Slight grammar and spelling nits; updated mx.Proxy URL; added

reference to EST's pyweak.
This commit is contained in:
Guido van Rossum 2000-11-28 13:43:00 +00:00
parent 4a75be97f2
commit 5f1f83ce6e
1 changed files with 14 additions and 12 deletions

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@ -15,7 +15,7 @@ Motivation
Caches (weak dictionaries)
There is a need to allow objects to be maintained to represent
There is a need to allow objects to be maintained that represent
external state, mapping a single instance to the external
reality, where allowing multiple instances to be mapped to the
same external resource would create unnecessary difficulty
@ -38,7 +38,7 @@ Motivation
back to disk in whole rather than locked & modified for
every use.
- Objects which are expensive to create, but may be needed by
- Objects that are expensive to create, but may be needed by
multiple internal consumers. Similar to the first case, but
not necessarily bound to external resources, and possibly
not an issue for shared state. Weak references are only
@ -78,7 +78,7 @@ Weak References in Java
tables. This can be a performance bottleneck if deallocations of
the stored objects are infrequent.
Java's "weak" references are most like Diane Hackborn's old vref
Java's "weak" references are most like Dianne Hackborn's old vref
proposal: a reference object refers to a single Python object,
but does not own a reference to that object. When that object is
deallocated, the reference object is invalidated. Users of the
@ -103,19 +103,17 @@ Weak References in Java
Previous Weak Reference Work in Python
Dianne Hackborn's proposed something called "virtual references".
'vref' objects were very similar to java.lang.ref.WeakReference
objects, except there was no equivalent to the invalidation
Dianne Hackborn has proposed something called "virtual references".
'vref' objects are very similar to java.lang.ref.WeakReference
objects, except there is no equivalent to the invalidation
queues. Implementing a "weak dictionary" would be just as
difficult as using only weak references (without the invalidation
queue) in Java. Information on this has disappeared from the Web.
Original discussion occurred in the comp.lang.python newsgroup; a
good archive of that may turn up something more.
queue) in Java. Information on this has disappeared from the Web,
but is included below as an Appendix.
Marc-André Lemburg's mx.Proxy package. These Web pages appear to
be unavailable at the moment.
Marc-André Lemburg's mx.Proxy package:
http://starship.python.net/crew/lemburg/
http://www.lemburg.com/files/python/mxProxy.html
The weakdict module by Dieter Maurer is implemented in C and
Python. It appears that the Web pages have not been updated since
@ -128,6 +126,10 @@ Previous Weak Reference Work in Python
http://sourceforge.net/projects/pyweakreference/
Eric Tiedemann has a weak dictionary implementation:
http://www.hyperreal.org/~est/python/weak/
Possible Applications