Rename HeapDump to ObjectDump

object_dump.go

@@ -0,0 +1,100 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"os"
+	"sort"
+)
+
+func NewObjectDump(file string) (*ObjectDump, error) {
+	heapDump := ObjectDump{File: file}
+	err := heapDump.Process()
+	return &heapDump, err
+}
+
+// ObjectDump contains all relevant data for a single heap dump.
+type ObjectDump struct {
+	File    string
+	Index   []string
+	Entries map[string]*Entry
+}
+
+// Process processes the heap dump
+func (s *ObjectDump) Process() error {
+	file, err := os.Open(s.File)
+	defer file.Close()
+
+	if err != nil {
+		return err
+	}
+
+	s.Entries = map[string]*Entry{}
+
+	reader := bufio.NewReader(file)
+	var offset int64 = -1
+	for {
+		offset++
+		line, err := reader.ReadBytes(byte('\n'))
+		if err == io.EOF {
+			break
+		} else if err != nil {
+			return err
+		}
+
+		entry, err := NewEntry(line)
+		if err != nil {
+			return err
+		}
+
+		entry.Offset = offset
+		s.Entries[entry.Index] = entry
+		s.Index = append(s.Index, entry.Index)
+	}
+
+	return nil
+}
+
+func (s *ObjectDump) PrintMatchingJSON(indexes *[]string) error {
+	file, err := os.Open(s.File)
+	defer file.Close()
+
+	if err != nil {
+		return err
+	}
+
+	reader := bufio.NewReader(file)
+	offsets := s.matchingOffsets(indexes)
+
+	var current int64 = 0
+	var offset int64 = -1
+
+	for {
+		offset++
+		line, err := reader.ReadBytes(byte('\n'))
+		if err == io.EOF {
+			break
+		} else if err != nil {
+			return err
+		}
+
+		if offset == offsets[current] {
+			current++
+			fmt.Print(string(line))
+		}
+	}
+
+	return nil
+}
+
+func (s *ObjectDump) matchingOffsets(indexes *[]string) []int64 {
+	var offsets []int64
+
+	for _, index := range *indexes {
+		offsets = append(offsets, s.Entries[index].Offset)
+	}
+
+	sort.Slice(offsets, func(i, j int) bool { return offsets[i] < offsets[j] })
+	return offsets
+}