Created
August 7, 2015 22:59
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#!/usr/local/bin/node | |
/* | |
SET a 10 | |
SET b 10 | |
NUMEQUALTO 10 2 | |
NUMEQUALTO 20 0 | |
SET b 30 | |
NUMEQUALTO 10 1 | |
END | |
*/ | |
function SimpleDatabase() | |
{ | |
// .. private variables | |
var reverseLookup = {}, | |
dataBag = {}; | |
// .. private methods | |
var update = function (dict, key, incr){ | |
if(!dict[key]){ | |
dict[key] = incr; | |
} | |
else{ | |
dict[key] += incr; | |
} | |
}, | |
set = function(args){ | |
var key = args[1], | |
value = parseInt( args[2] ); | |
key = key.toString(); | |
update(dataBag, key, value); | |
update(reverseLookup, value, 1); | |
}, | |
numEqualTo = function(args){ | |
var key = args[1]; | |
key = key.toString(); | |
return (reverseLookup[key] ? reverseLookup[key] : ''); | |
}, | |
get = function(args){ | |
var key = args[1]; | |
key = key.toString(); | |
return dataBag[key]; | |
}, | |
unset = function(args){ | |
var key = args[1], | |
val = dataBag[key]; | |
delete dataBag[key]; | |
reverseLookup[val] -= 1; | |
}; | |
// .. public methods | |
this.processCommand = function(cmd){ | |
var args = cmd.split('\n'), | |
args = args[0].split(' '); | |
// if(args && Array.isArray(args) && args.length > 0){} // .. do validation of the input args | |
switch(args[0]){ | |
case 'SET': | |
return set(args); | |
case 'NUMEQUALTO': | |
return numEqualTo(args); | |
case 'UNSET': | |
return unset(args); | |
case 'GET': | |
return get(args); | |
case 'END': | |
dataBag = {}; | |
reverseLookup = {}; | |
break; | |
} | |
}; | |
} | |
process.stdin.resume(); | |
process.stdin.setEncoding('utf8'); | |
var util = require('util'), | |
db = new SimpleDatabase(); | |
process.stdin.on('data', function (text) { | |
var out = db.processCommand(text); | |
if(out){ | |
console.log( out ); | |
} | |
}); |
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