Gyroscope / Framework Architecture
In addition to its intuitive and versatile user interface, Gyroscope is designed
to be flexible and resource efficient.
Gyroscope takes full advantage of the LCHH architecture
. The main loader is
the entry page (index.php), where the menu icons, left panel and tab view
loaders are defined.
The layout and panel sizes are explicitly controlled by a window manager
(viewport.js). The tab view is given the maximum possible screen real-estate.
The content in each loader is subsequently loaded through ajxpgn
Nano AJAX Library
In addition, Gyroscope offers higher level content loading functions:
addtab / reloadtab - load content in tabs; maintain tab order and layout
showview - loads content in the left panel; manages list order
listlookup - determines and populates the lookup loader
The above functions are further discussed in
"Building a List View"
All the server-side handlers are routed in a switch block, which is defined in
myservices.php. Note this file can take up other names, as long as the change
is reflected in settings.php
Note that the actual implementations of the handlers are stored in the icl
folder. These files are included only when their corresponding handling
functions are called. For example:
The advantage of routing all the handlers through a single file is having a
single point of control. The above switch structure distributes the
implementation in smaller files; this effectively reduces the memory
PHP evaluates scripts by first parsing them into internal structures for further
processing. This means larger scripts, or scripts that create big data objects
require more memory to run. The exact memory usage can be measured by
placing the following code at the end of the script:
<?php echo memory_get_usage(true); ?>
Also measure the memory usage of a blank PHP page.
You'll notice that the values are usually multiples of 262144, or 1024 x 256.
This is the least amount of memory PHP allocates for each script execution.
If the script requires more memory, PHP will assign another chunk of
262144 bytes of memory, until either sufficient memory is given, or an error
message "allowed memory of X bytes exhausted" is displayed.
This chunk of 262144 bytes is called a "segment". Counting segments is
more convenient than counting actual bytes. It also eliminates the differences
in pointer sizes in various server configurations.
has a direct impact on concurrency level, or the number of
users the application can support at any given time. Gyroscope honors the
golden standard of 1 segment memory consumption.
A complex web application could have many features. Picture a web-based
word processor, such as Google Docs. The user interface consists of many
buttons; each button has a client-side handler which further communicates
functions because the user typically uses a small portion of the functionality.
Gyroscope uses the ajxjs
function in the Nano AJAX Library
The "C" in LCHH is the content, or server response that's directly injected to the loader.
In a typical Gyroscope application, the content consists of textual information, event triggers and pivoting links to other views.
When the loader is populated with content, the LCHH cycle moves on.