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In CPS temporal, the data can be filtered based on three criteria
Datetime
DatetimePurpose Implementation Status parameter-name type Detail Example hoursData in last X
DateTime ( epoch time in nanoseconds )hours
Not Decided duration string 1d, 2h Data after a particular DateTime ( epoch time in nanoseconds )Data at a particular timeDateTime Yes after DateTime Format: 'YYYY-mm-ddTHH:MM:SS.SS-TZ'
Data before a particular
DateTime
Yes before DateTime Format: 'YYYY-mm-ddTHH:MM:SS.SS-TZ'
Last X network data
Not Decided - DataTypes in CPS Core
Dataspace & schema-set
- Dataspace & anchor
- Dataspace & multiple anchors - To improve performance, if there is a need to fetch data for multiple anchors.
- Dataspace
- Payload
- Based on a subsection or field in the payload. These criteria do need schema-set to be fixed to search in the same set of anchors
Adding payload filtering with DateTime criteria can make the query APIs complicated. Hence, we will implement the basic APIs first and will add complex ones when required.
Others ParametersParameters
| No | Name | Type | Default | Purpose | Example |
|---|---|---|---|---|---|
| 1 | index | int | The query output can have many rows so it is important to limit the fetched data. To limit the number of records and to provide pagination, these two parameters can be used. "index" parameter represents the page number, starts with 0, and maxSize is the page size. | ||
| 2 | maxSize | int | 1000 | ||
| 3 | point-in-time | DateTime | CurrentDateTime | Pagination does not work well if new data gets added which fulfils the search criteria. The user must provide this value to avoid this issue. |
Proposed APIs - Approach 1 - GET
In the GET APIs, all the filtering parameters are passed as query parameter.
1.1 Get anchor data which is added after
| No | API endpoint | Description | Example |
|---|---|---|---|
| 1. | GET /dataspaces/{dataspace-name}/anchors/{anchor-name}?after=<epoch-time>&maxSize=1000&?payload={"abcd" : "abcd"} | Return all the data entries for an anchor after the specified epoch in nanoseconds | |
| 2. | GET /dataspaces/{dataspace-name}/schema-sets/{schema-set}?after=<epochtime> | Return all the data entries based on provided schema-set after the specified epoch in nanoseconds. | |
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| Code Block |
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{
"nextRecordsLink": "cps-temporal/api/v1/dataspaces/{dataspace-name}/anchors/{anchor-name}?after=<epoch-time>&maxSize=1000&before=<epoch-time>&index=2&point-in-time=DATE",
"previousRecordsLink": "cps-temporal/api/v1/dataspaces/{dataspace-name}/anchors/{anchor-name}?after=<epoch-time>&maxSize=1000&before=<epoch-time>&index=0&point-in-time=DATE",
"records": [
{
"timestamp": "1234567788889",
"dataspace": "my-dataspace",
"schemaSet": "my-schema-set",
"anchor": "my-anchor",
"data": {
"status" : "UP"
}
}
]
} |
Open Items
- Datetime format format - YYYY-MM-DDTHH:MM:SS.microseconds-timezone