Move sharding functions for reuse
Move shardPaths and shardTests to android.ShardPaths and
android.ShardStrings for reuse in other packages.
Test: m checkbuild
Change-Id: I868802872c73616b80f56cbf11f959c01a8b793a
diff --git a/android/util.go b/android/util.go
index 0102442..71ded5e 100644
--- a/android/util.go
+++ b/android/util.go
@@ -319,3 +319,36 @@
return root, suffix, ext
}
+
+// ShardPaths takes a Paths, and returns a slice of Paths where each one has at most shardSize paths.
+func ShardPaths(paths Paths, shardSize int) []Paths {
+ if len(paths) == 0 {
+ return nil
+ }
+ ret := make([]Paths, 0, (len(paths)+shardSize-1)/shardSize)
+ for len(paths) > shardSize {
+ ret = append(ret, paths[0:shardSize])
+ paths = paths[shardSize:]
+ }
+ if len(paths) > 0 {
+ ret = append(ret, paths)
+ }
+ return ret
+}
+
+// ShardStrings takes a slice of strings, and returns a slice of slices of strings where each one has at most shardSize
+// elements.
+func ShardStrings(s []string, shardSize int) [][]string {
+ if len(s) == 0 {
+ return nil
+ }
+ ret := make([][]string, 0, (len(s)+shardSize-1)/shardSize)
+ for len(s) > shardSize {
+ ret = append(ret, s[0:shardSize])
+ s = s[shardSize:]
+ }
+ if len(s) > 0 {
+ ret = append(ret, s)
+ }
+ return ret
+}
diff --git a/android/util_test.go b/android/util_test.go
index 1df1c5a..90fefee 100644
--- a/android/util_test.go
+++ b/android/util_test.go
@@ -469,3 +469,102 @@
}
})
}
+
+func Test_Shard(t *testing.T) {
+ type args struct {
+ strings []string
+ shardSize int
+ }
+ tests := []struct {
+ name string
+ args args
+ want [][]string
+ }{
+ {
+ name: "empty",
+ args: args{
+ strings: nil,
+ shardSize: 1,
+ },
+ want: [][]string(nil),
+ },
+ {
+ name: "single shard",
+ args: args{
+ strings: []string{"a", "b"},
+ shardSize: 2,
+ },
+ want: [][]string{{"a", "b"}},
+ },
+ {
+ name: "single short shard",
+ args: args{
+ strings: []string{"a", "b"},
+ shardSize: 3,
+ },
+ want: [][]string{{"a", "b"}},
+ },
+ {
+ name: "shard per input",
+ args: args{
+ strings: []string{"a", "b", "c"},
+ shardSize: 1,
+ },
+ want: [][]string{{"a"}, {"b"}, {"c"}},
+ },
+ {
+ name: "balanced shards",
+ args: args{
+ strings: []string{"a", "b", "c", "d"},
+ shardSize: 2,
+ },
+ want: [][]string{{"a", "b"}, {"c", "d"}},
+ },
+ {
+ name: "unbalanced shards",
+ args: args{
+ strings: []string{"a", "b", "c"},
+ shardSize: 2,
+ },
+ want: [][]string{{"a", "b"}, {"c"}},
+ },
+ }
+ for _, tt := range tests {
+ t.Run(tt.name, func(t *testing.T) {
+ t.Run("strings", func(t *testing.T) {
+ if got := ShardStrings(tt.args.strings, tt.args.shardSize); !reflect.DeepEqual(got, tt.want) {
+ t.Errorf("ShardStrings(%v, %v) = %v, want %v",
+ tt.args.strings, tt.args.shardSize, got, tt.want)
+ }
+ })
+
+ t.Run("paths", func(t *testing.T) {
+ stringsToPaths := func(strings []string) Paths {
+ if strings == nil {
+ return nil
+ }
+ paths := make(Paths, len(strings))
+ for i, s := range strings {
+ paths[i] = PathForTesting(s)
+ }
+ return paths
+ }
+
+ paths := stringsToPaths(tt.args.strings)
+
+ var want []Paths
+ if sWant := tt.want; sWant != nil {
+ want = make([]Paths, len(sWant))
+ for i, w := range sWant {
+ want[i] = stringsToPaths(w)
+ }
+ }
+
+ if got := ShardPaths(paths, tt.args.shardSize); !reflect.DeepEqual(got, want) {
+ t.Errorf("ShardPaths(%v, %v) = %v, want %v",
+ paths, tt.args.shardSize, got, want)
+ }
+ })
+ })
+ }
+}