pkg/image: factor out from prog

Move image compression-related function to a separate package.
In preperation for subsequent changes that make decompression
more complex. Prog package is already large and complex.
Also makes running compression tests/benchmarks much faster.

1 files changed, 8 insertions, 6 deletions

diff --git a/prog/mutation.go b/prog/mutation.go
index 96e11516c..100c47a91 100644
--- a/prog/mutation.go
+++ b/prog/mutation.go
@@ -10,6 +10,8 @@ import (
 	"math/rand"
 	"sort"
 	"sync"
+
+	"github.com/google/syzkaller/pkg/image"
 )
 
 // Maximum length of generated binary blobs inserted into the program.
@@ -385,21 +387,21 @@ func (t *BufferType) mutate(r *randGen, s *state, arg Arg, ctx ArgCtx) (calls []
 
 var imageMu sync.Mutex
 
-func (r *randGen) mutateImage(image []byte) (data []byte, retry bool) {
-	if len(image) == 0 {
-		return image, true
+func (r *randGen) mutateImage(compressed []byte) (data []byte, retry bool) {
+	if len(compressed) == 0 {
+		return compressed, true
 	}
 	// Don't decompress more than one image at a time
 	// since it can consume lots of memory.
 	// Reconsider when/if we move mutation to the host process.
 	imageMu.Lock()
 	defer imageMu.Unlock()
-	data, err := Decompress(image)
+	data, err := image.Decompress(compressed)
 	if err != nil {
 		panic(fmt.Sprintf("could not decompress data: %v", err))
 	}
 	if len(data) == 0 {
-		return image, true // Do not mutate empty data.
+		return compressed, true // Do not mutate empty data.
 	}
 	hm := MakeGenericHeatmap(data, r.Rand)
 	for i := hm.NumMutations(); i > 0; i-- {
@@ -410,7 +412,7 @@ func (r *randGen) mutateImage(image []byte) (data []byte, retry bool) {
 		}
 		storeInt(data[index:], r.randInt(uint64(width*8)), width)
 	}
-	return Compress(data), false
+	return image.Compress(data), false
 }
 
 func mutateBufferSize(r *randGen, arg *DataArg, minLen, maxLen uint64) {