Goal: to add a new attribute on source code and propagate it through the Machine Level code to achieve further optimizations of custom address spaces.
How can I follow OpenCL's approach to add a new attribute like this? I have often thought that this mechanism should be “mostly” what I need, with address-space ‘0’ simply being “default”.
Related
When I use a map constructor like:
Person p = new Person(name: "Bob")
through something that is called via a grails.gsp.PageRenderer, the field values are not populated. When I use an empty constructor and then set the fields individually like:
Person p = new Person()
p.name = "Bob"
it succeeds. When I use the map constructor via a render call, it also succeeds.
Any ideas as to why this is the case?
Sample project is here in case anyone wants to dig deeper: https://github.com/danduke/constructor-test/
Actual use case, as requested by Jeff below:
I have a computationally expensive view to render. Essentially it's a multi-thousand page (when PDF'd) view of some data.
This view can be broken into smaller pieces, and I can reliably determine when each has changed.
I render one piece at a time, submitting each piece to a fixed size thread pool to avoid overloading the system. I left this out of the example project, as it has no bearing on the results.
I cache the rendered results and evict them by key when data in that portion of the view has changed. This is why I am using a page renderer.
Each template used may make use of various tag libraries.
Some tag libraries need to load data from other applications in order to display things properly (actual use case: loading preferences from a shared repository for whether particular items are enabled in the view)
When loaded, these items need to be turned into an object. In my case, it's a GORM object. This is why I am creating a new object at all.
There are quite a few opportunities for improvement in my actual use case, and I'm open to suggestions on that. However, the simplest possible (for me) demonstration of the problem still does suggest that there's a problem. I'm curious whether it should be possible to use map constructors in something called from a PageRenderer at all. I'm surprised that it doesn't work, and it feels like a bug, but obviously a very precise and edge case one.
"Technically it is a bug" (which is the best kind of bug!), and has been reported here: https://github.com/grails/grails-core/issues/11870
I'll update this if/when additional information is available.
Is there a standard way to update the SMBIOS table, to add new variables?
For example, if I would like to change a variable such as 'mainboard name', or more generically, add a new entry in the table to define custom struct and value, what would be the standard way to implement this, so that I can query this value with dmidecode, /sys/class/dmi, or libsmbios?
Obviously, the board manufacturers have tools to change such values in the SMBIOS table, and which can be accessed from operating system in a standard way.
The /sys/firmware/dmi/tables interface seems to be read-only. Can one write to the respective area under /dev/mem (using smbios_entry_point) to add new entries?
Is there an alternative standard and modern way to save such (custom) hardware information, to avoid having to query the hardware component directly? from UEFI?
There is such an option for COM Express® module. The PICMG specification depict an EEPROM on the Carrier Board that can hold SMBIOS data. Take a look at following specification:
https://www.picmg.org/wp-content/uploads/PICMG_EeeP_R1_0.pdf
There is a source code for updating the EEPROM at: https://sourceforge.net/projects/eapidk/
But in COM Express® Carrier Design Guide https://www.picmg.org/wp-content/uploads/PICMG_COMDG_2.0-RELEASED-2013-12-06.pdf there is following statement
The EEPROM stores configuration information for the system of the Carrier Board. The data
structure used is defined in the PICMG EEEP Specification. The Specification recommends but
does not require the use of this system configuration EEPROM. The Module BIOS may check
the Carrier Board configuration EEPROM but is not required to do so by the Specification.
Which allow BIOS/Firmware vendor to skip this EEPROM.
I'm using neo4j (but probably this also applies to other databases). The user can give his own key/value pairs. But i also need to define some properties by the system. How do i prevent a name clash (on the key)? I could prefix all the system properties, but it seems a bit weird. Also i could make another node and put all the system properties there, but that might make for some difficult queries. What's a good way to solve this?
Neo4jis property graph.
Basically, there is no magic there. You already mentioned all possible solutions.
From my perspective best solution is - add prefixes to user defined properties (for example #). This will keep queries simple enough, and doesn’t affect any performance problems.
Additionally, if this properties are only for READ and you are never going to run query against them, then you can look into storing JSON with user-defined data in your nodes:
SET n.user_data = ‘{“key”: “value”}’
When I use a TClientDataSet which is connected to a TxxxQuery component, I can add TFields to both components at design time. I recognized, when I don't specify the TFields in the TxxxQuery component, they are retrieved when the query is executed at runtime.
My questions is: Is there a performance difference when I add the TFields at design time to the TxxxQuery component?
When you add the fields at design time you get the strongly typed QueryName_FieldName fields you can use directly from code, skipping the name-based QueryName["FieldName"] lookup required if you don't have them.
From a performance stand-point the difference is most likely insignificant; From a language perspective having the fields added at design time provides better type safety, but only if you access the fields from code, and only if you use the QueryName_FieldName.Value syntax, not the named-based QueryName["FieldName"] syntax. If you use data-bound controls there's no difference.
I personally only add fields to TClientDataSet at design time when I need to use the client dataset without binding it to an other data source (ie: use it as a temporary table for reporting).
This is probably a very "dumb" question for whoever knows VirtualShellTools but I only started using it and couldn't find my answer in the demos' code. Please note that I'm also unfamiliar with virtualtreeview.
I use a VirtualExplorerTreeview to display a directory structure, linked with a VirtualExplorerListview to display a certain type of files in the selected directory as well as specific informations about them
I've been able to point them at the right place, link them as I wanted, filter everything in the listview, and looking at the demos I have a pretty good idea about how to add my own columns and draw it to display my custom data.
My issue lies with the Treeview: I would like to sort the directories displayed in the order I want; specifically, I want "My Docs" and other folder to appears first, then drives, then removable media. Looking in the TNamespace property I found how to distinguish them (Directory and Removable properties), but I don't know how to implement my own sort/what event I need. I tried CompareNode but that doesn't even seem to be called.
If you want to do everything yourself, then set toUserSort in the TVirtualExplorerTree.TreeOptions.VETMiscOptions property. That causes the control to just use the DoCompare method inherited from the virtual tree view, and that should call the OnCompareNodes event handler.
A better way is to provide a custom TShellSortHelper. Make a descendant of that class and override whichever methods you need. Create an instance of that class and assign it to the tree's SortHelper property. (The tree takes ownership of the helper; free the old one, but not the new one.) If the items are being sorted on a column that that class doesn't know how to compare, then handle the tree's OnCustomColumnCompare event.
To help you figure out exactly which methods you need to override or events you need to handle, set a breakpoint in TCustomVirtualExplorerTree.DoCompare and step through to see what gets called in various situations.