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version 1338, Fri Aug 15 19:39:06 2003 UTC version 1573, Sun Dec 28 00:14:24 2003 UTC
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  Changed, Enhanced, or Newly Deprecated Features   Changed, Enhanced, or Newly Deprecated Features
   
  - 'peak.running.scheduler.MainLoop' now supports using a "signal manager"   - Added 'config.iterKeys()' which iterates over all available configuration
    component (via the 'peak.running.signalManager' property) to process signals     keys in a given namespace (just property names for now).  The 'config:'
    while a 'run()' loop is in progress.  Signal managers can also be added or     namespace is now a 'naming.IReadContext', so you can navigate it with the
    removed at any time via the new 'peak.util.signal_stack' module.     'n2' command, and do things like 'ls -l config:peak.naming.schemes' to list
      all configured naming schemes.
   
    - Added 'config.parentProviding()' and 'config.parentsProviding()', which
      find the first (or all) parent components of a given component that support
      a given protocol.
   
    - Renamings/refactorings/deprecations in 'peak.config':
   
       'config.getProperty' -- use 'config.lookup()' instead
   
       'config.findUtility' -- use 'config.lookup()' instead
   
       'config.findUtilities' -- use 'config.iterValues()' instead
   
       'config.IPropertyMap' -- use 'config.IConfigMap' or 'config.IConfigurable'
   
       'config.PropertyMap' -- use 'config.ConfigMap' instead
   
       'config.setPropertyFor' -- DEPRECATED, see source for replacement code.
   
       'config.setRuleFor' -- DEPRECATED, see source for replacement code.
   
       'config.setDefaultFor' -- DEPRECATED, see source for replacement code.
   
       'config.instancePerComponent' -- DEPRECATED, use factories instead.
   
       'config.IConfigurationRoot' -- interface has changed; 'propertyNotFound' is
       no longer a method, and 'noMoreUtilities' is now 'noMoreValues'.
   
       'exceptions.PropertyNotFound' -- use 'exceptions.NameNotFound' instead.
   
       'exceptions.OutOfScope' -- REMOVED; it was not actually used in PEAK.
   
      In all cases, the old interface, class, or function is DEPRECATED and will
      go away in the alpha 4 release cycle.  Please take particular note of the
      fact that 'IConfigMap' offers virtually none of the convenience
      methods provided by 'IPropertyMap', so adjust your code accordingly.  Note
      also that even though there are plenty of references to 'IPropertyMap'
      remaining in PEAK itself, these are strictly to provide backward
      compatibility.  Once we enter the alpha 4 release cycle, these will go away.
   
    - Added 'config.MultiKey()' and 'config.UnionOf()' configuration key classes,
      to generalize existing specialty keys such as 'ProviderOf' and 'FactoryFor'.
      (The latter two are now defined in terms of the former two.)  Also, made
      classes and types usable as configuration keys.  This was needed for the
      above generalization, but also makes many other class-lookup concepts
      possible.  (Note that there may be some slight changes to the effective
      registration and lookup order of these and other configuration keys as of
      this change, as there were some previous errors and/or ambiguities to the
      lookup order that were not covered by the test suite.)
   
    - Added "[Import on Demand]" section type to .ini files, allowing you to
      define shortcuts for modules that you frequently reference in your
      configuration.  This lets you replace e.g. 'importString("foo.bar.baz:Spam")'
      with 'foo_baz.Spam' in expressions, by adding something like this::
   
       [Import on Demand]
       foo_bar = "foo.bar.baz"
   
      to your configuration.  The defined shortcut is then available for the
      remainder of that configuration file, and in any .ini files included from
      the current file.  See 'peak.ini' for an example and more info.
   
    - Logging-related interfaces have been moved into the 'peak.running.logs'
      module.  So, what used to be 'running.ILogger' is now 'logs.ILogger'.
   
    - Log events now use a standard component construction signature, and the
      class used for event objects is now configurable as the factory for
      'logs.ILogEvent'.  (See "[Component Factories]" in 'peak.ini'.)
   
    - By popular demand, 'logs.ILogger' (and its default implementation) now
      includes 'trace()', 'notice()', 'alert()' and 'emergency()' methods that use
      the corresponding 'syslog' priority levels.  'logs.IBasicLogger' has been
      added, to reflect the narrower interface provided by PEP 282, and there is
      an adapter that can extend PEP 282 loggers with the other methods.
   
    - The 'logging.logger:' URL scheme has been simplified to 'logger:'.  Please
      convert your scripts and configuration files, as the longer form will go
      away in the alpha 4 development cycle.
   
    - Added 'commands.lookupCommand()' to look up a command shortcut or URL, ala
      the 'peak' script or 'commands.Bootstrap' class.  Also added various
      'commands.ErrorSubcommand' subclasses to make it easier to issue errors
      from/for subcommands.
   
    - Added 'peak.core' as a minimal subset of 'peak.api'.  'peak.core' offers
      only "core" API packages and primitives, not the full set of available
      framework APIs.  'peak.api' will continue to expand as frameworks are added,
      but 'peak.core' will stay as small as practical.  ('peak.exceptions' may in
      fact end up being removed from 'peak.core', or at least renamed.)
   
    - Added 'peak.util.symbol' module, to contain 'NOT_GIVEN', 'NOT_FOUND', and
      the 'Symbol' class used to create them.
   
    - 'peak.running.tools' was promoted to 'peak.tools'.  'peak.running.supervisor'
      was also moved to 'peak.tools.supervisor', and a new 'peak help' command was
      added in 'peak.tools.api_help'.
   
    - Replaced the "[Provide Utilities]" section of .ini files with "[Component
      Factories]".  The new section type is easier to use, much more versatile,
      and does all registration and imports lazily.  See the 'peak.ini' file for
      docs.  "[Provide Utilities]" and 'config.ProvideInstance()' are now
      DEPRECATED, so please convert ASAP.
   
    - 'binding.Make()' now accepts configuration keys, using them to look up a
      factory object that's then invoked to create the attribute.  This makes it
      a lot easier to define a component with its own transaction service,
      'IBasicReactor', or other normally "global" component.  It also makes it
      easier to globally specify a factory class for some interface.  Factories
      are looked up under the 'config.FactoryFor(key)' configuration key.  (See
      below.)
   
    - Added 'config.FactoryFor(key)', a 'config.IConfigKey' implementation that
      provides a configuration namespace for factories.
   
      When you use 'binding.Make(ISomething)', it's roughly equivalent to::
   
           binding.Make(
               lambda self,d,a:
                   binding.lookupComponent(
                       self, config.FactoryFor(ISomething),
                       adaptTo = binding.IRecipe
                   )(self,d,a)
           )
   
      That is, the 'config.FactoryFor(ISomething)' is looked up and invoked.
   
    - Added 'config.CreateViaFactory(key)', a 'config.IRule' implementation that
      creates an implementation of 'key', by looking up 'config.FactoryFor(key)'
      and invoking it.
   
    - Added 'config.ruleForExpr(name,expr)', that returns a 'config.IRule' that
      computes the Python expression in the string 'expr'.  This is the mechanism
      used by configuration files to create rules, factored out into an API call
      so that configuration extensions can use it, too.
   
    - The 'referencedType' of a 'model.StructuralFeature' can now be any
      'binding.IComponentKey', not just a type or a string.  Types are also now
      implicitly component keys, which means you can use 'binding.Obtain(SomeType)'
      to look up 'SomeType'.  (Right now, this is no different than using 'SomeType'
      without the 'binding.Obtain()', but in future releases this will use a
      "class replacement service" to allow easy replacement of model and other
      collaborator classes, while implementing AOP-like features.)
   
    - Added 'naming.Indirect(key)', a 'binding.IComponentKey' that can be used to
      do an indirect lookup via another 'IComponentKey' (such as a name).
   
      Using 'naming.Indirect()', you can replace code like this::
   
           socket = binding.Obtain(
               lambda self: self.lookupComponent(self.socketURL),
               adaptTo=[IListeningSocket]
           )
   
      with code like this::
   
           socket = binding.Obtain(
               naming.Indirect('socketURL'), adaptTo=[IListeningSocket]
           )
   
    - Added 'peak.tools.supervisor', a mini-framework for pre-forking,
      multiprocess servers, such as for FastCGI.  The framework includes a ZConfig
      schema for process supervisors, and support for automatically forking new
      children (up to a predefined maximum, with a minimum interval between
      launches) when a socket has pending connections and all of its child
      processes are busy.  With this setup, you can take more advantage of
      multiprocessor machines for CPU-intensive services.
   
    - Standardized these characteristics of name and address syntax:
   
      * '//' at the beginning of URL bodies is *mandatory* when the URL begins
        with an "authority" as described by RFC 2396.  When the URL is not
        required to contain an authority (e.g. 'peak.storage.SQL.GenericSQL_URL'),
        the '//' is *optional*, and the canonical form of the URL will not include
        it.
   
      * Standardized names for RFC 2396 fields: 'user', 'passwd', 'host', and
        'port'.
   
    - Added 'peak.metamodels.ASDL', a metamodel for the Zephyr Abstract Syntax
      Description Language.  ASDL is a convenient way to describe a domain model
      for an abstract syntax tree (AST), and the models generated with the new
      ASDL tool can be combined with concrete syntax to create a complete parsing
      solution for "mini languages", possibly including the Python language
      itself.  (Future versions of the Python and Jython compilers are likely to
      use AST models based on ASDL, and in the current Python CVS sandbox there's
      already an ASDL model of Python's AST available.)
   
    - Enhanced 'fmtparse' and 'peak.model' to allow using types as syntax rules
      for parsing, including abstract types.  An abstract type's syntax is the
      union (using 'fmtparse.Alternatives') of the syntaxes of its subclasses
      (as specified by 'mdl_subclassNames').
   
    - Added 'IMainLoop.setExitCode()' and 'IMainLoop.childForked()' methods, to
      allow reactor-driven components to control the mainloop's exit code.
   
    - Added 'running.ISignalManager' and a default implementation.  Use its
      'addHandler()/removeHandler()' methods to add or remove signal handlers.
      Signal handlers define methods like 'def SIGCHLD(self,signum,frame):' that
      will be called when the associated signal is received.  All active handlers
      for a given signal are invoked, so you can easily have multiple components
      listen for 'SIGCHLD', for example.
   
    - Added 'IBasicReactor.crash()', which forces an immediate reactor loop exit,
      ignoring pending scheduled calls.
   
    - Added 'peak.running.commands.runMain()', a convenience function for starting
      an application's "main" command, that also makes it easy for forked child
      processes to exit and replace the parent process' "main".  The 'peak' script
      has now been shortened to::
   
          from peak.running import commands
          commands.runMain( commands.Bootstrap )
   
      so it's now much easier to create alternative startup scripts, if you need
      to, or to add an 'if __name__=="__main__"' clause to a module.
   
    - Added 'peak.util.mockdb', a "mock object" implementation of a DBAPI 2.0
      driver module.  'mockdb' connections can be told to 'expect()' queries
      and 'provide()' data to their callers, and will raise AssertionErrors when
      they are used in a way that doesn't conform to your supplied expectations.
      This is intended to be used for unit testing components that depend on
      a database connection: you can verify that they send the right SQL, and
      you can provide them with dummy data to use.  There is also a 'mockdb:' URL
      and peak.storage driver, so you can easily use a mock DB connection in place
      of a real one within a PEAK application, for testing purposes.  Note,
      however, that 'peak.util.mockdb' is a DBAPI 2.0 driver in itself, and thus
      can also be used to test DBAPI usage outside of PEAK.
   
    - SQL connection objects now provide an 'appConfig' attribute that is a
      driver-specific 'config.Namespace()'.  This allows you to easily set up
      configuration properties that are driver-specific.  For example, you could
      use properties to configure driver-specific SQL snippets, then access them
      via the connection's 'appConfig' namespace.  The namespaces are of the form
      'DRIVER.appConfig', where 'DRIVER' is the name of the DBAPI module for that
      connection type (e.g. 'pgdb', 'cx_Oracle', etc.).
   
    - Added 'config.Namespace()' convenience class for redirecting property
      lookups from one namespace to another.  See the docstring and 'peak.ini' for
      usage examples.  'PropertyName.of()' now returns 'Namespace' instances
      instead of 'PropertySet' instances.
   
    - DEPRECATED the 'config.PropertySet' class; please convert to using
      'config.Namespace', as 'PropertySet' will disappear in the 0.5alpha4 release
      cycle.
   
    - SQL connection objects now get their type converters from a distinct
      property namespace for each DBAPI driver.  For example a driver using the
      'cx_Oracle' module will get its type converters from the
      'cx_Oracle.sql_types' property namespace, instead of 'peak.sql_types'.  For
      backward compatibility, these driver-specific namespaces are set up to
      fall back to 'peak.sql_types' for their defaults.  Type converter
      construction has also been improved, to eliminate conversion overhead
      completely when no conversions are required for a specific query.  Also,
      SQL connections now offer a method that will create a row conversion
      function for a given result description and optional postprocessing
      function.  This new method should now be used in place of direct access to
      the 'typeMap' attribute of connection objects.
   
    - Added 'binding.Require', 'binding.Obtain', 'binding.Make', and
      'binding.Delegate'.  *ALL* other binding types are now DEPRECATED, and will
      go away before 0.5 beta is released:
   
      'requireBinding("info")' -- use 'Require("info")'
   
      'delegateTo("attr")' -- use 'Delegate("attr")'
   
      'New(type)' -- use 'Make(type)'
   
      'New("module.type")' -- use 'Make("module.type")'
   
      'bindTo(key)' -- use 'Obtain(key)'
   
      'Constant(value)' -- use 'Make(lambda: value)'
   
      'Acquire(key)' -- use 'Obtain(key, offerAs=[key,])'
   
      'Copy(value)' -- use 'Make(lambda: <expr to copy value>)'
   
      'whenAssembled(func)' -- use 'Make(func, uponAssembly=True)'
   
      'bindSequence(key1,key2,...)' -- use 'Obtain([key1,key,...])'
   
      'bindToProperty(x,y)' -- use 'Obtain(PropertyName(x),default=y)'
   
      'bindToParent()' -- use 'Obtain("..")'
   
      'bindToSelf()'  -- use 'Obtain(".")'
   
      'bindToUtilities()' -- no replacement; let me know if you're using this.
   
      Note that 'Make' and 'Obtain' also support sequences of recipes and keys,
      and in those cases will produce a sequence of the results from those recipes
      or keys.  Also, 'Make' will accept no-argument and one-argument callables,
      where 'Once' always required three-argument functions.  This should make it
      a lot easier to write short binding functions.
   
      Also, note that the 'activateUponAssembly' keyword is now 'uponAssembly',
      and 'isVolatile' is now 'noCache'.  (The old names will work as keyword
      arguments until the alpha 4 development cycle begins.)  The
      'binding.IActiveDescriptor' interface also changed as a result of this.
      Last, but not least, a 'binding.IRecipe' interface was added, to support the
      new 'binding.Make' type.
   
   
    - Added a 'lockName' attribute to 'runnning.AdaptiveTask', and a 'LockURL'
      setting to its ZConfig schema.  This allows a lockfile URL to be specified
      for adaptive tasks that need exclusive access to some resource while
      running.
   
    - A list or tuple of 'IComponentKey' instances is now treated as a single
      component key, that returns a tuple of the values returned by each
      constituent component key.  This means that 'binding.Obtain()' and
      'lookupComponent()' can now accept a list or tuple of component keys.  This
      makes 'bindSequence()' obsolete, so 'bindSequence()' is now DEPRECATED.
      'binding.bindSequence(key1,key2,...)' can now be replaced with
      'binding.Obtain([key1,key,...])', and will produce the same results.
   
    - 'naming.IBasicContext.lookup()' and 'naming.lookup()' now accept a 'default'
      argument, similar to that used by 'lookupComponent()' and most other
      lookup-like APIs in PEAK.  This change was made so that component lookups
      don't need to rely on catching 'exceptions.NameNotFound' errors to tell them
      when to use the default value.  This could hide 'NameNotFound' errors that
      were actually from a broken component somewhere in the lookup process.  (In
      general, it's probably a bad idea to have an exception that's used for both
      control flow and real errors!)
   
    - Added new 'version' tool that automatically edits files to update version
      information in them.  Just execute the 'version' file in the main PEAK
      source directory.  (Use '--help' for help.)  You can use this tool with your
      own projects by creating 'version' and 'version.dat' files in your project
      directory, similar to the ones used by PEAK.  The 'version' file is a ZConfig
      file that describes your project's version numbering scheme(s), formats,
      and the files that need to be edited, while the 'version.dat' file contains
      the current version number values.  Source for the tool, including the
      configuration file schema, is in the 'peak.tools.version' package.
      (Error handling and documentation, alas, are still minimal.)
   
    - Added new 'Alias' command in 'peak.running.commands'.  An 'Alias' instance
      can be used as a 'peak.running.shortcut' property that expands to another
      command with arbitrary arguments inserted before the original command's
      arguments.  Thus, one might alias 'mycommand' to 'runIni somefile --option',
      similar to command aliases in many shells.
   
    - 'naming.IName' is now derived from 'binding.IComponentKey', so names and
      addresses must now support the 'findComponent()' method.  All PEAK name and
      address types provide support for this.
   
    - The 'lookup()' method of 'binding.IComponentKey' is now called
      'findComponent()', to better distinguish it from 'lookup()' in
      'naming.IBasicContext', which does something very different.
   
    - 'binding.Obtain()' (formerly 'binding.bindTo()' and 'binding.bindSequence()')
      now pre-adapt their arguments to 'IComponentKey', to speed up lookups at
      runtime, and to ensure that errors due to an unusable parameter type occur
      at class creation time instead of waiting until lookup time.
   
    - There's a new 'peak.storage.files' module, with handy classes like
      'EditableFile'.  'EditableFile' is a class that lets you edit the contents
      of a file "in place", with atomic replacement of the original at transaction
      commit.  If the transaction is aborted, the original file is left unchanged.
   
    - 'peak.running.scheduler.UntwistedReactor' now supports a configuration
      property ('peak.running.reactor.checkInterval') to determine how long it
      should run 'select()' calls for, when there are no scheduled tasks.
   
    - 'peak.running.scheduler.MainLoop' now supports using a "signal
      handler" component (via the 'peak.running.mainLoop.signalHandler' property)
      to process signals while a 'run()' loop is in progress.  Signal handlers can
      also be added or removed at any time via the 'running.ISignalManager'
      service.
   
  - 'peak.running.commands.AbstractCommand' now offers a '_run()' method that   - 'peak.running.commands.AbstractCommand' now offers a '_run()' method that
    can be overridden in subclasses, instead of 'run()'.  If you override the     can be overridden in subclasses, instead of 'run()'.  If you override the
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    means you should change 'return foo, None' statements to just 'return foo'.     means you should change 'return foo, None' statements to just 'return foo'.
   
  - Property definition rules in an .ini file can now refer to 'rulePrefix' and   - Property definition rules in an .ini file can now refer to 'rulePrefix' and
    'ruleSuffix' variables.  'rulePrefix' is a '.'-terminated string,     'ruleSuffix' variables.  'rulePrefix' is a "."-terminated string,
    representing the name the rule was defined with.  For example, if the     representing the name the rule was defined with.  For example, if the
    rule was defined for '"foo.bar.*"', then 'rulePrefix' will be '"foo.bar."'.     rule was defined for '"foo.bar.*"', then 'rulePrefix' will be '"foo.bar."'
   
    The 'ruleSuffix' will be the portion of the 'propertyName' that follows     The 'ruleSuffix' will be the portion of the 'propertyName' that follows
    'rulePrefix'.  So, if looking up property '"foo.bar.baz"', then the     'rulePrefix'.  So, if looking up property '"foo.bar.baz"', then the
    '"foo.bar.*"' rule will execute with a 'ruleSuffix' of '"baz"'.  This should     '"foo.bar.*"' rule will execute with a 'ruleSuffix' of '"baz"'.  This should
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  Corrected Problems   Corrected Problems
   
     - 'peak.running.commands.CGICommand' could become confused on certain BSD
       variants (such as Mac OS/X), and assume it was running under FastCGI, even
       if it wasn't.  (Because the operating systems in question use socket pairs
       to implement pipes.)
   
     - Fixed some problems with the test suite when running under Python 2.3.
       PEAK itself worked fine, but the test suite was bitten by two minor
       semantic changes that took effect in 2.3, resulting in lots of error
       messages about ModuleType needing a parameter, and a test failure for
       'checkClassInfo' in the 'FrameInfoTest' test class.
   
     - Transaction participants that raised an error in their 'abortTransaction()'
       method, would not receive a 'finishTransaction()' call, the error was
       passed through to the transaction service's caller, and later participants
       might not have received an 'abortTransaction()' message either.
   
     - SQL connections didn't close their cursors before aborting a transaction
   
     - The logging system would raise an error if a log message with no arguments
       contained a '%' sign.
   
   - There was a typo in peak.naming.arithmetic that caused homogeneous non-URL    - There was a typo in peak.naming.arithmetic that caused homogeneous non-URL
     name subtraction to fail.      name subtraction to fail.
   


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