feat: allow reuse of random source

cli/random-data/README.md

@@ -21,17 +21,17 @@ USAGE
 OPTIONS:
   -b64
         base-64 encode output
-  -seed int
-        random seed, 0 or unset for current time
+  -seed string
+        random seed, leave empty to use random value
   -size int
         number of bytes to generate
 ```
 
 ## Examples
 
 ```sh
-random-data -size=64 -b64
-vRujjyEvx8lYiELflaDINvkm5nfueWGCdzEOxhRtz7N2EQjoyrpoMdVVOrwAgNO0tVojDAgu0JpU4hKSsdVl8A==
+random-data -size=64 -b64 -seed=hello
+ce6rEiwW4jN+E6pCW8UZErXC21sGpkTFuaPEW8VrtayX6nhbbSHOmkFQ1MoHbB2KU2J0ocATYGK4JFEsYNEtlA==
 ```
 
-Note: Specifying the same seed will produce the same results.
+Note: Specifying the same seed will produce the same results. Specifying no ssed procudes random results.

cli/random-data/main.go

@@ -6,7 +6,6 @@ import (
 	"flag"
 	"fmt"
 	"io"
-	"math/rand"
 	"os"
 
 	random "github.com/ipfs/go-test/random"
@@ -29,11 +28,11 @@ OPTIONS:
 
 	var (
 		b64  bool
-		seed int64
+		seed string
 		size int64
 	)
 	flag.BoolVar(&b64, "b64", false, "base-64 encode output")
-	flag.Int64Var(&seed, "seed", 0, "random seed, 0 or unset for current time")
+	flag.StringVar(&seed, "seed", "", "random seed, leave empty to use random value")
 	flag.Int64Var(&size, "size", 0, "number of bytes to generate")
 	flag.Parse()
 
@@ -54,12 +53,12 @@ OPTIONS:
 	}
 }
 
-func writeData(seed, size int64, b64 bool) error {
-	var rnd *rand.Rand
-	if seed == 0 {
-		rnd = random.NewRand()
+func writeData(seed string, size int64, b64 bool) error {
+	var rnd *random.Random
+	if seed == "" {
+		rnd = random.New()
 	} else {
-		rnd = random.NewSeededRand(seed)
+		rnd = random.NewSeeded(random.StringToSeed(seed))
 	}
 
 	var w io.Writer

cli/random-files/README.md

@@ -34,73 +34,72 @@ OPTIONS:
         randomize number of files, from 1 to -files
   -random-size
         randomize file size, from 1 to -filesize (default true)
-  -seed int
-        random seed, 0 for current time
+  -seed string
+        random seed, leave empty to use random value
 ```
 
 ## Examples
 
 ```sh
 > random-files -depth=2 -files=3 -seed=1701 foo
-foo/rwd67uvnj9yz-
-foo/7vovyvr9
-foo/fjv0w0
-foo/gyubi50rec5/
-foo/gyubi50rec5/vr6x-ce4uupj
-foo/gyubi50rec5/ob9ud0e8lt_2e
-foo/gyubi50rec5/11gip6zea
-foo/nzu5j29-sh-ku4/
-foo/nzu5j29-sh-ku4/vcs1629n
-foo/nzu5j29-sh-ku4/rky_i_qsxrp
-foo/nzu5j29-sh-ku4/xr1usy5ic0
-foo/w30dzrx2w4_d/
-foo/w30dzrx2w4_d/7ued6
-foo/w30dzrx2w4_d/r1d3j
-foo/w30dzrx2w4_d/av7d09i-av
-foo/s6ha-58/
-foo/s6ha-58/nukjsxg7t
-foo/s6ha-58/7of_84
-foo/s6ha-58/h0jgq8mu1n7u
-foo/tq_8/
-foo/tq_8/sx-a2jgmz_mk6
-foo/tq_8/9hzrksz8
-foo/tq_8/8b5swu
+foo/mts2ph
+foo/wsu46w33-df_v44c
+foo/fcuxmunecbs_de
+foo/vfpwv_asjhs2nz/
+foo/vfpwv_asjhs2nz/8533
+foo/vfpwv_asjhs2nz/8nj3jouo1xg_
+foo/vfpwv_asjhs2nz/v9awmhr
+foo/ujj95a/
+foo/ujj95a/n1mf
+foo/ujj95a/-taw_yfnc2
+foo/ujj95a/h5j-x7rkawl6zc8
+foo/v2isuq37wxt/
+foo/v2isuq37wxt/0v1od94eojxv
+foo/v2isuq37wxt/u4z-gcvoe4w
+foo/v2isuq37wxt/ogm2b-coenbu8t2
+foo/sn35leocdzm15l/
+foo/sn35leocdzm15l/b4w3
+foo/sn35leocdzm15l/f73xrgznl57
+foo/sn35leocdzm15l/7tt51n7lbvv9
+foo/m4ttn58z0x77sbo0/
+foo/m4ttn58z0x77sbo0/ydv5ld_4o7tvw7
+foo/m4ttn58z0x77sbo0/khdlmwfpegefix
+foo/m4ttn58z0x77sbo0/ud2mo
 ```
 
 It made:
 
 ```sh
 > tree foo
 foo
-├── 7vovyvr9
-├── fjv0w0
-├── gyubi50rec5
-│   ├── 11gip6zea
-│   ├── ob9ud0e8lt_2e
-│   └── vr6x-ce4uupj
-├── nzu5j29-sh-ku4
-│   ├── rky_i_qsxrp
-│   ├── vcs1629n
-│   └── xr1usy5ic0
-├── rwd67uvnj9yz-
-├── s6ha-58
-│   ├── 7of_84
-│   ├── h0jgq8mu1n7u
-│   └── nukjsxg7t
-├── tq_8
-│   ├── 8b5swu
-│   ├── 9hzrksz8
-│   └── sx-a2jgmz_mk6
-└── w30dzrx2w4_d
-    ├── 7ued6
-    ├── av7d09i-av
-    └── r1d3j
+├── fcuxmunecbs_de
+├── m4ttn58z0x77sbo0
+│   ├── khdlmwfpegefix
+│   ├── ud2mo
+│   └── ydv5ld_4o7tvw7
+├── mts2ph
+├── sn35leocdzm15l
+│   ├── 7tt51n7lbvv9
+│   ├── b4w3
+│   └── f73xrgznl57
+├── ujj95a
+│   ├── -taw_yfnc2
+│   ├── h5j-x7rkawl6zc8
+│   └── n1mf
+├── v2isuq37wxt
+│   ├── 0v1od94eojxv
+│   ├── ogm2b-coenbu8t2
+│   └── u4z-gcvoe4w
+├── vfpwv_asjhs2nz
+│   ├── 8533
+│   ├── 8nj3jouo1xg_
+│   └── v9awmhr
+└── wsu46w33-df_v44c
 
 6 directories, 18 files
 ```
 
-Note: Specifying the same seed will produce the same results.
-
+Note: Specifying the same seed will produce the same results. Specifying no ssed procudes random results.
 
 ### Acknowledgments
 

cli/random-files/main.go

@@ -38,7 +38,7 @@ OPTIONS:
 	flag.BoolVar(&cfg.RandomDirs, "random-dirs", cfg.RandomDirs, "randomize number of subdirectories, from 1 to -dirs")
 	flag.BoolVar(&cfg.RandomFiles, "random-files", cfg.RandomFiles, "randomize number of files, from 1 to -files")
 	flag.BoolVar(&cfg.RandomSize, "random-size", cfg.RandomSize, "randomize file size, from 1 to -filesize")
-	flag.Int64Var(&cfg.Seed, "seed", cfg.Seed, "random seed, 0 for current time")
+	flag.StringVar(&cfg.Seed, "seed", "", "random seed, leave empty to use random value")
 	flag.Parse()
 
 	paths = flag.Args()

random/doc.go

@@ -1,6 +1,7 @@
 // Package random provides functionality to generate pseudo-random test data.
 //
-// All random numbers and data are created deterministically using a
-// pseudo-random number generator. This generator's output is determined by the
-// value a seed that us set using the current time, or set explicitly.
+// All random numbers and data are created deterministically using the ChaCha8
+// pseudo-random number generator. This generator's output is determined by a
+// seed value that can be set explicitly. If not set, then cryptographically
+// secure random data is used as the seed.
 package random

random/files/files.go

@@ -4,16 +4,15 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"math/rand"
 	"os"
 	"path/filepath"
 
 	"github.com/ipfs/go-test/random"
 )
 
 const (
-	MinimumNameSize = 4
-	fileNameAlpha   = "abcdefghijklmnopqrstuvwxyz01234567890-_"
+	MinimumNameSize  = 4
+	fileNameAlphabet = "abcdefghijklmnopqrstuvwxyz0123456789-_"
 )
 
 // Config contains settings for creating random files and directories.
@@ -42,9 +41,9 @@ type Config struct {
 	// RandomSize specifies whether or not to randomize the file size from 1 to
 	// the value configured by FileSize.
 	RandomSize bool
-	// Seed sets the seen for the random number generator when set to a
-	// non-zero value.
-	Seed int64
+	// Seed sets the seed for the random number generator when set to a
+	// non-empty value.
+	Seed string
 }
 
 // DefaultConfig returns default settings for creating random files and
@@ -75,11 +74,11 @@ func Create(cfg Config, roots ...string) error {
 		return err
 	}
 
-	var rnd *rand.Rand
-	if cfg.Seed == 0 {
-		rnd = random.NewRand()
+	var rnd *random.Random
+	if cfg.Seed == "" {
+		rnd = random.New()
 	} else {
-		rnd = random.NewSeededRand(cfg.Seed)
+		rnd = random.NewSeeded(random.StringToSeed(cfg.Seed))
 	}
 
 	for _, root := range roots {
@@ -128,7 +127,7 @@ func RandomName(sizes ...int) string {
 		cfg = DefaultConfig()
 	}
 
-	return cfg.randomName(random.NewRand())
+	return cfg.randomName(random.New())
 }
 
 func (cfg *Config) validate() error {
@@ -165,11 +164,11 @@ func validateNameSize(minSize, maxSize int) error {
 	return nil
 }
 
-func (cfg *Config) writeTree(rnd *rand.Rand, root string, depth int) error {
+func (cfg *Config) writeTree(rnd *random.Random, root string, depth int) error {
 	nFiles := cfg.Files
 	if nFiles != 0 {
 		if cfg.RandomFiles && nFiles > 1 {
-			nFiles = rnd.Intn(nFiles) + 1
+			nFiles = rnd.IntN(nFiles) + 1
 		}
 
 		for i := 0; i < nFiles; i++ {
@@ -182,15 +181,15 @@ func (cfg *Config) writeTree(rnd *rand.Rand, root string, depth int) error {
 	return cfg.writeSubdirs(rnd, root, depth)
 }
 
-func (cfg *Config) writeSubdirs(rnd *rand.Rand, root string, depth int) error {
+func (cfg *Config) writeSubdirs(rnd *random.Random, root string, depth int) error {
 	if depth == cfg.Depth {
 		return nil
 	}
 	depth++
 
 	nDirs := cfg.Dirs
 	if cfg.RandomDirs && nDirs > 1 {
-		nDirs = rnd.Intn(nDirs) + 1
+		nDirs = rnd.IntN(nDirs) + 1
 	}
 
 	for i := 0; i < nDirs; i++ {
@@ -202,7 +201,7 @@ func (cfg *Config) writeSubdirs(rnd *rand.Rand, root string, depth int) error {
 	return nil
 }
 
-func (cfg *Config) writeSubdir(rnd *rand.Rand, root string, depth int) error {
+func (cfg *Config) writeSubdir(rnd *random.Random, root string, depth int) error {
 	name := cfg.randomName(rnd)
 	root = filepath.Join(root, name)
 	if err := os.MkdirAll(root, 0755); err != nil {
@@ -216,20 +215,24 @@ func (cfg *Config) writeSubdir(rnd *rand.Rand, root string, depth int) error {
 	return cfg.writeTree(rnd, root, depth)
 }
 
-func (cfg *Config) randomName(rnd *rand.Rand) string {
+func (cfg *Config) randomName(rnd *random.Random) string {
 	sizeDiff := cfg.NameMaxSize - cfg.NameMinSize
-	n := cfg.NameMinSize
+	size := cfg.NameMinSize
 	if sizeDiff != 0 {
-		n += rnd.Intn(sizeDiff)
+		size += rnd.IntN(sizeDiff + 1)
 	}
-	b := make([]byte, n)
-	for i := 0; i < n; i++ {
-		b[i] = fileNameAlpha[rnd.Intn(len(fileNameAlpha))]
+	if size <= 0 {
+		return ""
 	}
-	return string(b)
+	src := make([]byte, size)
+	rnd.Read(src)
+	for i := range src {
+		src[i] = fileNameAlphabet[src[i]%byte(len(fileNameAlphabet))]
+	}
+	return string(src)
 }
 
-func (cfg *Config) writeFile(rnd *rand.Rand, root string) error {
+func (cfg *Config) writeFile(rnd *random.Random, root string) error {
 	name := cfg.randomName(rnd)
 	filePath := filepath.Join(root, name)
 	f, err := os.Create(filePath)
@@ -240,7 +243,7 @@ func (cfg *Config) writeFile(rnd *rand.Rand, root string) error {
 	if cfg.FileSize > 0 {
 		fileSize := cfg.FileSize
 		if cfg.RandomSize && fileSize > 1 {
-			fileSize = rnd.Int63n(fileSize) + 1
+			fileSize = rnd.Int64N(fileSize) + 1
 		}
 
 		if _, err := io.CopyN(f, rnd, fileSize); err != nil {