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Lay

Description

The lay utility installs eggs. It leverages the index file generated by egg-tarballs-index and chicken-install to parallelize and speedup the eggs building process.

Usage

 
lay [-h] [-c] [-v] [-j jobs] [-z zcat] egg ...
    -h         display this help page and quit
    -c         clear the local cache before doing anything else
    -v         print verbose output
    -j jobs    use at most 'jobs' parallel processes (default: 4)
    -z zcat    use the specified 'zcat' program (default: zcat)

Details

The lay utility retrieves the eggs index file from the egg-tarballs directory of the running CHICKEN major release. A copy is kept in a local cache directory to avoid unnecessary downloads. A DAG representing eggs dependencies is generated from the eggs index file. The DAG file is cached too. The DAG is then resolved into levels. Each level contains independent eggs that can be built in parallel. Here comes the major advantage of using lay: multiple instances of chicken-install can be used to build the eggs at each level. As an example, to build version 6.3 of the spiffy egg we need to resolve 5 levels:

  1. (memory-mapped-files:0.4 srfi-18:0.1.7 matchable:1.2 srfi-14:0.2.1 srfi-1:0.5.1)
  2. (sendfile:2.0 uri-generic:3.3 defstruct:2.0 srfi-13:0.3.4)
  3. (base64:1.0 uri-common:2.0)
  4. (intarweb:2.1.0)
  5. (spiffy:6.3)

At the time of this writing, on a reasonably cheap VPS, building spiffy with plain chicken-install vs. using lay results in these times:

Author

Pietro Cerutti

Repository

https://code.ptrcrt.ch/lay

License

 
 Copyright (c) Pietro Cerutti
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
 modification, are permitted provided that the following conditions
 are met:
 
 1. Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.
 2. Redistributions in binary form must reproduce the above copyright
    notice, this list of conditions and the following disclaimer in the
    documentation and/or other materials provided with the distribution.
 
 THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 SUCH DAMAGE.

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