See the comments for an explanation of how properties are stored.
The trie structure is designed to scale better than the previous
array-based implementation. Searching an array with n properties
required average O(n) string compares of the entire key; searching the
trie requires average O(log n) string compares of each token (substrings
between '.' characters).
Change-Id: I491305bc7aca59609abcd871a5f33d97f89ce714
Signed-off-by: Greg Hackmann <ghackmann@google.com>
The property area is initially one 4K region, automatically expanding as
needed up to 64 regions.
To avoid duplicating code, __system_property_area_init() now allocates
and initializes the first region (previously it was allocated in init's
init_property_area() and initialized in bionic). For testing purposes,
__system_property_set_filename() may be used to override the file used
to map in regions.
Change-Id: Ibe00ef52464bfa590953c4699a6d98383b0142b1
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Move the implementation of writing to the system property area
from init to bionic, next to the reader implementation. This
will allow full property testing to be added to bionic tests.
Add new accessor and waiting functions to hide the implementation
from watchprops and various bionic users.
Also hide some of the implementation details of the property area
from init by moving them into _system_properties.h, and other details
from everybody by moving them into system_properties.h.
Change-Id: I9026e604109e30546b2849b60cab2e7e5ff00ba5
Currently, system properties are passed via the environment
variable ANDROID_PROPERTY_WORKSPACE and a file descriptor passed
from parent to child. This is insecure for setuid executables,
as the environment variable can be changed by the caller.
Modify system property handling so that we get the properties
from a root owned properties file, rather than using an
environment variable. Fall back to the environment variable
if the file doesn't exist.
Bug: 8045561
Change-Id: I54f3efa98cf7d63d88788da5ce0d19e34fd7851a
This property file is used for properties which are set at device
provisioning time or in the factory. They are never touched by
a software update or factory data reset and typically contain
data specific to the particular unit.
Change-Id: I2e7c2fe62cb684cb2449eea917c42b19462e89a5
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
