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[FEA] Provide shallow hash function for column_view #9140

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jrhemstad opened this issue Aug 27, 2021 · 2 comments · Fixed by #9185 or #9312
Closed

[FEA] Provide shallow hash function for column_view #9140

jrhemstad opened this issue Aug 27, 2021 · 2 comments · Fixed by #9185 or #9312
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@karthikeyann
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feature request New feature or request libcudf Affects libcudf (C++/CUDA) code.
Milestone
Time Series Analysis

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@jrhemstad
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Is your feature request related to a problem? Please describe.

I want to hash all of the "shallow" state of a column_view into a single value.

Describe the solution you'd like

I would like a constant time hash function that hashes all of the shallow state of a column_view such that for two column_views a and b then:

is_shallow_equal(a,b) => shallow_hash(a) == shallow_hash(b)

See also #9139
@jrhemstad jrhemstad added feature request New feature or request libcudf Affects libcudf (C++/CUDA) code. labels Aug 27, 2021
@jrhemstad jrhemstad mentioned this issue Aug 27, 2021
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@jrhemstad jrhemstad added this to the Time Series Analysis milestone Aug 30, 2021
@karthikeyann
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karthikeyann commented Sep 6, 2021 •
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Should shallow_hash be a public or detail API or only in src/ ?

@jrhemstad
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detail:: API.

@karthikeyann karthikeyann mentioned this issue Sep 7, 2021
Merged
rapids-bot bot pushed a commit that referenced this issue Sep 22, 2021
@karthikeyann
Add shallow hash function and shallow equality comparison for column_…
1cb527f 
…view (#9185)

Fixes #9140 
Added `shallow_hash(column_view)`
Added unit tests

It computes hash values based on the shallow states of `column_view`:
type, size, data pointer, null_mask pointer,  offset, and the hash value of the children. 
`null_count` is not used since it is a cached value and it may vary based on contents of `null_mask`, and may be pre-computed or not.

Fixes #9139
Added `is_shallow_equivalent(column_view, column_view)` ~shallow_equal~
Added unit tests

It compares two column_views based on the shallow states of column_view:
type, size, data pointer, null_mask pointer, offset, and the column_view of the children.
null_count is not used since it is a cached value and it may vary based on contents of null_mask, and may be pre-computed or not.

Authors:
  - Karthikeyan (https://github.com/karthikeyann)

Approvers:
  - Mark Harris (https://github.com/harrism)
  - Vyas Ramasubramani (https://github.com/vyasr)
  - Jake Hemstad (https://github.com/jrhemstad)
  - David Wendt (https://github.com/davidwendt)

URL: #9185
@karthikeyann karthikeyann mentioned this issue Sep 27, 2021
Merged
rapids-bot bot pushed a commit that referenced this issue Sep 27, 2021
@karthikeyann
Add shallow hash function and shallow equality comparison for column_…
0b007a5 
…view (#9312)

Fixes #9140 
Added `shallow_hash(column_view)`
Added unit tests
SWIPAT approval complete

It computes hash values based on the shallow states of `column_view`:
type, size, data pointer, null_mask pointer,  offset, and the hash value of the children. 
`null_count` is not used since it is a cached value and it may vary based on contents of `null_mask`, and may be pre-computed or not.

Fixes #9139
Added `is_shallow_equivalent(column_view, column_view)` ~shallow_equal~
Added unit tests

It compares two column_views based on the shallow states of column_view:
type, size, data pointer, null_mask pointer, offset, and the column_view of the children.
null_count is not used since it is a cached value and it may vary based on contents of null_mask, and may be pre-computed or not.

Authors:
  - Karthikeyan (https://github.com/karthikeyann)

Approvers:
  - Vyas Ramasubramani (https://github.com/vyasr)

URL: #9312
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@karthikeyann karthikeyann

Labels
feature request New feature or request libcudf Affects libcudf (C++/CUDA) code.
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Milestone
Time Series Analysis
2 participants
@karthikeyann @jrhemstad