/* GIO - GLib Input, Output and Streaming Library
*
* Copyright © 2011 Red Hat, Inc
*
* SPDX-License-Identifier: LGPL-2.1-or-later
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General
* Public License along with this library; if not, see .
*
* Authors: Alexander Larsson
*/
#include "config.h"
#include
#include "gresource.h"
#include
#include
#include
#include
#include
#include
#include
#include
#include "glib-private.h"
struct _GResource
{
int ref_count;
GvdbTable *table;
};
static void register_lazy_static_resources (void);
G_DEFINE_BOXED_TYPE (GResource, g_resource, g_resource_ref, g_resource_unref)
/**
* GResource:
*
* Applications and libraries often contain binary or textual data that is
* really part of the application, rather than user data. For instance
* [`GtkBuilder`](https://docs.gtk.org/gtk4/class.Builder.html) `.ui` files,
* splashscreen images, [class@Gio.Menu] markup XML, CSS files, icons, etc.
* These are often shipped as files in `$datadir/appname`, or manually
* included as literal strings in the code.
*
* The `GResource` API and the
* [`glib-compile-resources`](glib-compile-resources.html) program provide a
* convenient and efficient alternative to this which has some nice properties.
* You maintain the files as normal files, so it’s easy to edit them, but during
* the build the files are combined into a binary bundle that is linked into the
* executable. This means that loading the resource files are efficient (as they
* are already in memory, shared with other instances) and simple (no need to
* check for things like I/O errors or locate the files in the filesystem). It
* also makes it easier to create relocatable applications.
*
* Resource files can also be marked as compressed. Such files will be included
* in the resource bundle in a compressed form, but will be automatically
* uncompressed when the resource is used. This is very useful e.g. for larger
* text files that are parsed once (or rarely) and then thrown away.
*
* Resource files can also be marked to be preprocessed, by setting the value of the
* `preprocess` attribute to a comma-separated list of preprocessing options.
* The only options currently supported are:
*
* - `xml-stripblanks` which will use the [`xmllint`](man:xmllint(1)) command
* to strip ignorable whitespace from the XML file. For this to work,
* the `XMLLINT` environment variable must be set to the full path to
* the xmllint executable, or xmllint must be in the `PATH`; otherwise
* the preprocessing step is skipped.
*
* - `to-pixdata` (deprecated since gdk-pixbuf 2.32) which will use the
* `gdk-pixbuf-pixdata` command to convert images to the [`GdkPixdata`](https://docs.gtk.org/gdk-pixbuf/class.Pixdata.html)
* format, which allows you to create pixbufs directly using the data inside
* the resource file, rather than an (uncompressed) copy of it. For this, the
* `gdk-pixbuf-pixdata` program must be in the `PATH`, or the
* `GDK_PIXBUF_PIXDATA` environment variable must be set to the full path to
* the `gdk-pixbuf-pixdata` executable; otherwise the resource compiler will
* abort. `to-pixdata` has been deprecated since gdk-pixbuf 2.32, as
* `GResource` supports embedding modern image formats just as well. Instead
* of using it, embed a PNG or SVG file in your `GResource`.
*
* - `json-stripblanks` which will use the
* [`json-glib-format`](man:json-glib-format(1)) command to strip ignorable
* whitespace from the JSON file. For this to work, the `JSON_GLIB_FORMAT`
* environment variable must be set to the full path to the
* `json-glib-format` executable, or it must be in the `PATH`; otherwise the
* preprocessing step is skipped. In addition, at least version 1.6 of
* `json-glib-format` is required.
*
* Resource files will be exported in the `GResource` namespace using the
* combination of the given `prefix` and the filename from the `file` element.
* The `alias` attribute can be used to alter the filename to expose them at a
* different location in the resource namespace. Typically, this is used to
* include files from a different source directory without exposing the source
* directory in the resource namespace, as in the example below.
*
* Resource bundles are created by the
* [`glib-compile-resources`](glib-compile-resources.html) program
* which takes an XML file that describes the bundle, and a set of files that
* the XML references. These are combined into a binary resource bundle.
*
* An example resource description:
* ```xml
*
*
*
* data/splashscreen.png
* dialog.ui
* menumarkup.xml
* data/example.css
*
*
* ```
*
* This will create a resource bundle with the following files:
* ```
* /org/gtk/Example/data/splashscreen.png
* /org/gtk/Example/dialog.ui
* /org/gtk/Example/menumarkup.xml
* /org/gtk/Example/example.css
* ```
*
* Note that all resources in the process share the same namespace, so use
* Java-style path prefixes (like in the above example) to avoid conflicts.
*
* You can then use [`glib-compile-resources`](glib-compile-resources.html) to
* compile the XML to a binary bundle that you can load with
* [func@Gio.Resource.load]. However, it’s more common to use the
* `--generate-source` and `--generate-header` arguments to create a source file
* and header to link directly into your application.
* This will generate `get_resource()`, `register_resource()` and
* `unregister_resource()` functions, prefixed by the `--c-name` argument passed
* to [`glib-compile-resources`](glib-compile-resources.html). `get_resource()`
* returns the generated `GResource` object. The register and unregister
* functions register the resource so its files can be accessed using
* [func@Gio.resources_lookup_data].
*
* Once a `GResource` has been created and registered all the data in it can be
* accessed globally in the process by using API calls like
* [func@Gio.resources_open_stream] to stream the data or
* [func@Gio.resources_lookup_data] to get a direct pointer to the data. You can
* also use URIs like `resource:///org/gtk/Example/data/splashscreen.png` with
* [iface@Gio.File] to access the resource data.
*
* Some higher-level APIs, such as [`GtkApplication`](https://docs.gtk.org/gtk4/class.Application.html),
* will automatically load resources from certain well-known paths in the
* resource namespace as a convenience. See the documentation for those APIs
* for details.
*
* There are two forms of the generated source, the default version uses the
* compiler support for constructor and destructor functions (where available)
* to automatically create and register the `GResource` on startup or library
* load time. If you pass `--manual-register`, two functions to
* register/unregister the resource are created instead. This requires an
* explicit initialization call in your application/library, but it works on all
* platforms, even on the minor ones where constructors are not supported.
* (Constructor support is available for at least Win32, Mac OS and Linux.)
*
* Note that resource data can point directly into the data segment of e.g. a
* library, so if you are unloading libraries during runtime you need to be very
* careful with keeping around pointers to data from a resource, as this goes
* away when the library is unloaded. However, in practice this is not generally
* a problem, since most resource accesses are for your own resources, and
* resource data is often used once, during parsing, and then released.
*
* # Overlays
*
* When debugging a program or testing a change to an installed version, it is
* often useful to be able to replace resources in the program or library,
* without recompiling, for debugging or quick hacking and testing purposes.
* Since GLib 2.50, it is possible to use the `G_RESOURCE_OVERLAYS` environment
* variable to selectively overlay resources with replacements from the
* filesystem. It is a `G_SEARCHPATH_SEPARATOR`-separated list of substitutions
* to perform during resource lookups. It is ignored when running in a setuid
* process.
*
* A substitution has the form
*
* ```
* /org/gtk/libgtk=/home/desrt/gtk-overlay
* ```
*
* The part before the `=` is the resource subpath for which the overlay
* applies. The part after is a filesystem path which contains files and
* subdirectories as you would like to be loaded as resources with the
* equivalent names.
*
* In the example above, if an application tried to load a resource with the
* resource path `/org/gtk/libgtk/ui/gtkdialog.ui` then `GResource` would check
* the filesystem path `/home/desrt/gtk-overlay/ui/gtkdialog.ui`. If a file was
* found there, it would be used instead. This is an overlay, not an outright
* replacement, which means that if a file is not found at that path, the
* built-in version will be used instead. Whiteouts are not currently
* supported.
*
* Substitutions must start with a slash, and must not contain a trailing slash
* before the `=`. The path after the slash should ideally be absolute, but
* this is not strictly required. It is possible to overlay the location of a
* single resource with an individual file.
*
* Since: 2.32
*/
/**
* GStaticResource:
*
* `GStaticResource` is an opaque data structure and can only be accessed
* using the following functions.
**/
typedef gboolean (* CheckCandidate) (const gchar *candidate, gpointer user_data);
static gboolean
open_overlay_stream (const gchar *candidate,
gpointer user_data)
{
GInputStream **res = (GInputStream **) user_data;
GError *error = NULL;
GFile *file;
file = g_file_new_for_path (candidate);
*res = (GInputStream *) g_file_read (file, NULL, &error);
if (*res)
{
g_message ("Opened file '%s' as a resource overlay", candidate);
}
else
{
if (!g_error_matches (error, G_IO_ERROR, G_IO_ERROR_NOT_FOUND))
g_warning ("Can't open overlay file '%s': %s", candidate, error->message);
g_error_free (error);
}
g_object_unref (file);
return *res != NULL;
}
static gboolean
get_overlay_bytes (const gchar *candidate,
gpointer user_data)
{
GBytes **res = (GBytes **) user_data;
GMappedFile *mapped_file;
GError *error = NULL;
mapped_file = g_mapped_file_new (candidate, FALSE, &error);
if (mapped_file)
{
g_message ("Mapped file '%s' as a resource overlay", candidate);
*res = g_mapped_file_get_bytes (mapped_file);
g_mapped_file_unref (mapped_file);
}
else
{
if (!g_error_matches (error, G_FILE_ERROR, G_FILE_ERROR_NOENT))
g_warning ("Can't mmap overlay file '%s': %s", candidate, error->message);
g_error_free (error);
}
return *res != NULL;
}
static gboolean
enumerate_overlay_dir (const gchar *candidate,
gpointer user_data)
{
GHashTable **hash = (GHashTable **) user_data;
GError *error = NULL;
GDir *dir;
const gchar *name;
dir = g_dir_open (candidate, 0, &error);
if (dir)
{
if (*hash == NULL)
/* note: keep in sync with same line below */
*hash = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, NULL);
g_message ("Enumerating directory '%s' as resource overlay", candidate);
while ((name = g_dir_read_name (dir)))
{
gchar *fullname = g_build_filename (candidate, name, NULL);
/* match gvdb behaviour by suffixing "/" on dirs */
if (g_file_test (fullname, G_FILE_TEST_IS_DIR))
g_hash_table_add (*hash, g_strconcat (name, "/", NULL));
else
g_hash_table_add (*hash, g_strdup (name));
g_free (fullname);
}
g_dir_close (dir);
}
else
{
if (!g_error_matches (error, G_FILE_ERROR, G_FILE_ERROR_NOENT))
g_warning ("Can't enumerate overlay directory '%s': %s", candidate, error->message);
g_error_free (error);
return FALSE;
}
/* We may want to enumerate results from more than one overlay
* directory.
*/
return FALSE;
}
typedef struct {
gsize size;
guint32 flags;
} InfoData;
static gboolean
get_overlay_info (const gchar *candidate,
gpointer user_data)
{
InfoData *info = user_data;
GStatBuf buf;
if (g_stat (candidate, &buf) < 0)
return FALSE;
info->size = buf.st_size;
info->flags = G_RESOURCE_FLAGS_NONE;
return TRUE;
}
static gboolean
g_resource_find_overlay (const gchar *path,
CheckCandidate check,
gpointer user_data)
{
/* This is a null-terminated array of replacement strings (with '=' inside) */
static const gchar * const *overlay_dirs;
gboolean res = FALSE;
size_t path_len = 0;
gint i;
/* We try to be very fast in case there are no overlays. Otherwise,
* we can take a bit more time...
*/
if (g_once_init_enter_pointer (&overlay_dirs))
{
gboolean is_setuid = GLIB_PRIVATE_CALL (g_check_setuid) ();
const gchar * const *result;
const gchar *envvar;
/* Don’t load overlays if setuid, as they could allow reading privileged
* files. */
envvar = !is_setuid ? g_getenv ("G_RESOURCE_OVERLAYS") : NULL;
if (envvar != NULL)
{
gchar **parts;
gint j;
parts = g_strsplit (envvar, G_SEARCHPATH_SEPARATOR_S, 0);
/* Sanity check the parts, dropping those that are invalid.
* 'i' may grow faster than 'j'.
*/
for (i = j = 0; parts[i]; i++)
{
gchar *part = parts[i];
gchar *eq;
eq = strchr (part, '=');
if (eq == NULL)
{
g_critical ("G_RESOURCE_OVERLAYS segment '%s' lacks '='. Ignoring.", part);
g_free (part);
continue;
}
if (eq == part)
{
g_critical ("G_RESOURCE_OVERLAYS segment '%s' lacks path before '='. Ignoring.", part);
g_free (part);
continue;
}
if (eq[1] == '\0')
{
g_critical ("G_RESOURCE_OVERLAYS segment '%s' lacks path after '='. Ignoring", part);
g_free (part);
continue;
}
if (part[0] != '/')
{
g_critical ("G_RESOURCE_OVERLAYS segment '%s' lacks leading '/'. Ignoring.", part);
g_free (part);
continue;
}
if (eq[-1] == '/')
{
g_critical ("G_RESOURCE_OVERLAYS segment '%s' has trailing '/' before '='. Ignoring", part);
g_free (part);
continue;
}
if (!g_path_is_absolute (eq + 1))
{
g_critical ("G_RESOURCE_OVERLAYS segment '%s' does not have an absolute path after '='. Ignoring", part);
g_free (part);
continue;
}
g_message ("Adding GResources overlay '%s'", part);
parts[j++] = part;
}
parts[j] = NULL;
result = (const gchar **) parts;
}
else
{
/* We go out of the way to avoid malloc() in the normal case
* where the environment variable is not set.
*/
static const gchar *const empty_strv[0 + 1] = { 0 };
result = empty_strv;
}
g_once_init_leave_pointer (&overlay_dirs, result);
}
for (i = 0; overlay_dirs[i]; i++)
{
const gchar *src;
size_t src_len;
const gchar *dst;
size_t dst_len;
gchar *candidate;
{
gchar *eq;
/* split the overlay into src/dst */
src = overlay_dirs[i];
eq = strchr (src, '=');
g_assert (eq); /* we checked this already */
src_len = eq - src;
dst = eq + 1;
/* hold off on dst_len because we will probably fail the checks below */
}
if (i == 0)
path_len = strlen (path);
/* The entire path is too short to match the source */
if (path_len < src_len)
continue;
/* It doesn't match the source */
if (memcmp (path, src, src_len) != 0)
continue;
/* The prefix matches, but it's not a complete path component */
if (path[src_len] && path[src_len] != '/')
continue;
/* OK. Now we need this. */
dst_len = strlen (dst);
/* The candidate will be composed of:
*
* dst + remaining_path + nul
*/
candidate = g_malloc (dst_len + (path_len - src_len) + 1);
memcpy (candidate, dst, dst_len);
memcpy (candidate + dst_len, path + src_len, path_len - src_len);
candidate[dst_len + (path_len - src_len)] = '\0';
/* No matter what, 'r' is what we need, including the case where
* we are trying to enumerate a directory.
*/
res = (* check) (candidate, user_data);
g_free (candidate);
if (res)
break;
}
return res;
}
/**
* g_resource_error_quark:
*
* Gets the [struct@Gio.Resource] Error Quark.
*
* Returns: a [type@GLib.Quark]
*
* Since: 2.32
*/
G_DEFINE_QUARK (g-resource-error-quark, g_resource_error)
/**
* g_resource_ref:
* @resource: A [struct@Gio.Resource]
*
* Atomically increments the reference count of @resource by one.
*
* This function is threadsafe and may be called from any thread.
*
* Returns: The passed in [struct@Gio.Resource]
*
* Since: 2.32
**/
GResource *
g_resource_ref (GResource *resource)
{
g_atomic_int_inc (&resource->ref_count);
return resource;
}
/**
* g_resource_unref:
* @resource: A [struct@Gio.Resource]
*
* Atomically decrements the reference count of @resource by one.
*
* If the reference count drops to 0, all memory allocated by the resource is
* released. This function is threadsafe and may be called from any
* thread.
*
* Since: 2.32
**/
void
g_resource_unref (GResource *resource)
{
if (g_atomic_int_dec_and_test (&resource->ref_count))
{
gvdb_table_free (resource->table);
g_free (resource);
}
}
/*< internal >
* g_resource_new_from_table:
* @table: (transfer full): a GvdbTable
*
* Returns: (transfer full): a new #GResource for @table
*/
static GResource *
g_resource_new_from_table (GvdbTable *table)
{
GResource *resource;
resource = g_new (GResource, 1);
resource->ref_count = 1;
resource->table = table;
return resource;
}
static void
g_resource_error_from_gvdb_table_error (GError **g_resource_error,
GError *gvdb_table_error /* (transfer full) */)
{
if (g_error_matches (gvdb_table_error, G_FILE_ERROR, G_FILE_ERROR_INVAL))
g_set_error_literal (g_resource_error,
G_RESOURCE_ERROR, G_RESOURCE_ERROR_INTERNAL,
gvdb_table_error->message);
else
g_propagate_error (g_resource_error, g_steal_pointer (&gvdb_table_error));
g_clear_error (&gvdb_table_error);
}
/**
* g_resource_new_from_data:
* @data: A [struct@GLib.Bytes]
* @error: return location for a [type@GLib.Error], or `NULL`
*
* Creates a [struct@Gio.Resource] from a reference to the binary resource bundle.
*
* This will keep a reference to @data while the resource lives, so
* the data should not be modified or freed.
*
* If you want to use this resource in the global resource namespace you need
* to register it with [func@Gio.resources_register].
*
* Note: @data must be backed by memory that is at least pointer aligned.
* Otherwise this function will internally create a copy of the memory since
* GLib 2.56, or in older versions fail and exit the process.
*
* If @data is empty or corrupt, %G_RESOURCE_ERROR_INTERNAL will be returned.
*
* Returns: (transfer full): a new [struct@Gio.Resource], or `NULL` on error
*
* Since: 2.32
**/
GResource *
g_resource_new_from_data (GBytes *data,
GError **error)
{
GvdbTable *table;
gboolean unref_data = FALSE;
GError *local_error = NULL;
if (((guintptr) g_bytes_get_data (data, NULL)) % sizeof (gpointer) != 0)
{
data = g_bytes_new (g_bytes_get_data (data, NULL),
g_bytes_get_size (data));
unref_data = TRUE;
}
table = gvdb_table_new_from_bytes (data, TRUE, &local_error);
if (unref_data)
g_bytes_unref (data);
if (table == NULL)
{
g_resource_error_from_gvdb_table_error (error, g_steal_pointer (&local_error));
return NULL;
}
return g_resource_new_from_table (table);
}
/**
* g_resource_load:
* @filename: (type filename): the path of a filename to load, in the GLib filename encoding
* @error: return location for a [type@GLib.Error], or `NULL`
*
* Loads a binary resource bundle and creates a [struct@Gio.Resource]
* representation of it, allowing you to query it for data.
*
* If you want to use this resource in the global resource namespace you need
* to register it with [func@Gio.resources_register].
*
* If @filename is empty or the data in it is corrupt,
* %G_RESOURCE_ERROR_INTERNAL will be returned. If @filename doesn’t exist, or
* there is an error in reading it, an error from [ctor@GLib.MappedFile.new]
* will be returned.
*
* Returns: (transfer full): a new [struct@Gio.Resource], or `NULL` on error
*
* Since: 2.32
**/
GResource *
g_resource_load (const gchar *filename,
GError **error)
{
GvdbTable *table;
GError *local_error = NULL;
table = gvdb_table_new (filename, FALSE, &local_error);
if (table == NULL)
{
g_resource_error_from_gvdb_table_error (error, g_steal_pointer (&local_error));
return NULL;
}
return g_resource_new_from_table (table);
}
static void
set_error_not_found (GError **error,
const char *path)
{
/* Avoid looking up the translation if it’s not going to be used. This is a hot path. */
if (error != NULL)
g_set_error (error, G_RESOURCE_ERROR, G_RESOURCE_ERROR_NOT_FOUND,
_("The resource at “%s” does not exist"),
path);
}
/* The only error this can return is %G_RESOURCE_ERROR_NOT_FOUND. */
static gboolean
do_lookup (GResource *resource,
const gchar *path,
GResourceLookupFlags lookup_flags,
gsize *size,
guint32 *flags,
const void **data,
gsize *data_size,
GError **error)
{
char *free_path = NULL;
gsize path_len;
gboolean res = FALSE;
GVariant *value;
/* Drop any trailing slash. */
path_len = strlen (path);
if (path_len >= 1 && path[path_len-1] == '/')
{
path = free_path = g_strdup (path);
free_path[path_len-1] = 0;
}
value = gvdb_table_get_raw_value (resource->table, path);
if (value == NULL)
{
set_error_not_found (error, path);
}
else
{
guint32 _size, _flags;
GVariant *array;
g_variant_get (value, "(uu@ay)",
&_size,
&_flags,
&array);
_size = GUINT32_FROM_LE (_size);
_flags = GUINT32_FROM_LE (_flags);
if (size)
*size = _size;
if (flags)
*flags = _flags;
if (data)
*data = g_variant_get_data (array);
if (data_size)
{
/* Don't report trailing newline that non-compressed files has */
if (_flags & G_RESOURCE_FLAGS_COMPRESSED)
*data_size = g_variant_get_size (array);
else
*data_size = g_variant_get_size (array) - 1;
}
g_variant_unref (array);
g_variant_unref (value);
res = TRUE;
}
g_free (free_path);
return res;
}
/**
* g_resource_open_stream:
* @resource: A [struct@Gio.Resource]
* @path: A path name inside the resource
* @lookup_flags: A [flags@Gio.ResourceLookupFlags]
* @error: return location for a [type@GLib.Error], or `NULL`
*
* Looks for a file at the specified @path in the resource and
* returns a [class@Gio.InputStream] that lets you read the data.
*
* @lookup_flags controls the behaviour of the lookup.
*
* The only error this can return is %G_RESOURCE_ERROR_NOT_FOUND, if @path was
* not found in @resource.
*
* Returns: (transfer full): [class@Gio.InputStream] or `NULL` on error
*
* Since: 2.32
**/
GInputStream *
g_resource_open_stream (GResource *resource,
const gchar *path,
GResourceLookupFlags lookup_flags,
GError **error)
{
const void *data;
gsize data_size;
guint32 flags;
GInputStream *stream, *stream2;
if (!do_lookup (resource, path, lookup_flags, NULL, &flags, &data, &data_size, error))
return NULL;
stream = g_memory_input_stream_new_from_data (data, data_size, NULL);
g_object_set_data_full (G_OBJECT (stream), "g-resource",
g_resource_ref (resource),
(GDestroyNotify)g_resource_unref);
if (flags & G_RESOURCE_FLAGS_COMPRESSED)
{
GZlibDecompressor *decompressor =
g_zlib_decompressor_new (G_ZLIB_COMPRESSOR_FORMAT_ZLIB);
stream2 = g_converter_input_stream_new (stream, G_CONVERTER (decompressor));
g_object_unref (decompressor);
g_object_unref (stream);
stream = stream2;
}
return stream;
}
static GBytes *resource_to_bytes (GResource *resource,
const char *path,
size_t size,
const void *data,
size_t data_size,
guint32 flags,
GError **error);
/**
* g_resource_lookup_data:
* @resource: A [struct@Gio.Resource]
* @path: A path name inside the resource
* @lookup_flags: A [flags@Gio.ResourceLookupFlags]
* @error: return location for a [type@GLib.Error], or `NULL`
*
* Looks for a file at the specified @path in the resource and
* returns a [struct@GLib.Bytes] that lets you directly access the data in
* memory.
*
* The data is always followed by a zero byte, so you
* can safely use the data as a C string. However, that byte
* is not included in the size of the [struct@GLib.Bytes].
*
* For uncompressed resource files this is a pointer directly into
* the resource bundle, which is typically in some read-only data section
* in the program binary. For compressed files, memory is allocated on
* the heap and the data is automatically uncompressed.
*
* @lookup_flags controls the behaviour of the lookup.
*
* This can return error %G_RESOURCE_ERROR_NOT_FOUND if @path was not found in
* @resource, or %G_RESOURCE_ERROR_INTERNAL if decompression of a compressed
* resource failed.
*
* Returns: (transfer full): [struct@GLib.Bytes] or `NULL` on error
*
* Since: 2.32
**/
GBytes *
g_resource_lookup_data (GResource *resource,
const gchar *path,
GResourceLookupFlags lookup_flags,
GError **error)
{
const void *data;
guint32 flags;
gsize data_size;
gsize size;
if (!do_lookup (resource, path, lookup_flags, &size, &flags, &data, &data_size, error))
return NULL;
return resource_to_bytes (resource, path, size, data, data_size, flags, error);
}
static GBytes *
resource_to_bytes (GResource *resource,
const char *path,
size_t size,
const void *data,
size_t data_size,
guint32 flags,
GError **error)
{
if (size == 0)
return g_bytes_new_with_free_func ("", 0, (GDestroyNotify) g_resource_unref, g_resource_ref (resource));
else if (flags & G_RESOURCE_FLAGS_COMPRESSED)
{
char *uncompressed, *d;
const char *s;
GConverterResult res;
gsize d_size, s_size;
gsize bytes_read, bytes_written;
GZlibDecompressor *decompressor =
g_zlib_decompressor_new (G_ZLIB_COMPRESSOR_FORMAT_ZLIB);
uncompressed = g_malloc (size + 1);
s = data;
s_size = data_size;
d = uncompressed;
d_size = size;
do
{
res = g_converter_convert (G_CONVERTER (decompressor),
s, s_size,
d, d_size,
G_CONVERTER_INPUT_AT_END,
&bytes_read,
&bytes_written,
NULL);
if (res == G_CONVERTER_ERROR)
{
g_free (uncompressed);
g_object_unref (decompressor);
g_set_error (error, G_RESOURCE_ERROR, G_RESOURCE_ERROR_INTERNAL,
_("The resource at “%s” failed to decompress"),
path);
return NULL;
}
s += bytes_read;
s_size -= bytes_read;
d += bytes_written;
d_size -= bytes_written;
}
while (res != G_CONVERTER_FINISHED);
uncompressed[size] = 0; /* Zero terminate */
g_object_unref (decompressor);
return g_bytes_new_take (uncompressed, size);
}
else
return g_bytes_new_with_free_func (data, data_size, (GDestroyNotify)g_resource_unref, g_resource_ref (resource));
}
/**
* g_resource_get_info:
* @resource: A [struct@Gio.Resource]
* @path: A path name inside the resource
* @lookup_flags: A [flags@Gio.ResourceLookupFlags]
* @size: (out) (optional): a location to place the length of the contents of the file,
* or `NULL` if the length is not needed
* @flags: (out) (optional): a location to place the flags about the file,
* or `NULL` if the length is not needed
* @error: return location for a [type@GLib.Error], or `NULL`
*
* Looks for a file at the specified @path in the resource and
* if found returns information about it.
*
* @lookup_flags controls the behaviour of the lookup.
*
* The only error this can return is %G_RESOURCE_ERROR_NOT_FOUND, if @path was
* not found in @resource.
*
* Returns: `TRUE` if the file was found, `FALSE` if there were errors
*
* Since: 2.32
**/
gboolean
g_resource_get_info (GResource *resource,
const gchar *path,
GResourceLookupFlags lookup_flags,
gsize *size,
guint32 *flags,
GError **error)
{
return do_lookup (resource, path, lookup_flags, size, flags, NULL, NULL, error);
}
static inline const char *
ensure_slash_suffix (const char *path,
char *local_str,
gsize len,
char **free_path)
{
gsize path_len;
path_len = strlen (path);
if G_UNLIKELY (path[path_len-1] != '/')
{
if (path_len < len - 2)
{
/*
* We got a path that does not have a trailing /. It is not the
* ideal use of this API as we require trailing / for our lookup
* into gvdb. Some degenerate application configurations can hit
* this code path quite a bit, so we try to avoid using the
* g_strconcat()/g_free().
*/
memcpy (local_str, path, path_len);
local_str[path_len] = '/';
local_str[path_len+1] = 0;
return local_str;
}
else
{
*free_path = g_strconcat (path, "/", NULL);
return *free_path;
}
}
else
{
return path;
}
}
/**
* g_resource_enumerate_children:
* @resource: A [struct@Gio.Resource]
* @path: A path name inside the resource
* @lookup_flags: A [flags@Gio.ResourceLookupFlags]
* @error: return location for a [type@GLib.Error], or `NULL`
*
* Returns all the names of children at the specified @path in the resource.
*
* The return result is a `NULL` terminated list of strings which should
* be released with [func@GLib.strfreev].
*
* If @path is invalid or does not exist in the [struct@Gio.Resource],
* %G_RESOURCE_ERROR_NOT_FOUND will be returned.
*
* @lookup_flags controls the behaviour of the lookup.
*
* Returns: (array zero-terminated=1) (transfer full): an array of constant strings
*
* Since: 2.32
**/
gchar **
g_resource_enumerate_children (GResource *resource,
const gchar *path,
GResourceLookupFlags lookup_flags,
GError **error)
{
/* Size of 256 is arbitrarily chosen based on being large enough
* for pretty much everything we come across, but not cumbersome
* on the stack. It also matches common cacheline sizes.
*/
gchar local_str[256];
const char *path_with_slash;
char *free_path = NULL;
gchar **children;
if (*path == 0)
{
set_error_not_found (error, path);
return NULL;
}
path_with_slash = ensure_slash_suffix (path, local_str, sizeof (local_str), &free_path);
children = gvdb_table_list (resource->table, path_with_slash);
g_free (free_path);
if (children == NULL)
{
set_error_not_found (error, path);
return NULL;
}
return children;
}
/**
* g_resource_has_children:
* @resource: A #GResource
* @path: A pathname inside the resource
*
* Returns whether the specified @path in the resource
* has children.
*
* Returns: %TRUE if @path has children
*
* Since: 2.84
*/
gboolean
g_resource_has_children (GResource *resource,
const char *path)
{
/* Size of 256 is arbitrarily chosen based on being large enough
* for pretty much everything we come across, but not cumbersome
* on the stack. It also matches common cacheline sizes.
*/
char local_str[256];
const char *path_with_slash;
guint n;
char *freeme = NULL;
if (*path == 0)
return FALSE;
path_with_slash = ensure_slash_suffix (path, local_str, sizeof (local_str), &freeme);
n = gvdb_table_n_children (resource->table, path_with_slash);
g_free (freeme);
return n > 0;
}
static GRWLock resources_lock;
static GList *registered_resources;
/* This is updated atomically, so we can append to it and check for NULL outside the
lock, but all other accesses are done under the write lock */
static GStaticResource *lazy_register_resources;
static void
g_resources_register_unlocked (GResource *resource)
{
registered_resources = g_list_prepend (registered_resources, g_resource_ref (resource));
}
static void
g_resources_unregister_unlocked (GResource *resource)
{
GList *resource_link = g_list_find (registered_resources, resource);
if (resource_link == NULL)
{
g_warning ("Tried to remove not registered resource");
}
else
{
g_resource_unref (resource_link->data);
registered_resources = g_list_delete_link (registered_resources, resource_link);
}
}
/**
* g_resources_register:
* @resource: A [struct@Gio.Resource]
*
* Registers the resource with the process-global set of resources.
*
* Once a resource is registered the files in it can be accessed
* with the global resource lookup functions like
* [func@Gio.resources_lookup_data].
*
* Since: 2.32
**/
void
g_resources_register (GResource *resource)
{
g_rw_lock_writer_lock (&resources_lock);
g_resources_register_unlocked (resource);
g_rw_lock_writer_unlock (&resources_lock);
}
/**
* g_resources_unregister:
* @resource: A [struct@Gio.Resource]
*
* Unregisters the resource from the process-global set of resources.
*
* Since: 2.32
**/
void
g_resources_unregister (GResource *resource)
{
g_rw_lock_writer_lock (&resources_lock);
g_resources_unregister_unlocked (resource);
g_rw_lock_writer_unlock (&resources_lock);
}
/**
* g_resources_open_stream:
* @path: A path name inside the resource
* @lookup_flags: A [flags@Gio.ResourceLookupFlags]
* @error: return location for a [type@GLib.Error], or `NULL`
*
* Looks for a file at the specified @path in the set of
* globally registered resources and returns a [class@Gio.InputStream]
* that lets you read the data.
*
* @lookup_flags controls the behaviour of the lookup.
*
* Returns: (transfer full): [class@Gio.InputStream] or `NULL` on error
*
* Since: 2.32
**/
GInputStream *
g_resources_open_stream (const gchar *path,
GResourceLookupFlags lookup_flags,
GError **error)
{
GInputStream *res = NULL;
GList *l;
GInputStream *stream;
if (g_resource_find_overlay (path, open_overlay_stream, &res))
return res;
register_lazy_static_resources ();
g_rw_lock_reader_lock (&resources_lock);
for (l = registered_resources; l != NULL; l = l->next)
{
GResource *r = l->data;
stream = g_resource_open_stream (r, path, lookup_flags, NULL);
if (stream == NULL)
{
/* g_resource_open_stream() guarantees it only fails with
* %G_RESOURCE_ERROR_NOT_FOUND */
}
else
{
res = stream;
break;
}
}
if (l == NULL)
set_error_not_found (error, path);
g_rw_lock_reader_unlock (&resources_lock);
return res;
}
/**
* g_resources_lookup_data:
* @path: A path name inside the resource
* @lookup_flags: A [flags@Gio.ResourceLookupFlags]
* @error: return location for a [type@GLib.Error], or `NULL`
*
* Looks for a file at the specified @path in the set of
* globally registered resources and returns a [struct@GLib.Bytes] that
* lets you directly access the data in memory.
*
* The data is always followed by a zero byte, so you
* can safely use the data as a C string. However, that byte
* is not included in the size of the [struct@GLib.Bytes].
*
* For uncompressed resource files this is a pointer directly into
* the resource bundle, which is typically in some read-only data section
* in the program binary. For compressed files we allocate memory on
* the heap and automatically uncompress the data.
*
* @lookup_flags controls the behaviour of the lookup.
*
* Returns: (transfer full): [struct@GLib.Bytes] or `NULL` on error
*
* Since: 2.32
**/
GBytes *
g_resources_lookup_data (const gchar *path,
GResourceLookupFlags lookup_flags,
GError **error)
{
GBytes *res = NULL;
GList *l;
if (g_resource_find_overlay (path, get_overlay_bytes, &res))
return res;
register_lazy_static_resources ();
g_rw_lock_reader_lock (&resources_lock);
for (l = registered_resources; l != NULL; l = l->next)
{
GResource *r = l->data;
const void *data;
guint32 flags;
gsize data_size;
gsize size;
/* This is essentially g_resource_lookup_data(), but split up so we can
* avoid allocating a #GError if the resource is not found. */
if (do_lookup (r, path, lookup_flags, &size, &flags, &data, &data_size, NULL))
{
res = resource_to_bytes (r, path, size, data, data_size, flags, error);
break;
}
}
if (l == NULL)
set_error_not_found (error, path);
g_rw_lock_reader_unlock (&resources_lock);
return res;
}
/**
* g_resources_enumerate_children:
* @path: A path name inside the resource
* @lookup_flags: A [flags@Gio.ResourceLookupFlags]
* @error: return location for a [type@GLib.Error], or `NULL`
*
* Returns all the names of children at the specified @path in the set of
* globally registered resources.
*
* The return result is a `NULL` terminated list of strings which should
* be released with [func@GLib.strfreev].
*
* @lookup_flags controls the behaviour of the lookup.
*
* Returns: (array zero-terminated=1) (transfer full): an array of constant strings
*
* Since: 2.32
**/
gchar **
g_resources_enumerate_children (const gchar *path,
GResourceLookupFlags lookup_flags,
GError **error)
{
GHashTable *hash = NULL;
GList *l;
char **children;
int i;
/* This will enumerate actual files found in overlay directories but
* will not enumerate the overlays themselves. For example, if we
* have an overlay "/org/gtk=/path/to/files" and we enumerate "/org"
* then we will not see "gtk" in the result set unless it is provided
* by another resource file.
*
* This is probably not going to be a problem since if we are doing
* such an overlay, we probably will already have that path.
*/
g_resource_find_overlay (path, enumerate_overlay_dir, &hash);
register_lazy_static_resources ();
g_rw_lock_reader_lock (&resources_lock);
for (l = registered_resources; l != NULL; l = l->next)
{
GResource *r = l->data;
children = g_resource_enumerate_children (r, path, 0, NULL);
if (children != NULL)
{
if (hash == NULL)
/* note: keep in sync with same line above */
hash = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, NULL);
for (i = 0; children[i] != NULL; i++)
g_hash_table_add (hash, children[i]);
g_free (children);
}
}
g_rw_lock_reader_unlock (&resources_lock);
if (hash == NULL)
{
set_error_not_found (error, path);
return NULL;
}
else
{
children = (gchar **) g_hash_table_get_keys_as_array (hash, NULL);
g_hash_table_steal_all (hash);
g_hash_table_destroy (hash);
return children;
}
}
/**
* g_resources_has_children:
* @path: A pathname
*
* Returns whether the specified @path in the set of
* globally registered resources has children.
*
* Returns: %TRUE if @patch has children
*
* Since: 2.84
*/
gboolean
g_resources_has_children (const char *path)
{
register_lazy_static_resources ();
g_rw_lock_reader_lock (&resources_lock);
for (GList *l = registered_resources; l != NULL; l = l->next)
{
GResource *r = l->data;
if (g_resource_has_children (r, path))
{
g_rw_lock_reader_unlock (&resources_lock);
return TRUE;
}
}
g_rw_lock_reader_unlock (&resources_lock);
return FALSE;
}
/**
* g_resources_get_info:
* @path: A path name inside the resource
* @lookup_flags: A [flags@Gio.ResourceLookupFlags]
* @size: (out) (optional): a location to place the length of the contents of the file,
* or `NULL` if the length is not needed
* @flags: (out) (optional): a location to place the [flags@Gio.ResourceFlags] about the file,
* or `NULL` if the flags are not needed
* @error: return location for a [type@GLib.Error], or `NULL`
*
* Looks for a file at the specified @path in the set of
* globally registered resources and if found returns information about it.
*
* @lookup_flags controls the behaviour of the lookup.
*
* Returns: `TRUE` if the file was found, `FALSE` if there were errors
*
* Since: 2.32
**/
gboolean
g_resources_get_info (const gchar *path,
GResourceLookupFlags lookup_flags,
gsize *size,
guint32 *flags,
GError **error)
{
gboolean res = FALSE;
GList *l;
InfoData info;
if (g_resource_find_overlay (path, get_overlay_info, &info))
{
if (size)
*size = info.size;
if (flags)
*flags = info.flags;
return TRUE;
}
register_lazy_static_resources ();
g_rw_lock_reader_lock (&resources_lock);
for (l = registered_resources; l != NULL; l = l->next)
{
GResource *r = l->data;
if (g_resource_get_info (r, path, lookup_flags, size, flags, NULL))
{
res = TRUE;
break;
}
}
if (l == NULL)
set_error_not_found (error, path);
g_rw_lock_reader_unlock (&resources_lock);
return res;
}
/* This code is to handle registration of resources very early, from a constructor.
* At that point we'd like to do minimal work, to avoid ordering issues. For instance,
* we're not allowed to use g_malloc, as the user need to be able to call g_mem_set_vtable
* before the first call to g_malloc.
*
* So, what we do at construction time is that we just register a static structure on
* a list of resources that need to be initialized, and then later, when doing any lookups
* in the global list of registered resources, or when getting a reference to the
* lazily initialized resource we lazily create and register all the GResources on
* the lazy list.
*
* To avoid having to use locks in the constructor, and having to grab the writer lock
* when checking the lazy registering list we update lazy_register_resources in
* a lock-less fashion (atomic prepend-only, atomic replace with NULL). However, all
* operations except:
* * check if there are any resources to lazily initialize
* * Add a static resource to the lazy init list
* Do use the full writer lock for protection.
*/
static void
register_lazy_static_resources_unlocked (void)
{
GStaticResource *list = g_atomic_pointer_get (&lazy_register_resources);
while (!g_atomic_pointer_compare_and_exchange_full (&lazy_register_resources, list, NULL, &list))
;
while (list != NULL)
{
GBytes *bytes = g_bytes_new_static (list->data, list->data_len);
GResource *resource = g_resource_new_from_data (bytes, NULL);
if (resource)
{
g_resources_register_unlocked (resource);
g_atomic_pointer_set (&list->resource, resource);
}
g_bytes_unref (bytes);
list = list->next;
}
}
static void
register_lazy_static_resources (void)
{
if (g_atomic_pointer_get (&lazy_register_resources) == NULL)
return;
g_rw_lock_writer_lock (&resources_lock);
register_lazy_static_resources_unlocked ();
g_rw_lock_writer_unlock (&resources_lock);
}
/**
* g_static_resource_init:
* @static_resource: pointer to a static [struct@Gio.StaticResource]
*
* Initializes a [struct@Gio.Resource] from static data using a
* [struct@Gio.StaticResource].
*
* This is normally used by code generated by
* [`glib-compile-resources`](glib-compile-resources.html)
* and is not typically used by other code.
*
* Since: 2.32
**/
void
g_static_resource_init (GStaticResource *static_resource)
{
GStaticResource *next;
g_return_if_fail (static_resource != NULL);
g_return_if_fail (static_resource->next == NULL);
g_return_if_fail (static_resource != g_atomic_pointer_get (&lazy_register_resources));
do
{
next = g_atomic_pointer_get (&lazy_register_resources);
static_resource->next = next;
}
while (!g_atomic_pointer_compare_and_exchange (&lazy_register_resources, next, static_resource));
}
/**
* g_static_resource_fini:
* @static_resource: pointer to a static [struct@Gio.StaticResource]
*
* Finalizes a [struct@Gio.Resource] initialized by
* [method@Gio.StaticResource.init].
*
* This is normally used by code generated by
* [`glib-compile-resources`](glib-compile-resources.html)
* and is not typically used by other code.
*
* Since: 2.32
**/
void
g_static_resource_fini (GStaticResource *static_resource)
{
GResource *resource;
g_rw_lock_writer_lock (&resources_lock);
register_lazy_static_resources_unlocked ();
resource = g_atomic_pointer_exchange (&static_resource->resource, NULL);
if (resource)
{
/* There should be at least two references to the resource now: one for
* static_resource->resource, and one in the registered_resources list. */
g_assert (g_atomic_int_get (&resource->ref_count) >= 2);
g_resources_unregister_unlocked (resource);
g_resource_unref (resource);
}
g_rw_lock_writer_unlock (&resources_lock);
}
/**
* g_static_resource_get_resource:
* @static_resource: pointer to a static [struct@Gio.StaticResource]
*
* Gets the [struct@Gio.Resource] that was registered by a call to
* [method@Gio.StaticResource.init].
*
* This is normally used by code generated by
* [`glib-compile-resources`](glib-compile-resources.html)
* and is not typically used by other code.
*
* Returns: (transfer none): a [struct@Gio.Resource]
*
* Since: 2.32
**/
GResource *
g_static_resource_get_resource (GStaticResource *static_resource)
{
register_lazy_static_resources ();
return g_atomic_pointer_get (&static_resource->resource);
}