Zarr¶
Usage
use Zarr;
or
import Zarr;
Support for reading and writing of Zarr stores.
Support is limited to v2 Zarr arrays stored on local filesystems. NFS is not supported. The module uses c-blosc to compress and decompress chunks. Zarr specification: https://zarr-specs.readthedocs.io/en/latest/v2/v2.0.html
- config param zarrProfiling = false¶
Turns on/off profiling of Zarr IO
- iter zarrProfilingResults() throws¶
Returns a map of profiling results for Zarr IO operations. The keys are the names of the operations and the values are the total time spent in each operation across all threads. Requires that zarrProfiling be set to true.
- proc resetZarrProfiling()¶
Resets the profiling timer for Zarr IO operations. Should only be used when compiled with zarrProfiling set to true.
- record zarrMetadataV2¶
- var zarr_format : int¶
- var chunks : list(int)¶
- var dtype : string¶
- var shape : list(int)¶
- var compressor : string¶
- record zarrMetadataV2Required¶
- var zarr_format : int¶
- var chunks : list(int)¶
- var dtype : string¶
- var shape : list(int)¶
- record zarrMetadataV3¶
Unused until support is added for v3.0 stores
- var zarr_format : int¶
- var node_type : string¶
- var shape : list(int)¶
- var data_type : string¶
- var dimension_names : list(string)¶
- proc getLocalChunks(D: domain(?), localD: domain(?), chunkShape: ?dimCount*int) : domain(dimCount)¶
Returns the indices of the chunks that contain elements present in a subdomain of the array.
- proc getChunkDomain(chunkShape: ?dimCount*int, chunkIndex: dimCount*int)¶
Returns the domain of a chunk for a store with a given chunk shape.
- Arguments:
chunkShape – A tuple of the extents of the dimensions of each chunk in the store.
chunkIndex – A tuple of the indices of the chunk to get the domain for.
- Returns:
The domain of the chunk.
- proc readChunk(param dimCount: int, chunkPath: string, chunkDomain: domain(dimCount), ref arraySlice: [] ?t) throws¶
Reads a chunk from storage and fills arraySlice with its corresponding values.
- Arguments:
dimCount – Dimensionality of the array being read.
chunkPath – Relative or absolute path to the chunk being read.
chunkDomain – Domain of the chunk being read. Because boundary chunks are padded with zeros, the chunk’s domain may be larger in some dimensions than the array’s.
arraySlice – Reference to the portion of the calling locale’s section of the array that this chunk will update. The domain of this slice should be a subset of the chunk’s.
- Throws:
Error – If the decompression fails
- proc writeChunk(param dimCount, chunkPath: string, chunkDomain: domain(dimCount), ref arraySlice: [] ?t, bloscLevel: int(32) = 9, compressor: string = "blosclz") throws¶
Updates a chunk in storage with a locale’s contribution to that chunk. The calling function is expected to manage synchronization among locales. If the locale contributes the entire chunk, it will immediately compress and write the chunk’s data. If the contribution is partial, it decompresses the chunk, updates the necessary values, then compresses and writes the chunk to storage.
- Arguments:
dimCount – Dimensionality of the array being written.
chunkPath – Relative or absolute path to the chunk being written.
chunkDomain – Domain of the chunk being updated. Because boundary chunks are padded with zeros, the chunk’s domain may be larger in some dimensions than the array’s.
arraySlice – The portion of the array that the calling locale contributes to this chunk.
bloscLevel – Compression level to use. 0 indicates no compression, 9 (default) indicates maximum compression. Values outside of this range will be clipped to a value between 0 and 9.
- Throws:
Error – If the compression fails
- proc readZarrArray(directoryPath: string, type dtype, param dimCount: int, bloscThreads: int(32) = 1, targetLocales: [] locale = Locales) throws¶
Reads a v2.0 zarr store from storage using all locales, returning a block distributed array. Each locale reads and decompresses the chunks with elements in its subdomain. This method assumes a shared filesystem where all nodes can access the store directory.
- Arguments:
directoryPath – Relative or absolute path to the root of the zarr store. The store is expected to contain a ‘.zarray’ metadata file
dtype – Chapel type of the store’s data
dimCount – Dimensionality of the zarr array
bloscThreads – The number of threads to use during compression (default=1)
targetLocales – The locales to use for reading the array in the shape the array will be distributed
- proc writeZarrArray(directoryPath: string, const ref A: [?domainType] ?dtype, chunkShape: ?dimCount*int, bloscLevel: int(32) = 9, compressor = "blosclz") throws¶
Writes an array to storage as a v2.0 zarr store. The array metadata and chunks will be stored within the directoryPath directory, which is created if it does not yet exist. The chunks will have the dimensions given in the chunkShape argument. This function writes chunks in parallel, and supports distributed execution. It assumes a shared filesystem where all nodes can access the store directory.
- Arguments:
directoryPath – Relative or absolute path to the root of the zarr store. The directory and all necessary parent directories will be created if it does not exist.
A – The array to write to storage.
chunkShape – The dimension extents to use when breaking A into chunks.
bloscLevel – Compression level to use. 0 indicates no compression, 9 (default) indicates maximum compression.
compressor – Compression algorithm to use. Supported values are “blosclz” (default), “lz4”, “lz4hc”, “zlib”, and “zstd”.
- proc readZarrArrayPartial(directoryPath: string, type dtype, param dimCount: int, partialDomain, bloscThreads: int(32) = 1, targetLocales: [] locale = Locales) throws¶
Reads part of a v2.0 zarr store from storage using all locales, returning a block distributed array. Each locale reads and decompresses the chunks with elements in its subdomain. This method assumes a shared filesystem where all nodes can access the store directory.
- Arguments:
directoryPath – Relative or absolute path to the root of the zarr store. The store is expected to contain a ‘.zarray’ metadata file
dtype – Chapel type of the store’s data
dimCount – Dimensionality of the zarr array
partialDomain – The domain of the elements of the array that should be read
bloscThreads – The number of threads to use during compression (default=1)
targetLocales – The locales to use for reading the array in the shape the array will be distributed
- proc readZarrArrayLocal(directoryPath: string, type dtype, param dimCount: int) throws¶
Reads a v2.0 zarr store from storage using a single locale, returning a locally allocated array. This method assumes a shared filesystem where the current locale can access the store directory.
- Arguments:
directoryPath – Relative or absolute path to the root of the zarr store. The store is expected to contain a ‘.zarray’ metadata file
dtype – Chapel type of the store’s data
dimCount – Dimensionality of the zarr array
- proc writeZarrArrayLocal(directoryPath: string, ref A: [?domainType] ?dtype, chunkShape: ?dimCount*int, bloscLevel: int(32) = 9, compressor = "blosclz") throws¶
Writes an array to storage as a v2.0 zarr store using a single locale. The array metadata and chunks will be stored within the directoryPath directory, which is created if it does not yet exist. The chunks will have the dimensions given in the`chunkShape` argument.
- Arguments:
directoryPath – Relative or absolute path to the root of the zarr store. The directory and all necessary parent directories will be created if it does not exist.
A – The array to write to storage.
chunkShape – The dimension extents to use when breaking A into chunks.
bloscLevel – Compression level to use. 0 indicates no compression, 9 (default) indicates maximum compression.
compressor – Compression algorithm to use. Supported values are “blosclz” (default), “lz4”, “lz4hc”, “zlib”, and “zstd”.
- proc updateZarrChunk(directoryPath: string, ref A: [?domainType] ?dtype, chunkIndex: ?dimCount*int) throws¶
Updates a single chunk within a Zarr store with the data in A. The Zarr store and the associated metadata file must already exist.
- Arguments:
directoryPath – Relative or absolute path to the root of the zarr store. This directory should exist and contain a ‘.zarray’ metadata file.
A – The array to update the chunk with.
chunkIndex – The index of the chunk to update.
bloscThreads – The number of threads to use during compression (default=1)
- proc updateZarrChunk(directoryPath: string, ref A: [?domainType] ?dtype, chunkIndex: int) throws