bufferheap.go

package main

import (
	"os"
)

type BufferHeap struct {
	bp     *BufferPool
	Size   int
	report *Report
}

func NewBufferHeap(file string, recordSize, blockSize, capacity int, report *Report) *BufferHeap {

	info, err := os.Stat(file)

	if err != nil {
		panic(err)
	}

	size := int(info.Size() / int64(recordSize))

	return &BufferHeap{
		NewBufferPool(file, recordSize, blockSize, capacity, report),
		size,
		report,
	}
}

func (heap *BufferHeap) Len() int {
	return heap.Size
}

func (heap *BufferHeap) Less(i, j int) bool {
	i64 := int64(i)
	j64 := int64(j)
	return heap.bp.GetRecord(i64).Key < heap.bp.GetRecord(j64).Key
}

func (heap *BufferHeap) Swap(i, j int) {
	i64 := int64(i)
	j64 := int64(j)
	iRecord := heap.bp.GetRecord(i64)
	jRecord := heap.bp.GetRecord(j64)

	heap.bp.WriteRecord(jRecord, i64)
	heap.bp.WriteRecord(iRecord, j64)
}

func (heap *BufferHeap) Sort() {
	heap.report.Start()
	HeapSort(heap)
	heap.report.End()
}

func (heap *BufferHeap) Shutdown() {
	heap.bp.Shutdown()
}