40 lines
1.5 KiB
Markdown
40 lines
1.5 KiB
Markdown
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# Definitions
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* A dpp is two hash strings joined by the character ":"
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We call the first chain chid and the second phid.
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* The chid and phid are hash strings of certain values.
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We call the set of these values Documents.
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Here we define these values.
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# Chid
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The chid is the part of dpp that defines a device, be it a computer,
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a hard drive, etc. The chid is the most important part of a dpp since
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anyone who comes across a device should be able to play it.
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The chid is made up of four values:
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* type
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* manufacturer
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* model
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* serial_number
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type represents the device type according to the devicehub.
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These values are always represented in lowercase.
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These values have to be ordered and concatenated with the character "-"
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So:
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{type}-{manufacturer}-{model}-{serial_number}
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For example:
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```
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HardDrive-Seagate-ST500LT0121DG15-S3P9A81F
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```
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In computer types this combination is not perfect and **can lead to collisions**.
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That is why we need a value that is reliable and comes from the manufacturer.
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# Phid
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The values of the phid do not have to be reproducible. For this reason, each inventory can establish its own values and its order as a document.
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It is important that each inventory store the document in string so that it can reproduce exactly the document that was hashed. So a document can be verifiable.
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In the case of the DeviceHub, we use as the chid document all the values that the Workbench collects that describe the hardware's own data.
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These data change depending on the version of the Workbench used.
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