HW7 is completed

hw07_file_copying/copy.go

@@ -2,14 +2,70 @@ package main
 
 import (
 	"errors"
+	"fmt"
+	"github.com/cheggaaa/pb"
+	"io"
+	"os"
 )
 
 var (
-	ErrUnsupportedFile       = errors.New("unsupported file")
+	// ErrUnsupportedFile       = errors.New("unsupported file")
 	ErrOffsetExceedsFileSize = errors.New("offset exceeds file size")
+	ErrTheSameFile           = errors.New("you are trying to rewrite the source file")
 )
 
 func Copy(fromPath, toPath string, offset, limit int64) error {
-	// Place your code here.
+	if fromPath == toPath {
+		return ErrTheSameFile
+	}
+
+	inFile, err := os.Open(fromPath)
+	if err != nil {
+		return fmt.Errorf("open input file: %w", err)
+	}
+
+	defer inFile.Close()
+
+	fileStat, err := os.Stat(fromPath)
+	if err != nil {
+		return fmt.Errorf("read input file info: %w", err)
+	}
+
+	fileSize := fileStat.Size()
+	if fileSize < offset {
+		return ErrOffsetExceedsFileSize
+	}
+
+	if limit == 0 {
+		limit = fileSize
+	}
+
+	if limit > fileSize-offset {
+		limit = fileSize - offset
+	}
+
+	outFile, err := os.Create(toPath)
+	if err != nil {
+		return fmt.Errorf("open output file: %w", err)
+	}
+
+	defer outFile.Close()
+
+	if offset > 0 {
+		inFile.Seek(offset, io.SeekStart)
+	}
+
+	bar := pb.StartNew(int(limit))
+	bar.Start()
+
+	reader := bar.NewProxyReader(inFile)
+
+	_, err = io.CopyN(outFile, reader, limit)
+	if err != nil {
+		return fmt.Errorf("copy data to file: %w", err)
+	}
+
+	bar.Finish()
+
 	return nil
 }

hw07_file_copying/copy_test.go

@@ -1,7 +1,59 @@
 package main
 
-import "testing"
+import (
+	"crypto/md5"
+	"fmt"
+	"github.com/stretchr/testify/require"
+	"io"
+	"os"
+	"testing"
+)
+
+func FileMD5(path string) string {
+	h := md5.New()
+	f, err := os.Open(path)
+	if err != nil {
+		panic(err)
+	}
+	defer f.Close()
+	_, err = io.Copy(h, f)
+	if err != nil {
+		panic(err)
+	}
+	return fmt.Sprintf("%x", h.Sum(nil))
+}
 
 func TestCopy(t *testing.T) {
-	// Place your code here.
+	err := Copy("testdata/file_does_not_exist.txt", "/tmp/copy_offset0_limit0.txt", 0, 0)
+	require.Error(t, err)
+
+	err = Copy("testdata/input.txt", "testdata/input.txt", 0, 0)
+	require.Error(t, err)
+
+	err = Copy("testdata/input.txt", "/tmp/offset_is_bigger_then_file_size.txt", 100000, 0)
+	require.Error(t, err)
+
+	err = Copy("testdata/input.txt", "/tmp/copy_offset0_limit0.txt", 0, 0)
+	require.NoError(t, err)
+	require.Equal(t, FileMD5("testdata/out_offset0_limit0.txt"), FileMD5("/tmp/copy_offset0_limit0.txt"))
+
+	err = Copy("testdata/input.txt", "/tmp/copy_offset0_limit10.txt", 0, 10)
+	require.NoError(t, err)
+	require.Equal(t, FileMD5("testdata/out_offset0_limit10.txt"), FileMD5("/tmp/copy_offset0_limit10.txt"))
+
+	err = Copy("testdata/input.txt", "/tmp/copy_offset0_limit1000.txt", 0, 1000)
+	require.NoError(t, err)
+	require.Equal(t, FileMD5("testdata/out_offset0_limit1000.txt"), FileMD5("/tmp/copy_offset0_limit1000.txt"))
+
+	err = Copy("testdata/input.txt", "/tmp/copy_offset0_limit10000.txt", 0, 10000)
+	require.NoError(t, err)
+	require.Equal(t, FileMD5("testdata/out_offset0_limit10000.txt"), FileMD5("/tmp/copy_offset0_limit10000.txt"))
+
+	err = Copy("testdata/input.txt", "/tmp/copy_offset100_limit1000.txt", 100, 1000)
+	require.NoError(t, err)
+	require.Equal(t, FileMD5("testdata/out_offset100_limit1000.txt"), FileMD5("/tmp/copy_offset100_limit1000.txt"))
+
+	err = Copy("testdata/input.txt", "/tmp/copy_offset6000_limit1000.txt", 6000, 1000)
+	require.NoError(t, err)
+	require.Equal(t, FileMD5("testdata/out_offset6000_limit1000.txt"), FileMD5("/tmp/copy_offset6000_limit1000.txt"))
 }

hw07_file_copying/go.mod

@@ -1,3 +1,12 @@
-module github.com/fixme_my_friend/hw07_file_copying
+module github.com/sofiiakulish/hw07_file_copying
 
 go 1.16
+
+require (
+	github.com/cheggaaa/pb v1.0.29
+	github.com/fatih/color v1.10.0 // indirect
+	github.com/mattn/go-runewidth v0.0.12 // indirect
+	github.com/rivo/uniseg v0.2.0 // indirect
+	github.com/stretchr/testify v1.8.0
+	golang.org/x/sys v0.0.0-20220503163025-988cb79eb6c6 // indirect
+)

hw07_file_copying/go.sum

@@ -0,0 +1,39 @@
+github.com/cheggaaa/pb v1.0.29 h1:FckUN5ngEk2LpvuG0fw1GEFx6LtyY2pWI/Z2QgCnEYo=
+github.com/cheggaaa/pb v1.0.29/go.mod h1:W40334L7FMC5JKWldsTWbdGjLo0RxUKK73K+TuPxX30=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/fatih/color v1.9.0/go.mod h1:eQcE1qtQxscV5RaZvpXrrb8Drkc3/DdQ+uUYCNjL+zU=
+github.com/fatih/color v1.10.0 h1:s36xzo75JdqLaaWoiEHk767eHiwo0598uUxyfiPkDsg=
+github.com/fatih/color v1.10.0/go.mod h1:ELkj/draVOlAH/xkhN6mQ50Qd0MPOk5AAr3maGEBuJM=
+github.com/mattn/go-colorable v0.1.4/go.mod h1:U0ppj6V5qS13XJ6of8GYAs25YV2eR4EVcfRqFIhoBtE=
+github.com/mattn/go-colorable v0.1.8 h1:c1ghPdyEDarC70ftn0y+A/Ee++9zz8ljHG1b13eJ0s8=
+github.com/mattn/go-colorable v0.1.8/go.mod h1:u6P/XSegPjTcexA+o6vUJrdnUu04hMope9wVRipJSqc=
+github.com/mattn/go-isatty v0.0.8/go.mod h1:Iq45c/XA43vh69/j3iqttzPXn0bhXyGjM0Hdxcsrc5s=
+github.com/mattn/go-isatty v0.0.11/go.mod h1:PhnuNfih5lzO57/f3n+odYbM4JtupLOxQOAqxQCu2WE=
+github.com/mattn/go-isatty v0.0.12 h1:wuysRhFDzyxgEmMf5xjvJ2M9dZoWAXNNr5LSBS7uHXY=
+github.com/mattn/go-isatty v0.0.12/go.mod h1:cbi8OIDigv2wuxKPP5vlRcQ1OAZbq2CE4Kysco4FUpU=
+github.com/mattn/go-runewidth v0.0.4/go.mod h1:LwmH8dsx7+W8Uxz3IHJYH5QSwggIsqBzpuz5H//U1FU=
+github.com/mattn/go-runewidth v0.0.12 h1:Y41i/hVW3Pgwr8gV+J23B9YEY0zxjptBuCWEaxmAOow=
+github.com/mattn/go-runewidth v0.0.12/go.mod h1:RAqKPSqVFrSLVXbA8x7dzmKdmGzieGRCM46jaSJTDAk=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/rivo/uniseg v0.1.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
+github.com/rivo/uniseg v0.2.0 h1:S1pD9weZBuJdFmowNwbpi7BJ8TNftyUImj/0WQi72jY=
+github.com/rivo/uniseg v0.2.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
+github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/stretchr/testify v1.8.0 h1:pSgiaMZlXftHpm5L7V1+rVB+AZJydKsMxsQBIJw4PKk=
+github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
+golang.org/x/sys v0.0.0-20190222072716-a9d3bda3a223/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20191026070338-33540a1f6037/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200116001909-b77594299b42/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200223170610-d5e6a3e2c0ae/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20220503163025-988cb79eb6c6 h1:nonptSpoQ4vQjyraW20DXPAglgQfVnM9ZC6MmNLMR60=
+golang.org/x/sys v0.0.0-20220503163025-988cb79eb6c6/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

hw07_file_copying/main.go

@@ -18,5 +18,5 @@ func init() {
 
 func main() {
 	flag.Parse()
-	// Place your code here.
+ 	Copy(from, to, offset, limit)
 }