, you can set the memctx field of the config
parameter, to a pointer to anything you like, and which will be passed through as the ctx parameter to every
ASSETSYS_MALLOC/ASSETSYS_FREE call. For example, if you are doing memory tracking, you can pass a pointer to your
tracking data as memctx, and in your custom allocation/deallocation function, you can cast the ctx param back to the
right type, and access the tracking data.
If no custom allocator is defined, assetsys.h will default to malloc and free from the C runtime library.
assetsys.h makes use of asserts to report usage errors and code errors. By default, it makes use of the C runtime
library assert macro, which only executes in debug builds. However, it allows for substituting with your own assert
function or macro using the following code:
#define ASSETSYS_IMPLEMENTATION
#define ASSETSYS_ASSERT( condition ) ( my_custom_assert( condition ) )
#include "assetsys.h"
Note that if you only want the asserts to trigger in debug builds, you must add a check for this in your custom assert.
assetsys.h makes use of the miniz library for parsing and decompressing zip files. It includes the entire miniz source
code inside assetsys.h, so normally you don't have to worry about it. However, in the case where you might already be
using miniz in some other part of the program, you can tell assetsys.h to not include the implementation for miniz. It
will still include the miniz definitions, and if you don't include the miniz implementation elsewhere, you will get a
linker error. To exclude the miniz implementation, simply define ASSETSYS_NO_MINIZ before including assetsys.h, like
this:
#define ASSETSYS_IMPLEMENTATION
#define ASSETSYS_NO_MINIZ
#include "assetsys.h"
assetsys_t* assetsys_create( void* memctx )
Creates a new assetsys instance. assetsys.h does not use any global variables, all data it needs is accessed through the instance created by calling assetsys_create. Different instances can be used safely from different threads, but if using the same instance from multiple threads, it is up to the user to make sure functions are not called concurrently, for example by adding a mutex lock around each call.
void assetsys_destroy( assetsys_t* sys )
Destroys an assetsys instance, releasing all the resources used by it.
assetsys_error_t assetsys_mount( assetsys_t* sys, char const* path, char const* mount_as )
Mounts the data source path, making all its files accessible through this assetsys instance. The data source can be
either a folder or an archive file (a standard .zip file, with or without compression). path must be a relative path,
and must use forward slash / as path separator, never backslash, regardless of platform. It must not end with a path
separator. The string mount_as will be prepended to all mounted files, and can be passed as an empty string "" if
desired. mount_as may not contain the characters backslash \ or colon :. It must not end with a path separator.
assetsys_mount will return ASSETSYS_ERROR_INVALID_PARAMETER if either path or mount_as is NULL. It will return
ASSETSYS_ERROR_INVALID_PATH if the conditions detailed above are not met, or if the file or folder specified by path
could not be found. If path indicates a file, and it is not a valid archive file, assetsys_mount returns
ASSETSYS_ERROR_FAILED_TO_READ_ZIP.
If multiple mounts contains the same file and it is accessible through the same full path (whether because of the
mount_as prefix or not), the last mounted data source will be used when loading that file.
assetsys_error_t assetsys_dismount( assetsys_t* sys, char const* path, char const* mounted_as )
Removes a data source which was mounted by calling assetsys_mount. path and mounted_as must be the same as was
used when mounting. If path is NULL, assetsys_dismount returns ASSETSYS_ERROR_INVALID_PARAMETER. If mounted_as
is NULL, or no matching mount could be found, it returns ASSETSYS_ERROR_INVALID_MOUNT.
assetsys_error_t assetsys_file( assetsys_t* sys, char const* path, assetsys_file_t* file )
Retrieves a handle for the file specified by path. path needs to be an absolute path, including the mount_as
prefix specified when the data source was mounted, and matching is case insensitive. The mounts are searched in reverse
order they were added, and if a file with the specified path could not be found, assetsys_file returns
ASSETSYS_ERROR_FILE_NOT_FOUND. The handle is written to file, which must be a pointer to a assetsys_file_t
variable declared by the caller. The handle is used in calls to assetsys_file_load and assetsys_file_size. The
handle is only valid until any mounts are modified by calling assetsys_mount or assetsys_dismount.
assetsys_error_t assetsys_file_load( assetsys_t* sys, assetsys_file_t file, void* buffer )
Load the data from the file specified by the handle file (initialized by calling assetsys_file) and writes it into
the memory indicated by buffer. This memory buffer must be large enough to fit the entire file. To find out how large
the buffer needs to be, call assetsys_file_size. If the file could not be loaded, assetsys_file_load returns
ASSETSYS_ERROR_FAILED_TO_READ_FILE.
int assetsys_file_size( assetsys_t* sys, assetsys_file_t file )
Returns the size, in bytes, of the file specified by the handle file (initialized by calling assetsys_file). If the
file handle is not valid, assetsys_file_size returns 0.
int assetsys_file_count( assetsys_t* sys, char const* path )
Returns the number of files in the directory with the specified path, or 0 if the path is invalid. path needs to be an
absolute path, including the mount_as prefix specified when the data source was mounted, and matching is case
insensitive. assetsys_file_count returns the total number of files from all mounts, which fall under the path.
char const* assetsys_file_name( assetsys_t* sys, char const* path, int index )
Returns the filename and extension (but not the full path) of one of the files in the specified path. path needs to be
an absolute path, including the mount_as prefix specified when the data source was mounted, and matching is case
insensitive. index needs to be between 0 and one less than the count returned by calling assetsys_file_count with
the same path. If the path is invalid or index is out of range, assetsys_file_name returns NULL.
char const* assetsys_file_path( assetsys_t* sys, char const* path, int index )
Returns the full path, including filename and extension, of one of the files in the specified path. path needs to be
an absolute path, including the mount_as prefix specified when the data source was mounted, and matching is case
insensitive. index needs to be between 0 and one less than the count returned by calling assetsys_file_count with
the same path. If the path is invalid or index is out of range, assetsys_file_path returns NULL.
int assetsys_subdir_count( assetsys_t* sys, char const* path )
Returns the number of subdirectories in the directory with the specified path, or 0 if the path is invalid. path needs
to be an absolute path, including the mount_as prefix specified when the data source was mounted, and matching is case
insensitive. assetsys_subdir_count returns the total number of directories from all mounts, which fall under the path.
char const* assetsys_subdir_name( assetsys_t* sys, char const* path, int index )
Returns the name (but not the full path) of one of the subdirectories in the specified path. path needs to be an
absolute path, including the mount_as prefix specified when the data source was mounted, and matching is case
insensitive. index needs to be between 0 and one less than the count returned by calling assetsys_subdir_count with
the same path. If the path is invalid or index is out of range, assetsys_subdir_name returns NULL.
char const* assetsys_subdir_path( assetsys_t* sys, char const* path, int index )
Returns the name, including the full path, of one of the files in the specified path. path needs to be an absolute
path, including the mount_as prefix specified when the data source was mounted, and matching is case insensitive.
index needs to be between 0 and one less than the count returned by calling assetsys_subdir_count with the same
path. If the path is invalid or index is out of range, assetsys_subdir_path returns NULL.