Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Convert external chunking documentation to doxygen #5131

Merged
merged 4 commits into from
Nov 21, 2024

Conversation

byrnHDF
Copy link
Contributor

@byrnHDF byrnHDF commented Nov 19, 2024

No description provided.

@byrnHDF byrnHDF added Priority - 1. High 🔼 These are important issues that should be resolved in the next release Component - Documentation Doxygen, markdown, etc. Type - Improvement Improvements that don't add a new feature or functionality labels Nov 19, 2024
@byrnHDF byrnHDF self-assigned this Nov 19, 2024
lrknox
lrknox previously approved these changes Nov 19, 2024
* </tr>
* </table>
*
* The HDF5 library treats chunks as atomic objects -- disk I/O is always in terms of complete chunks (Parallel versions
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

lower case p in Parallel

* \section sec_hdf5_chunk_issues_data The Raw Data Chunk Cache
* It's obvious from Figure 2 that calling #H5Dwrite many times from the application would result in poor performance even
* if the data being written all falls within a single chunk. A raw data chunk cache layer was added between the top of
* the filter stack and the bottom of the byte modification layer (The raw data chunk cache was added before the second alpha release.).
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

The comment in parens is obsolete and should be removed.

* \li A chunk which has just entered the cache is favored.
* \li A chunk which has been completely read or completely written but not partially read or written is penalized according
* to some application specified weighting between zero and one.
* \li A chunk which is larger than the maximum cache size is not eligible for caching.
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

@fortnern - Does this section need revising?

* </tr>
* </table>
*
* Although the application eventually overwrites every chunk completely the library has know way of knowing this before
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

"no way", not "know way"

* </table>
*
* Although the application eventually overwrites every chunk completely the library has know way of knowing this before
* hand since most calls to #H5Dwrite modify only a portion of any given chunk. Therefore, the first modification of a
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

beforehand is one word

* Although the application eventually overwrites every chunk completely the library has know way of knowing this before
* hand since most calls to #H5Dwrite modify only a portion of any given chunk. Therefore, the first modification of a
* chunk will cause the chunk to be read from disk into the chunk buffer through the filter pipeline. Eventually HDF5 might
* contain a data set transfer property that can turn off this read operation resulting in write efficiency which is equal
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

dataset

*
* Large B-trees have two disadvantages:
* \li The file storage overhead is higher and more disk I/O is required to traverse the tree from root to leaves.
* \li The increased number of B-tree nodes will result in higher contention for the meta data cache.
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

metadata, not meta data

@derobins
Copy link
Member

it's nice to move this into the UG. We're going to need to revisit this text in the future, since a lot of it was clearly written before HDF5 1.10 and is a little obsolete.

@derobins derobins changed the title Convert Compression external md files to doxygen Convert external chunking documentation to doxygen Nov 20, 2024
@derobins derobins merged commit 7315776 into HDFGroup:develop Nov 21, 2024
67 of 69 checks passed
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
Component - Documentation Doxygen, markdown, etc. Priority - 1. High 🔼 These are important issues that should be resolved in the next release Type - Improvement Improvements that don't add a new feature or functionality
Projects
None yet
Development

Successfully merging this pull request may close these issues.

3 participants