Hi there,
I am using the STL map and I print the map using:
map <string, float> ngram_token_index ;
map <string, float>::iterator map_iter ;
//read the map
...
// print the map
for ( map_iter = ngram_token_index.begin() ; map_iter != ngram_token_index.end() ; map_iter++ )
cout << ... (2 Replies)
Help me please with STL source code that works on Windows
I've found on Inet STL MRU Cache (it compiles fine with Studio 2008), but when trying to build it with Kdevelop (g++ is the compiler) I've got a series of error. One of them I've placed in the source code. If it's important I can post here... (0 Replies)
hi all
i have a tree structure:
root --- node 1 to node 10
in each node --- sub node 1 to sub node 10
in each sub node --- leaf node 1 to leaf node 10
i have to print this in following fashion:
root ---- n1 ---- sn1 ---- l1, l2, l3, ....., l10
n1 ---- sn2 ---- l1, l2, l3,... (2 Replies)
Hi, guys.
I am working on a project right now. But when I debug my code, I can't see the values in stl container, e.g vector, map. Can anyone help me, please. I am really frustrated:wall:. I am using code::blocks IDE, by the way. Thanks in advance...... (0 Replies)
Hi all,
I pass to the transform algorithm two vectors, and the suma function.
#include <algorithm>
#include <iostream>
#include <iterator>
#include <vector>
using namespace std;
class Duo{
public:
int one;
int two;
};
Duo suma(Duo first, Duo last){
Duo ret;
... (1 Reply)
Discussion started by: santiagorf
1 Replies
LEARN ABOUT DEBIAN
bup-margin
bup-margin(1) General Commands Manual bup-margin(1)NAME
bup-margin - figure out your deduplication safety margin
SYNOPSIS
bup margin [options...]
DESCRIPTION
bup margin iterates through all objects in your bup repository, calculating the largest number of prefix bits shared between any two
entries. This number, n, identifies the longest subset of SHA-1 you could use and still encounter a collision between your object ids.
For example, one system that was tested had a collection of 11 million objects (70 GB), and bup margin returned 45. That means a 46-bit
hash would be sufficient to avoid all collisions among that set of objects; each object in that repository could be uniquely identified by
its first 46 bits.
The number of bits needed seems to increase by about 1 or 2 for every doubling of the number of objects. Since SHA-1 hashes have 160 bits,
that leaves 115 bits of margin. Of course, because SHA-1 hashes are essentially random, it's theoretically possible to use many more bits
with far fewer objects.
If you're paranoid about the possibility of SHA-1 collisions, you can monitor your repository by running bup margin occasionally to see if
you're getting dangerously close to 160 bits.
OPTIONS --predict
Guess the offset into each index file where a particular object will appear, and report the maximum deviation of the correct answer
from the guess. This is potentially useful for tuning an interpolation search algorithm.
--ignore-midx
don't use .midx files, use only .idx files. This is only really useful when used with --predict.
EXAMPLE
$ bup margin
Reading indexes: 100.00% (1612581/1612581), done.
40
40 matching prefix bits
1.94 bits per doubling
120 bits (61.86 doublings) remaining
4.19338e+18 times larger is possible
Everyone on earth could have 625878182 data sets
like yours, all in one repository, and we would
expect 1 object collision.
$ bup margin --predict
PackIdxList: using 1 index.
Reading indexes: 100.00% (1612581/1612581), done.
915 of 1612581 (0.057%)
SEE ALSO bup-midx(1), bup-save(1)BUP
Part of the bup(1) suite.
AUTHORS
Avery Pennarun <apenwarr@gmail.com>.
Bup unknown-bup-margin(1)