var BufferPool = require('../lib/BufferPool');
require('should');

describe('BufferPool', function() {  
  describe('#ctor', function() {
    it('allocates pool', function() {
      var db = new BufferPool(1000);
      db.size.should.eql(1000);
    })
  })
  describe('#get', function() {
    it('grows the pool if necessary', function() {
      var db = new BufferPool(1000);
      var buf = db.get(2000);
      db.size.should.be.above(1000);
      db.used.should.eql(2000);
      buf.length.should.eql(2000);
    })
    it('grows the pool after the first call, if necessary', function() {
      var db = new BufferPool(1000);
      var buf = db.get(1000);
      db.used.should.eql(1000);
      db.size.should.eql(1000);
      buf.length.should.eql(1000);
      var buf2 = db.get(1000);
      db.used.should.eql(2000);
      db.size.should.be.above(1000);
      buf2.length.should.eql(1000);
    })
    it('grows the pool according to the growStrategy if necessary', function() {
      var db = new BufferPool(1000, function(db, length) {
        return db.size + 2345;
      });
      var buf = db.get(2000);
      db.size.should.eql(3345);
      buf.length.should.eql(2000);
    })
    it('doesnt grow the pool if theres enough room available', function() {
      var db = new BufferPool(1000);
      var buf = db.get(1000);
      db.size.should.eql(1000);
      buf.length.should.eql(1000);      
    })
  })
  describe('#reset', function() {
    it('shinks the pool', function() {
      var db = new BufferPool(1000);
      var buf = db.get(2000);
      db.reset();
      db.size.should.eql(1000);
    })
    it('shrinks the pool according to the shrinkStrategy', function() {
      var db = new BufferPool(1000, function(db, length) {
        return db.used + length;
      }, function(db) {
        return 0;
      });
      var buf = db.get(2000);
      db.reset();
      db.size.should.eql(0);
    })
  })
})