12. Module Reference

This chapter contains all the documentation auto-generated from the source code. It is probably not terribly useful for reading through, but may be useful as a searchable reference.

12.1. piwheels.master

12.2. piwheels.master.db

12.3. piwheels.master.cloud_gazer

12.4. piwheels.master.the_oracle

12.5. piwheels.master.seraph

12.6. piwheels.master.the_architect

12.7. piwheels.master.slave_driver

12.8. piwheels.master.mr_chase

12.9. piwheels.master.file_juggler

12.10. piwheels.master.big_brother

12.11. piwheels.master.the_secretary

12.12. piwheels.master.the_scribe

12.13. piwheels.slave

12.14. piwheels.slave.builder

12.15. piwheels.initdb

Contains the functions that make up the piw-initdb script.


This is the main function for the piw-initdb script. It creates the piwheels database required by the master or, if it already exists, upgrades it to the current version of the application.

piwheels.initdb.detect_users(conn, test_user)[source]

Test that the user for conn is a cluster superuser (so we can drop and create anything we want in the database), and that test_user (which will be granted limited rights to various objects for the purposes of the piw-master script) exists and is not a cluster superuser.


Detect the version of the database. This is typically done by reading the contents of the configuration table, but before that was added we can guess a couple of versions based on what tables exist (or don’t). Returns None if the database appears uninitialized, and raises RuntimeError is the version is so ancient we can’t do anything with it.


Return an SQLAlchemy connection to the specified dsn or raise RuntimeError if the database doesn’t exist (the administrator is expected to create the database before running this script).


Generate the script to get the database from version (the result of detect_version()) to the current version of the software. If version is None, this is simply the contents of the sql/create_piwheels.sql script. Otherwise, it is a concatenation of various update scripts.


This is an extremely crude statement splitter for PostgreSQL’s dialect of SQL. It understands --comments, "quoted identifiers", 'string literals' and $delim$ extended strings $delim$, but not E'\escaped strings' or /* C-style comments */. If you start using such things in the update scripts, you’ll need to extend this function to accommodate them.

It returns a generator which yields individiual statements from script, delimited by semi-colon terminators.

12.16. piwheels.importer

12.17. piwheels.remove

12.18. piwheels.transport

12.19. piwheels.protocols

12.20. piwheels.tasks

12.21. piwheels.states

This module defines several classes which permit interested tasks to track the state of build slaves (SlaveState), file transfers (TransferState), build attempts (BuildState) and build artifacts (FileState).

class piwheels.states.FileState(filename, filesize, filehash, package_tag, package_version_tag, py_version_tag, abi_tag, platform_tag, dependencies, transferred=False)[source]

Represents the state of an individual build artifact (a package file, or wheel) including its filename, filesize, the SHA256 filehash, and various tags extracted from the build. Also tracks whether or not the file has been transferred.

  • filename (str) – The original filename of the build artifact.
  • filesize (int) – The size of the file in bytes.
  • filehash (str) – The SHA256 hash of the file contents.
  • package_tag (str) – The package tag extracted from the filename (first “-” separated component).
  • package_version_tag (str) – The package version tag extracted from the filename (second “-” separated component).
  • py_version_tag (str) – The python version tag extracted from the filename (third from last “-” separated component).
  • abi_tag (str) – The python ABI tag extracted from the filename (second from last “-” separated component).
  • platform_tag (str) – The platform tag extracted from the filename (last “-” separated component).
  • dependencies (set) – The set of dependencies that are required to use this particular wheel.
  • transferred (bool) – True if the file has been transferred from the build slave that generated it to the file server.

Convert the FileState object into a simpler list for serialization and transport.

classmethod from_message(value)[source]

Convert the output from as_message() back into a BuildState.


Called to set transferred to True after a file transfer has been successfully verified.

class piwheels.states.BuildState(slave_id, package, version, abi_tag, status, duration, output, files, build_id=None)[source]

Represents the state of a package build including the package, version, status, build duration, and all the lines of output. The files attribute is a mapping containing details of each successfully built package file.

  • slave_id (int) – The master’s identifier for the build slave.
  • package (str) – The name of the package to build.
  • version (str) – The version number of the package to build.
  • abi_tag (str) – The ABI for which the build was attempted (must not be 'none').
  • status (bool) – True if the build succeeded, False if it failed.
  • duration (timedelta) – The amount of time (in seconds) it took to complete the build.
  • output (str) – The log output of the build.
  • files (dict) – A mapping of filenames to FileState objects for each artifact produced by the build.
  • build_id (int) – The integer identifier generated for the build by the database (None until the build has been inserted into the database).

Convert the BuildState, and its nested FileState objects into simpler lists for serialization and transport.

classmethod from_message(value)[source]

Convert the output from as_message() back into a BuildState.


Called to fill in the build’s ID in the backend database.


A mapping of filename to FileState instances.


Returns the filename of the next file that needs transferring or None if all files have been transferred.


Returns True if all files have been transferred.

class piwheels.states.SlaveState(address, timeout, native_py_version, native_abi, native_platform, label)[source]

Tracks the state of a build slave. The master updates this state which each request and reply sent to and received from the slave, and this class in turn manages the associated BuildState (accessible from build) and TransferState (accessible from transfer). The class also tracks the time a request was last seen from the build slave, and includes a kill() method.

class piwheels.states.TransferState(slave_id, file_state)[source]

Tracks the state of a file transfer. All file transfers are held in temporary locations until verify() indicates the transfer was successful, at which point they are atomically renamed into their final location.

The state is intimately tied to the file transfer protocol and includes methods to write a recevied chunk(), and to determine the next chunk to fetch(), as well as a property to determine when the transfer is done.

12.22. piwheels.ranges

A set of utility routines for efficiently tracking byte ranges within a stream. These are used to track which chunks of a file have been received during file transfers from build slaves.

See FileJuggler for the usage of these functions.


Given a list of ranges in ascending order, this generator function returns the list with any overlapping ranges consolidated into individual ranges. For example:

>>> list(consolidate([range(0, 5), range(4, 10)]))
[range(0, 10)]
>>> list(consolidate([range(0, 5), range(5, 10)]))
[range(0, 10)]
>>> list(consolidate([range(0, 5), range(6, 10)]))
[range(0, 5), range(6, 10)]
piwheels.ranges.exclude(ranges, ex)[source]

Given a list of non-overlapping ranges in ascending order, and a range ex to exclude, this generator function returns ranges with all values covered by ex removed from any contained ranges. For example:

>>> list(exclude([range(10)], range(2)))
[range(2, 10)]
>>> list(exclude([range(10)], range(2, 4)))
[range(0, 2), range(4, 10)]
piwheels.ranges.intersect(range1, range2)[source]

Given two ranges range1 and range2 (which must both have a step of 1), returns the range formed by the intersection of the two ranges, or None if the ranges do not overlap. For example:

>>> intersect(range(10), range(5))
range(0, 5)
>>> intersect(range(10), range(10, 2))
>>> intersect(range(10), range(2, 5))
range(2, 5)
piwheels.ranges.split(ranges, i)[source]

Given a list of non-overlapping ranges in ascending order, this generator function returns the list with the range containing i split into two ranges, one ending at i and the other starting at i. If i is not contained in any of the ranges, then ranges is returned unchanged. For example:

>>> list(split([range(10)], 5))
[range(0, 5), range(5, 10)]
>>> list(split([range(10)], 0))
[range(0, 10)]
>>> list(split([range(10)], 20))
[range(0, 10)]