.parallelRangedDownload

Internal helper for the opt-in parallel download path (Feature A). Splits
<code>[0, size)</code> into <code>n</code> contiguous byte ranges and fetches them concurrently
with one <code>curl</code> handle per part (each carrying its own <code>Range:</code> header) via
<code>curl</code>'s multi interface. On success the parts are concatenated in order
and the total size is verified to equal <code>size</code>, so the result is
byte-identical to a single-stream download. Returns <code>FALSE</code> (rather than
erroring) on any partial failure or size mismatch, so the caller can fall
back to single-stream.

internal

A collection of high-level, machine- and OS-independent tools
for making reproducible and reusable content in R.
The two workhorse functions are 'Cache()' and 'prepInputs()'.
'Cache()' allows for nested caching, is robust to environments and objects
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Both functions have been developed to be foundational components of data
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cloud storage of cached objects allowing for sharing between users. Several
advanced options are available, see '?reproducibleOptions()'.

Eliot J B

reproducible

Enhance Reproducibility of R Code

Eliot J B McIntire

Alex M Chubaty

Tati Micheletti

Ceres Barros

Ian Eddy

His Majesty the King in Right of Canada, as represented by the Minister of Natural Resources Canada 

.parallelRangedDownload function

<dl><dt>url</dt>
<dd>The (already-resolved, range-capable) URL.</dd>
<dt>destFile</dt>
<dd>The destination file path to assemble into.</dd>
<dt>size</dt>
<dd>Total expected size in bytes (from <code>.probeRange()</code>).</dd>
<dt>n</dt>
<dd>Number of parallel streams (<code>reproducible.parallel.streams</code>).</dd>
<dt>verbose</dt>
<dd>Numeric verbosity level.</dd></dl>

Arguments

Download a file in parallel using HTTP Range requests — .parallelRangedDownload

<dl>

<dt>url</dt>
<dd>The (already-resolved, range-capable) URL.</dd>


<dt>destFile</dt>
<dd>The destination file path to assemble into.</dd>


<dt>size</dt>
<dd>Total expected size in bytes (from <code>.probeRange()</code>).</dd>


<dt>n</dt>
<dd>Number of parallel streams (<code>reproducible.parallel.streams</code>).</dd>


<dt>verbose</dt>
<dd>Numeric verbosity level.</dd>

</dl>

.parallelRangedDownload: Download a file in parallel using HTTP Range requests

Description

Usage

Value

Arguments