(original) (raw)

On Dec 10, 2012, at 7:04 PM, Mark Shannon <mark@hotpy.org> wrote:

Another approach is to pre-allocate the two-thirds maximum

(This is simple and fast but gives the smallest space savings.)

What do you mean by maximum?

A dict with an index table size of 8 gets resized when it is two-thirds full,

so the maximum number of entries is 5\. If you pre-allocate five entries

for the initial dict, you've spent 5 \* 24 bytes + 8 bytes for the indices

for a total of 128 bytes. This compares to the current table of 8 \* 24 bytes

totaling 192 bytes.

Many other strategies are possible. The proof-of-concept code

uses the one employed by regular python lists.

Their growth pattern is: 0, 4, 8, 16, 25, 35, 46, 58, 72, 88, ....

This produces nice memory savings for entry lists.

If you have a suggested allocation pattern or other

constructive suggestion, it would be would welcome.

Further sniping and unsubstantiated FUD would not.

Raymond