SIRTX Glossary
List of common terms used with SIRTX
SIRTX uses a number of terms from related domains as well as its own. This glossary is intended to help users to get familiar with the SIRTX vocabulary.
Index
- Tag
- A tag is an abstract entity that holds all metadata of a subject. Each tag is associated with exactly one subject.
- Subject
- A subject is abstract (e.g. a concept like "reading") or specific (something one can touch) "thing". Each subject is associated with exactly one tag.
- Object
- An object is programming interface that allows access to a specific tag-subject pair.
- Handle
- A handle is a way code (e.g. a function) can access an object (any system resource). It is similar to file descriptor (or file handle) on POSIX systems.
- Link
- Link is a collective term for relations and metadata.
- Relation
- A relation is a connection between two tags.
- Metadata
- Metadata is a value connected to a tag. It can be understood as a degenerated relation.
- Function
- A function is code that can be called to accomplish some task. Other systems call this a command, program, or executable.
- Port
- Ports are interfaces of functions. They are used to provide input and output to them. Other systems call these arguments, operands, inputs, and outputs.
- Logical
-
Logical:A logical is a name associated with a tag for quick access by a user-friendly alias.
logical - Function number
- Many functions have in addition to their name also a number for easy access on numeric keyboards
- sni (SIRTX numerical identifier)
-
Logical:A sirtx numerical identifier is a numerical identifier that is given to many core tags. It is used mostly internally, for programming, and scripting. It can also be used as a shortcut to access the tag in question. See the list for more details.
sni - sid (small-identifier)
-
Logical:A small identifier is a numerical identifier given to some tags of general interest. This list is not part of SIRTX, however the system features specific support for it to ease use and interoperation.
sid - virtual handle
- A virtual handle is a handle of a boxed native/simple type that uses some properties of the memory layout in order to store its data. Virtual handles do not require any storage (only the pointer to them). They provide a very powerful middle ground between boxed and unboxed types as they come with most of the benefits of both worlds.
- Bit bucket, Byte bucket, bb
-
Logical:The bit bucket is a device that accepts all input and discards it. Reading from it results in no data returned (short read). This is similar to
bb/dev/nullorNULon other systems. - zeros
-
Logical:The zeros device accepts all input just like the bit bucket. On reading, it will return an endless stream of zero bytes. This is similar to
zeros/dev/zeroon other systems. - full
-
Logical:The full device reports a out of space condition (
fullraen:38,raes:NOSPC) on write. Reading from it will result a stream of zeros alike zeros. - urandom
-
Logical:The user random device will return an endless stream of random bytes on read. SIRTX tries to provide a stream as random as possible. However, due to limitations of the size of the internal entropy pool this device might not provide cryptographically strong randomness. It is however better than classic
urandomrand(3)implementations. The system will constantly try to reseed the entropy pool. On write the written data will be used to reseed the entropy pool. It is undefined if the written data will alter the entropy estimation. - Accumulator, ac
-
Logical:The accumulator is port found by default in the session context. It can be used freely by the user to store temporary values. It can be assumed to be present, even on systems so small that no custom ports can be defined.
ac