mirror of
https://github.com/nosqlbench/nosqlbench.git
synced 2024-12-24 16:00:09 -06:00
69 lines
2.8 KiB
Markdown
69 lines
2.8 KiB
Markdown
# NBIO API
|
|
|
|
The NBIO class provides a way to access file and URL resources from within
|
|
a running NoSQLBench process. This centralizes the logic for accessing
|
|
files in classpath, filesystem, or on the net.
|
|
|
|
Managing file, classpath, and URL resources when you need access to all of
|
|
them can be complicated business. The NBIO API was introduced to
|
|
consolidate this into one easy-to-use API with substantial testing. It
|
|
also provides a uniform interface for accessing all of these resource
|
|
types so that users have a consistent experience regardless of where their
|
|
source data lives.
|
|
|
|
## Design Intent
|
|
|
|
Unless there is a good reason to avoid it, developers should delegate to
|
|
the NBUI API _anywhere_ in NoSQLBench that a user needs to load a file.
|
|
This imbues such call sites with the ability to read local and remote
|
|
resources with no further effort required by the programmer.
|
|
|
|
## API Usage
|
|
|
|
To use this API, simply call one of the following methods and use method
|
|
chaining to delve into what you are looking for:
|
|
|
|
- `NBIO.all()...` - Look in the filesystem, the classpath, and on the
|
|
net (for any patterns which are a URL).
|
|
- `NBIO.fs()...` - Look only in the filesystem.
|
|
- `NBIO.classpath()...` - Look only in the classpath.
|
|
- `NBIO.local()...` - Look in filesystem or classpath.
|
|
- `NBIO.remote()...` - Look only for remote resources.
|
|
|
|
## Searching Semantics
|
|
|
|
The fluent-style API will layout the following search parameters for you.
|
|
The details on these are explained in the javadoc which will be provided
|
|
in most cases as you expand the API. Each of these search parameters
|
|
supports zero or more values, and all values are searched that are
|
|
provided.
|
|
|
|
- `prefix(...)` - Zero or more prefix paths to search.
|
|
- `name(...)` - Zero or more resources or filenames or urls to look for.
|
|
- `extension(...)` - Zero or more extensions to try to match with.
|
|
|
|
## Getting Results
|
|
|
|
At runtime, the local process has visibility to many things. Due to how
|
|
classpath resources are assembled in pre-JDPA days, it is possible to find
|
|
multiple resources under the same name. Thus, you have to be specific
|
|
about how many you expect to find, and thus what is considered an error
|
|
condition:
|
|
|
|
- `list()` - All found content in one list
|
|
- `one()` - A single source of content should be found -- more or less is
|
|
an error.
|
|
- `first()` - At least one source of content should be found, and you only
|
|
want to see the first one.
|
|
- `resolveEach()` - List of lists, allows full cardinality visibility when
|
|
using the bulk interface with multiple name terms.
|
|
|
|
## Consuming Content
|
|
|
|
To support efficient resolution and consumption of local and remote
|
|
content, the type of element returned by the NBIO API is a _Content_
|
|
object. However, it provides convenient accessors for getting content when
|
|
needed. Remote content will be read lazily only once per NBIO result.
|
|
Local content is also read lazily, but it is not cached until GC.
|
|
|